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  • 151.
    Skoglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Locally applied Simvastatin Improves Fracture Healing in Mice2007In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 8, no 98Article in journal (Refereed)
    Abstract [en]

    Background: HMG-CoA reductase inhibitors, statins, are widely prescribed to lower cholesterol. High doses of orally administered simvastatin has previously been shown to improve fracture healing in a mouse femur fracture model. In this study, simvastatin was administered either subcutaneously or directly to the fracture area, with the goal of stimulating fracture repair at acceptable doses.

    Methods: Femur fractures were produced in 70 mature male Balb-C mice and stabilized with marrow-nailing. Three experiments were performed. Firstly, 20 mice received subcutaneous injections of either simvastatin (20 mg) or vehicle. Secondly, 30 mice were divided into three groups of 10 mice receiving continuous subcutaneous delivery of the vehicle substance, the vehicle with 5 mg or with 10 mg of simvastatin per kg bodyweight per day. Finally, in 20 mice, a silicone tube was led from an osmotic mini-pump to the fracture area. In this way, 10 mice received an approximate local dose of simvastatin of 0.1 mg per kg per day for the duration of the experiment and 10 mice received the vehicle compound. All treatments lasted until the end of the experiment. Bilateral femurs were harvested 14 days post-operative. Biomechanical tests were performed by way of three-point bending. Data was analysed with ANOVA, Scheffé's post-hoc test and Student's unpaired t-test.

    Results: With daily simvastatin injections, no effects could be demonstrated for any of the parameters examined. Continuous systemic delivery resulted in a 160% larger force at failure. Continuous local delivery of simvastatin resulted in a 170% larger force at failure as well as a twofold larger energy uptake.

    Conclusion: This study found a dramatic positive effect on biomechanical parameters of fracture healing by simvastatin treatment directly applied to the fracture area.

  • 152.
    Skoglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Forslund, Carina
    Department of Orthopedics, Lund University Hospital, Lund, Sweden.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Simvastatin Improves Fracture Healing in Mice2002In: Journal of bone and mineral research, ISSN 0884-0431, Vol. 17, no 111, p. 2004-2008Article in journal (Refereed)
    Abstract [en]

    Recently, several articles have been published dealing with the anabolic effects on bone by statins. Mundy and associates discovered that several statins were able to activate the promotor of bone morphogenetic protein (BMP) 2. Additionally, oral simvastatin and lovastatin increased the cancellous bone volume in rats, presumably an effect of the increase of BMP-2. Other studies have followed, with conflicting results; some have found a positive bone metabolic effect of statins and others have not. Studies published so far have focused on osteoporosis. In this study, femur fractures were produced in 81 mature male BALB/c mice and stabilized with marrow-nailing. Forty-one mice were given a diet prepared with simvastatin, so that each mouse received an approximate dose of 120 mg/kg of body weight per day. The remaining mice received the same diet with the exception of the simvastatin. Bilateral femurs were harvested at 8, 14, and 21 days postoperatively (po), the marrow-nail was extracted, and diameters were measured. Biomechanical tests were performed on 42 mice, by way of three-point bending. Histological specimens were prepared using standard techniques. For statistical analysis, ANOVA with Scheffé’s post hoc test was used. At 8 days, the fracture callus was too soft for meaningful biomechanical testing. At 14 days, the callus of the simvastatin-treated mice had a 53% larger transverse area than controls (p = 0.001), the force required to break the bone was 63% greater (p = 0.001), and the energy uptake was increased by 150% (p = 0.0008). Stiffness and modulus of elasticity were not significantly affected. At 21 days, the fractures were histologically healed and the mechanical differences had disappeared. The contralateral unbroken bone showed a slight increase in transverse area because of the simvastatin treatment, but there was no significant effect on the force required to break the bone or on energy uptake. These results point to a new possibility in the treatment of fractures.

  • 153.
    Skoglund, Björn
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Holmertz, Jonas
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Systemic and Local Ibandronate Enhance Screw Fixation2004In: Journal of Orthopaedic Reserach, ISSN 0736-0266, Vol. 22, no 5, p. 1108-1113Article in journal (Refereed)
    Abstract [en]

    The trauma involved with inserting implants into bone leads to an activation of the inflammatory response and an activation of osteoclasts. In addition, apoptosis of osteocytes in the surrounding area has been implicated in further activation of osteoclasts. If the balance between resorption and bone formation shortly after implantation favours resorption, an impairment of early fixation might ensue.Because bisphosphonates inhibit resorption, this study analyses whether they can improve early fixation. Stainless steel screws (M 1.7) were inserted into the tibiae of 76 male Sprague-Dawley rats. Daily subcutaneous injections of ibandronate (3 μg) or saline were given to 20 rats. The remaining rats received ibandronate or saline directly applied into the drill hole before the screw was inserted. Tibiae were harvested at 14 days. Mechanical tests were performed on 50 tibiae. Systemically treated tibiae were tested for pull-out strength alone. Locally treated tibiae were tested for either pull-out or torque resistance. The remaining 18 tibiae were prepared for histology.Systemic ibandronate increased the pull-out force at failure by 30% (p=0.04). Local treatment increased the force at failure by 15% (p=0.02) and stiffness by 28% (p=0.01). In the removal torque measurements, local ibandronate increased the torque-moment at failure by 60% (p=0.04), and the maximum friction moment by 51% (p=0.04). Energy for turning the screw 1/4 revolution was increased by 68% (p=0.02).These results demonstrate that early remodeling events plays an important role in screw fixation, and that systemic or local bisphosphonate treatment could be an effective pharmacological path to improve early implant fixation.

  • 154.
    Skripitz, R
    et al.
    University Hospital Rostock.
    Johansson, H R
    Sinai Hospital Baltimore.
    Ulrich, S D
    Sinai Hospital Baltimore.
    Werner, A
    University Hospital Eppendorf.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Effect of alendronate and intermittent parathyroid hormone on implant fixation in ovariectomized rats2009In: JOURNAL OF ORTHOPAEDIC SCIENCE, ISSN 0949-2658, Vol. 14, no 2, p. 138-143Article in journal (Refereed)
    Abstract [en]

    Intermittent administration of parathyroid hormone (PTH) leads to bone formation by increasing osteoblast numbers and activity levels. Animal studies have shown that intermittent PTH administration increases implant fixation in normal rats. The purpose of this study was to analyze the osseous incorporation of an implant in osteoporotic rats while treating them with intermittent PTH (1-34) or alendronate.

    A total of 36 ovariectomized (OVX) Wistar rats were randomized into three groups. Polymethylmethacrylate cement rods were implanted in one tibia in each rat. The three groups received daily PTH (60 mu g/kg body weight [BW]), alendronate (200 mu g/kg BW), or saline (0.5 ml/kg BW). A sham-ovariectomized group (n = 12) was treated with saline. After 2 weeks, the area around the implants was analyzed by histomorphometry for bone volume density (BVD) and implant bone contact. Bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry.

    The BVD was higher in the specimens treated with PTH than in the other groups. PTH improved the BVD, BMD, and implant bone contact. Alendronate doubled the implant bone contact compared to the OVX and sham groups but did not improve BVD or BMD.

    These findings confirm that intermittent PTH enhances implant fixation in osteoporotic bone. The clinical significance of these findings is that application of intermittent PTH may be beneficial for early implant fixation in fractures, nonunions, and prosthetic replacements when bone density is decreased.

  • 155.
    Soderberg, B.
    et al.
    Söderberg, B., Scandinavian Orthopaedic Laboratory, Helsingborg Hospital, Helsingborg, Sweden, Scandinavian Orthopaedic Laboratory, Helsingborg Hospital, 251 87 Helsingborg, Sweden.
    Ryd, Leif
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine .
    Persson, B.M.
    Department of Orthopaedics, University Hospital, Lund, Sweden.
    Roentgen Stereophotogrammetric Analysis of Motion between the Bone and the Socket in a Transtibial Amputation Prosthesis: A Case Study2003In: Journal of prosthetics and orthotics, ISSN 1040-8800, E-ISSN 1534-6331, Vol. 15, no 3, p. 95-99Article in journal (Refereed)
    Abstract [en]

    High-tech development within prosthetics for lower limb amputees can benefit from high-tech methods to study the socket fit. Roentgen stereophotogrammetry is one such method with high resolution to study stability with point motion and segment motion simultaneously to show how well bonded the socket is to the stump. It has been used to follow results of total joint replacement concerning loosening and wear of components. In this study, one transtibial amputee was examined with tantalum bone markers implanted through skin and also glued into the hard socket. Four different prosthetic suspensions were used, and we simulated four different gait cycle positions and recorded the micromotions between the tibial bone segment and the hard socket three-dimensionally. The vertical motion varied 10 to 30 mm and the AP motion 0 to 15 mm. For the first time, we could measure rotation of the socket on the stump about a vertical axis. The rotation in the transversal plane was 7.5 outward. Airtight sleeve with expulsion valve gave the best stability.

  • 156.
    Svernlov, Birgitta
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Plastic Surgery, Hand Surgery and Burns. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of Plastic Surgery, Hand surgery UHL.
    Larsson, M.
    Rehn, K.
    Östergötlands Läns Landsting.
    Adolfsson, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Conservative treatment of the cubital tunnel syndrome2009In: Journal of Hand Surgery: European Volume, ISSN 1753-1934, Vol. 34, no 2, p. 201-207Article in journal (Refereed)
    Abstract [en]

    Conservative treatment of the cubital tunnel syndrome was evaluated in a randomised study of 70 patients with mild or moderate symptoms (Dellon, 1989). All patients were informed about the cause of symptoms and allocated to three groups: night splinting, nerve gliding and control. Evaluation consisted of Canadian Occupational Performance Measure, visual analogue pain scales, strength measurements and neurophysiological examination, before treatment and after six months. Fifty-seven patients were followed for six months. Fifty-one (89.5%) were improved at the follow-up. There were no significant differences between the groups in any of the recorded variables. Night splints and nerve gliding exercises did not add favourably. Routine neurophysiological examination seems unnecessary since 76% of the patients with typical symptoms had normal findings and 75% with pathological findings improved. Patients with mild or moderate symptoms have a good prognosis if they are informed of the causes of the condition and how to avoid provocation.

  • 157.
    Svernlöv, Birgitta
    et al.
    Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Sinnescentrum, Department of Plastic Surgery, Hand surgery UHL.
    Adolfsson, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Non-operative treatment regime including eccentric training for lateral humeral epicondylalgia2001In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 11, no 6, p. 328-334Article in journal (Refereed)
    Abstract [en]

    In a pilot study 38 patients with lateral humeral epicondylalgia were randomly allocated to two treatment groups. Group S (stretching) was treated with a contract-relax-stretching program while group E (eccentric exercise) underwent an eccentric exercise program. Both groups also received forearm bands and wrist support nightly. The programs were carried out daily at home during 12 weeks. Evaluation before and 3, 6 and 12 months after treatment, included subjective assessment of symptoms using visual analogue scales and grip strength measurements. Thirty-five patients were available for follow-up. Five patients, three in group S and two in group E, did not complete the programs due to increased pain while 30 (86%) reported complete recovery or improvement. Reduced pain and increased grip strength were seen in both treatment groups but 12 out of 17 patients (71%) in group E rated themselves as completely recovered as compared to 7 out of 18 (39%) in group S (P=0.09), and in group E the increase in grip strength after 6 months was statistically significantly larger than in group S. In a second study the eccentric training regime was used in a consecutive series of 129 patients with lateral epicondy lalgia. The patients were divided into two groups with one group consisting of patients with less than one year duration of symtoms and the other comprised patients with a duration of symptoms for more than one year. The results of treatment were evaluated in the same way as in the pilot study, and also after 3.4 years using the scoring system by Verhaar et al. At the end of the treatment period statistically significant improvements were seen in all VAS recordings and in grip strength. After 3.4 years 38% had excellent, 28% good, 25% fair and 9% poor results according to the score. In the self-rated outcome 54% regarded themselves as completely recovered, 43% improved, 2% unchanged and 2% worse. No significant differences were seen between patients with a duration of symptoms for more than one year compared to patients with symptoms for less than one year. The eccentric training regime can considerably reduce symptoms in a majority of patients with lateral humeral epicondylalgia, regardless of duration, and is possibly superior to conventional stretching.

