Purpose Acute trauma-related rotator cuff tears are believed to have better healing potential than chronic tears due to less degenerative changes of the tendons. However, the histopathological condition of tendons from trauma-related tears is not well investigated. The purpose of this study was to explore specific histopathological features in tendons from acute trauma-related full-thickness rotator cuff tears and to compare them to findings in tendons from nontraumatic, chronic tears. Methods In a prospective cohort study, 62 previously asymptomatic patients [14 women, median age 61 years (range 42-75)] with trauma-related full-thickness rotator cuff tears were consecutively included. Arthroscopic repair was performed within 30 (median, IQR 25-37) days after the injury. During surgery, tissue biopsies were harvested from the supraspinatus tendons in 53 (86%) of the patients. In addition, similar biopsies were harvested from 10 patients undergoing surgery for chronic tears without history of trauma. All tissue samples were examined by a well-experienced pathologist under light microscope. Tendon degeneration was determined using the Bonar score whereas immunostaining was used for proliferation (Ki67), inflammation (CD45), apoptosis (p53) and haemosiderin staining to study traces of bleeding. Results The median (IQR) Bonar score for the acute trauma-related biopsies was 10.5 (7.5-14.5) compared to 11 (5-12.8) for the control group with no statistically significant difference between the groups. No statistically significant between-group difference was found for the inflammatory index whereas tendons from patients with trauma-related full-thickness rotator cuff tears had statistically significantly higher apoptosis [3.1 (0.5-8.9) vs. 0.1 (0-1.5), p = 0.003] and proliferation [4.0 (1.8-6.9) vs. 0.4 (0-2.0), p = 0.001) indices than those undergoing surgery for chronic tears. Positive haemosiderin staining was found in 34% of tissue samples from patients with trauma-related tears compared to 10% in the control group (n.s). Conclusion This study suggests that there is no difference with regard to degenerative changes between supraspinatus tendons harvested from patients with acute, trauma-related rotator cuff tears and patients with nontraumatic, chronic tears.

Background: Healing failure after rotator cuff repair is a challenging problem. Acute, trauma-related tears are considered a separate entity and are often treated surgically. The aim of this study was to identify factors associated with healing failure in previously asymp-tomatic patients with trauma-related rotator cuff tears treated with early arthroscopic repair. Methods: This study included 62 consecutively recruited patients (23% women; median age, 61 years; age range, 42-75 years) with acute symptoms in a previously asymptomatic shoulder and a magnetic resonance imaging-verified full-thickness rotator cuff tear after shoulder trauma. All patients were offered, and underwent, early arthroscopic repair, during which a biopsy specimen was har-vested from the supraspinatus tendon and analyzed for signs of degeneration. Of the patients, 57 (92%) completed 1-year follow-up and underwent assessment of repair integrity on magnetic resonance images according to the Sugaya classification. Risk factors for heal-ing failure were investigated using a causal-relation diagram where age, body mass index, tendon degeneration (Bonar score), diabetes mellitus, fatty infiltration (FI), sex, smoking, tear location regarding integrity of the rotator cable, and tear size (number of ruptured tendons and tendon retraction) were included and analyzed. Results: Healing failure at 1 year was identified in 37% of patients (n = 21). A high degree of FI of the supraspinatus muscle (P = .01), a tear location including disruption of rotator cable integrity (P = .01), and old age (P = .03) were associated with healing failure. Tendon degeneration as determined by histopathology was not associated with healing failure at 1-year follow-up (P = .63). Conclusion: Older age, increased FI of the supraspinatus muscle, and a tear including disruption of the rotator cable increased the risk of healing failure after early arthroscopic repair in patients with trauma-related full-thickness rotator cuff tears. Level of evidence: Level I; Prospective Cohort Design; Prognosis Study

Background

No previous studies have investigated what biopsychosocial factors are associated with self‐reported work ability in conservatively managed patients with cervical radiculopathy.

Objective

To develop a theoretical model of factors and potential processes associated with variation in work ability based on a thorough assessment of biopsychosocial variables in conservatively managed patients with cervical radiculopathy.

Design

Cross‐sectional observational study.

Setting

Tertiary neurosurgery clinic.

Patients

A total of 144 conservatively managed patients with cervical pain and radiculopathy participated in the study.

Methods

From 64 biopsychosocial candidate variables, significant (P < .05) bivariate correlators with Work Ability Index (WAI) were entered as independent variables in a categorical regression. Elastic net regularization maintained the most parsimonious set of independent variables significantly associated with variation in WAI as the dependent variable. Process analysis of significant independent variable associations with WAI was performed.

Main Outcome Measurement

WAI.

Results

From 42 bivariate correlates of WAI, multivariate regression displayed a total of seven variables that were significantly (F [25,98] = 5.74, P < .05) associated with 65.8% of the variation in WAI. The Neck Disability Index (NDI) and Fear‐Avoidance Beliefs Questionnaire Work subscale (FABQ‐W) were significant individual factors within the final regression model. Process analysis displayed FABQ‐W having a significant specific indirect association with the direct association between NDI and WAI, with the model associated with 77% of the variability in WAI (F [2,84] = 141.17, P < .001).

Conclusion

Of 64 candidate biopsychosocial factors, NDI and FABQ‐W were the most significant multivariate correlates with work ability. FABQ‐W has a significant indirect association with baseline NDI scores and perceived work ability. This warrants future research trialing work‐related fear avoidance interventions in conservatively managed patients with cervical radiculopathy.

Level of Evidence

III

Background and purpose - Swedish clinical guidelines for osteoarthritis (OA) prioritize patient education, exercise, and-if necessary-weight reduction before considering adjunct pharmacological intervention. Contrariwise, we investigated the proportion and type of dispensed analgesic prescriptions in Sweden received by patients during 3 years before commencing non-pharmacological primary care interventions for OA (2008-2016) compared with the general population. Furthermore, we analyzed the proportion of analgesic prescriptions dispensed before (2008-2012) compared with after (2012-2016) guideline publication in terms of concordance with clinical guideline recommendations. Patients and methods - Patients with hip or knee OA (n = 72,069) from the Better Management of OA national quality register receiving non-pharmacological interventions in primary care between 2008 and 2016 were included (OA cohort). An age, sex, and residence matched reference cohort (n = 216,207) was formed from the Swedish Total Population Register. Based on a period 3 years prior to inclusion in the OA cohort, Swedish Prescribed Drug Register data was linked to both the OA and reference cohorts. Results - Compared with the reference cohort, a distinctly larger proportion of the OA cohort had dispensed prescriptions for most types of analgesics, increasing exponentially each year prior to commencing non-pharmacological intervention. Since guideline publication, the proportion of the OA cohort having no dispensed prescription analgesics prior to non-pharmacological primary care intervention concordantly increased by 5.0% (95% CI 4.2-5.9). Furthermore, dispensed prescriptions concordantly decreased for non-selective NSAIDs -8.6% (CI -9.6 to -7.6), weak opioids -6.8% (CI -7.7 to -5.9), glucosamine -9.5% (CI -9.8 to -8.8). and hyaluronic acid -1.6% (CI -1.8 to -1.5) but discordantly increased for strong opioids 2.8% (CI 2.1-3.4) and glucocorticoid intra-articular injection for hip OA 2.1% (CI 1.0-3.1). Interpretation - In Sweden, dispensed prescription of analgesics commonly occurred before initiating non-pharmacological primary care interventions for OA but reduced modestly after guideline publication, which prioritizes non-pharmacological before pharmacological interventions. Additional modest improvements occurred in the stepped-care prioritization of analgesic prescription types. However, future strategies are required to curb an increase of strong opioids prescription for OA and glucocorticoid intra-articular injection for hip OA.

