Arthroscopic surgery for knee osteoarthritis

Background: Knee osteoarthritis is a progressive disease that initially affects the articular cartilage. Observational studies have shown benefits for arthroscopic debridement on the osteoarthritic knee, but other recent studies have yielded conflicting results that suggest arthroscopic debridement may not be effective. Objectives: To identify the effectiveness of arthroscopic debridement in knee osteoarthritis on pain and function. Search Strategy: The authors searched the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2006), Medline (1966 to August 2006), CINAHL (1982 to 2006), EMBASE (1988 to 2006), and Web of Science (1900 to 2006), and screened the bibliographies, reference lists, and cited Web sites of papers. Selection Criteria:The authors included randomized controlled trials (RCTs) or controlled clinical trials assessing effectiveness of arthroscopic debridement compared with another surgical procedure (including sham or placebo surgery and other nonsurgical interventions) in patients with a diagnosis of primary or secondary osteoarthritis of the knee who did not have other joint involvement or conditions requiring long-term use of nonsteroidal anti-inflammatory drugs. The main outcomes were pain relief and improved function of the knee. Data Collection and Analysis: Two review authors independently selected trials for inclusion, assessed trial quality, and extracted the data. Results are presented using weighted mean difference for continuous data and relative risk for dichotomous data, as well as the number needed to treat (NNT) and the number needed to harm (NNH). Main Results: Three RCTs, with a total of 271 patients, were included. They had different comparison groups and a moderate risk of bias. One study compared arthroscopic debridement with lavage and with sham surgery. The study found no significant difference when compared with lavage. Compared with sham surgery, the study found worse outcomes for arthroscopic debridement at two weeks (weighted mean difference for pain = 8.7; 95% confidence interval [CI], 1.7 to 15.8; function = 7.7; 95% Cl, 1.1 to 14.3; NNH = 5) and no significant difference at two years. The second trial, at higher risk of bias, compared arthroscopic debridement with arthroscopic washout and found that arthroscopic debridement significantly reduced knee pain compared with washout at five years (relative risk = 5.5; 95% Cl, 1.7 to 15.5; NNT = 3). The third trial, also at higher risk of bias, compared arthroscopic debridement with closed-needle lavage and found no significant difference. Authors' Conclusions: There is high-quality evidence that arthroscopic debridement has no benefit for typical osteoarthritis of the knee (mechanical or inflammatory causes).