  • 158.
    Svernlöv, Birgitta
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Plastic Surgery, Hand Surgery and Burns. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Hultgren, Eva
    Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Adolfsson, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Medial epicondylalgia (golfer’s elbow) treated by eccentric exercise2012In: Shoulder & Elbow, ISSN 1758-5732, Vol. 4, no 1, p. 50-55Article in journal (Refereed)
    Abstract [en]

    Background: Eccentric exercises have been successfully used in the treatment of Achilles and patellar tendinopathies, as well as lateral epicondylalgia. No studies have explored the same treatment for medial epicondylalgia (golfer’s elbow).

    Methods: Twenty consecutive adults with a clinical diagnosis of medial epicondylalgia were treated with eccentric exercise over 3 months in this prospective case series. The programme was based on home training. There were 11 women and nine men, with a mean age of 47 years, and a mean duration of symptoms of 19 months. At baseline, at 3 months and after a mean of 11 years, pain was assessed by three independent visual analogue scales (VAS) and grip strength using a Jamar dynamometer (Sammons Preston Inc., Jackson, MI, USA). At the 11-year follow-up, patients also reported their satisfaction on a 100-mm VAS and completed the Disabilities of Arm, Shoulder and Hand questionnaire.

    Results: Pain decreased significantly in all measured variables at both assessment occasions (all p < 0.0001). Grip strength in the affected arm/hand increased significantly after 3 months (p = 0.009).

    Discussion: Twelve weeks of eccentric training reduced pain and increased grip strength in patients with medial epicondylalgia. It is a safe, uncomplicated and cost-effective method, with only a minimum contribution from a physiotherapist.

  • 159.
    Svernlöv, Birgitta
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Plastic Surgery, Hand Surgery and Burns. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Nylander, Göran
    Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Linköping University, Faculty of Health Sciences.
    Adolfsson, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Patient-reported outcome of surgical treatment of nerve entrapments in the proximal forearm2011In: Advances in orthopedics, ISSN 2090-3472, Vol. 2011, p. 727689-Article in journal (Refereed)
    Abstract [en]

    The outcome of decompression for long-standing symptoms of nerve entrapments in the proximal forearm was investigated in a retrospective study of 205 patients using a self-assessment questionnaire, 45 months after the operation. The questionnaire consisted of visual analogue scale recordings of pre- and postoperative pain during rest and activity, questions about remaining symptoms and appreciation of the result and the Disabilities of Arm, Shoulder and Hand form (DASH). Altogether, 59% of the patients were satisfied, 58% considered themselves improved, and 3% as being entirely relieved of all symptoms. Pain decreased significantly (P = 0.001). There was a significant correlation between preoperative duration and patient perceived post-operative pain. Preoperative pain was a chief complaint, and pain reduction appears to be the principal gain of the operation. Although the majority of the patients benefited from the operation, a substantial proportion was not satisfied. There is apparently room for improvement of the diagnostic and surgical methods applied in this study.

  • 160.
    Tagesson (Sonesson), Sofi
    et al.
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Öberg, Birgitta
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences.
    Good, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Kvist, Joanna
    Linköping University, Department of Medical and Health Sciences, Physiotherapy. Linköping University, Faculty of Health Sciences.
    A comprehensive rehabilitation program with quadriceps strengthening in closed versus open kinetic chain in patients with anterior cruciate ligament deficiency: a randomized clinical trial evaluating dynamic tibial translation and muscle function2008In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 36, no 2, p. 298-307Article in journal (Refereed)
    Abstract [en]

    Background: There is no consensus regarding the optimal rehabilitation regimen for increasing quadriceps strength after anterior cruciate ligament (ACL) injury.

    Hypothesis: A comprehensive rehabilitation program supplemented with quadriceps strengthening in open kinetic chain (OKC) exercise will increase quadriceps strength and improve knee function without increasing static or dynamic sagittal tibial translation, compared with the same comprehensive rehabilitation program supplemented with quadriceps strengthening in closed kinetic chain (CKC) exercise, in patients with acute ACL deficiency.

    Study Design: Randomized controlled trial; Level of evidence, 1.

    Methods: Forty-two patients were tested a mean of 43 days (range, 20–96 days) after an ACL injury. Patients were randomized to rehabilitation with CKC quadriceps strengthening (11 men and 9 women) or OKC quadriceps strengthening (13 men and 9 women). Aside from these quadriceps exercises, the 2 rehabilitation programs were identical. Patients were assessed after 4 months of rehabilitation. Sagittal static translation and dynamic tibial translation were evaluated with a CA-4000 electrogoniometer. Muscle strength, jump performance, and muscle activation were also assessed. Functional outcome was evaluated by determining the Lysholm score and the Knee Injury and Osteoarthritis Outcome Score.

    Results: There were no group differences in static or dynamic translation after rehabilitation. The OKC group had significantly greater isokinetic quadriceps strength after rehabilitation (P = .009). The hamstring strength, performance on the 1-repetition-maximum squat test, muscle activation, jump performance, and functional outcome did not differ between groups.

    Conclusions: Rehabilitation with OKC quadriceps exercise led to significantly greater quadriceps strength compared with rehabilitation with CKC quadriceps exercise. Hamstring strength, static and dynamic translation, and functional outcome were similar between groups. Patients with ACL deficiency may need OKC quadriceps strengthening to regain good muscle torque.

  • 161.
    Tengvall, Pentti
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Skoglund, Björn
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Askendal, Agneta
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Surface Immobilized Bisphosphonate Improves Stainless-Steel Screw Fixation in Rats2004In: Biomaterials, ISSN 0142-9612, Vol. 25, no 11, p. 2133-2138Article in journal (Refereed)
    Abstract [en]

    An increase in the mechanical fixation in bone of metallic biomaterials is considered advantageous in joint replacement and fracture surgery. Different approaches to improve fixation may be e.g. surface roughening, Ca-mineral coating or surface immobilization of growth factors or drugs. In the present work, bisphosphonate, a class of drugs that inhibit bone resorption, was immobilized onto stainless-steel screws.

    The screws were first roughened and coated with immobilized and cross-linked fibrinogen. Subsequently, an N-bisphosphonate, pamidronate, was immobilized onto fibrinogen, and another N-bisphosphonate, ibandronate, adsorbed on top of this. The so coated screws were inserted into the tibiae of eight male Sprague-Dawley rats. Another eight rats received screws prepared in the same way, but without the bisphosphonate coating. Pullout strength tests were performed after 2 weeks of implantation.

    The results showed a 28% (p=0.0009) higher pullout force and 90% increased pullout energy for the bisphosphonate coated screws, and support the idea that surface immobilized bisphosphonates can be used to improve biomaterials fixation in bone.

  • 162.
    Thompson, M.S.
    et al.
    Center for Musculoskeletal Surgery, Charite-University of Medicine, Berlin, Germany.
    Flivik, G.
    Department of Orthopaedics, Lund University Hospital, Lund, Sweden.
    Juliusson, R.
    Department of Orthopaedics, Lund University Hospital, Lund, Sweden.
    Odgaard, A.
    Orthopaedic Research Laboratory, Aarhus University Hospital, Aarhus, Denmark.
    Ryd, Leif
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine .
    A comparison of structural and mechanical properties in cancellous bone from the femoral head and acetabulum2004In: Proceedings of the Institution of mechanical engineers. Part H, journal of engineering in medicine, ISSN 0954-4119, E-ISSN 2041-3033, Vol. 218, no 6, p. 425-429Article in journal (Refereed)
    Abstract [en]

    Mechanical interlock obtained by penetration of bone cement into cancellous bone is critical to the success of cemented total hip replacement (THR). Although acetabular component loosening is an important mode of THR failure, the properties of acetabular cancellous bone relevant to cement penetration are not well characterized. Bone biopsies (9 mm diameter, 10 mm long) were taken from the articular surfaces of the acetabulum and femoral head during total hip replacement. After mechanical and chemical defatting the two groups of bone specimens were characterized using flow measurement, mechanical testing and finally serial sectioning and three-dimensional computer reconstruction. The mean permeabilities of the acetabular group (1.064 × 10-10 m2) and femoral group (1.155 × 10-10 m2) were calculated from the flow measurements, which used saline solution and a static pressure of 9.8 kPa. The mean Young's modulus, measured non-destructively, was 47.4 MPa for the femoral group and 116.4 MPa for the acetabular group. Three-dimensional computer reconstruction of the specimens showed no significant differences in connectivity and porosity between the groups. Results obtained using femoral head cancellous bone to investigate bone cement penetration and fixation are directly relevant to fixation in the acetabulum. © IMechE 2004.

  • 163.
    Thompson, M.S.
    et al.
    Department of Orthopaedics, Lund University Hospital, Lund 22185, Sweden.
    McCarthy, I.D.
    Department of Orthopaedics, Lund University Hospital, Lund 22185, Sweden.
    Lidgren, L.
    Department of Orthopaedics, Lund University Hospital, Lund 22185, Sweden.
    Ryd, Leif
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine .
    Compressive and Shear Properties of Commercially Available Polyurethane Foams2003In: Journal of Biomechanical Engineering, ISSN 0148-0731, E-ISSN 1528-8951, Vol. 125, no 5, p. 732-734Article in journal (Refereed)
    Abstract [en]

    Background: The shear properties of rigid polyurethane (PU-R) foams, routinely used to simulate cancellous bone, are not well characterized. Method of approach: The present assessment of the shear and compressive properties of four grades of Sawbones "Rigid cellular" PU-R foam tested 20 mm gauge diameter dumb-bell specimens in torsion and under axial loading. Results: Shear moduli ranged from 13.3 to 99.7 MPa, shear strengths from 0.7 MPa to 4.2 MPa. Compressive yield strains varied little with density while shear yield strains had peak values with "200 kgm-3" grade. Conclusions: PU-R foams may be used to simulate the elastic but not failure properties of cancellous bone.

  • 164.
    Tillander, Bo
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    The Supraspinatus Tendon: Clinical and histopathological aspects2001Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The supraspinatus tendon is an important structure of the rotator cuff. Subacromial impingement is a common reason for shoulder pain. Despite extensive scientific work in this field, the cause of impingement syndrome is still not fully understood. The general aim of the present thesis was to generate new knowledge with respect to pathogenesis and treatment of impingement syndrome. A combination of animal and clinical studies were performed. Different methods were used such as histology, immunohistochemistry, development and assessment of a novel measuring device and clinical and radiological assessment.

    Thirty rats were injected with triamcinolone or saline into the subacromial bursa. After five corticosteroid injections, we found focal inflammation, degradation and fragmentation of collagen bundles in the supraspinatus tendon, whereas the control specimens were normal (p=0.035).

    Subacromial bursitis was induced by injections of carrageenan into the subacromial space (n=28). Fibrocartilaginous metaplasia and bony metaplasia were found in the supraspinatus tendon. Even in specimens with no histologic changes of the collagen bundles the staining for fibronectin was significantly increased.

    The distance between the anterolateral acromion and the supraspinatus tendon was measured in patients with impingement syndrome intraoperatively (n=30) and in controls (instability, n=15). The mean value of the subacromial distance in controls was 16 mm, the 95% mean confidence limits between 14 and 18 mm. The mean value in the group of patients with impingement syndrome was 8 mm before and 16 mm after the decompression.

    Fifty patients were reviewed after arthroscopic subacromial decompression. Twenty-five showed calcific deposits in the rotator cuff on radiographs preoperatively. In 13 patients the calcific deposits totally disappeared postoperatively. In another six patients the calcifications had decreased in size. Four patients still showed calcifications, which were 5 mm or greater in size. The postoperative results measured by the Constant score were almost identical in the calcific and the non-calcific groups. Tillander 010916 8 Human surgical supraspinatus tendon specimens were studied from patients with impingement (n=16), ruptured supraspinatus tendons (n=7) and controls (n=10). Degradation of tendinous tissue and fibrin were found only in some specimens from ruptures. The difference in fibronectin staining was significant between controls and patients with a rupture (p=0.002). Fibrosis and thinning of fascicles seemed to be a more non-specific finding, appearing in control, impingement and rupture specimens.

