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Aspenberg, Per
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Publications (10 of 209) Show all publications
Dietrich, F., Aspenberg, P. & Eliasson, P. (2022). Dexamethasone Enhances Achilles Tendon Healing in an Animal Injury Model, and the Effects Are Dependent on Dose, Administration Time, and Mechanical Loading Stimulation. American Journal of Sports Medicine, 50(5), 1306-1316, Article ID 03635465221077101.
Open this publication in new window or tab >>Dexamethasone Enhances Achilles Tendon Healing in an Animal Injury Model, and the Effects Are Dependent on Dose, Administration Time, and Mechanical Loading Stimulation
2022 (English)In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 50, no 5, p. 1306-1316, article id 03635465221077101Article in journal (Refereed) Published
Abstract [en]

Background: Corticosteroid treatments such as dexamethasone are commonly used to treat tendinopathy but with mixed outcomes. Although this treatment can cause tendon rupture, it can also stimulate the tendon to heal. However, the mechanisms behind corticosteroid treatment during tendon healing are yet to be understood. Purpose: To comprehend when and how dexamethasone treatment can ameliorate injured tendons by using a rat model of Achilles tendon healing. Study Design: Controlled laboratory study. Methods: An overall 320 rats were used for a sequence of 6 experiments. We investigated whether the drug effect was time-, dose-, and load-dependent. Additionally, morphological data and drug administration routes were examined. Healing tendons were tested mechanically or used for histological examination 12 days after transection. Blood was collected for flow cytometry analysis in 1 experiment. Results: We found that the circadian rhythm and drug injection timing influenced the treatment outcome. Dexamethasone treatment at the right time point (days 7-11) and dose (0.1 mg/kg) significantly improved the material properties of the healing tendon, while the adverse effects were reduced. Local dexamethasone treatment did not lead to increased peak stress, but it triggered systemic granulocytosis and lymphopenia. Mechanical loading (full or moderate) is essential for the positive effects of dexamethasone, as complete unloading leads to the absence of improvements. Conclusion: We conclude that dexamethasone treatment to improve Achilles tendon healing is dose- and time-dependent, and positive effects are perceived even in a partly unloaded condition.

Place, publisher, year, edition, pages
Sage Publications Inc, 2022
Keywords
corticosteroids; repair; resolution; rat; calcaneal tendon; biomechanics
National Category
Surgery
Identifiers
urn:nbn:se:liu:diva-183597 (URN)10.1177/03635465221077101 (DOI)000764184200001 ()35234541 (PubMedID)
Available from: 2022-03-15 Created: 2022-03-15 Last updated: 2023-05-04Bibliographically approved
Rendek, Z., Bon Beckman, L., Schepull, T., Dånmark, I., Aspenberg, P., Schilcher, J. & Eliasson, P. (2022). Early Tensile Loading in Nonsurgically Treated Achilles Tendon Ruptures Leads to a Larger Tendon Callus and a Lower Elastic Modulus: A Randomized Controlled Trial. American Journal of Sports Medicine, 50(12), 3286-3298
Open this publication in new window or tab >>Early Tensile Loading in Nonsurgically Treated Achilles Tendon Ruptures Leads to a Larger Tendon Callus and a Lower Elastic Modulus: A Randomized Controlled Trial
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2022 (English)In: American Journal of Sports Medicine, ISSN 0363-5465, E-ISSN 1552-3365, Vol. 50, no 12, p. 3286-3298Article in journal (Refereed) Published
Abstract [en]