The results of a randomised trial with bisphosphonate-coated dental implants have been reported previously. Each patient received one coated and one uncoated implant in a double-blind split-mouth design study. After 6 months of osseointegration, resonance frequency analysis indicated better fixation of the coated implants. Reduced marginal bone resorption was also shown. However, it was not known whether the advantage of the bisphosphonate coating would persist over time. The radiographic results at 5 years after implant installation are reported herein. A blinded investigator measured marginal resorption on fresh radiographs obtained for 14 of the 16 patients (two had died) and compared these with the post-implantation images. Non-parametric statistics were used. All implants functioned well. The median marginal bone loss for control implants was found to be 0.70 mm, which is less than usually reported in the literature. The bisphosphonate-coated implants showed even less resorption (median 0.20 mm). The median difference within each pair of implants after 5 years of use was 0.34 mm (95% confidence interval 0.00-0.75 mm; P = 0.04). The present data suggest that bisphosphonate-coated implants enable prolonged preservation of the marginal bone.

OBJECTIVES: The objective of this clinical study was to evaluate the effect of a bisphosphonate coating on a titanium implant on the implant stability quotient (ISQ) and the radiographic marginal bone levels at implants during early healing (2-8 weeks).

MATERIALS AND METHODS: In a randomized double-blind trial with internal controls, 16 patients received a dental implant coated with zoledronate and one uncoated implant as a control. The coated and uncoated implants which were visually indistinguishable were bone level titanium implants with a moderately rough surface and a microthreaded neck. ISQ values were obtained at insertion and at 2, 4, 6, and 8 weeks. Radiographs were obtained at insertion and at 8 weeks. The primary outcome was the difference in ISQ values between the coated implants and the control implants at 4 and 6 weeks, corrected for insertion values. The secondary outcome was loss of marginal bone level from insertion to 8 weeks.

RESULTS: Implant stability quotient values remained largely constant over the 8 weeks, and there was no significant difference between coated and uncoated implants at any time point. There was 0.12 (SD 0.10) mm marginal bone loss at the control implants and 0.04 (SD 0.08) mm at the coated implants. The difference was 0.17 mm; SD 0.14; p < 0.006). On blind qualitative scoring, 13 of the 15 control implants and two of 15 coated implants showed small marginal bone defects (p = 0.003).

CONCLUSIONS: There were no statistically significant differences observed in ISQ values between the coated and uncoated implants during the early healing. There was less marginal bone loss at the coated implants.

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Post-traumatic and post-operative stiffness of the elbow joint is relatively common and may in pronounced cases markedly interfere with normal upper extremity function.Soft-tissue contractures and heterotopic bone formation are two major causes of limited movement.Extensive recent research has elucidated many of the pathways contributing to these conditions, but the exact mechanisms are still unknown.In the early phase of soft-tissue contractures conservative treatment may be valuable, but in longstanding cases operative treatment is often necessary.Several different options are available depending on the severity of the condition and the underlying offending structures. Surgical treatment may allow significant gains in movement but rarely complete restoration, and complications are not uncommon.The following presentation reviews the recent literature on pathomechanisms and treatment alternatives. Cite this article: EFORT Open Rev 2018;3 DOI: 10.1302/2058-5241.3.170062.

The gleno-humeral joint is by far the most mobile in the human body but also afflicted by dislocations, predominantly anterior. Surgical stabilisation is often successful but failures not uncommon. The following review describes potential causes of failure and highlights the need of adapting surgical methods to pathomorphology.

Background: The majority of simple elbow dislocations (no associated fractures) can be treated nonoperatively with a short period of immobilization followed by guided aftercare. This case series describes the soft tissue injuries in a rare subset of patients in whom the elbow redislocated despite adequate immobilization. Methods: During a 6-year period, 8 patients were identified. They were all treated with reduction and casting in 90 degrees of flexion or more. At 1 week of follow-up, redislocation had occurred in all patients and open soft tissue repair was performed. The injuries were documented and the patients were followed up clinically and with radiographs. Results: Extensive soft tissue injuries, including both collateral ligament injuries and muscle origin avulsions from either or both sides, were found in all patients. The functional result at follow-up was satisfactory in all patients. Conclusion: Vast soft tissue injuries including both collateral ligaments and muscle origins should be expected in the event of early severe instability of a dislocated elbow joint. (C) 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Objective: To develop sets of core and optional recommended domains for describing and evaluating Osteoarthritis Management Programs (OAMPs), with a focus on hip and knee Osteoarthritis (OA). Design: We conducted a 3-round modified Delphi survey involving an international group of researchers, health professionals, health administrators and people with OA. In Round 1, participants ranked the importance of 75 outcome and descriptive domains in five categories: patient impacts, implementation outcomes, and characteristics of the OAMP and its participants and clinicians. Domains ranked as "important" or "essential" by & GE;80% of participants were retained, and participants could suggest addi-tional domains. In Round 2, participants rated their level of agreement that each domain was essential for evaluating OAMPs: 0 = strongly disagree to 10 = strongly agree. A domain was retained if & GE;80% rated it & GE;6. In Round 3, participants rated remaining domains using same scale as in Round 2; a domain was recommended as "core" if & GE;80% of participants rated it & GE;9 and as "optional" if & GE;80% rated it & GE;7. Results: A total of 178 individuals from 26 countries participated; 85 completed all survey rounds. Only one domain, "ability to participate in daily activities", met criteria for a core domain; 25 domains met criteria for an optional recommendation: 8 Patient Impacts, 5 Implementation Outcomes, 5 Participant Characteristics, 3 OAMP Characteristics and 4 Clinician Characteristics. Conclusion: The ability of patients with OA to participate in daily activities should be evaluated in all OAMPs. Teams evaluating OAMPs should consider including domains from the optional recommended set, with representation from all five categories and based on stakeholder priorities in their local context. Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International.

Wear debris particles released from prosthetic bearing surfaces and mechanical instability of implants are two main causes of periprosthetic osteolysis. While particle-induced loosening has been studied extensively, mechanisms through which mechanical factors lead to implant loosening have been less investigated. This study compares the transcriptional profiles associated with osteolysis in a rat model for aseptic loosening, induced by either mechanical instability or titanium particles. Rats were exposed to mechanical instability or titanium particles. After 15 min, 3, 48 or 120 h from start of the stimulation, gene expression changes in periprosthetic bone tissue was determined by microarray analysis. Microarray data were analyzed by PANTHER Gene List Analysis tool and Ingenuity Pathway Analysis (IPA). Both types of osteolytic stimulation led to gene regulation in comparison to unstimulated controls after 3, 48 or 120 h. However, when mechanical instability was compared to titanium particles, no gene showed a statistically significant difference (fold change = ± 1.5 and adjusted p-value = 0.05) at any time point. There was a remarkable similarity in numbers and functional classification of regulated genes. Pathway analysis showed several inflammatory pathways activated by both stimuli, including Acute Phase Response signaling, IL-6 signaling and Oncostatin M signaling. Quantitative PCR confirmed the changes in expression of key genes involved in osteolysis observed by global transcriptomics. Inflammatory mediators including interleukin (IL)-6, IL-1ß, chemokine (C-C motif) ligand (CCL)2, prostaglandin-endoperoxide synthase (Ptgs)2 and leukemia inhibitory factor (LIF) showed strong upregulation, as assessed by both microarray and qPCR. By investigating genome-wide expression changes we show that, despite the different nature of mechanical implant instability and titanium particles, osteolysis seems to be induced through similar biological and signaling pathways in this rat model for aseptic loosening. Pathways associated to the innate inflammatory response appear to be a major driver for osteolysis. Our findings implicate early restriction of inflammation to be critical to prevent or mitigate osteolysis and aseptic loosening of orthopedic implants.

