The role of joint distraction in the treatment of knee osteoarthritis: a systematic review and quantitative analysis.

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 ∆WOMAC index, ∆VAS pain score, and ∆joint 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.