    In conclusion, subacromial corticosteroid injections may cause rupture of the supraspinatus tendon. Metaplasia of the supraspinatus tendon may play a role in the pathogenesis of impingement and rupture of the supraspinatus tendon. The subacromial distance can be measured intraoperatively and was shown to be lower in patients with impingement than in patients with instability. Calcifications disappear or decrease in size after arthroscopic subacromial decompression and do not seem to influence the postoperative outcome in patients with impingement. Degradation of tendon tissue, fibrin and fibronectin appear to be signs of tendon degeneration, whereas fibrosis and thinning of fascicles were found also in controls.

    List of papers
    1. Effect of steroid injections on the rotator cuff: An experimental study in rats
    Open this publication in new window or tab >>Effect of steroid injections on the rotator cuff: An experimental study in rats
    1999 (English)In: Journal of shoulder and elbow surgery, ISSN 1058-2746, Vol. 8, no 3, p. 271-274Article in journal (Refereed) Published
    Abstract [en]

    The aim of this study was to evaluate the effects of repeated steroid injections into the subacromial space. Thirty rats were injected either 3 or 5 times with triamcinolone in a dosage equivalent to that given to human beings or 3 or 5 times with saline into the subacromial space. One rat received no injection. The supraspinatus and infraspinatus tendons were evaluated macroscopically and microscopically. Two different staining methods were used on each sample including hematoxylin eosin and Miller's elastin/van Gieson's solution. After 5 steroid injections, we found focal inflammation, necrosis, and fragmentation of collagen bundles in the tendon in 4 of 7 rats. The tendons of the controls showed a normal structure (P < .05). There were no pathologic changes among the rats that were injected with triamcinolone 3 times. These results show that repeated subacromial injections of triamcinolone may cause damage to the rotator cuff of the rat. This finding may indicate cautious use of subacromial steroid injections in human beings.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13704 (URN)10.1016/S1058-2746(99)90141-6 (DOI)
    Available from: 2001-11-27 Created: 2001-11-27 Last updated: 2009-08-21
    2. Carrageenan-induced subacromial bursitis caused changes in the rat's rotator cuff
    Open this publication in new window or tab >>Carrageenan-induced subacromial bursitis caused changes in the rat's rotator cuff
    2001 (English)In: Journal of Orthopaedic Research, ISSN 0736-0266, Vol. 19, no 3, p. 441-447Article in journal (Refereed) Published
    Abstract [en]

    This study was designed to investigate the histologic expression of the rat's supra- and infraspinatus tendons in carrageenan-induced subacromial bursitis. Thirty-two rats received subacromial injections with carrageenan (n = 28) or saline (n = 4). The tendons were analysed microscopically after staining with hematoxyline eosin, Van Giesons hematoxyline and immunofluorescent staining of fibronectin and fibrinogen. In the controls (saline × 10) and group A (carrageenan × 5) there were no changes in the tendons. In group B (carrageenan × 10) 3/8 rats showed macrophages between the collagen fibres and an increased staining of fibronectin. In group C (double dosis carrageenan) all rats had signs of fibrocartilaginous metaplasia in the supraspinatus tendon. In eight of these specimens even bony metaplasia was seen. The infraspinatus tendon showed fibrosis but no fibro-cartilaginous metaplasia. The results showed that iatrogenic bursitis after carrageenan subacromial injections was associated with marked changes of the supraspinatus tendon.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13705 (URN)10.1016/S0736-0266(00)90022-6 (DOI)
    Available from: 2001-11-27 Created: 2001-11-27 Last updated: 2009-08-21
    3. Intraoperative measurements of the subacromial distance
    Open this publication in new window or tab >>Intraoperative measurements of the subacromial distance
    2002 (English)In: Arthroscopy : the journal of arthroscopic & related surgery, ISSN 0749-8063, Vol. 18, no 4, p. 347-352Article in journal (Refereed) Published
    Abstract [en]

    Purpose: The purpose of this study was 2-fold: to document the accuracy of a new measuring device and to intraoperatively compare the subacromial distance between controls and patients with impingement syndrome before and after arthroscopic subacromial decompression (ASD).

    Type of Study: Clinical study.

    Methods: When performing an ASD, it is important that bone resection is adequate. Today the correct subacromial distance after bone resection is only assessed by eye, directly or indirectly. The subacromial distance was measured between the anterolateral corner of the acromion and the supraspinatus tendon in the lateral decubitus position. The device was inserted 2 to 3 cm below the anterolateral acromion. There was no subacromial pathology among the controls (n = 15, mean age, 28 years). In 30 patients with impingement syndrome (average age, 53 years) an ASD was performed. The subacromial distance was measured after bursectomy and then after bone resection. Intraindividual and interindividual assessment was performed.

    Results: The mean value of the subacromial distance in controls was 16 mm, the 95% confidence limits between 14 and 18 mm. The mean value in the group of patients with impingement syndrome was 8 mm before and 16 mm after the decompression. Due to the pressure within the subacromial space, the subacromial distance increased 1 mm. Intraindividual measurements never varied more than 1 mm (n = 5). The correlation coefficient between the measurements by both authors was 0.99.

    Conclusions: In this study, we assessed and described the use of a measuring device that enables the surgeon to quantify the subacromial distance before and after bone resection. After bone resection, the mean value of the subacromial distance was well within the control values. The amount of bone resected varied from 5 to 13 mm. This new device enables documentation in clinical work as well as in research.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13706 (URN)10.1053/jars.2002.30040 (DOI)
    Available from: 2001-11-27 Created: 2001-11-27 Last updated: 2009-08-21
    4. Change of calcifications after arthroscopic subacromial decompression
    Open this publication in new window or tab >>Change of calcifications after arthroscopic subacromial decompression
    1998 (English)In: Journal of shoulder and elbow surgery, ISSN 1058-2746, Vol. 7, no 3, p. 213-217Article in journal (Refereed) Published
    Abstract [en]

    Fifty patients were reviewed after arthroscopic subacromial decompression. Twenty-five had calcific deposits in the rotator cuff visible on x-ray evaluation. Each patient with calcification was matched with a patient without calcification who had a similar state of the rotator cuff, date of surgery, age, and sex. The calcific deposits were left untouched in all cases. No significant difference was found in the postoperative outcome between the patients in the two groups measured by the Constant score. Before surgery 7 (28%) patients had calcifications of < 5 mm, and 18 (72%) patients had calcifications that were > or = 5 mm. At a 2-year follow-up (n = 24) these figures were 20 (83%) and 4 (17%), respectively (p < 0.001). Postoperative x-ray evaluations revealed a disappearance or decrease in size of the calcific deposits in 19 (79%) of the patients. These results provide new information on the course of calcifying tendinitis, which may indicate that we can leave calcific deposits untouched within the rotator cuff when performing arthroscopic subacromial decompression.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13707 (URN)
    Available from: 2001-11-27 Created: 2001-11-27 Last updated: 2009-08-21
    5. Human biopsies in the rotator cuff disease
    Open this publication in new window or tab >>Human biopsies in the rotator cuff disease
    (English)Manuscript (preprint) (Other (popular science, discussion, etc.))
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13708 (URN)
    Available from: 2001-11-27 Created: 2001-11-27 Last updated: 2010-01-14
  • 165.
    Tillander, Bo
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Franzen, L.
    Franzén, L., Department of Pathology, University Hospital of Örebro, S-701 85 Örebro, Sweden.
    Norlin, Rolf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Fibronectin, MMP-1 and histologic changes in rotator cuff disease2002In: Journal of Orthopaedic Research, ISSN 0736-0266, E-ISSN 1554-527X, Vol. 20, no 6, p. 1358-1364Article in journal (Refereed)
    Abstract [en]

    This study was designed to investigate human surgical specimens from patients with impingement (n = 16), ruptured supraspinatus tendons (n = 7), frozen shoulder (n = 2) and controls (n = 9) with respect to histological changes and the presence of fibronectin and Matrix metalloprotease-1 (MMP-1). The biopsy of the middle part of the supraspinatus tendons was analyzed microscopically after staining with hematoxyline eosin, Van Giesons hematoxyline and Phospho Tungstic Acid Hematoxyline for visualization of fibrin. Immunofluorescent stainings for fibronectin and MMP-1 were performed. Histology and immunofluorescence were assessed blindly. Necrotic tendinous tissue and fibrin were found only in some specimens from ruptures. The staining for fibronectin was significantly increased among patients with a rupture. MMP-1 was, however, only infrequently found in specimens from patients with impingement and ruptures. Fibrosis and thinning of fascicles seemed to be a more non-specific finding, appearing in control, impingement and rupture specimens. In conclusion, necrotic tendinous tissue, fibrin and fibronectin appear to be signs of tendon degeneration, whereas fibrosis and thinning of fascicles were found also in controls. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.

  • 166.
    Tillander, Bo
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Franzén, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Karlsson, Maria H.
    Norlin, Rolf
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Effect of steroid injections on the rotator cuff: An experimental study in rats1999In: Journal of shoulder and elbow surgery, ISSN 1058-2746, Vol. 8, no 3, p. 271-274Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to evaluate the effects of repeated steroid injections into the subacromial space. Thirty rats were injected either 3 or 5 times with triamcinolone in a dosage equivalent to that given to human beings or 3 or 5 times with saline into the subacromial space. One rat received no injection. The supraspinatus and infraspinatus tendons were evaluated macroscopically and microscopically. Two different staining methods were used on each sample including hematoxylin eosin and Miller's elastin/van Gieson's solution. After 5 steroid injections, we found focal inflammation, necrosis, and fragmentation of collagen bundles in the tendon in 4 of 7 rats. The tendons of the controls showed a normal structure (P < .05). There were no pathologic changes among the rats that were injected with triamcinolone 3 times. These results show that repeated subacromial injections of triamcinolone may cause damage to the rotator cuff of the rat. This finding may indicate cautious use of subacromial steroid injections in human beings.

  • 167.
    Tillander, Bo
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Franzén, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Nilsson, Elise
    Department of Pathology, University Hospital of Malmö, Malmö, Sweden.
    Norlin, Rolf
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Carrageenan-induced subacromial bursitis caused changes in the rat's rotator cuff2001In: Journal of Orthopaedic Research, ISSN 0736-0266, Vol. 19, no 3, p. 441-447Article in journal (Refereed)
    Abstract [en]

    This study was designed to investigate the histologic expression of the rat's supra- and infraspinatus tendons in carrageenan-induced subacromial bursitis. Thirty-two rats received subacromial injections with carrageenan (n = 28) or saline (n = 4). The tendons were analysed microscopically after staining with hematoxyline eosin, Van Giesons hematoxyline and immunofluorescent staining of fibronectin and fibrinogen. In the controls (saline × 10) and group A (carrageenan × 5) there were no changes in the tendons. In group B (carrageenan × 10) 3/8 rats showed macrophages between the collagen fibres and an increased staining of fibronectin. In group C (double dosis carrageenan) all rats had signs of fibrocartilaginous metaplasia in the supraspinatus tendon. In eight of these specimens even bony metaplasia was seen. The infraspinatus tendon showed fibrosis but no fibro-cartilaginous metaplasia. The results showed that iatrogenic bursitis after carrageenan subacromial injections was associated with marked changes of the supraspinatus tendon.

  • 168.
    Tillander, Bo
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Franzén, Lennart
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Pathology and Clinical Genetics.
    Nilsson, Elise
    Department of Pathology, University Hospital of Malmö, Malmö, Sweden.
    Norlin, Rolf
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Human biopsies in the rotator cuff diseaseManuscript (preprint) (Other (popular science, discussion, etc.))
  • 169.
    Tillander, Bo
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Ledin, Torbjörn
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery . Östergötlands Läns Landsting, Reconstruction Centre, Department of ENT - Head and Neck Surgery UHL.
    Nordqvist, P.
    Melerit Medical AB, Linköping, Sweden.
    Skarman, E.
    Melerit Medical AB, Linköping, Sweden.
    Wahlström, Ola
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    A virtual reality trauma simulator2004In: Medical teacher, ISSN 0142-159X, E-ISSN 1466-187X, Vol. 26, no 2, p. 189-191Article in journal (Refereed)
    Abstract [en]

    The authors have evaluated a trauma simulator based on virtual reality techniques. Ten surgeons and 15 medical students performed distal locking of a femoral nail (A). Furthermore, 10 medical students performed simulated osteosynthesis of a femoral neck fracture (B). Total surgery time (A) (mean value) was shorter for surgeons (108 s) compared with students (157 s) at the first (p = 0.033), second (102 respectively 138 s, p = 0.13) and third (96 respectively 160 s, p = 0.15) operation. Total fluoroscopy time (A) (mean value) was shorter for surgeons compared with students at the first (45 respectively 89s p = 0.001), second (48 respectively 83 s, p = 0.02) and third (50 respectively 107 s, p = 0.10) operation. The positioning of the hip nails (B) improved between the first and last trial. Total surgery and fluoroscopy time were reduced. All participants thought that this and similar simulators should be part of the programme and that this simulator would be helpful if they were about to learn the procedures).