BackgroundIn Sweden, most children with slipped capital femoral epiphysis (SCFE) are operated on with a single smooth pin or a short-threaded screw, allowing further growth of the femoral neck. Using the Swedish Pediatric Orthopaedic Quality registry, SPOQ, we investigated whether angular remodelling occurs adjacent to the proximal femoral epiphysis after fixation of SCFE using implants, allowing continued growth of the femoral neck.MethodsDuring 2008-2010 a total national population of 155 children were reported to the SPOQ registry. Following our strict inclusion criteria, radiographs of 51 hips were further assessed. The lateral Head Shaft Angle (HSA), the Notzli 3-point alpha-angle, the anatomic alpha-angle, and the Anterior Offset Ratio (AOR) on the first postoperative radiographs and at follow-up were measured to describe the occurrence of remodelling. Slip severity was categorised as mild, moderate or severe according to postoperative HSA.ResultsMean and SD values for the change in HSA were 3,7 degrees (5,0 degrees), for 3-point alpha-angle 6,8 degrees (8,9 degrees), and anatomic alpha-angle 13,0 degrees (16,3 degrees). The overall increase in AOR was 0,038 (0.069). There were no significant differences between the slip severity groups.ConclusionsWe found limited angular remodelling after in situ fixation with smooth pins or short threaded screws for SCFE. The angular remodelling and the reduction of the CAM deformity was less than previously described after fixation of SCFE with similar implants. Results about the same magnitude with non-growth sparing techniques suggest that factors other than longitudinal growth of the femoral neck are important for angular remodelling.

Purpose: To assess whether patient-reported outcomes (psychological factors, appraisals of knee function, and physical activity participation) were associated with satisfaction with knee function after anterior cruciate ligament (ACL) reconstruction. Methods: Participants who were aged 18 to 45 years and a minimum 12 months post primary ACL reconstruction completed a questionnaire battery evaluating knee self-efficacy, knee-related quality of life, self-reported function, and physical activity participation. Participants responses to the question "If you were to spend the rest of your life with your knee just the way it has been in the last week, would you feel.... (7-point ordinal scale; 1 = happy, 7 = unhappy)" were categorized as satisfied, mostly satisfied, or dissatisfied and used as the primary outcome. Ordinal regression was used to examine associations between independent variables and the primary outcome. Results: A total of 177 participants were included at an average of 3 years after primary ACL reconstruction. At follow-up, 44% reported they would be satisfied, 28% mostly satisfied, and 28% dissatisfied with the outcome of ACL reconstruction. There were significant differences in psychological responses and appraisal of knee function between the 3 groups (P = .001), and significantly more people in the satisfied group had returned to their preinjury activity (58%) than in the mostly satisfied (28%) and dissatisfied (26%) groups (P = .001). Multivariable analysis demonstrated that the odds of being satisfied increased by a factor of 3 with higher self-efficacy, greater knee-related quality of life, and returning to the preinjury activity. Conclusions: People who had returned to their preinjury physical activity and who reported higher knee-related self-efficacy and quality of life were more likely to be satisfied with the outcome of ACL reconstruction.

ObjectiveTo investigate the experiences of healthcare staff in nursing homes during the COVID-19 pandemic.DesignIndividual interviews. Latent qualitative content analysis.SettingTen nursing homes in Sweden.SubjectsPhysicians, nurses and nurse assistants working in Swedish nursing homes.Main outcome measuresParticipants' experiences of working in nursing homes during the COVID-19 pandemic.ResultsFour manifest categories were found, namely: Balancing restrictions and allocation of scarce resources with care needs; Prioritizing and acting against moral values in advance care planning; Distrust in cooperation and Leadership and staff turnover - a factor for moral distress. The latent theme Experiences of handling ethical challenges caused by the COVID-19 pandemic gave a deeper meaning to the categories.ConclusionDuring the pandemic, nursing home staff encountered ethical challenges that caused moral distress. Moral distress stemmed from not being given adequate conditions to perform their work properly, and thus not being able to give the residents adequate care. Another aspect of moral distress originated from feeling forced to act against their moral values when a course of action was considered to cause discomfort or harm to a resident. Alerting employers and policymakers to the harm and inequality experienced by staff and the difficulty in delivering appropriate care is essential. Making proposals for improvements and developing guidelines together with staff to recognize their role and to develop better guidance for good care is vital in order to support and sustain the nursing home workforce. The COVID-19 pandemic has affected both patients and staff in nursing homes, in Sweden and worldwide.Our study highlights that during the COVID-19 pandemic, nursing home staff encountered several ethical challenges which caused moral distress.Moral distress stemmed from not being given adequate conditions to perform their work, thus not giving the residents appropriate care.Moral distress could also originate from nursing home staff's feeling of being forced to act against their moral values.

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When stress fractures started to show up in the femurs of elderly ladies, it was soon evident that bisphosphonate use lay behind, and the absolute risk increase due to bisphosphonate use was reasonably well estimated already in 2008. Thereafter followed a period of confusion: the term atypical fracture was introduced, with a definition so vague that the true stress fractures tended to disappear in a cloud of ambiguity. This cast doubt on the association with bisphosphonates. The association was then re-established by large epidemiological studies based on radiographic adjudication. Atypical fractures are largely caused by bisphosphonates. With a correct indication, bisphosphonates prevent many more fractures than they cause, at least during the first years of use. With an incorrect indication they are likely to cause more harm than good. (C) 2016 Elsevier Ltd. All rights reserved.

[No abstract available]

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Background: Osteoporosis drugs might affect fracture-healing. We therefore studied the effects of teriparatide in comparison with risedronate on recovery after pertrochanteric hip fractures. Methods: The study was a randomized, multicenter, active-controlled, 78-week trial comparing teriparatide (20 mg/day) with risedronate (35 mg/week) initiated within 2 weeks after fixation of a low-trauma pertrochanteric hip fracture (AO/OTA 31-A1 or 31-A2). The main inclusion criteria were a bone mineral density T-score of amp;lt;=-22.0 and 25-OH-vitamin D of amp;gt;= 9.2 ng/mL. During the first 26 weeks, patients received study medication with oral or injectable placebo plus calcium and vitamin D in a double-blinded fashion. Secondary (Timed Up-and-Go [TUG] test, hip pain, Short Form [SF]-36 health status, and safety) and exploratory (radiographic outcomes and ability to walk) 26-week end points are reported. Results: Of the 224 patients who were randomized, 171 (86 teriparatide, 85 risedronate) were included in the analysis. The mean age was 77 +/- 8 years, 77% were female, and 26% had a prior history of low-trauma fracture. The teriparatide group completed the TUG test in a shorter time at 6, 12, 18, and 26 weeks (differences of 25.7, -4.4, -3.1, and -3.1 seconds, respectively; p = 0.021 for the overall difference). They also reported less pain on a visual analog scale immediately after the TUG test at 12 and 18 weeks (adjusted absolute differences of 10.6 and 11.9 mm, respectively; p amp;lt; 0.05). There were no significant between-group differences in the SF-36 score, Charnley hip pain score, ability to walk, or use of walking aids during follow-up. Radiographic healing at 6, 12, and 26 weeks, mechanical failure of the implant (teriparatide, 7; risedronate, 8), loss of reduction (teriparatide, 2; risedronate, 4), and nonunion (0 cases) were not significantly different. Mild hypercalcemia and hyperuricemia were more frequent with teriparatide. Conclusions: Teriparatide was associated with less pain and a shorter time to complete the TUG test between 6 and 26 weeks compared with risedronate. Other fracture-recovery outcomes were similar. The results should be interpreted with caution as these were secondary end points.

