Registration and reporting characteristics of trials investigating exercise therapy following total knee arthroplasty: a systematic review
DOI:
https://doi.org/10.2340/17453674.2026.46047Keywords:
Exercise Therapy, Knee, Knee Replacement, Osteoarthrosis, Trial RegistrationAbstract
Background and purpose: Prospectively registering the primary trial outcome is important to reduce selective outcome reporting and increase the trustworthiness of findings, which guide clinical practice. The objectives of our systematic review were to explore and compare the reporting characteristics of prospectively and non-prospectively registered trials investigating exercise therapy following total knee arthroplasty.
Methods: Randomized trials comparing effects of exercise therapy after total knee arthroplasty for osteoarthritis were identified in 4 databases from 2000 to August 12, 2024. One primary outcome per trial was extracted, using a pre-specified hierarchical algorithm, irrespective of outcome domain. Pooled standardized mean differences (SMDs) were calculated on pre-specified outcome domains, and risk-of-bias assessed using the Cochrane Risk-of-Bias tool v2.
Results: 94 trials, comprising 9,396 participants, were included, of which 13 were prospectively registered, 33 retrospectively registered, and 48 unregistered. A single primary outcome was defined in 44% of the 94 trials, and 4 trials reported a primary outcome consistent with a prospective registration. The pooled SMD of primary outcomes was 0.06 (95% confidence interval [CI] −0.03 to 0.16) for prospectively registered trials, 0.67 (CI 0.22–1.11) for retrospectively registered trials, and 0.59 (CI 0.32–0.86) for unregistered trials. Lower risk-of-bias ratings and higher proportions of intention-to-treat adherence, dropout reporting, and adverse event reporting were observed among prospectively registered trials.
Conclusion: Among prospectively registered trials we showed smaller effect size estimates between interventions with lower risk-of-bias ratings, and higher proportions of intention-to-treat adherence, dropout reporting, and adverse event reporting in contrast to trials without prospective registration; furthermore, clear specification of a single primary outcome was uncommon among trials evaluating exercise therapy after total knee arthroplasty.
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Artz N, Elvers K T, Lowe C M, Sackley C, Jepson P, Beswick A D. Effectiveness of physiotherapy exercise following total knee replacement: systematic review and meta-analysis. BMC Musculoskelet Disord 2015; 16(1): 15. doi: 10.1186/s12891-015-0469-6.
Skoffer B, Dalgas U, Mechlenburg I. Progressive resistance training before and after total hip and knee arthroplasty: a systematic review. Clin Rehabil 2015; 29(1): 14-29. doi: 10.1177/0269215514537093.
Florez-García M, García-Pérez F, Curbelo R, Pérez-Porta I, Nishishinya B, Rosario Lozano MP, et al. Efficacy and safety of home-based exercises versus individualized supervised outpatient physical therapy programs after total knee arthroplasty: a systematic review and meta-analysis. Knee Surg Sports Traumatol Arthrosc 2017; 25(11): 3340-53. doi: 10.1007/s00167-016-4231-x.
Sattler L N, Hing W A, Vertullo C J. What is the evidence to support early supervised exercise therapy after primary total knee replacement? A systematic review and meta-analysis. BMC Musculoskelet Disord 2019; 20(1): 1-11. doi: 10.1186/s12891-019-2415-5.
Buhagiar M A, Naylor J M, Harris I A, Xuan W, Adie S, Lewin A. Assessment of outcomes of inpatient or clinic-based vs home-based rehabilitation after total knee arthroplasty: a systematic review and meta-analysis. JAMA Netw Open 2019; 2(4): e192810-e192810. doi: 10.1001/jamanetworkopen.2019.2810.
Mark-Christensen T, Juhl C, Thorborg K, Bandholm T. Is physical rehabilitation superior to no physical rehabilitation following total knee arthroplasty? A systematic review and meta-analysis. medRxiv 2020; 2020.04.29.20084392. doi: 10.1101/2020.04.29.20084392.
Alrawashdeh W, Eschweiler J, Migliorini F, El Mansy Y, Tingart M, Rath B. Effectiveness of total knee arthroplasty rehabilitation programmes: a systematic review and meta-analysis. J Rehabil Med 2021; 53(6): jrm00200. doi: 10.2340/16501977-2827 PubMed PMID: 33846757.
Chaudhry Y P, Hayes H, Wells Z, Papadelis E, Khanuja H S, Deirmengian C. Not all patients need supervised physical therapy after primary total knee arthroplasty: a systematic review and meta-analysis. Cureus 2023; 15(2): e35232. doi: 10.7759/cureus.35232 PubMed PMID: 36968854; PubMed Central PMCID: PMC10032555.
Konnyu K J, Thoma L M, Cao W, Aaron R K, Panagiotou O A, Bhuma M R, et al. Rehabilitation for total knee arthroplasty: a systematic review. Am J Phys Med Rehabil 2023; 102(1): 19-33. doi: 10.1097/PHM.0000000000002008 PubMed PMID: 35302953.
Koster A, Stevens M, van Keeken H, Westerveld S, Seeber G H. Effectiveness and therapeutic validity of physiotherapeutic exercise starting within one year following total and unicompartmental knee arthroplasty for osteoarthritis: a systematic review. Eur Rev Aging Phys Act 2023; 20(1): 8. doi: 10.1186/s11556-023-00317-4.
Frieden T R. Evidence for health decision making—beyond randomized, controlled trials. New Eng J Med 2017; 377(5): 465-75. doi: 10.1056/NEJMra1614394.
Deaton A, Cartwright N. Understanding and misunderstanding randomized controlled trials. Soc Sci Med 2018; 210: 2-21. doi: 10.1016/j.socscimed.2017.12.005.