  • 170.
    Tillander, Bo
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Norlin, Rolf
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Change of calcifications after arthroscopic subacromial decompression1998In: Journal of shoulder and elbow surgery, ISSN 1058-2746, Vol. 7, no 3, p. 213-217Article in journal (Refereed)
    Abstract [en]

    Fifty patients were reviewed after arthroscopic subacromial decompression. Twenty-five had calcific deposits in the rotator cuff visible on x-ray evaluation. Each patient with calcification was matched with a patient without calcification who had a similar state of the rotator cuff, date of surgery, age, and sex. The calcific deposits were left untouched in all cases. No significant difference was found in the postoperative outcome between the patients in the two groups measured by the Constant score. Before surgery 7 (28%) patients had calcifications of < 5 mm, and 18 (72%) patients had calcifications that were > or = 5 mm. At a 2-year follow-up (n = 24) these figures were 20 (83%) and 4 (17%), respectively (p < 0.001). Postoperative x-ray evaluations revealed a disappearance or decrease in size of the calcific deposits in 19 (79%) of the patients. These results provide new information on the course of calcifying tendinitis, which may indicate that we can leave calcific deposits untouched within the rotator cuff when performing arthroscopic subacromial decompression.

  • 171.
    Tillander, Bo
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Norlin, Rolf
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Intraoperative measurement of shoulder translation2001In: Journal of shoulder and elbow surgery, ISSN 1058-2746, E-ISSN 1532-6500, Vol. 10, no 4, p. 358-364Article in journal (Refereed)
    Abstract [en]

    Assessing laxity of the shoulder joint in patients who are under anesthesia is a standard procedure before arthroscopy. The aim of this study was to evaluate a novel instrument for quick and reliable intraoperative measurement of glenohumeral translation. Previous testing of various designs has resulted in a device secured by 1 pin in the acromion and 1 pin in the proximal humerus. These pins are interconnected by a sliding ruler that gives translation values in millimeter increments as the laxity tests are performed. Comparison between manual arbitrary approximation of laxity and instrumented translation measurements showed that manual testing is reasonably good for assessment of anterior and posterior translation, without, however, providing values of translation in millimeter increments. The low correlation between manual assessment and instrumented inferior translation measurements indicates that inferior translation is more difficult to approximate manually. The shoulder translation tester was used in 102 patients. The mean values for clinically stable shoulders (n = 58) were 5 mm for anterior translation, 5 mm for posterior translation, and 4 mm for inferior translation. The corresponding values in unstable shoulders were significantly higher than in the stable shoulders, especially in patients with multidirectional instability. We conclude that the shoulder translation tester is easy and quick to use. It provides quantitative values of translation and will thus contribute information for correct diagnosis, therapy, and documentation.

  • 172.
    Tillander, Bo
    et al.
    Linköping University, Department of Neuroscience and Locomotion.
    Norlin, Rolf
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Intraoperative measurements of the subacromial distance2002In: Arthroscopy : the journal of arthroscopic & related surgery, ISSN 0749-8063, Vol. 18, no 4, p. 347-352Article in journal (Refereed)
    Abstract [en]

    Purpose: The purpose of this study was 2-fold: to document the accuracy of a new measuring device and to intraoperatively compare the subacromial distance between controls and patients with impingement syndrome before and after arthroscopic subacromial decompression (ASD).

    Type of Study: Clinical study.

    Methods: When performing an ASD, it is important that bone resection is adequate. Today the correct subacromial distance after bone resection is only assessed by eye, directly or indirectly. The subacromial distance was measured between the anterolateral corner of the acromion and the supraspinatus tendon in the lateral decubitus position. The device was inserted 2 to 3 cm below the anterolateral acromion. There was no subacromial pathology among the controls (n = 15, mean age, 28 years). In 30 patients with impingement syndrome (average age, 53 years) an ASD was performed. The subacromial distance was measured after bursectomy and then after bone resection. Intraindividual and interindividual assessment was performed.

    Results: The mean value of the subacromial distance in controls was 16 mm, the 95% confidence limits between 14 and 18 mm. The mean value in the group of patients with impingement syndrome was 8 mm before and 16 mm after the decompression. Due to the pressure within the subacromial space, the subacromial distance increased 1 mm. Intraindividual measurements never varied more than 1 mm (n = 5). The correlation coefficient between the measurements by both authors was 0.99.

    Conclusions: In this study, we assessed and described the use of a measuring device that enables the surgeon to quantify the subacromial distance before and after bone resection. After bone resection, the mean value of the subacromial distance was well within the control values. The amount of bone resected varied from 5 to 13 mm. This new device enables documentation in clinical work as well as in research.

  • 173.
    Timpka, Toomas
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Business support and Development, Department of Health and Care Development.
    Jacobsson, Jenny
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. Swedish Athlet Assoc, Sweden.
    Bargoria, Victor
    Linköping University. Moi University, Kenya.
    Periard, Julien D.
    Aspetar Orthopaed and Sports Medical Hospital, Qatar.
    Racinais, Sebastien
    Aspetar Orthopaed and Sports Medical Hospital, Qatar.
    Ronsen, Ola
    Medical and Antidoping Commiss, Monaco; Aker Solut, Norway.
    Halje, Karin
    Region Östergötland, Local Health Care Services in Central Östergötland.
    Andersson, Christer A.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Dahlström, Örjan
    Linköping University, Department of Behavioural Sciences and Learning, Disability Research. Linköping University, Faculty of Arts and Sciences. Linköping University, The Swedish Institute for Disability Research.
    Spreco, Armin
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Edouard, Pascal
    University Hospital St Etienne, France; University of Lyon, France; Medical Commiss, France.
    Alonso, Juan-Manuel
    Medical and Antidoping Commiss, Monaco; Aspetar Orthopaed and Sports Medical Hospital, Qatar.
    Preparticipation predictors for championship injury and illness: cohort study at the Beijing 2015 International Association of Athletics Federations World Championships2017In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480, Vol. 51, no 4, p. 272-+Article in journal (Refereed)
    Abstract [en]

    Objectives To determine preparticipation predictors of injury and illness at a major Athletics championship. Methods A cohort study design was used. Before the 2015 International Association of Athletics Federations World Championships in Athletics, all 207 registered national teams were approached about partaking in a study of preparticipation health; 50 teams accepted. The athletes (n=957) in the participating teams were invited to complete a preparticipation health questionnaire (PHQ). New injuries and illnesses that occurred at the championships were prospectively recorded. Logistic regression analyses were performed with simple and multiple models using any in-championship injury and in-championship illness as outcomes. Results The PHQ was completed by 307 (32.1%) of the invited athletes; 116 athletes (38.3%) reported an injury symptom during the month before the championships, while 40 athletes (13%) reported an illness symptom. 20 (6.5%) of the participating athletes sustained a health problem during the championships. Endurance athletes were almost 10-fold more likely to sustain an in-championship illness than speed/power athletes (OR, 9.88; 95% CI 1.20 to 81.31; p=0.033). Participants reporting a preparticipation gradual-onset injury symptom were three times more likely (OR, 3.09; 95% CI 1.08 to 8.79; p=0.035) and those reporting an illness symptom causing anxiety were fivefold more likely (OR, 5.56; 95% CI 1.34 to 23.15; p=0.018) to sustain an in-championship injury. Summary and conclusions Analyses of preparticipation predictors of injury and illness at a major Athletics championship suggest that endurance athletes require particular clinical attention. Preparticipation symptoms causing anxiety are interesting predictors for in-championship health problems.

  • 174.
    Valstar, E.R.
    et al.
    Department of Orthopaedics, Leiden University Medical Center, Leiden, Netherlands, Quantitative Imaging Group, Department of Imaging Science and Technology, Delft University of Technology, Delft, Netherlands.
    Gill, R.
    Nuffield Department of Orthopaedic Surgery, University of Oxford, Nuffield Orthopaedic Centre, Oxford, United Kingdom.
    Ryd, Leif
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine .
    Flivik, G.
    Department of Orthopedics, Lund University Hospital, Lund, Sweden.
    Borlin, N.
    Börlin, N., Department of Computing Science, Umeå University, Umeå, Sweden.
    Karrholm, J.
    Kärrholm, J., Department of Orthopaedics, Sahlgrenska University Hospital, Göteborg, Sweden.
    Guidelines for standardization of radiostereometry (RSA) of implants2005In: Acta Orthopaedica, ISSN 1745-3674, E-ISSN 1745-3682, Vol. 76, no 4, p. 563-572Article in journal (Refereed)
    Abstract [en]

    There is a need for standardization of radiostereometric (RSA) investigations to facilitate comparison of outcome reported from different research groups. In this document, 6 research centers have agreed upon standards for terminology, description and use of RSA arrangement including radiographic set-up and techniques. Consensus regarding minimum requirements for marker stability and scatter, choice of coordinate systems, and preferred way of describing prosthetic micromotion is of special interest. Some notes on data interpretation are also presented. Validation of RSA should be standardized by preparation of protocols for assessment of accuracy and precision. Practical issues related to loading of the joint by weight bearing or other conditions, follow-up intervals, length of follow-up, radiation dose, and the exclusion of patients due to technical errors are considered. Finally, we present a checklist of standardized output that should be included in any clinical RSA paper. This document will form the basis of a detailed standardization protocol under supervision of ISO and the European Standards Working Group on Joint Replacement Implants (CEN/TC 285/WG4). This protocol will facilitate inclusion of RSA in a standard protocol for implant testing before it is released for general use. Such a protocol-also including other recognized clinical outcome parameters-will reduce the risk of implanting potentially inferior prostheses on a large scale. Copyright© Taylor & Francis 2005.

  • 175.
    van der Donk, S
    et al.
    Univ Nijmegen, Med Ctr, Dept Orthoped, Orthoped Res Lab, NL-6500 HB Nijmegen, Netherlands Univ Lund Hosp, Dept Orthoped, S-22185 Lund, Sweden Linkoping Univ Hosp, Dept Orthoped, S-58185 Linkoping, Sweden.
    Buma, P
    Univ Nijmegen, Med Ctr, Dept Orthoped, Orthoped Res Lab, NL-6500 HB Nijmegen, Netherlands Univ Lund Hosp, Dept Orthoped, S-22185 Lund, Sweden Linkoping Univ Hosp, Dept Orthoped, S-58185 Linkoping, Sweden.
    Aspenberg, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Schreurs, BW
    Univ Nijmegen, Med Ctr, Dept Orthoped, Orthoped Res Lab, NL-6500 HB Nijmegen, Netherlands Univ Lund Hosp, Dept Orthoped, S-22185 Lund, Sweden Linkoping Univ Hosp, Dept Orthoped, S-58185 Linkoping, Sweden.
    Similarity of bone ingrowth in rats and goats: A bone chamber study2001In: Laboratory animal science (Chicago), ISSN 0023-6764, Vol. 51, no 4, p. 336-340Article in journal (Refereed)
    Abstract [en]

    Bone ingrowth has been studied extensively in rats by use of bone chambers. However, it is not known whether results in small animals, with respect to bone ingrowth processes, are similar in large animals, in which more realistic models are often used. Since the metabolic rate in small animals is, in general, higher than that in larger species, we hypothesized that bone ingrowth in chambers develops more rapidly in small animals. Therefore, identical bone chambers were placed in the tibias of rats and goats. After 6 and 12 weeks, histologic and histomorphometric examinations were carried out to measure bone and tissue ingrowth distances. Bone ingrowth was higher in both species at 12, compared with 6 weeks (P < 0.01). Tissue ingrowth in general (including soft tissue) was less in rats than in goats at both time periods (P < 0.001). However, bone ingrowth did not differ between species. Thus, when differences in size of an osseous defect are corrected for, there seems to be only little influence of differences in body size.