Background: Early tensile loading improves material properties of healing Achilles tendon ruptures in animal models and in surgically treated human ruptures. However, the effect of such rehabilitation in patients who are nonsurgically treated remains unknown. Hypothesis: In nonsurgically treated Achilles tendon ruptures, early tensile loading would lead to higher elastic modulus 19 weeks after the injury compared with controls. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: Between October 2015 and November 2018, a total of 40 nonsurgically treated patients with acute Achilles tendon rupture were randomized to an early tensile loading (loaded group) or control group. Tantalum bead markers were inserted percutaneously into the tendon stumps 2 weeks after the injury to allow high-precision measurements of callus deformation under mechanical testing. The loaded group used a training pedal twice daily to produce a gradual increase in tensile load during the following 5 weeks. Both groups were allowed full weightbearing in an ankle orthosis and unloaded range of motion exercises. Patients were followed clinically and via roentgen stereophotogrammetric analysis and computed tomography at 7, 19, and 52 weeks after the injury. Results: The mean +/- standard deviation elastic modulus at 19 weeks was 95.6 +/- 38.2 MPa in the loaded group and 108 +/- 45.2 MPa in controls (P = .37). The elastic modulus increased in both groups, although it was lower in the loaded group at all time points. Tendon cross-sectional area increased from 7 weeks to 19 weeks, from 231 +/- 99.5 to 388 +/- 142 mm(2) in the loaded group and from 188 +/- 65.4 to 335 +/- 87.2 mm(2) in controls (P < .001 for the effect of time). Cross-sectional area for the loaded group versus controls at 52 weeks was 302 +/- 62.4 mm(2) versus 252 +/- 49.2 mm(2), respectively (P = .03). Gap elongation was 7.35 +/- 13.9 mm in the loaded group versus 2.86 +/- 5.52 mm in controls (P = .27). Conclusion: Early tensile loading in nonsurgically treated Achilles tendon ruptures did not lead to higher elastic modulus in the healing tendon but altered the structural properties of the tendon via an increased tendon thickness. Registration: NCT0280575 (ClinicalTrials.gov identifier).

Place, publisher, year, edition, pages
Sage Publications Inc, 2022
Keywords
Achilles tendon rupture; tendon healing; loading; rehabilitation; nonsurgical treatment
National Category
Surgery
Identifiers
urn:nbn:se:liu:diva-188135 (URN)10.1177/03635465221117780 (DOI)000845015100001 ()36005394 (PubMedID)
Available from: 2022-09-06 Created: 2022-09-06 Last updated: 2023-05-04Bibliographically approved
Schilcher, J., Bernhardsson, M. & Aspenberg, P. (2019). Chronic anterior tibial stress fractures in athletes: No crack but intense remodelling. Scandinavian Journal of Medicine and Science in Sports, 29(10), 1521-1528
Open this publication in new window or tab >>Chronic anterior tibial stress fractures in athletes: No crack but intense remodelling
2019 (English)In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 29, no 10, p. 1521-1528Article in journal (Refereed) Published
Abstract [en]

PURPOSE: Delayed healing of anterior tibial stress fractures in athletes is related to high tensional forces acting across a putative fracture gap. These forces lead to crack propagation and create strains that exceed tissue differentiation thresholds for new bone to form in the gap. The "dreaded black line" is a radiographic hallmark sign of stress fractures considered to represent a transverse fracture gap. However, whether a fracture gap truly exists at the microscopic level remains unclear. The aim of this study was to describe the area of the "dreaded black line" microscopically and to identify signs of delayed healing.

METHODS: Between 2011 and 2016 we included seven athletes with chronic anterior mid-shaft tibial stress fractures. The fracture site was excised as a cylindrical biopsy. The biopsy was evaluated with micro-CT and histology. The formation of new bone in the defect was evaluated radiographically.

RESULTS: The "dreaded black line" seen on preoperative radiographs in all patients could not be seen on the microscopic level. Instead, the area of the putative crack showed widened resorption cavities, lined with active osteoblasts, and surrounded by immature bone. This area of intense remodelling seemed to create a false impression of a fracture line on radiographs. Complete cortical continuity was restored at the biopsy site at median eight months (range six to 13 months).

CONCLUSION: Tibial stress fractures in athletes normally show no fracture defect, but a region of increased remodelling. The healing process is already ongoing but seems mechanically insufficient. 