Background: healing after rupture of the Achilles tendon can be described in terms of mechanical properties of the new-formed tissue, constituting the tendon callus. In previous human studies, the elastic modulus and the density remained almost constant during 3 months after mobilization started, and then improved up to one year. So far, time-dependent deformation of the healing human tendon has not been reported.

Methods: in a series of 16 patients, operated with Achilles tendon suture, we implanted tantalum beads into the tendon and measured the distance between them repeatedly during 3 min of constant loading, using an ordinary image intensifier. The patients unloaded their leg for 30 min before the test. To avoid bias, all images were investigated in a randomized and blinded order.

Results: total strain during 3 min of constant loading at 7 weeks post injury amounted to 5%, and at 19 weeks to 3%. About half of the strain, after the loading was applied, occurred during the second and third min. Considerable strain also occurred just before loading, when the patient was told that a load would be applied, but before this was actually done.

Conclusion: the measurements were crude, and this study should be seen as a pilot. Still, viscoelastic properties seem to dominate the mechanical behavior the healing Achilles tendon from start of mobilization to 19 weeks, at least when tested after 30 min rest. This deserves further studies with more precise methods.

Objectives

To investigate champion long-distance runners’ strategies for managing injury and illness symptoms and staying well.

Design

Qualitative research study.

Methods

Twelve long-distance runners were interviewed immediately after having competed in World Championships finals. Thematic analysis was used to categorise and structure the data. The results were presented as primary themes and overarching constructs representing connections between the primary themes.

Results

The champion runners’ basic tactic to manage symptoms of ill health was characterized by rapid adjustment of sports load and a strong incentive to learn from experience and professional advice. This tactic was named here educated flexibility. A secondary exigency tactic was associated with reaching short-term goals and a consequential acceptance of health hazards. The runners used economic and other environmental strain to explain use of the exigency tactic. Most champion runners’ long-term strategy to stay well included both tactics successfully combined to maintain a performance level assuring a regular income. Avoidance of letting environmental strain and health problems create vicious circles was at the centre of these strategies.

Conclusions

Champion runners’ main strategy to stay well and sustain their superiority in performance was characterized by constantly paying attention to symptoms of ill health, listening to medical advice, and not letting environmental strain interfere with adjustment of sports load. Many top-level runners originate from global regions where formal education programs and health insurance plans are poorly regulated and supported. Bio-psychosocial models including empowerment at individual and systems levels should be considered when health services are planned for professional runners.

Local delivery of antibiotics as prophylaxis for prosthetic joint infections (PJIs) is frequently used during total hip replacement surgery. Morselized bone allograft impregnated with vancomycin and tobramycin (TobraVanc) could provide effective prophylaxis against bacteria commonly associated with PJIs. In this study, the concentrations of antibiotics released by bone allograft impregnated with TobraVanc were determined by using an in vitro bioassay system entailing measuring inhibition zone diameters caused by antibiotic-impregnated bone chips cast in agar against standard curves. The concentrations were determined in samples of TobraVanc-impregnated bone graft taken before and after the application of the bone graft in the patients undergoing acetabular revision surgery. Antibiotic-impregnated bone grafts, sampled prior to application in the patient, delivered antibiotics in the concentration ranges of 730-9,800 mg/L for tobramycin and 1,300-11,000 mg/L for vancomycin. Samples taken after application in the patient released lower concentrations of tobramycin (490-1,900 mg/L; P &lt; 0.01) and vancomycin (3,000-5,100 mg/L; P &lt; 0.05); however, these concentrations remained well above the tobramycin minimum inhibitory concentrations (MICs) for investigated, highly tobramycin-resistant Staphylococcus epidermidis strains (MICs &gt; 256 mg/L). At the tested concentrations, bone graft material mixed with TobraVanc delivered antibiotics in potent concentrations above the MICs for bacteria causing PJIs. Clinical trials are needed to evaluate the efficacy and risk of TobraVanc-impregnated bone graft as a prophylactic agent for patients undergoing hip replacement surgery.

Background and purpose - Teriparatide accelerates fracture healing in animals and probably in man. Abaloparatide is a new drug with similar although not identical effects on the teriparatide receptor. Given at 4 times the teriparatide dose in a human osteoporosis trial, abaloparatide increased bone density more than teriparatide, and both reduced fracture risk. We investigated in mice whether abaloparatide stimulates fracture healing, and if it does so with the suggested dose effect relation (4:1). Patients and methods - In a validated mouse model for metaphyseal healing (burr hole with screw pull-out), 96 mice were randomly allocated to 11 groups: control (saline), teriparatide or abaloparatide, where teriparatide and abaloparatide were given at 5 different doses each. In a femoral shaft osteotomy model, 24 mice were randomly allocated to 3 groups: control (saline), teriparatide (15 mu g/kg) or abaloparatide (60 mu g/kg). Each treatment was given daily via subcutaneous injections. Results were evaluated by mechanical testing and microCT. Results - In the metaphyseal model, a dose-dependent increase in screw pull-out force could be seen. In a linear regression analysis (r = 0.78) each increase in ln(dose) by 1 (regardless of drug type) was associated with an increase in pull-out force by 1.50 N (SE 0.18) (p amp;lt; 0.001). Changing drug from teriparatide to abaloparatide increased the force by 1.41 N (SE 0.60; p = 0.02). In the diaphyseal model, the callus density was 23% (SD 10), 38% (SD 10), and 47% (SD 2) for control, for teriparatide and abaloparatide respectively. Both drugs were significantly different from controls (p = 0.001 and p = 0.008), but not from each other. Interpretation - Both drugs improve fracture healing, but in these mouse models, the potency per mu g of abaloparatide seems only 2.5 times that of teriparatide, rather than the 4:1 relation chosen in the clinical abaloparatide-teriparatide comparison trial.

Background and purpose - Fracture healing in the shaft is usually described as a sequence of events, starting with inflammation, which triggers mesenchymal tissue formation in successive steps. Most clinical fractures engage cancellous bone. We here describe fracture healing in cancellous bone, focusing on the timing of inflammatory and mesenchymal cell type appearance at the site of injury. Material and methods - Rats received a proximal tibial drill hole, A subgroup received clodronate-containing liposomes before or after surgery. The tibiae were analyzed with micro-CT and immunohistochemistry 1 to 7 days after injury. Results - Granulocytes (myeloperoxidase) appeared in moderate numbers within the hole at day 1 and then gradually disappeared. Macrophage expression (CD68) was seen on day 1, increased until day 3, and then decreased. Mesenchymal cells (vimentin) had already accumulated in the periphery of the hole on day 1. Mesenchymal cells dominated in the entire lesion on day 3, now producing extracellular matrix. A modest number of preosteoblasts (RUNX2) were seen on day 1 and peaked on day 4. Osteoid was seen on day 4 in the traumatized region, with a distinct border to the uninjured surrounding marrow. Clodronate liposomes given before the injury reduced the volume of bone formation at day 7, but no reduction in macrophage numbers could be detected. Interpretation - The typical sequence of events in shaft fractures was not seen. Mesenchymal cells appeared simultaneously with granulocyte and macrophage arrival. Clodronate liposomes, known to reduce macrophage numbers, seemed to be associated with the delineation of the volume of tissue to be replaced by bone.