  • 176. van der Donk, S
    et al.
    Weernink, T
    Buma, P
    Aspenberg, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Slooff, TJJH
    Schreurs, BW
    Rinsing morselized allografts improves bone and tissue ingrowth2003In: Clinical Orthopaedics and Related Research, ISSN 0009-921X, E-ISSN 1528-1132, no 408, p. 302-310Article in journal (Refereed)
    Abstract [en]

    Bone defects in revision hip surgery can be reconstructed with impacted morselized bone grafts. Rinsing these trabecular allografts may enhance graft incorporation by washing out immunogenic factors present in blood, marrow, and fat. However, it has been proposed that impaction of the graft releases biologically active factors, which can provide sufficient activity to stimulate new bone formation. Rinsing before impaction could enhance bone allograft incorporation, but rinsing after impaction could diminish the incorporation process of impacted bone graft. To study the effect of rinsing and impaction of morselized bone grafts on bone ingrowth, a bone chamber study was done in goats. Autografts and allografts were divided into three treatment groups: (A) impacted, (B) rinsed and impacted, and (C) rinsed, impacted, rinsed, and impacted again. Ten goats received three bone chambers in each proximal tibia. The chambers were filled with either allograft or autograft, yielding six different implants per goat. After 6 weeks, histologic analyses were done and bone and tissue ingrowth were measured. New bone and total tissue ingrowth were higher in autografts than in allografts, especially in the non-rinsed group. With rinsing, total tissue ingrowth increased in the allograft group to approach that of autografts. Rinsing after impaction did not additionally alter bone ingrowth. The current findings show that incorporation of allografts can be improved by rinsing the grafts before impaction.

  • 177.
    Virchenko, Olena
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Stimulation of tendon repair by platelet concentrate, CDMP-2 and mechanical loading in animal models2007Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Growth factor delivery may be useful to accelerate the rate of tendon healing. We studied Platelet Concentrate, which in effect can be regarded as a cocktail of growth factors relevant for tendon healing. In a rat Achilles tendon transection model, one postoperative injection of Platelet Concentrate resulted in increased strength even 3 weeks later.

    Mechanical stimulation improves the repair of ruptured tendons. We studied the effects of platelets upon Achilles tendon regenerates in rats 3, 5 and 14 days after transection, either unloaded or mechanically stimulated. At 14 days, physical activity and platelets increased repair independently. Unloading decreased the mechanical properties of the repair tissue to less than half of normal. Moreover, the platelets had no effect without loading.

    Thrombin, which we used for platelet activation, improved healing of the rat Achilles tendon by itself. Conversely, continuous inhibition of thrombin by low molecular weight heparin (LMWH) inhibited tendon repair. However, intermittent inhibition, similar to clinical thromboprophylaxis, had no effect on tendon healing.

    Cartilage Derived Morphogenetic Protein-2 (CDMP-2) can improve tendon healing in loaded defect models. We now studied unloaded repair in a rabbit patellar tendon model. Two hours postoperative, the rabbits received CDMP-2 injected into the haematoma. The healing tendon became 65 % stronger than controls. We then studied Achilles tendon healing with CDMP-2 injections in sheep, to get a bigger animal model. There was an unexpectedly high variation of repair in these animals, and the study turned out to be underpowered. Spontaneous ruptures in humans have a more variable geometry than in our sheep model, so humans can also be expected to vary a lot in mechanical characteristics of Achilles tendon repair. This accentuates the importance of individualized rehabilitation programs.

    In conclusion, both platelet concentrate and CDMP-2 injections might be of interest for clinical use as a complement to surgical or conservative treatment of tendon ruptures. Platelet treatment for tendon ruptures should probably be combined with early physiotherapy.

    List of papers
    1. Platelet concentrate injection improves Achilles tendon repair in rats
    Open this publication in new window or tab >>Platelet concentrate injection improves Achilles tendon repair in rats
    2004 (English)In: Acta Orthopaedica Scandinavica, ISSN 1745-3674, Vol. 75, no 1, p. 93-99Article in journal (Refereed) Published
    Abstract [en]

    Background:Blood platelets release a cocktail of growth factors when activated, some of which are thought to initiate and stimulate repair.

    Experiment and findings: We studied whether a platelet concentrate injection would improve Achilles tendon repair in an established rat model. The Achilles tendon was transected and a 3 mm segment removed. After 6h, a platelet concentrate was injected percutaneously into the hematoma. This increased tendon callus strength and stiffness by about 30 % after 1 week, which persisted for as long as 3 weeks after the injection. At this time, the mechanical testing indicated an improvement in material characteristics - i.e., greater maturation of the tendon callus. This was confirmed by blinded histological scoring.

    Interpretation: Platelet concentrate may prove useful for the treatment of Achilles tendon ruptures.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13012 (URN)10.1080/00016470410001708190 (DOI)
    Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2018-02-27
    2. Independent and additive stimulation of tendon repair by thrombin and platelets
    Open this publication in new window or tab >>Independent and additive stimulation of tendon repair by thrombin and platelets
    2006 (English)In: Acta Orthopaedica, ISSN 1745-3674, Vol. 77, no 6, p. 960-966Article in journal (Refereed) Published
    Abstract [en]

    Background Platelet concentrate application with added thrombin improves Achilles tendon repair in the rat. Upon tissue injury, platelets are activated by thrombin, which has many biological properties in common with growth factors. We wanted to differentiate the effect of platelets from that of thrombin.

    Methods The Achilles tendon was transected in 50 rats. Platelet gel was prepared from the blood of 10 other rats. The rats were given either platelet gel with active or neutralized thrombin implanted into the defect during the operation, or a local injection 6h postoperatively with 50 μL of either platelet concentrate, thrombin or saline. The rats were killed after 14 days and the tendons were mechanically tested.

    Results Compared to saline, platelet gel caused a 42% increase in force at failure, a 90% increase in energy, and a 61% increase in ultimate stress. Platelet gel with neutralized thrombin caused a 22% increase in force at failure, and energy and stress were less elevated. Injected platelet concentrate caused a 24% increase in force at failure, and thrombin caused a 10% increase. These effects and the differences between treatments were statistically significant.

    Interpretation Platelets and thrombin had independent and additive stimulatory effects on tendon repair. The clinical relevance is so far unknown.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13013 (URN)10.1080/17453670610013295 (DOI)
    Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2009-06-08
    3. How can one platelet injection after tendon injury lead to a stronger tendon after 4 weeks?: Interplay between early regeneration and mechanical stimulation
    Open this publication in new window or tab >>How can one platelet injection after tendon injury lead to a stronger tendon after 4 weeks?: Interplay between early regeneration and mechanical stimulation
    2006 (English)In: Acta Orthopaedica, ISSN 1745-3674, Vol. 77, no 5, p. 806-812Article in journal (Refereed) Published
    Abstract [en]

    Background Mechanical stimulation improves the repair of ruptured tendons. Injection of a platelet concentrate (platelet-rich plasma, PRP) can also improve repair in several animal models. In a rat Achilles tendon transection model, 1 postoperative injection resulted in increased strength after 4 weeks. Considering the short half-lives of factors released by platelets, this very late effect calls for an explanation.

    Methods We studied the effects of platelets on Achilles tendon regenerates in rats 3, 5 and 14 days after transection. The tendons were either unloaded by Botulinum toxin A (Botox) injections into the calf muscles, or mechanically stimulated in activity cages. No Botox injections and ordinary cages, respectively, served as controls. Repair was evaluated by tensile testing.

    Results At 14 days, unloading (with Botox) abolished any effect of the platelets and reduced the mechanical properties of the repair tissue to less than half of normal. Thus, some mechanical stimulation is a prerequisite for the effect of platelets at 14 days. Without Botox, both activity and platelets increased repair independently of each other. However, at 3 and 5 days, platelets improved the mechanical properties in Botox-treated rats.

    Interpretation Platelets influence only the early phases of regeneration, but this allows mechanical stimulation to start driving neo-tendon development at an earlier time point, which kept it constantly ahead of the controls.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13014 (URN)10.1080/17453670610013033 (DOI)
    Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2009-06-08
    4. Low Molecular Weight Heparin impairs tendon repair
    Open this publication in new window or tab >>Low Molecular Weight Heparin impairs tendon repair
    2008 (English)In: Journal of Bone and Joint Surgery, ISSN 0301-620X, E-ISSN 2044-5377, Vol. 90-B, no 3, p. 388-392Article in journal (Refereed) Published
    Abstract [en]

    Thrombin has many biological properties similar to those of growth factors. In a previous study, we showed that thrombin improves healing of the rat tendo Achillis. Low molecular weight heparin (LMWH) inhibits the activity and the generation of thrombin. We therefore considered that LMWH at a thromboprophylactic dose might inhibit tendon repair.

    Transection of the tendo Achillis was carried out in 86 rats and the healing tested mechanically. Low molecular weight heparin (dalateparin) was either injected a few minutes before the operation and then given continuously with an osmotic mini pump for seven days, or given as one injection before the operation. In another experiment ,we gave LMWH or a placebo by injection twice daily. The anti-factor Xa activity was analysed.

    Continuous treatment with LMWH impaired tendon healing. After seven days, this treatment caused a 33% reduction in force at failure, a 20% reduction in stiffness and a 67% reduction in energy uptake. However, if injected twice daily, LMWH had no effect on tendon healing. Anti-factor Xa activity was increased by LMWH treatment, but was normal between intermittent injections.

    Low molecular weight heparin delays tendon repair if given continuously, but not if injected intermittently, probably because the anti-factor Xa activity between injections returns to normal, allowing sufficient thrombin stimulation for repair. These findings indicate the need for caution in the assessment of long-acting thrombin and factor Xa inhibitors.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13015 (URN)10.1302/0301-620X.90B3.19493 (DOI)
    Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2017-12-13
    5. CDMP-2 injection improves early tendon healing in a rabbit model for surgical repair
    Open this publication in new window or tab >>CDMP-2 injection improves early tendon healing in a rabbit model for surgical repair
    2005 (English)In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, Vol. 15, no 4, p. 260-264Article in journal (Refereed) Published
    Abstract [en]

    This study examines the hypothesis that cartilage-derived morphogenic protein-2 (CDMP-2) can improve tendon healing after surgical repair. We have previously found improved tendon healing by applying CDMP-2 in models for conservative treatment with mechanically loaded Achilles tendon defects in rats and rabbits. In this study, the patellar tendon was unloaded by patello- tibial cerclage and cut transversely in 40 rabbits. Two hours post-operative, the rabbits received a dose of 20 μg of CDMP-2 or vehicle injected into the hematoma. Specimens were harvested after 14 and 28 days and evaluated by biomechanical testing, radiography and histology. At 14 days, CDMP-2 caused a 65% increase in force at failure, a 50% increase in ultimate stress and a 57% increase in stiffness, as compared with controls. There was no effect on callus size. At 28 days, no differences between the treatment groups could be demonstrated. No bone or cartilage was found in any tendon or regenerated tissue at any time point. Thus, early tendon repair can be stimulated by CDMP-2 in an unloaded model. These results suggest that CDMP-2 might be of interest for clinical use as a complement to surgical treatment of tendon ruptures.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-13016 (URN)10.1111/j.1600-0838.2005.00462.x (DOI)
    Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2009-06-08
    6. Early Achilles tendon repair in sheep
    Open this publication in new window or tab >>Early Achilles tendon repair in sheep
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:liu:diva-13017 (URN)
    Available from: 2008-03-13 Created: 2008-03-13 Last updated: 2010-01-13
  • 178.
    Virchenko, Olena
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    How can one platelet injection after tendon injury lead to a stronger tendon after 4 weeks?: Interplay between early regeneration and mechanical stimulation2006In: Acta Orthopaedica, ISSN 1745-3674, Vol. 77, no 5, p. 806-812Article in journal (Refereed)
    Abstract [en]

    Background Mechanical stimulation improves the repair of ruptured tendons. Injection of a platelet concentrate (platelet-rich plasma, PRP) can also improve repair in several animal models. In a rat Achilles tendon transection model, 1 postoperative injection resulted in increased strength after 4 weeks. Considering the short half-lives of factors released by platelets, this very late effect calls for an explanation.

    Methods We studied the effects of platelets on Achilles tendon regenerates in rats 3, 5 and 14 days after transection. The tendons were either unloaded by Botulinum toxin A (Botox) injections into the calf muscles, or mechanically stimulated in activity cages. No Botox injections and ordinary cages, respectively, served as controls. Repair was evaluated by tensile testing.