Reito A, Overgaard S. Editorial: Why the randomized controlled trial is still at the apex and the gold standard for evaluating new medical and surgical interventions. Acta Orthop 2025; 96: 873-4. doi: 10.2340/17453674.2025.44947.
Bandholm T, Christensen R, Thorborg K, Treweek S, Henriksen M. Preparing for what the reporting checklists will not tell you: the PREPARE Trial guide for planning clinical research to avoid research waste. B J Sports Med 2017; 51(20): 1494-501. doi: 10.1136/bjsports-2017-097527.
World Medical Association. WMA Declaration of Helsinki: Ethical Principles for Medical Research Involving Human Subjects. [Internet] 2017. Available from: https://www.wma.net/policies-post/wma-declaration-of-helsinki-ethical-principles-for-medical-research-involving-human-subjects/ [accessed November 15, 2017].
WHO. Trial registration [Internet]. [cited 2025 May 15]. Available from: https://www.who.int/tools/clinical-trials-registry-platform/network/trial-registration
ICMJE | About ICMJE | Clinical Trials Registration [Internet]. [cited 2025 May 15]. Available from: https://www.icmje.org/about-icmje/faqs/clinical-trials-registration/
Christensen R, Ranstam J, Overgaard S, Wagner P. Guidelines for a structured manuscript: atatistical methods and reporting in biomedical research journals. Acta Orthop 2023; 94: 243-9. doi: 10.2340/17453674.2023.11656.
Andrade C. The primary outcome measure and its importance in clinical trials. J Clin Psychiatry 2015; 76(10). doi: 10.4088/JCP.15f10377.
Andrade C. HARKing, cherry-picking, P-hacking, fishing expeditions, and data dredging and mining as questionable research practices. J Clin Psychiatry 2021; 82(1): 20f13804. doi: 10.4088/JCP.20f13804.
Cook C, Garcia A N. Post-randomization bias. J Man Manip Ther 2020; 28(2): 69-71. doi: 10.1080/10669817.2020.1739153.
Dwan K, Altman D G, Arnaiz J A, Bloom J, Chan A W, Cronin E, et al. Systematic review of the empirical evidence of study publication bias and outcome reporting bias. Siegfried N, editor. PLoS ONE 2008; 3(8): e3081. doi: 10.1371/journal.pone.0003081.
Dwan K, Altman D G, Clarke M, Gamble C, Higgins J P T, Sterne J A C, et al. Evidence for the selective reporting of analyses and discrepancies in clinical trials: a systematic review of cohort studies of clinical trials. PLoS Med 2014; 11(6): e1001666. doi: 10.1371/journal.pmed.1001666.
Goldacre B, Drysdale H, Dale A, Milosevic I, Slade E, Hartley P, et al. COMPare: a prospective cohort study correcting and monitoring 58 misreported trials in real time. Trials 2019; 20(1): 118. doi: 10.1186/s13063-019-3173-2.
Dechartres A, Ravaud P, Atal I, Riveros C, Boutron I. Association between trial registration and treatment effect estimates: a meta-epidemiological study. BMC Med 2016; 14(1): 100. doi: 10.1186/s12916-016-0639-x.
Grønfeldt B, Husted R, Brødsgaard R, Holst L, Chapple C, Kallemose T, et al. Trial registration and reporting characteristics of trials investigating exercise-based rehabilitation following total knee arthroplasty: a systematic review [Internet]. OSF; 2019 [cited 2025 Jun 26]. Available from: https://osf.io/kwqcb/ doi: 10.17605/OSF.IO/KWQCB.
Higgins J, Li T, Deeks J. Chapter 6: Choosing effect measures and computing estimates of effect [last updated August 2023]. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page M J, et al. Cochrane Handbook for Systematic Reviews of Interventions version 6.5. Cochrane, 2024. [Internet]. [cited 2025 Jun 5]. Available from: cochrane.org/handbook.
Sterne J A C, Savović J, Page M J, Elbers R G, Blencowe N S, Boutron I, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ 2019; l4898. doi: 10.1136/bmj.l4898.
Higgins J P T. Measuring inconsistency in meta-analyses. BMJ 2003; 327(7414): 557-60. doi: 10.1136/bmj.327.7414.557.
Cohen J. Statistical Power Analysis for the Behavioral Sciences 2. Hillsdale, NJ: Lawrence Erlbaum; 1988. 579 p.
Page M J, McKenzie J E, Bossuyt P M, Boutron I, Hoffmann T C, Mulrow C D, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021; 372:n71. doi: 10.1136/bmj.n71.
Riley S P, Swanson B T, Shaffer S M, Sawyer S F, Cleland J A. The unknown prevalence of postrandomization bias in 15 physical therapy journals: a methods review. J Orthop Sports Phys Ther 2021; 51(11): 542_50. doi: 10.2519/jospt.2021.10491.
Großhennig A, Thomas N H, Brannath W, Koch A. How to avoid concerns with the interpretation of two primary endpoints if significant superiority in one is sufficient for formal proof of efficacy. Pharm Stat 2023; 22(5): 836-45. doi: 10.1002/pst.2314.
Arienti C, Armijo-Olivo S, Ferriero G, Feys P, Hoogeboom T, Kiekens C, et al. The influence of bias in randomized controlled trials on rehabilitation intervention effect estimates: what we have learned from meta-epidemiological studies. Eur J Phys Rehabil Med 2023; 60(1): 135-44. doi: 10.23736/S1973-9087.23.08310-7.
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Copyright (c) 2026 Birk Mygind Grønfeldt, Rasmus S Husted, Rasmus H Brødsgaard, Line Holst, Thomas Kallemose, Cathy M Chapple, Carsten B Juhl, Thomas Bandholm
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