Surgical interventions for symptomatic mild to moderate knee osteoarthritis

Background Osteoarthritis affecting the knee is common and represents a continuum of disease from early cartilage thinning to full‐thickness cartilage loss, bony erosion, and deformity. Many studies do not stratify their results based on the severity of the disease at baseline or recruitment. Objectives To assess the benefits and harms of surgical intervention for the management of symptomatic mild to moderate knee osteoarthritis defined as knee pain and radiographic evidence of non‐end stage osteoarthritis (Kellgren‐Lawrence grade 1, 2, 3 or equivalent on MRI/arthroscopy). Outcomes of interest included pain, function, radiographic progression, quality of life, short‐term serious adverse events, re‐operation rates and withdrawals due to adverse events. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase up to May 2018. We also conducted searches of ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. Authors of trials were contacted if some but not all their participants appeared to fit our inclusion criteria. Selection criteria We included randomised controlled trials that compared surgery to non‐surgical interventions (including sham and placebo control groups, exercise or physiotherapy, and analgesic or other medication), injectable therapies, and trials that compared one type of surgical intervention to another surgical intervention in people with symptomatic mild to moderate knee osteoarthritis. Data collection and analysis Two review authors independently selected trials and extracted data using standardised forms. We analysed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. Main results A total of five studies involving 566 participants were identified as eligible for this review. Single studies compared arthroscopic partial meniscectomy to physical therapy (320 participants), arthroscopic surgery (debridement ± synovectomy ± chondroplasty) to closed needle joint lavage with saline (32 participants) and high tibial osteotomy surgery to knee joint distraction surgery (62 participants). Two studies (152 participants) compared arthroscopic surgery (washout ± debridement; debridement) to a hyaluronic acid injection. Only one study was at low risk of selection bias, and due to the difficulty of blinding participants to their treatment, all studies were at risk of performance and detecti