As cytotoxic (CD8(+)) T cells seem to impair shaft fracture healing, we hypothesized that depletion of CD8(+) cells would instead improve healing of cancellous bone. Additionally, we also tested if CD8-depletion would influence the healing of ruptured Achilles tendons. Rats received a single injection of either anti-CD8 antibodies or saline and put through surgery 24 h later. Three different surgical interventions were performed as follows: (1) a drill hole in the proximal tibia with microCT (BV/TV) to assess bone formation; (2) a screw in the proximal tibia with mechanical evaluation (pull-out force) to assess fracture healing; (3) Achilles tendon transection with mechanical evaluation (force-at-failure) to assess tendon healing. Furthermore, CD8-depletion was confirmed with flow cytometry on peripheral blood. Flow cytometric analysis confirmed depletion of CD8(+) cells (p amp;lt; 0.001). Contrary to our hypothesis, depletion of CD8(+) cells reduced the implant pull-out force by 19% (p amp;lt; 0.05) and stiffness by 34% (p amp;lt; 0.01), although the bone formation in the drill holes was the same as in the controls. Tendon healing was unaffected by CD8-depletion. Our results suggest that CD8(+) cells have an important part in cancellous bone healing.

Bisphosphonates improve implant fixation in randomised clinical trials of knee prostheses, hip prostheses and dental implants. However, a limited amount of bone resorption is required for bisphosphonates to exert an effect. Anti-RANKL treatment does not have this limitation, and we therefore tested whether if they might be more effective for improvement of implant fixation. This is of interest, as anti-RANKL treatment with denosumab is now in common clinical use. Male SD rats received a stain-less steel screw in the right proximal tibia and a drill hole in the left (n = 42). They were randomised to subcutaneous injections of either alendronate (20 mu g/kg/day), alendronate (200 mu g/kg/day), osteoprotegerin with an Fc tag (OPG-Fc; 8 mg/kg, twice weekly), or saline control. After 4 weeks, the fixation of the steel screw was measured by pull-out test. The tibia with the drill hole was evaluated with mu CT. OPG-Fc increased the pull-out force compared to saline controls by 153% (p less than 0.001). There was no significant difference between OPG-Fc and the alendronate groups. OPG-Fc increased the bone density (BV/TV) in the previous drill hole compared to controls 7-fold (p less than 0.001). This increase was higher than with any alendronate dose (p less than 0.001). OPG-Fc increased the bone density of the L5 vertebral body, but there was no significant difference between OPG-Fc and alendronate. Our results suggest that screw fixation in cancellous bone can be dramatically improved by an antiRANKL agent. The effect was comparable to very high bisphosphonate doses. Screw insertion in cancellous bone elicits a metaphyseal fracture healing response, and our findings might be relevant not only for implant fixation, but also for fracture healing in cancellous bone.

Background and purpose - Cancellous bone appears to heal by mechanisms different from shaft fracture healing. There is a paucity of animal models for fractures in cancellous bone, especially with mechanical evaluation. One proposed model consists of a screw in the proximal tibia of rodents, evaluated by pull-out testing. We evaluated this model in rats by comparing it to the healing of empty drill holes, in order to explain its relevance for fracture healing in cancellous bone. To determine the sensitivity to external influences, we also compared the response to drugs that influence bone healing. Methods - Mechanical fixation of the screws was measured by pull-out test and related to the density of the new bone formed around similar, but radiolucent, PMMA screws. The pull-out force was also related to the bone density in drill holes at various time points, as measured by microCT. Results - The initial bone formation was similar in drill holes and around the screw, and appeared to be reflected by the pull-out force. Both models responded similarly to alendronate or teriparatide (PTH). Later, the models became different as the bone that initially filled the drill hole was resorbed to restore the bone marrow cavity, whereas on the implant surface a thin layer of bone remained, making it change gradually from a trauma-related model to an implant fixation model. Interpretation - The similar initial bone formation in the different models suggests that pull-out testing in the screw model is relevant for assessment of metaphyseal bone healing. The subsequent remodeling would not be of clinical relevance in either model.

Background and purpose — [18F]Fluoride ([18F]NaF) PET scan is frequently used for estimation of bone healing rate and extent in cases of bone allografting and fracture healing. Some authors claim that [18F]NaF uptake is a measure of osteoblastic activity, calcium metabolism, or bone turnover. Based on the known affinity of fluoride to hydroxyapatite, we challenged this view.

Methods — 10 male rats received crushed, frozen allogeneic cortical bone fragments in a pouch in the abdominal wall on the right side, and hydroxyapatite granules on left side. [18F]NaF was injected intravenously after 7 days. 60 minutes later, the rats were killed and [18F]NaF uptake was visualized in a PET/CT scanner. Specimens were retrieved for micro CT and histology.

Results — MicroCT and histology showed no signs of new bone at the implant sites. Still, the implants showed a very high [18F]NaF uptake, on a par with the most actively growing and remodeling sites around the knee joint.

Interpretation — [18F]NaF binds with high affinity to dead bone and calcium phosphate materials. Hence, an [18F]NaF PET/CT scan does not allow for sound conclusions about new bone ingrowth into bone allograft, healing activity in long bone shaft fractures with necrotic fragments, or remodeling around calcium phosphate coated prostheses

Background and purpose - Healing of shaft fractures is commonly described as regards external callus. We wanted to clarify the role of the bone marrow compartment in the healing of stable shaft fractures. Patients and methods - A longitudinal furrow was milled along the longitudinal axis of the femoral shaft in mice. The exposed bone marrow under the furrow was scooped out. The mice were then randomized to no further treatment, or to receiving 2 silicone plugs in the medullary canal distal and proximal to the defect. The plugs isolated the remaining marrow from contact with the defect. Results were studied with histology and flow cytometry. Results - Without silicone plugs, the marrow defect was filled with new bone marrow-like tissue by day 5, and new bone was seen already on day 10. The new bone was seen only at the level of the cortical injury, where it seemed to form simultaneously in the entire region of the removed cortex. The new bone seemed not to invade the marrow compartment, and there was a sharp edge between new bone and marrow. The regenerated marrow was similar to uninjured marrow, but contained considerably more cells. In the specimens with plugs, the marrow compartment was either filled with loose scar tissue, or empty, and there was only minimal bone formation, mainly located around the edges of the cortical injury. Interpretation - Marrow regeneration in the defect seemed to be a prerequisite for normal cortical healing. Shaft fracture treatment should perhaps pay more attention to the local bone marrow.

