Arthroscopic surgery may not benefit patients with degenerative knee disease

Arthroscopic surgery does not appear to offer lasting benefit in patients with knee pain and degenerative knee disease, according to a new study.

Researchers performed a systematic review and meta-analysis to determine the benefits and harms of arthroscopic knee surgery (partial meniscectomy, debridement, or both) in middle-aged or older patients. Randomized trials published from 2000 to August 2014 that assessed the benefit of such surgery versus nonsurgical treatments (sham surgery, exercise, and medical treatment) in patients with or without radiographic signs of osteoarthritis were included in the analysis. Randomized trials, cohort studies, register-based studies, and case series that assessed harms were also included. The main outcome measures were pain and physical function.

Results were published online June 16 by The BMJ.

Nine trials looked at the benefit of arthroscopic knee surgery, and 9 studies looked at harms. Because measures of benefit in the different studies were reported differently, the effect size of the studies as measured as standardized mean difference was transformed into a visual analog scale ranging from 0 to 100 mm. In the main analysis, which combined primary endpoints of the original trials 3 to 24 months after surgery, interventions (including arthroscopic surgery) yielded a small benefit compared with controls on the outcome of pain (effect size, 0.14; 9%% CI, 0.03 to 0.26), corresponding to a benefit of 2.4 mm (95% CI, 0.4 to 4.3 mm) on a visual analogue scale of 0 to 100. Baseline measures of pain in the different studies ranged from 36 to 63 mm; a shift of 15 to 20 mm on the analog pain scale is commonly suggested as representing a clinically relevant difference for pain.

Additionally, for comparison, a similar effect size is seen with use of acetaminophen for pain relief. Interventions including arthroscopic surgery showed a small benefit at 3 to 6 months but no benefit after that time period up to 24 months. Physical function did not appear to benefit from any of the interventions or control treatments.

To combine data regarding harms, the numbers of adverse events were transformed into log odds of events and were reported as the number of adverse events per 1,000 procedures. Harms associated with arthroscopic surgery included symptomatic deep venous thrombosis, pulmonary embolism, infection, and death; of these, symptomatic deep venous thrombosis was the most common (4.13 events per 1,000 procedures; 95% CI, 1.78 to 9.60 events per 1,000 procedures).

The researchers noted that the included randomized, controlled trials of arthroscopic surgery were small; that some trials had inadequate blinding; and that no systematic literature search was performed for harms associated with such control treatments as exercise, among other limitations. However, based on their results, they concluded that arthroscopic surgery for degenerative knee disease yields “small inconsequential benefit” in middle-aged and older adults and is associated with harms.

“Taken together, these findings do not support the practise of arthroscopic surgery for middle aged or older patients with knee pain with or without signs of osteoarthritis,” the authors wrote. They recommended that middle-aged patients with knee pain and meniscal tears be considered to have early-stage osteoarthritis and said that they should be treated accordingly with information, exercise, and, when needed, weight loss.

The author of an accompanying editorial noted that while patients do improve after arthroscopic surgery, this improvement is usually no better than that seen with control treatment. In addition, he noted that while risks associated with both nonsurgical treatment and arthroscopic surgery are rare, those associated with the latter are more serious.

“Supporting or justifying a procedure with the potential for serious harm, even if this is rare, is difficult when that procedure offers patients no more benefit than a placebo,” the editorialist wrote. “We may be close to a tipping point where the weight of evidence against arthroscopic knee surgery for pain is enough to overcome concerns about the quality of the studies, confirmation bias, and vested interests. When that point is reached, we should anticipate a swift reversal of established practice.”