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
Stress fracture, fracture healing, histology, tibia
National Category
Orthopaedics
Identifiers
urn:nbn:se:liu:diva-157071 (URN)10.1111/sms.13466 (DOI)000488616400008 ()31102562 (PubMedID)
Funder
Region ÖstergötlandSwedish Research CouncilSwedish National Centre for Research in Sports
Available from: 2019-05-27 Created: 2019-05-27 Last updated: 2019-11-14
Bernhardsson, M., Dietrich, F., Tätting, L., Eliasson, P. & Aspenberg, P. (2019). Depletion of cytotoxic (CD8+) T cells impairs implant fixation in rat cancellous bone. Journal of Orthopaedic Research, 37(4), 805-811
Open this publication in new window or tab >>Depletion of cytotoxic (CD8+) T cells impairs implant fixation in rat cancellous bone
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2019 (English)In: Journal of Orthopaedic Research, ISSN 0736-0266, E-ISSN 1554-527X, Vol. 37, no 4, p. 805-811Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
bone healing; cancellous; tendon healing; cytotoxic T cells; CD8 depletion
National Category
Orthopaedics
Identifiers
urn:nbn:se:liu:diva-157559 (URN)10.1002/jor.24246 (DOI)000467082100001 ()30737834 (PubMedID)2-s2.0-85062344231 (Scopus ID)
Note

Funding Agencies|Swedish Research Council [2031-47-5]; AFA insurance company EU 159 7th framework program [FP7/2007-2013, 279239]; Linkoping 160 University

Available from: 2019-06-22 Created: 2019-06-22 Last updated: 2019-06-25Bibliographically approved
Abtahi, J., Henefalk, G. & Aspenberg, P. (2019). Impact of a zoledronate coating on early post-surgical implant stability and marginal bone resorption in the maxilla-A split-mouth randomized clinical trial.. Clinical Oral Implants Research, 30(1), 49-58
Open this publication in new window or tab >>Impact of a zoledronate coating on early post-surgical implant stability and marginal bone resorption in the maxilla-A split-mouth randomized clinical trial.
2019 (English)In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 30, no 1, p. 49-58Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
dental implant, fibrinogen, maxilla, radiography
National Category
Orthopaedics
Identifiers
urn:nbn:se:liu:diva-153634 (URN)10.1111/clr.13391 (DOI)000456748800004 ()30565741 (PubMedID)
Available from: 2019-01-06 Created: 2019-01-06 Last updated: 2021-02-12
Aspenberg, P., Michaëlsson, K., Rydholm, A. & Svensson, O. (2018). Artrosskolan: evidensen måste stärkas. Läkartidningen, 115
Open this publication in new window or tab >>Artrosskolan: evidensen måste stärkas
2018 (English)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 115Article in journal, Editorial material (Other academic) Published
Place, publisher, year, edition, pages
Läkartidningen Förlag AB, 2018
National Category
Orthopaedics
Identifiers
urn:nbn:se:liu:diva-152530 (URN)29381178 (PubMedID)
Available from: 2019-03-28 Created: 2019-03-28 Last updated: 2019-04-02Bibliographically approved
Aspenberg, P. (2017). Apropå! En arrogant organisation. Läkartidningen, 114
Open this publication in new window or tab >>Apropå! En arrogant organisation
2017 (Swedish)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 114Article in journal, Editorial material (Other academic) Published
Abstract [en]

n/a

Place, publisher, year, edition, pages
Stockholm, Sweden: Läkartidningen Förlag AB, 2017
National Category
Health Sciences Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-146347 (URN)29292934 (PubMedID)
Available from: 2018-04-07 Created: 2018-04-07 Last updated: 2019-02-01Bibliographically approved
Aspenberg, P. (2017). Beslut att operera kopplat till ortopeders attityder till kirurgi. Läkartidningen, 114(41)
Open this publication in new window or tab >>Beslut att operera kopplat till ortopeders attityder till kirurgi
2017 (English)In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 114, no 41Article in journal, Editorial material (Refereed) Published
Abstract [en]