Background: CT is often used for fracture evaluation following knee trauma and to diagnose ACL injuries would also be valuable. Purpose: To investigate the diagnostic accuracy of dual energy CT (DECT) for detection of ACL tears in acute and subacute knee injuries. Material and Methods: Patients with suspected ACL injury were imaged with DECT and MRI. Clinically blinded DECT images were independently read twice by two radiologists. ACL was classified as normal or abnormal. Arthroscopy served as reference method. Sensitivity and positive predictive value (PPV) were calculated, and diagnostic performance between DECT and MRI was assessed. Results: 48 patients (26 M, 22 F, mean age 23 years, range 15-37 years) were imaged with a mean of 25 days following trauma. Of these, 21 patients underwent arthroscopy with a mean of 195 days after trauma. Arthroscopy revealed 19 ACL tears and 2 ACLs with no tear. The combined sensitivity was 76.3% (95% CI 66.8-85.9) and 86.8 (95% CI 71.9-95.6) for DECT and MRI, respectively. There was no statistically significant difference between these two methods (p = .223). The positive predictive value (PPV) was 93.5 (95% CI 84.3-98.2) and 91.7 (95% CI 77.5-98.3) for DECT and MRI, respectively. Conclusion: DECT has lower sensitivity to detect an ACL rupture than MRI, but the difference is not statistically significant. The PPV is high in both methods.

Purpose: To find the optimal imaging parameters for a photon-counting detector CT (PCD-CT) and to compare it to an energy-integrating detector CT (EID-CT) in terms of image quality and metal artefact severity using a metal-containing bovine knee specimen. Methods: A bovine knee with a stainless-steel plate and screws was imaged in a whole-body research PCD-CT at 120 kV and 140 kV and in an EID dual-source CT (DSCT) at Sn150 kV and 80/Sn150 kV. PCD-CT virtual monoenergetic 72 and 150 keV images and EID-CT images processed with and without metal artefact reduction algorithms (iMAR) were compared. Four radiologists rated the visualisation of bony structures and metal artefact severity. The Friedman test and Wilcoxon signed-rank test with Bonferronis correction were used. P-values of &lt;= 0.0001 were considered statistically significant. Distributions of HU values of regions of interest (ROIs) in artefact-affected areas were analysed.Results: PCD-CT 140 kV 150 keV images received the highest scores and were significantly better than EID-CT Sn150 kV images. PCD-CT 72 keV images were rated significantly lower than all the others. HU-value variation was larger in the 120 kV and the 72 keV images. The ROI analysis revealed no large difference between scanners regarding artefact severity.Conclusion: PCD-CT 140 kV 150 keV images of a metal-containing bovine knee specimen provided the best image quality. They were superior to, or as good as, the best EID-CT images; even without the presumed advantage of tin filter and metal artefact reduction algorithms. PCD-CT is a promising method for reducing metal artefacts.

Purpose The critical shoulder angle (CSA) and the acromion index (AI) are measurements of acromial shape reported as predictors of degenerative rotator cuff tears (RCT) and glenohumeral osteoarthritis (GH OA). Whether they are the cause or effect of shoulder pathologies is uncertain since pre-morbid radiographs most often are lacking. The main aim of this study was to investigate if CSA or AI were related to the development of RCT or GH OA after 20 years. A secondary aim was to investigate if the CSA and AI had changed over time. Methods In the hospital archive, 273 preoperative plain shoulder radiographs were found of patients scheduled for elective surgery other than cuff repair and arthroplasty. Forty-five images fulfilled the strict criteria published by Suter and Henninger (2015) and were used to measure CSA and AI with two independent assessors. No patient had any sign of OA in the index radiographs or any information in the medical records indicating RCT. After a median of 20 (16-22) years, 30 of these patients were radiologically re-examined with bilateral true frontal views and ultrasound of the rotator cuff. There were 19 men (20 study shoulders) and 11 females (12 study shoulders). Results Mean age at follow-up was 56 (32-78) years. There was no correlation between CSA (r = 0.02) (n.s) or AI (r = - 0.13) (n.s) in the primary radiographs and OA at follow-up. Nor was any correlation found between index CSA (r = 0.12) (n.s) or AI (r = - 0.13) (n.s) and RCT at follow-up. Mean difference in CSA was - 1.7 (- 10-3) degrees and mean AI difference was - 0.04 (- 0.13-0.09) between the first and the second radiographs, 20 years later. Bilaterally, mean CSA was 32 and AI 0.61 at follow-up. Conclusion In this study, no correlation between the CSA, AI and development of OA or RCT could be found. The mean CSA and AI decreased over a 20-year period but the difference was very small. No difference was found between the study shoulders and the contralaterals. These findings question previously reported etiological associations between scapular anatomy and the development of OA or RCT and thereby the use of these calculations as the basis of treatment.

Background and purpose — We have previously shown that specific exercises reduced the need for surgery in subacromial painpatients at 1-year follow-up. We have now investigated whetherthis result was maintained after 5 years and compared the outcomesof surgery and non-surgical treatment.Patients and methods — 97 patients were included in the previouslyreported randomized study of patients on a waiting list forsurgery. These patients were randomized to specifi c or unspecifi cexercises. After 3 months of exercises the patients were asked ifthey still wanted surgery and this was also assessed at the present5-year follow-up. The 1-year assessment included Constant–Murley score, DASH, VAS at night, rest and activity, EQ-5D, andEQ-VAS. All these outcome assessments were repeated after 5years in 91 of the patients.Results — At the 5-year follow-up more patients in the specifi cexercise group had declined surgery, 33 of 47 as compared with16 of 44 (p = 0.001) in the unspecifi c exercise group. The meanConstant–Murley score continued to improve between the 1- and5-year follow-ups in both surgically and non-surgically treatedgroups. On a group level there was no clinically relevant changebetween 1 and 5 years in any of the other outcome measuresregardless of treatment.Interpretation — This 5-year follow-up of a previously publishedrandomized controlled trial found that specifi c exercisesreduced the need for surgery in patients with subacromial pain.Patients not responding to specifi c exercises may achieve similargood results with surgery. These fi ndings emphasize that a specifi cexercise program may serve as a selection tool for surgery.

