Thumbs Down on Arthroscopic Knee Surgery

Carr A. Editorials: Arthroscopic surgery for degenerative knee. Overused, ineffective, and potentially harmful. 16 June 2015;350:h2983 doi: 10.1136/bmj.h2983

Thorlund JB, Juhl CB, Roos EM, Lohmander LS. Research: Arthroscopic surgery for degenerative knee: systematic review and meta-analysis of benefits and harms.16 June 2015;350:h2747 doi: http://dx.doi.org/10.1136/bmj.h2747

This systemic review and meta-analysis found no significant benefit to arthroscopic knee surgery. The harms of arthroscopic knee surgery are rare but serious, including death. In contrast, non-surgical exercise therapy does have benefits and no serious harms.

The review covered 9trials with 1,270 middle-aged or older patients with knee pain and degenerative disease, with or without radiographic signs of osteoarthritis, who were randomized to surgery involving partial meniscectomy, debridement, or both; or to control groups with placebo surgery or exercise.

Interventions including arthroscopy showed a benefit at 3 and 6 months of 3-5 mm on a 0-100 mm visual analogue scale, but that benefit disappeared after 6 months.

A separate analysis of larger, non-randomized trials calculated the harms. Mortality was 1 per 1,000 procedures (confidence interval 0.04-24). Deep vein thrombosis was 4 per 1,000 procedures (confidence interval 1.8-9.6). Every year, more than 700,000 knee arthroscopies are done in the US and 150,000 in the United Kingdom.

The research report and editorial argue that knee arthroscopy is often performed based on MRI of abnormalities, such as meniscal tears, osteophytes, cartilage damage, and bone marrow lesions, which are common in painful knees but also common in the general asymptomatic population. Patients with early stage knee osteoarthritis should be treated according to the guidelines, with information, exercise, and weight loss, they write.

“In light of this evidence, why is arthroscopy still so common?” asks Andy Carr in an editorial, which discusses biases and flaws in scientific studies.

“Surgeon confirmation bias in combination with financial aspects and administrative policies may be factors more powerful than evidence in driving practice patterns,” conclude the investigators.