    Results At 14 days, unloading (with Botox) abolished any effect of the platelets and reduced the mechanical properties of the repair tissue to less than half of normal. Thus, some mechanical stimulation is a prerequisite for the effect of platelets at 14 days. Without Botox, both activity and platelets increased repair independently of each other. However, at 3 and 5 days, platelets improved the mechanical properties in Botox-treated rats.

    Interpretation Platelets influence only the early phases of regeneration, but this allows mechanical stimulation to start driving neo-tendon development at an earlier time point, which kept it constantly ahead of the controls.

  • 179.
    Virchenko, Olena
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Fahlgren, Anna
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine.
    Rundgren, Mats
    Department of Physiology and Pharmacology Karolinska Institutet, Stockholm.
    Aspenberg, Per
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Early Achilles tendon healing in sheep2008In: Archives of Orthopaedic and Trauma Surgery, ISSN 0936-8051, E-ISSN 1434-3916, Vol. 128, no 9, p. 1001-1006Article in journal (Refereed)
    Abstract [en]

    Introduction: The biomechanics of early tendon healing is important for designing post-injury training, but this has not been described in an animal model, similar to humans in size. We measured elastic and viscoelastic properties of a tendon regenerate in sheep, in a study designed to see the effects of exogenously applying the growth and differentiation factor CDMP-2. This is the first description of early tendon healing in sheep Achilles tendons. Materials and methods: Twenty female sheep underwent Achilles tendon transection without suturing or immobilization. Two hours after the operation, 100 μg of CDMP-2 or placebo was injected into the hematoma. The sheep were slaughtered after 3 weeks, and tendon regenerates tested for viscoelastic properties by cyclical loading, before a destructive tensile test. Thereafter, all specimens were examined by high resolution computerized tomography (CT), and histology. Results: The tendon regenerate formed a sleeve, around the tendon stumps. Failure occurred between the regenerate sleeve and the tendon stumps. There was an unexpectedly large variation in force at failure. In the CDMP-2 group, force correlated with regenerate transverse area, but not in the controls. Thus, the variation in maximum stress was smaller in the CDMP-2 group (P = 0.009). Although the force at failure was only a tenth of normal, the capacity to store elastic energy was already near normal (hysteresis 16%). The mean transverse area, force at failure and stiffness were all about 30% larger in the CDMP-2 group, but this was not significant. There were no signs of bone or cartilage formation on CT or histology. Conclusions: Results are compatible with a positive effect of CDMP-2, but the power was too low to demonstrate any such effect. Considering that spontaneous ruptures in humans are likely to have a more variable geometry than in this model, humans can also be expected to vary a lot in early mechanical characteristics. This emphasizes the importance of individualized rehabilitation programs. The low hysteresis suggests that the energy storing capacity is rather easy for the tissues to develop, possibly it is harder to create appropriate energy dissipation, in order to avoid re-rupture. © Springer-Verlag 2008.

  • 180.
    Virchenko, Olena
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Grenegård, Magnus
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Independent and additive stimulation of tendon repair by thrombin and platelets2006In: Acta Orthopaedica, ISSN 1745-3674, Vol. 77, no 6, p. 960-966Article in journal (Refereed)
    Abstract [en]

    Background Platelet concentrate application with added thrombin improves Achilles tendon repair in the rat. Upon tissue injury, platelets are activated by thrombin, which has many biological properties in common with growth factors. We wanted to differentiate the effect of platelets from that of thrombin.

    Methods The Achilles tendon was transected in 50 rats. Platelet gel was prepared from the blood of 10 other rats. The rats were given either platelet gel with active or neutralized thrombin implanted into the defect during the operation, or a local injection 6h postoperatively with 50 μL of either platelet concentrate, thrombin or saline. The rats were killed after 14 days and the tendons were mechanically tested.

    Results Compared to saline, platelet gel caused a 42% increase in force at failure, a 90% increase in energy, and a 61% increase in ultimate stress. Platelet gel with neutralized thrombin caused a 22% increase in force at failure, and energy and stress were less elevated. Injected platelet concentrate caused a 24% increase in force at failure, and thrombin caused a 10% increase. These effects and the differences between treatments were statistically significant.

    Interpretation Platelets and thrombin had independent and additive stimulatory effects on tendon repair. The clinical relevance is so far unknown.

  • 181.
    Virchenko, Olena
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Lindahl, Tomas
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Low Molecular Weight Heparin impairs tendon repair2008In: Journal of Bone and Joint Surgery, ISSN 0301-620X, E-ISSN 2044-5377, Vol. 90-B, no 3, p. 388-392Article in journal (Refereed)
    Abstract [en]

    Thrombin has many biological properties similar to those of growth factors. In a previous study, we showed that thrombin improves healing of the rat tendo Achillis. Low molecular weight heparin (LMWH) inhibits the activity and the generation of thrombin. We therefore considered that LMWH at a thromboprophylactic dose might inhibit tendon repair.

    Transection of the tendo Achillis was carried out in 86 rats and the healing tested mechanically. Low molecular weight heparin (dalateparin) was either injected a few minutes before the operation and then given continuously with an osmotic mini pump for seven days, or given as one injection before the operation. In another experiment ,we gave LMWH or a placebo by injection twice daily. The anti-factor Xa activity was analysed.

    Continuous treatment with LMWH impaired tendon healing. After seven days, this treatment caused a 33% reduction in force at failure, a 20% reduction in stiffness and a 67% reduction in energy uptake. However, if injected twice daily, LMWH had no effect on tendon healing. Anti-factor Xa activity was increased by LMWH treatment, but was normal between intermittent injections.

    Low molecular weight heparin delays tendon repair if given continuously, but not if injected intermittently, probably because the anti-factor Xa activity between injections returns to normal, allowing sufficient thrombin stimulation for repair. These findings indicate the need for caution in the assessment of long-acting thrombin and factor Xa inhibitors.

  • 182.
    Virchenko, Olena
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Skoglund, Björn
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Fahlgren, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    CDMP-2 injection improves early tendon healing in a rabbit model for surgical repair2005In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, Vol. 15, no 4, p. 260-264Article in journal (Refereed)
    Abstract [en]

    This study examines the hypothesis that cartilage-derived morphogenic protein-2 (CDMP-2) can improve tendon healing after surgical repair. We have previously found improved tendon healing by applying CDMP-2 in models for conservative treatment with mechanically loaded Achilles tendon defects in rats and rabbits. In this study, the patellar tendon was unloaded by patello- tibial cerclage and cut transversely in 40 rabbits. Two hours post-operative, the rabbits received a dose of 20 μg of CDMP-2 or vehicle injected into the hematoma. Specimens were harvested after 14 and 28 days and evaluated by biomechanical testing, radiography and histology. At 14 days, CDMP-2 caused a 65% increase in force at failure, a 50% increase in ultimate stress and a 57% increase in stiffness, as compared with controls. There was no effect on callus size. At 28 days, no differences between the treatment groups could be demonstrated. No bone or cartilage was found in any tendon or regenerated tissue at any time point. Thus, early tendon repair can be stimulated by CDMP-2 in an unloaded model. These results suggest that CDMP-2 might be of interest for clinical use as a complement to surgical treatment of tendon ruptures.

  • 183.
    Wahlström, Ola
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Commentaries:  in International Journal of Therapy and Rehabilitation, vol 18, issue 12, pp2011In: International Journal of Therapy and Rehabilitation, ISSN 1741-1645, E-ISSN 1759-779X, Vol. 18, no 12, p. 680-Article in journal (Other academic)
    Abstract [en]

    [No abstract available]

  • 184.
    Wahlström, Ola
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Knutsson, Hans
    Linköping University, Department of Electrical Engineering, Computer Vision. Linköping University, The Institute of Technology.
    A Device for Generation of Electromagnetic Fields of Extremely Low Frequency1984In: Journal of Biomedical Engineering, ISSN 0141-5425, Vol. 6, no 4, p. 293-296Article in journal (Refereed)
    Abstract [en]

    A new device for generation of electromagnetic fields at extra low frequencies, to be used in fracture treatment, is described. The device involves a coil and a battery powered noise-generator. An alternating magnetic field of 4 × 10−4T (4 Gauss) (RMS value) with a frequency range 1–1000 Hz is generated. Results from a controlled randomized study of fresh fractures have shown significant differences (p < 0.01) between the treated group and the control group. The results are encouraging and motivate further investigations with this method.

  • 185.
    Wahlström, Ola
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Linder, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Chemistry.
    Ansell, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Kalén, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Söderström, Mats
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Magnusson, Per
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Diagnostics, Department of Clinical Chemistry.
    Acidic preparations of lysed platelets upregulate proliferative pathways in osteoblast-like cells as demonstrated by genome-wide microarray analysis2011In: Platelets, ISSN 0953-7104, E-ISSN 1369-1635, Vol. 22, no 6, p. 452-460Article in journal (Refereed)
    Abstract [en]

    latelets contain numerous growth factors essential for wound and fracture healing. We investigated the gene expression in human osteoblast-like cells stimulated with lysed platelets prepared in acidic, neutral, or alkaline buffers. Lysed platelets prepared in buffers at pH 5.4, 7.4, and 7.9, were added after neutralization to hFOB 1.19 cells. Genome-wide microarray analysis was performed using the Affymetrix GeneChip 7G Scanner. Biometric, cluster, and pathway analyses were performed with GeneSpring GX. Biometric analyses demonstrated that 53 genes were differentially regulated (p andlt;= 0.005, andgt;= 2-fold increase). Pathway analysis revealed 10 significant pathways of which eight are common ones regulating bone formation and cancer growth. Eleven genes were selected for quantitative real-time polymerase chain reaction (PCR) based on the microarray analysis of the lysed platelets prepared in the pH 5.4 experiments. In conclusion, acidic preparations of lysed platelet concentrates release factors essential for cell proliferation and particularly cell metabolism under hypoxic conditions. The genetic response from these factors was dominated by genes associated with the same pathways observed in bone formation and cancer growth. Activation of TGF-beta in the acidic preparation could be a stimulatory key factor of cell proliferation. These results support the hypothesis that acidification of platelets modifies the stimulatory response of mesenchymal cells in vitro, which is analogous with the observed milieu of a low pH present in wound and fracture sites, as well as in growing tumors.

  • 186.
    Wahlström, Ola
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Linder, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Chemistry.
    Kalén, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Magnusson, Per
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Chemistry.
    Acidic preparations of platelet concentrates release bone morphogenetic protein-2.2008In: Acta orthopaedica, ISSN 1745-3682, Vol. 79, no 3, p. 433-437Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND PURPOSE: Growth factors released from platelets have potent effects on fracture and wound healing. The acidic tide of wound healing, i.e. the pH within wounds and fractures, changes from acidic pH to neutral and alkaline pH as the healing process progresses. We investigated the influence of pH on lysed platelet concentrates regarding the release of growth factors. MATERIAL AND METHODS: Platelet concentrates free of leukocyte components were lysed and incubated in buffers with pH between 4.3 and 8.6. Bone morphogenetic protein-2 (BMP-2), platelet-derived growth factor (PDGF), transforming growth factor-beta(TGF-beta), and vascular endothelial growth factor (VEGF) were measured by quantitative enzyme-linked immunosorbent assays. RESULTS: PDGF, TGF-beta, and VEGF were present in all platelet preparations but the levels varied in a pH-dependent fashion. BMP-2 was only detected in the most acidic preparation (pH 4.3), which is interesting since BMP-2 has been reported to be an endogenous mediator of fracture repair and to be responsible for the initiation of fracture healing. INTERPRETATION: Our findings indicate that platelets release substantial amounts of BMP-2 only under conditions of low pH, the milieu associated with the critical initial stage of fracture healing.

