Introduction: Knee osteoarthritis is a major cause of pain and disability for which joint distraction is a potential treatment to delay the need for knee arthroplasty. This systematic review aims to assess the short-and long-term clinical and structural outcomes following knee joint distraction (KJD). Methods: MEDLINE, EMBASE, Scopus, and Web of Science databases were searched from the date of inception to 26th June 2019. Clinical studies investigating joint distraction for knee osteoarthritis with outcomes including ΔWOMAC index, ΔVAS pain score, and Δjoint space width were included. The review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO)-CRD42018087032. Results: Nine studies comprising a total of 507 patients were included. There were four randomized controlled trials (RCTs), five open prospective cohort studies, and one case series. Overall, there were significant improvements in WOMAC index, VAS pain score and joint space width following KJD, which persisted up to 9 years. KJD also demonstrated comparable clinical outcomes with high tibial osteotomy and total knee arthroplasty. Conclusion: There is moderate quality evidence supporting the beneficial outcomes of joint distraction for knee osteoarthritis. Larger RCTs with longer follow-up (>1 year) are necessary to establish the true effect size of this procedure.

BackgroundOsteoarthritis is a degenerative joint disease that is highly prevalent worldwide. Knee osteoarthritis is the most common form of osteoarthritis and is a major cause of pain and disability. However, there remains a lack of treatments available that have demonstrated effectiveness in stopping or reversing the degenerative process. Joint distraction has emerged as a viable alternative in the treatment of knee osteoarthritis to delay the need for knee arthroplasty.MethodsAn electronic search will be conducted on MEDLINE, EMBASE, Web of Science, CINAHL, Cochrane and EBSCO databases. Clinical studies investigating joint distraction for knee osteoarthritis, which reported clinical or structural outcomes including ∆WOMAC index, ∆VAS pain score and ∆joint space width will be included. Risk of bias will be assessed using the Newcastle-Ottawa Scale for observational studies and Cochrane Collaboration tool for randomised controlled trials. Quality of studies will be assessed using the modified Coleman methodology score.DiscussionThis systematic review will summarise the short- and long-term clinical and structural outcomes following joint distraction for knee osteoarthritis. The findings from this review will establish the quality of currently available evidence, which will determine the need for further studies to establish the true effect size of this procedure.Systematic review registrationPROSPERO CRD42018087032