[No abstract available]

Place, publisher, year, edition, pages
Läkartidningen Förlag, 2017
National Category
Orthopaedics
Identifiers
urn:nbn:se:liu:diva-147019 (URN)2-s2.0-85031295393 (Scopus ID)
Available from: 2018-04-09 Created: 2018-04-09 Last updated: 2018-04-24
Blomgran, P., Blomgran, R., Ernerudh, J. & Aspenberg, P. (2017). Cox-2 inhibition and the composition of inflammatory cell populations during early and mid-time tendon healing. Muscles, ligaments and Tendons journal, 7(2), 223-229
Open this publication in new window or tab >>Cox-2 inhibition and the composition of inflammatory cell populations during early and mid-time tendon healing
2017 (English)In: Muscles, ligaments and Tendons journal, ISSN 2240-4554, Vol. 7, no 2, p. 223-229Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
Rome, Italy: CIC Edizioni Internazionali, 2017
Keywords
tendon healing; NSAID; inflammation; rat model; flow cytometry
National Category
Pharmacology and Toxicology
Identifiers
urn:nbn:se:liu:diva-142352 (URN)10.11138/mltj/2017.7.2.223 (DOI)
Available from: 2017-10-27 Created: 2017-10-27 Last updated: 2022-03-04
Sandberg, O., Bernhardsson, M. & Aspenberg, P. (2017). Earlier effect of alendronate in mouse metaphyseal versus diaphyseal bone healing. Journal of Orthopaedic Research, 35(4), 793-799
Open this publication in new window or tab >>Earlier effect of alendronate in mouse metaphyseal versus diaphyseal bone healing
2017 (English)In: Journal of Orthopaedic Research, ISSN 0736-0266, E-ISSN 1554-527X, Vol. 35, no 4, p. 793-799Article in journal (Refereed) Published
Abstract [en]

Healing of injured cancellous bone is characterized by a transient stage of rapid bone formation throughout the traumatized bone volume, often followed by similarly rapid resorption. This is different from the slower diaphyseal healing via an external callus. We, therefore, hypothesized that antiresorptive treatment might have an earlier positive effect in cancellous bone healing than in diaphyseal fractures. One hundred and twenty-three male C57bl6 mice received either an internally stabilized diaphyseal osteotomy of the femur or a screw inserted into the tibial metaphysis. The mice were randomized to daily alendronate injections (200 μg/kg/day), or control injections, and killed for mechanical testing after 14, 21, or 28 days. The hypothesis was tested by a three-way Anova (time, site, and drug). The ultimate force was increased by bisphosphonate treatment in both models. There was a significant interaction between time, site, and drug (p < 0.001) so that the full positive effect of alendronate was evident in the metaphysis at 14 days, but first after 28 days in the diaphysis. While the early effect in the metaphysis might be translated into earlier healing, the late effect in the diaphysis was due to delayed remodeling of the callus, which might have less clinical importance. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
Keywords
fracture, bisphosphonate, metaphysis, cancellous bone, trabecular bone, alendronate
National Category
Clinical Medicine Orthopaedics Nursing
Identifiers
urn:nbn:se:liu:diva-130921 (URN)10.1002/jor.23316 (DOI)000399728400008 ()27233101 (PubMedID)
Funder
Swedish Research CouncilLinköpings universitetÖstergötland County CouncilEU, FP7, Seventh Framework Programme
Note

Funding agencies: Swedish Research Council [VR 02031-47-5]; Linkoping University; Ostergotland County Council; European Communitys Seventh Framework Programme [FP7/2007-2013]

Available from: 2016-08-31 Created: 2016-08-31 Last updated: 2018-05-03Bibliographically approved
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