  • 187.
    Wahlström, Ola
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Linder, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Chemistry.
    Kalén, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Magnusson, Per
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Laboratory Medicine, Department of Clinical Chemistry.
    Variation of pH in lysed platelet concentrates influence proliferation and alkaline phosphatase activity in human osteoblast-like cells.2007In: Platelets, ISSN 0953-7104, E-ISSN 1369-1635, Vol. 18, no 2, p. 113-118Article in journal (Refereed)
    Abstract [en]

    Activated platelets release a multifaceted blend of growth factors that has stimulatory effects on mesenchymal cells, both in vitro and in vivo, which imply beneficial effects on wound repair and tissue regeneration. Previous studies on fibroblast cultures have revealed that more potent growth factors, with respect to cell proliferation, are released in acidic preparations of lysed platelet concentrates in comparison with neutral and alkaline preparations. The current study was intended to investigate the influence of pH on lysed platelet concentrates with respect to release of growth factors, cell proliferation and alkaline phosphatase (ALP) activity in human osteoblast-like cells (hFOB 1.19). Cell proliferation was assessed with the MTT kit, ALP activity by conventional enzymatic reaction kinetics and growth factors platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta) by enzyme-linked immunosorbent assays. Osteoblast-like cells were stimulated with lysed platelet concentrates preincubated at pH 4.4, 5.4, 7.4, and 7.6. A 3-13-fold increase of cell proliferation was found in comparison with controls and the most evident increase was observed with platelets activated at pH 5.4. The highest ALP activity was observed in preparations at pH 7.6. Platelets incubated in an acidic environment (pH 5.4) induced a higher proliferation compared with preincubation at neutral or alkaline pH and the level of PDGF was also found to be higher in acidic preincubations. The level of TGF-beta was, in contrast, lowest at pH 4.4. We suggest, based on these experimental findings, that acidic milieu influence platelets to release growth factors more potent to stimulate osteoblast proliferation than neutral and alkaline platelet preparations. Lysed platelet concentrates prepared at an alkaline pH might release additional components with stimulating effects resulting in other features than cell proliferation. This is the first report, to our knowledge, about a pH dependent stimulatory effect of lysed platelet concentrates on human osteoblast-like cell proliferation. Lysed platelet concentrates, preincubated in acidic or alkaline buffers, may benefit fracture healing, implant fixation and might also be advantageous in the treatment of wounds with platelet constituents; however, this has to be investigated in extended experimental and clinical settings.

  • 188.
    Wahlström, Ola
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Risto, Olof
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Kalén, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Linder, Cecilia
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Chemistry.
    Ansell, Anna
    Linköping University, Department of Clinical and Experimental Medicine, Oto-Rhiono-Laryngology and Head & Neck Surgery. Linköping University, Faculty of Health Sciences.
    Söderström, Mats
    Linköping University, Department of Clinical and Experimental Medicine, Cell Biology. Linköping University, Faculty of Health Sciences.
    Magnusson, Per
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Chemistry. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Chemistry.
    Acidic preparations of lysed platelets up-regulate proliferative and vascular genes, and the TGFBR pathway in osteoblast-like cells in BONE, vol 48, issue , pp S118-S1182011In: BONE, Elsevier Science B.V., Amsterdam. , 2011, Vol. 48, p. S118-S118Conference paper (Refereed)
    Abstract [en]

    n/a

  • 189.
    Wermelin, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences.
    Surface bound bisphosphonate for implant fixation in bone2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    During the surgical preparation of bone, prior to insertion of an implant, bone will be traumatized which leads to local resorption. Consequently, early implant fixation might be reduced. Impaired early fixation, as evidenced by radiostereometry, has been associated with increased risk of late loosening. Bisphosphonates are known to inhibit bone resorption by osteoclasts and have shown to increase implant fixation when administered systemically or locally directly at the bone prior to implant insertion.

    A method to bind bisphosphonates directly to the implant was developed. Stainless steel screws were coated with crosslinked fibrinogen, serving as an anchor for bisphosphonate attachment. The screws were inserted in the tibial metaphysis in rats and implant fixation was analyzed with pullout measurements. Bisphosphonate coated screws turned out to have 28 % higher pullout force at 2 weeks compared to control screws with the fibrinogen coating only. The next experiment was designed to measure at what stage in the healing process the strongest bisphosphonate effect was gained. Bisphosphonate coated screws were expected to reduce the resorption of the traumatized bone. However, no decreased fixation was found in the control group. Instead, the fixation increased with time, and so did the effect of the bisphosphonates. At 8 weeks, the pullout force was twice as high for screws with bisphosphonate compared to control screws. By histology at 8 weeks, a bone envelope was found around bisphosphonate coated screws but absent around control screws. Thus, the anti catabolic action of the bisphosphonate resulted in an increased amount of bone surrounding the bisphosphonate screws.

    Titanium is generally considered to be better fixated in bone compared to stainless steel. The coating technique was found to be applicable on titanium as well, again with improved fixation.

    A majority of fractures occur in osteoporotic bone. Despite the relatively low amount of bisphosphonates at the screws, the bisphosphonate coating improved implant fixation at 2 weeks also in rats made osteoporotic by ovariectomy.

    In conclusion, bisphosphonates bound to titanium or stainless steel screws coated with fibrinogen increased fixation in bone, in rats. These results suggest that the bisphosphonate and fibrinogen coating might improve the fixation of screw shaped implants and possibly also arthroplasties, in humans.

    List of papers
    1. Surface-bound bisphosphonates enhance screw fixation in rats—increasing effect up to 8 weeks after insertion
    Open this publication in new window or tab >>Surface-bound bisphosphonates enhance screw fixation in rats—increasing effect up to 8 weeks after insertion
    2007 (English)In: Acta Orthopaedica, ISSN 1745-3674, E-ISSN 1745-3682, Vol. 78, no 3, p. 385-392Article in journal (Refereed) Published
    Abstract [en]

    Background: A bisphosphonate coating improves screw fixation 2 weeks after implantation in cancellous bone. This study on rats examined further development of fixation over time for screws inserted in cancellous and cortical bone.

    Methods: SS screws were coated with a multiple layer of fibrinogen. Half of the screws were coated further with bisphosphonates, which were linked to the fibrinogen. The screws were inserted in cancellous and cortical bone in rats. The rats were killed after 5 h, 4 days, 1, 2, 4, 8, and 24 weeks, and fixation was evaluated by pullout test.

    Results: There was a gradual increase in pull-out force over time in both cancellous and cortical bone. The bisphosphonate coating improved fixation. Moreover, the difference between the bisphosphonate and control groups increased with time. The pull-out force was almost twice that of the controls for screws inserted in cancellous bone at 8 weeks. Energy uptake was increased more than 3-fold.

    Discussion: The energy uptake and pull-out force of a screw depends on the bone engaged with the threads. Thus, the presence of bisphosphonates increased the amount or quality of this bone by affecting the resorp-tion/formation in a positive way. The increased effect of the bisphosphonates with time thus suggests that bisphosphonate is retained within the remodeling bone, with a positive effect on its gradual adaptation to the implant.

    Place, publisher, year, edition, pages
    Talyor & Francis, 2007
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-15306 (URN)10.1080/17453670710013979 (DOI)
    Available from: 2008-10-30 Created: 2008-10-30 Last updated: 2017-12-14Bibliographically approved
    2. Bisphosphonate coating on titanium screws increases mechanical fixation in rat tibia after two weeks
    Open this publication in new window or tab >>Bisphosphonate coating on titanium screws increases mechanical fixation in rat tibia after two weeks
    2008 (English)In: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 86A, no 1, p. 220-227Article in journal (Refereed) Published
    Abstract [en]

    Recently published data indicate that immobilized N-bisphosphonate enhances the pullout force and energy uptake of implanted stainless steel screws at 2 weeks in rat tibia. This study compares titanium screws with and without a bisphosphonate coating in the same animal model. The screws were first coated with an 100-nm thick crosslinked fibrinogen film. Pamidronate was subsequently immobilized into this film via EDC/NHS-activated carboxyl groups within the fibrinogen matrix, and finally another N-bisphosphonate, ibandronate, was physically adsorbed. The release kinetics of immobilized 14C-alendronate was measured in buffer up to 724 h and showed a 60% release within 8 h. Mechanical tests demonstrated a 32% (p = 0.04) and 48% (p = 0.02) larger pullout force and energy until failure after 2 weeks of implantation, compared to uncoated titanium screws. A control study with physically adsorbed pamidronate showed no effect on mechanical fixation, probably due to a too small adsorbed amount. We conclude that the fixation of titanium implants in bone can be improved by fibrinogen matrix-bound bisphosphonates.

    Place, publisher, year, edition, pages
    Hoboken, NJ, United States: John Wiley & Sons, 2008
    Keywords
    Bisphosphonate, pull-out, titanium, drug release, gamma sterilization, stainless steel, rat, fibrinogen, coating
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-15307 (URN)10.1002/jbm.a.31583 (DOI)000256459500021 ()
    Available from: 2008-10-30 Created: 2008-10-30 Last updated: 2017-12-14Bibliographically approved
    3. Stainless steel screws coated with bisphosphonates gave stronger fixation and more surrounding bone. Histomorphometry in rats
    Open this publication in new window or tab >>Stainless steel screws coated with bisphosphonates gave stronger fixation and more surrounding bone. Histomorphometry in rats
    Show others...
    2008 (English)In: Bone, ISSN 8756-3282, E-ISSN 1873-2763, Vol. 42, no 2, p. 365-371Article in journal (Refereed) Published
    Abstract [en]

    Coating of stainless steel screws with bisphosphonate in a fibrinogen matrix leads to an enhancement of the pullout strength 2 weeks after insertion in rat tibiae. This effect then increases over time until at least 8 weeks. The pullout force reflects the mechanical properties of the bone within the threads, which acts as a screw nut. The aim of the present study was to find descriptive and morphometric histological correlates to the increased pullout strength. Because the bisphosphonates are applied via the implant surface, we also measured bone to implant contact and how far away from the surface any effects could be seen.

    Stainless steel screws underwent one of three treatments: uncoated control, controls coated with a layer of cross-linked fibrinogen, or screws further modified with bisphosphonates covalently linked and physically adsorbed to the fibrinogen layer. At 1 (n = 33) and 8 (n = 27) weeks, bone to implant contact and bone area density in the threads were measured, as well as bone area density at 250 and 500 μm from the outer edge of the threads. Additionally, removal torque for each screw treatment was measured at 2 weeks (n = 28).

    At 8 weeks, the part of the bisphosphonate screw that was located in the marrow cavity had become surrounded with bone, whereas there was almost no bone surrounding the controls. The bone area density in the threads along the entire bisphosphonate screw was increased by 40% compared with uncoated controls, and at 250 μm distance it was more than doubled. At 1 week, coated screws had less implant–bone contact, but at 8 weeks there was no difference between uncoated and bisphosphonate-coated screws. The bisphosphonate screws had 50% increased removal torque at 2 weeks compared to uncoated screws. Howship's lacunae and osteoclasts were found near the screws with bisphosphonates at 8 weeks, suggesting that some bone remodeling took place near the implant, in spite of the presence of bisphosphonates.

    Place, publisher, year, edition, pages
    Elsevier/ScienceDirect, 2008
    Keywords
    Histomorphometry; Stainless steel; Torque removal; Bisphosphonate; Implant fixation
    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-15308 (URN)10.1016/j.bone.2007.10.013 (DOI)
    Available from: 2008-10-30 Created: 2008-10-30 Last updated: 2017-12-14Bibliographically approved
    4. A bisphosphonate coating improves the bony fixation of stainless steel screws in ovariectomized rats
    Open this publication in new window or tab >>A bisphosphonate coating improves the bony fixation of stainless steel screws in ovariectomized rats
    2008 (English)Article in journal (Refereed) Submitted
    Abstract [en]

    Background: Bisphosphonate coatings improve the fixation of implants in bone. Stainless steels screws inserted in the rat tibia become encapsulated by new bone if they are coated with bisphosphonates in a crosslinked fibrinogen matrix. Thereby, the coating leads to a gradual increase in pull-out force. We now investigate if this bisphosphonate coating is capable to improve the mechanical fixation also in osteoporotic bone.

    Methods: Stainless steel screws were coated with a thin crosslinked fibrinogen matrix. With EDC/NHS coupling technique, pamidronate was bound to carboxylic groups and ibandronate was adsorbed in the fibrinogen matrix. Uncoated stainless steel screws and bisphosphonatecoated screws were inserted bilaterally in the proximal tibia in 10 ovariectomized and 10 sham operated rats. At 2 weeks pull-out force and energy was measured.

    Results: In the ovariectomized rats, pull-out force was 53 % higher for bisphosphonate coated screws compared to control screws. Energy was 44 % higher. The sham operated rats showed a higher variation, and no effect of the coating was found.