Background: Anterosuperior rotator cuff tears with a displaced long head of the biceps tendon are most often trauma-related, and patients with these conditions often present with severe pain and shoulder dysfunction. Repair of the subscapularis and supraspinatus and a biceps tenodesis or a tenotomy are the recommended treatments based on retrospective studies. The aim of this study was to prospectively evaluate clinical and structural treatment outcome in a cohort of trauma-related anterosuperior injuries in patients with previously healthy shoulders. Materials and methods: Patients seeking care for a suspected rotator cuff injury after shoulder trauma were screened according to a protocol including clinical examination, baseline scoring with Western Ontario Rotator Cuff Index (WORC) and numeric rating scale of pain, ultrasound, and magnetic resonance imaging (MRI). Those with anterosuperior injuries were offered surgical treatment, structured postoperative physiotherapy, and inclusion in the present study with 1-year follow-up, including MRI, baseline scores, Constant-Murley score, and Patient Global Impression of Change. Thirty-three patients (78% men) with a mean age of 59 (40-76) years were included. Results: All patients had a biceps pulley lesion, a displaced biceps tendon, and incomplete full-thickness subscapularis and supraspinatus tears. Six patients declined surgery. At follow-up, the operated patients reached a median WORC score of 86% and a median change from baseline to follow-up of 50% (P = .0001). Pain decreased (P = .0001) at rest, at night, and during activity. The median Constant-Murley score was 86% of the contralateral nonoperated shoulder, 58% of the contralateral abduction strength recovered after surgery, and 86% reported that they were recovered or much improved. All repairs and tenodeses healed except for 2 supraspinatus tendons. The 6 nonoperated patients reached a median WORC score of 90, a change in the median value from baseline to follow-up of 31, but reported more pain, and a smaller proportion considered themselves as recovered or much improved. In all patients, the 1-year MRIs had signal changes in the upper muscular portion of subscapularis, consistent with fatty infiltration, regardless of operative or nonoperative treatment. Conclusion: Anterosuperior rotator cuff injury with an associated pulley lesion and displaced long head of the biceps tendon may be treated successfully with surgery as the majority of patients in our cohort clinically recovered or were much improved without pain after a year. With a 1-year perspective, nonoperatively treated patients may also reach a reasonable clinical outcome. Independently of treatment or tendon healing, residual subscapularis muscle injury was seen, which may have long-term implications. (C) 2020 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Background: Ultrasonography (US) has been suggested as a valuable complement to clinical and radiologic examinations in elbow trauma. Magnetic resonance imaging (MRI) has been the method of choice, despite fair to moderate inter -rater reliability (IRR). US has potential advantages but is assessor dependent and the IRR scarcely examined. The primary aim of the present study was to investigate IRR for US and secondarily interobserver agreement (IOA) between US and MRI in the acute phase after elbow trauma. Acute phase was defined as 2 weeks and, if applicable, the following weekend. The hypothesis was that US reliability would be at least substantial for complete muscle or ligament lesions. Methods: A total of 116 patients (50 men, median age 47 [range 19-87] years) who had an elbow trauma with dislocation and/or fracture were included. Exclusion criteria were prior injury to the same elbow, and US and/or MRI not possible within 16 days. During US, the condition of muscle origins at the epicondyles and collateral and annular ligament complexes was recorded in a predesigned protocol, with the alternatives intact, partially or completely torn. Seventy-two patients had a second US examination the same day by an independent upper extremity surgeon, and 58 of the 116 patients underwent an MRI before or after the US, evaluated by 2 radiologists using the same protocol. IOA and IRR between assessors and modalities were analyzed with kappa statistics and interpreted according to Landis and Koch. Perfect agreement (PA) was reported in percentages. Results: US examination within 2 weeks was feasible with tolerable discomfort. Defining muscle origins and ligaments as intact or completely torn, the US IRR ranged from substantial to near perfect (kappa 0.63-1, PA 93%-100%). Intact tissues vs. tear (partial and complete tear combined) or intact vs. partial vs. complete tear resulted in kappa values from moderate to substantial and PA 74%-96% with lowest reliability for the muscle origins. The IOA between MRI and US ranged from fair to near perfect for no tear vs. complete tear (kappa 0.25-1, PA 65%-100%). Agreement between no tear and tear (partial and complete together) ranged from fair to substantial (0.25-0.66, PA 63%-89%) and no tear vs. partial or complete tear ranged from fair to moderate (0.25-0.53, PA 50%-79%). Conclusion: US in the acute setting is suitable and reliable for diagnosis of ligament injuries in the elbow and is in addition fast, cheap, and easily accessible. The agreement with MRI seems to vary with the structure assessed and severity of the lesions, ranging from fair to near perfect. Level of evidence: Level III; Diagnostic Study (c) 2024 The Author(s). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Loading influences tendon healing, and so does inflammation. We hypothesized that the two are connected. 48 rats underwent Achilles tendon transection. Half of the rats received Botox injections into calf muscles to reduce mechanical loading. Cells from the regenerating tissue were analyzed by flow cytometry. In the loaded group, the regenerating tissue contained 83% leukocytes (CD45(+)) day 1, and 23% day 10. The M1/M2 macrophage ratio (CCR7/CD206) peaked at day 3, while T helper (CD3(+)CD4(+)) and T-reg cells (CD25(+) Foxp3(+)) increased over time. With Botox, markers associated with down-regulation of inflammation were more common day 5 (CD163, CD206, CD25, Foxp3), and M1 or M2 macrophages and T-reg cells were virtually absent day 10, while still present with full loading. The primary variable, CCR7/CD206 ratio day 5, was higher with full loading (p = 0.001) and the T-reg cell fraction was lower (p amp;lt; 0.001). Free cage activity loading is known to increase size and strength of the tendon in this model compared to Botox. Loading now appeared to delay the switch to an M2 type of inflammation with more T-reg cells. It seems a prolonged M1 phase due to loading might make the tendon regenerate bigger.

Background: During early tendon healing, the cells within the regenerating tissue are, to a large part, inflammatory leukocytes (CD45+). In a rat Achilles tendon healing model, the inflammation resolves between 5 and 10 days. In the same model, Cox inhibitors (NSAIDs) impair healing when given during the first 5 days, but have a positive effect if given later. We tested the hypothesis that a Cox inhibitor would exert these effects by influencing inflammation, and thereby the composition of the inflammatory cell subpopulations.Methods: Achilles tendon transection was performed in 44 animals. Animals were randomized to either parecoxib or saline injections. Healing was evaluated by mechanical testing day 7 after surgery and by flow cytometry day 3 and 10.Results: Cross-sectional area, peak force and stiffness were reduced by parecoxib 31, 33, and 25% respectively (p=0.005, p=0.002, and p=0.005). By flow cytometry, there was a strong effect of time (p<0.001) on virtually all inflammatory cell subpopulations (CD45, CD11b, CD68, CCR7, CD163, CD206, CD3, CD4), but no significant effect of parecoxib at any time point.Conclusion: The results suggest that the negative effects of Cox inhibitors on tendon healing might be exerted mainly via mechanisms not directly related to inflammatory cells.

Inflammation initiates tendon healing and then normally resolves more or less completely. Unresolved inflammation might disturb the remodeling process. We hypothesized that suppression of inflammation during the early remodeling phase by systemic dexamethasone treatment can improve healing. 36 rats underwent Achilles tendon transection and were randomized to dexamethasone or saline on days 0-4 after surgery (early inflammatory phase), and euthanasia day 7. Another 54 rats received injections days 5-9 (early remodeling phase) and were euthanized day 12 for mechanical, histological and flow cytometric evaluation. Dexamethasone treatment days 0-4 reduced the cross-sectional area, peak force and stiffness by day 7 to less than half (p amp;lt; 0.001 for all), while material properties (peak stress and elastic modulus) were not significantly affected. In contrast, dexamethasone treatment days 5-9 increased peak force by 39% (p = 0.002) and stiffness by 58% (p amp;lt; 0.001). The cross-sectional area was reduced by 42% (p amp;lt; 0.001). Peak stress and elastic modulus were more than doubled (p amp;lt; 0.001 for both). Semi-quantitative histology at day 12 showed that late dexamethasone treatment improved collagen alignment, and flow cytometry revealed reduced numbers of CD8a(+) cytotoxic T cells in the tendon callus. These results suggest that downregulation of lingering inflammation during the early remodeling phase can improve healing.

Background. Macrophages are a heterogeneous cell population that plays an important role in the initiation of the inflammatory response to trauma as well as its resolution during healing. However, their role during Achilles tendon healing is unclear. The aim of this study was to investigate if macrophage reduction by using clodronate liposome inject ion would influence the mechanical properties of the healing tendon. Methods. The right Achilles tendon of 46 rats were transected and left to heal spontaneously (day 0). The reduction of macrophages during the inflammatory phase of tendon healing was studied by injecting clodronate liposomes day - 3, - 1 and 1. To study the early remodeling phase, clodronate was injected day 3, 5 and 7. The controls received saline and the rats were evaluated by mechanical testing day 7 and 12, respectively. Results. Clodronate injections during the inflammatory phase increased transverse area (p = 0.006) and stiffness (p = 0.044) day 7. In contrast, no significant effects were seen at day 12. Flow cytometry evaluation confirmed reduction of mature and polarized macrophages. Conclusions. Reduction of macrophages during the inflammatory phase of Achilles tendon healing influenced the mechanical properties, suggesting a regulatory role of macrophages during this phase.