    Conclusion: The coating was sufficient to improve fixation in ovariectomized rats

    National Category
    Surgery
    Identifiers
    urn:nbn:se:liu:diva-15309 (URN)
    Available from: 2008-10-30 Created: 2008-10-30 Last updated: 2009-08-21Bibliographically approved
  • 190.
    Wermelin, Karin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Linderbäck Stenfors, Paula
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Bisphosphonate coating on titanium screws increases mechanical fixation in rat tibia after two weeks2008In: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 86A, no 1, p. 220-227Article in journal (Refereed)
    Abstract [en]

    Recently published data indicate that immobilized N-bisphosphonate enhances the pullout force and energy uptake of implanted stainless steel screws at 2 weeks in rat tibia. This study compares titanium screws with and without a bisphosphonate coating in the same animal model. The screws were first coated with an 100-nm thick crosslinked fibrinogen film. Pamidronate was subsequently immobilized into this film via EDC/NHS-activated carboxyl groups within the fibrinogen matrix, and finally another N-bisphosphonate, ibandronate, was physically adsorbed. The release kinetics of immobilized 14C-alendronate was measured in buffer up to 724 h and showed a 60% release within 8 h. Mechanical tests demonstrated a 32% (p = 0.04) and 48% (p = 0.02) larger pullout force and energy until failure after 2 weeks of implantation, compared to uncoated titanium screws. A control study with physically adsorbed pamidronate showed no effect on mechanical fixation, probably due to a too small adsorbed amount. We conclude that the fixation of titanium implants in bone can be improved by fibrinogen matrix-bound bisphosphonates.

  • 191.
    Wermelin, Karin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Suska, F.
    Department of Biomaterials, Inst. of Surgical Sciences, Sahlgrenska Academy at Göteborg University, Box 412, SE-405 30 Göteborg, Sweden.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Thomsen, P.
    Department of Biomaterials, Inst. of Surgical Sciences, Sahlgrenska Academy at Göteborg University, Box 412, SE-405 30 Göteborg, Sweden.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Stainless steel screws coated with bisphosphonates gave stronger fixation and more surrounding bone. Histomorphometry in rats2008In: Bone, ISSN 8756-3282, E-ISSN 1873-2763, Vol. 42, no 2, p. 365-371Article in journal (Refereed)
    Abstract [en]

    Coating of stainless steel screws with bisphosphonate in a fibrinogen matrix leads to an enhancement of the pullout strength 2 weeks after insertion in rat tibiae. This effect then increases over time until at least 8 weeks. The pullout force reflects the mechanical properties of the bone within the threads, which acts as a screw nut. The aim of the present study was to find descriptive and morphometric histological correlates to the increased pullout strength. Because the bisphosphonates are applied via the implant surface, we also measured bone to implant contact and how far away from the surface any effects could be seen.

    Stainless steel screws underwent one of three treatments: uncoated control, controls coated with a layer of cross-linked fibrinogen, or screws further modified with bisphosphonates covalently linked and physically adsorbed to the fibrinogen layer. At 1 (n = 33) and 8 (n = 27) weeks, bone to implant contact and bone area density in the threads were measured, as well as bone area density at 250 and 500 μm from the outer edge of the threads. Additionally, removal torque for each screw treatment was measured at 2 weeks (n = 28).

    At 8 weeks, the part of the bisphosphonate screw that was located in the marrow cavity had become surrounded with bone, whereas there was almost no bone surrounding the controls. The bone area density in the threads along the entire bisphosphonate screw was increased by 40% compared with uncoated controls, and at 250 μm distance it was more than doubled. At 1 week, coated screws had less implant–bone contact, but at 8 weeks there was no difference between uncoated and bisphosphonate-coated screws. The bisphosphonate screws had 50% increased removal torque at 2 weeks compared to uncoated screws. Howship's lacunae and osteoclasts were found near the screws with bisphosphonates at 8 weeks, suggesting that some bone remodeling took place near the implant, in spite of the presence of bisphosphonates.

  • 192.
    Wermelin, Karin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    A bisphosphonate coating improves the bony fixation of stainless steel screws in ovariectomized rats2008Article in journal (Refereed)
    Abstract [en]

    Background: Bisphosphonate coatings improve the fixation of implants in bone. Stainless steels screws inserted in the rat tibia become encapsulated by new bone if they are coated with bisphosphonates in a crosslinked fibrinogen matrix. Thereby, the coating leads to a gradual increase in pull-out force. We now investigate if this bisphosphonate coating is capable to improve the mechanical fixation also in osteoporotic bone.

    Methods: Stainless steel screws were coated with a thin crosslinked fibrinogen matrix. With EDC/NHS coupling technique, pamidronate was bound to carboxylic groups and ibandronate was adsorbed in the fibrinogen matrix. Uncoated stainless steel screws and bisphosphonatecoated screws were inserted bilaterally in the proximal tibia in 10 ovariectomized and 10 sham operated rats. At 2 weeks pull-out force and energy was measured.

    Results: In the ovariectomized rats, pull-out force was 53 % higher for bisphosphonate coated screws compared to control screws. Energy was 44 % higher. The sham operated rats showed a higher variation, and no effect of the coating was found.

    Conclusion: The coating was sufficient to improve fixation in ovariectomized rats

  • 193.
    Wermelin, Karin
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences.
    Tengvall, Pentti
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics . Linköping University, The Institute of Technology.
    Aspenberg, Per
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Surface-bound bisphosphonates enhance screw fixation in rats—increasing effect up to 8 weeks after insertion2007In: Acta Orthopaedica, ISSN 1745-3674, E-ISSN 1745-3682, Vol. 78, no 3, p. 385-392Article in journal (Refereed)
    Abstract [en]

    Background: A bisphosphonate coating improves screw fixation 2 weeks after implantation in cancellous bone. This study on rats examined further development of fixation over time for screws inserted in cancellous and cortical bone.

    Methods: SS screws were coated with a multiple layer of fibrinogen. Half of the screws were coated further with bisphosphonates, which were linked to the fibrinogen. The screws were inserted in cancellous and cortical bone in rats. The rats were killed after 5 h, 4 days, 1, 2, 4, 8, and 24 weeks, and fixation was evaluated by pullout test.

    Results: There was a gradual increase in pull-out force over time in both cancellous and cortical bone. The bisphosphonate coating improved fixation. Moreover, the difference between the bisphosphonate and control groups increased with time. The pull-out force was almost twice that of the controls for screws inserted in cancellous bone at 8 weeks. Energy uptake was increased more than 3-fold.

    Discussion: The energy uptake and pull-out force of a screw depends on the bone engaged with the threads. Thus, the presence of bisphosphonates increased the amount or quality of this bone by affecting the resorp-tion/formation in a positive way. The increased effect of the bisphosphonates with time thus suggests that bisphosphonate is retained within the remodeling bone, with a positive effect on its gradual adaptation to the implant.

  • 194. Yuan, X
    et al.
    Ryd, Leif
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine .
    Tanner, KE
    Linkoping Univ Hosp, Dept Orthopaed, S-58185 Linkoping, Sweden Univ Lund Hosp, S-22185 Lund, Sweden.
    Lidgren, L
    Linkoping Univ Hosp, Dept Orthopaed, S-58185 Linkoping, Sweden Univ Lund Hosp, S-22185 Lund, Sweden.
    Roentgen single-plane photogrammetric analysis (RSPA) - A new approach to the study of musculoskeletal movement2002In: Journal of Bone and Joint Surgery, ISSN 0301-620X, E-ISSN 2044-5377, Vol. 84B, no 6, p. 908-914Article in journal (Refereed)
    Abstract [en]

    We present a new approach for the accurate reconstruction of three-dimensional skeletal positions using roentgen single-plane photogrammetric analysis (RSPA). This technique uses a minimum of three markers embedded in each segment which allow continuous, real-time, internal skeletal movement to be measured from single-plane images, provided that the precise distance between the markers is known. A simulation study indicated that the error propagation in this approach is influenced by focus position, object position, the number of control points, the accuracy of the previous measurement of the distance between markers and the accuracy of image measurement. For reconstruction of normal movement of the knee with an input measurement error Of SD = 0.02 mm, the rotational and translational differences between reconstructed and original movement were less than 0.27degrees and 0.9 mm, respectively. Our results showed that the accuracy of RSPA is sufficient for the analysis of most movement of joints. This approach can be applied in combination with force measurements for dynamic studies of the musculoskeletal system.

  • 195.
    Öberg, Tommy
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine . Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Oberg, U.
    Öberg, U., Department of Physiotherapy, County Hospital, Eksjö, Sweden.
    Sviden, G.
    Svidén, G., Department of Rehabilition, Jönköping University, PO Box 1026, SE-551 11 Jönköping, Sweden.
    Persson, A.N.
    Department of Occupational Therapy, County Hospital, Eksjö, Sweden.
    Functional capacity after hip arthroplasty: A comparison between evaluation with three standard instruments and a personal interview2005In: Scandinavian Journal of Occupational Therapy, ISSN 1103-8128, E-ISSN 1651-2014, Vol. 12, no 1, p. 18-28Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to compare the information obtained from three standard instruments used in physiotherapy and occupational therapy and with information acquired from an unstructured interview. Ten patients with osteoarthritis of the hip were consecutively picked from the waiting list at an orthopedic clinic. All were examined before and six months after arthroplasty. The study layout is a mixture of quantitative and qualitative evaluation. The three instruments used were SF-36 (self-reported health-related quality of life), FAS (an instrument for evaluation of lower extremity dysfunction), and the COPM (for evaluation of self-experienced activity level). All patients were also interviewed in a free, unstructured interview, and data were analyzed with a phenomenological approach. All methods could describe function and activity status of the patients very well, and they were also responsive to postoperative improvement. Together the three instruments gave such good information that almost no extra information was obtained through the interviews. On the other hand, the interviews served as powerful validation of the three instruments. The information in the three separate instruments is qualitatively different, and one instrument cannot replace another. They cannot be replaced by the interview either, because the instruments provide the therapist with specific and structured information that is important for further treatment planning and follow-up. © 2005 Taylor & Francis.

  • 196.
    Öhrn, Annica
    et al.
    Linköping University, Department of Medical and Health Sciences, Health Technology Assessment and Health Economics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Health and Developmental Care, Patient Safety.
    Olai, Anders
    Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Spinal Surgery.
    Rutberg, Hans
    Östergötlands Läns Landsting, Patient Security. Linköping University, Department of Medical and Health Sciences, Health Technology Assessment and Health Economics. Linköping University, Faculty of Health Sciences.
    Nilsen, Per
    Linköping University, Department of Medical and Health Sciences, Social Medicine and Public Health Science. Linköping University, Faculty of Health Sciences.
    Tropp, Hans
    Linköping University, Department of Clinical and Experimental Medicine, Orthopaedics and Sports Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Orthopaedics in Linköping.
    Adverse events in spine surgery in Sweden: A comparison of patient claims data and national quality register (Swespine) data2011In: Acta Orthopaedica, ISSN 1745-3674, E-ISSN 1745-3682, Vol. 82, no 6, p. 727-731Article in journal (Refereed)
    Abstract [en]

    Background and purpose: Our knowledge of complications and adverse events in spinal surgery is limited, especially concerning incidence and consequences. We therefore investigated adverse events in spine surgery in Sweden by comparing patient claims data from the County Councils' Mutual Insurance Company register with data from the National Swedish Spine Register (Swespine).

    Methods: We analyzed patient claims (n = 182) to the insurance company after spine surgery performed between 2003 and 2005. The medical records of the patients filing these claims were reviewed and compared with Swespine data for the same period.

    Results: Two-thirds (119/182, 65%) of patients who claimed economic compensation from the insurance company were registered in Swespine. Of the 210 complications associated with these 182 claims, only 74 were listed in Swespine. The most common causes of compensated injuries (n = 139) were dural lesions (n = 40) and wound infections (n = 30). Clinical outcome based on global assessment, leg pain, disability, and quality of health was worse for patients who claimed economic compensation than for the total group of Swespine patients.

    Interpretation: We found considerable under-reporting of complications in Swespine. Dural lesions and infections were not well recorded, although they were important reasons for problems and contributed to high levels of disability. By analyzing data from more than one source, we obtained a better understanding of the patterns of adverse events and outcomes after spine surgery.

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