We excised the fracture site in 8 patients with incomplete atypical femoral fractures by drilling an 11-mmdiameter hole. New bone formation could be seen in the hole within a normal time frame. Delayed healing of these fractures might be unrelated to an impaired capacity to form bone. Introduction Incomplete atypical femoral fractures (undisplaced cracks) heal slowly or not at all, and often progress to a complete fracture with minimal trauma. The impaired healing has been attributed to an impaired biologic healing capacity related to bisphosphonate use, or, alternatively, to the mechanical environment within the fracture crack. This study aimed to investigate the capacity for bone formation after resection of the fracture site. Methods Between 2008 and 2014, we recruited eight patients with incomplete atypical femoral fractures. All used oral bisphosphonates before the fracture for on average 8 years (range 4 to 15) and complained of thigh pain. The fractures were stabilized with reamed cephalomedullary nails. During surgery, the fracture site in the lateral cortex was resected with a cylindrical drill (diameter 11.5 mm). The cylindrical cortical defect allowed radiographic evaluation of new bone formation, and the patients were followed clinically and radiologically for 24 months (range 15 to 92). Results After 3 months, newly formed bone could be seen in the cortical defects in all patients. After 13-26 months, the previous defects showed continuous cortical bone. At final follow-up, all patients reported full recovery of pre-surgical complaints. No complications occurred and no reoperations were performed. Conclusions New bone formation occurred within a time frame that appears normal for healing of cortical bone defects. This suggests that the capacity to form new bone is intact.

Introduction In Sweden, roughly 3000 patients are reoperated each year due to pain and loss of function related to a loosened hip or knee prosthesis. These reoperations are strenuous for the patient, technically demanding and costly for the healthcare system. Any such reoperation that can be prevented would be of great benefit. Bisphosphonates are drugs that inhibit osteoclast function. Several clinical trials suggest that bisphosphonates lead to improved implant fixation and one small study even indicates better functional outcome. Furthermore, in epidemiological studies, bisphosphonates have been shown to decrease the rate of revision for aseptic loosening by half. Thus, there are several indirect indications that bisphosphonates could improve patient-reported outcome, but no firm evidence. Methods and analysis This is a pragmatic randomised, placebo-controlled, double-blinded, academic clinical trial of a single postoperative dose of zoledronic acid, in patients younger than 80 years undergoing primary total hip or knee replacement for osteoarthritis. Participants will be recruited from two orthopaedic departments. All surgeries will be performed, and study drugs given at Motala Hospital, Sweden. The primary endpoint is to investigate between-group differences in the Hip dysfunction and Osteoarthritis Outcome Score and the Knee injury and Osteoarthritis Outcome Score at 3-year follow-up. Secondary outcomes will be investigated at 1 year, 3 years and 6 years, and stratified for hip and knee implants. These secondary endpoints are supportive, exploratory or explanatory. A total of 1000 patients will be included in the study. Ethics and dissemination The study has been approved by the Regional Ethical Review Board in Linkoping (DNR 2015/286-31). The study will be reported in accordance with the Consolidated Standards of Reporting Trials statement for pharmacological trials. The results will be submitted for publication in peer-reviewed academic journals and disseminated to patient organisations and the media.

Background: Stable fixation of joint replacement implants is essential to achieve osseointegration in uncemented implants. In acetabular revisions, screws often need to be utilized in quadrants other than the historically so-called "safe" zones to attain sufficient stability. The primary aim of this study was to determine whether preoperative three-dimensional (3D) planning for acetabular revision surgery influences screw length, specifically in the superior pubic ramus (SPR). Methods: Between March 2017 and December 2021, 20 patients underwent preoperative twodimensional (2D) planning (2D group), and 30 patients underwent 3D planning following the implementation of a new 3D planning software into clinical practice in September 2019 (3D group). Two observers, blinded to the groups, measured the total screw length, screw penetration depth, and cup position on available postoperative computed tomography examinations. For statistical comparisons, the mean measurement from the 2 observers was used. Results: The median total screw lengths in the SPR were 16 mm in the 2D group and 25 mm in the 3D group (P = .004) and 40.5 mm compared with 50.5 mm in the ilium (P = .019). Median screw penetration depths in the SPR were 0 mm in the 2D group and 1.25 mm in the 3D group (P = .049). Conclusion: Longer screws were used in the SPR and ilium when preoperative 3D planning was conducted. Due to the study design, we were not able to evaluate whether longer screws lead to better fixation. Further studies are needed to elucidate this question. (c) 2024 The Authors. Published by Elsevier Inc. on behalf of The American Association of Hip and Knee Surgeons. This is an open access article under the CC BY license.

Supraphysiological loading induced by unstable orthopedic implants initiates osteoclast formation, which results in bone degradation. We aimed to investigate which mechanosensitive cells in the peri-implant environment produce osteoclast-stimulating factors and how the production of these factors is stimulated by supraphysiological loading. The release of osteoclast-stimulating factors by different types of isolated bone marrow-derived hematopoietic and mesenchymal stem cells from six osteoarthritic patients was analyzed after one hour of supraphysiological loading (3.0 ± 0.2 Pa, 1 Hz) by adding their conditioned medium to osteoclast precursors. Monocytes produced factors that enhanced osteoclastogenesis by 1.6 ± 0.07-fold and mesenchymal stem cells by 1.4 ± 0.07-fold. Medium from osteoprogenitors and pre-osteoblasts enhanced osteoclastogenesis by 1.3 ± 0.09-fold and 1.4 ± 0.03-fold, respectively, where medium from four patients elicited a response and two did not. Next generation sequencing analysis of osteoprogenitors revealed that genes encoding for inflammation-related pathways and cytoskeletal rearrangements were regulated differently between responders and non-responders. Our data suggest that released osteoclast-stimulating soluble factors by progenitor cells in the bone marrow after supraphysiological loading may be related to cytoskeletal arrangement in an inflammatory environment. This connection could be relevant to better understand the aseptic loosening process of orthopedic implants.

Purpose

The pelvic incidence (PI) is used to describe the sagittal spino-pelvic alignment. In previous studies, radiographs were used, leading to less accuracy in establishing the three-dimensional (3D) spino-pelvic parameters. The purpose of this study is to analyze the differences in the 3D sagittal spino-pelvic alignment in adolescent idiopathic scoliosis (AIS) subjects and non-scoliotic controls.

Methods

Thirty-seven female AIS patients that underwent preoperative supine low-dose computed tomography imaging of the spine, hips and pelvis as part of their general workup were included and compared to 44 non-scoliotic age-matched female controls. A previously validated computerized method was used to measure the PI in 3D, as the angle between the line orthogonal to the inclination of the sacral endplate and the line connecting the center of the sacral endplate with the hip axis.

Results

The PI was on average 46.8° ± 12.4° in AIS patients and 41.3° ± 11.4° in controls (p = 0.025), with a higher PI in Lenke type 5 curves (50.6° ± 16.2°) as compared to controls (p = 0.042), whereas the Lenke type 1 curves (45.9° ± 12.2°) did not differ from controls (p = 0.141).

Conclusion

Lenke type 5 curves show a significantly higher PI than controls, whereas the Lenke type 1 curves did not differ from controls. This suggests a role of pelvic morphology and spino-pelvic alignment in the pathogenesis of idiopathic scoliosis. Further longitudinal studies should explore the exact role of the PI in the initiation and progression of different AIS types.