Arthroscopic surgeries for patients with established knee osteoarthritis are becoming less common due to a lack of clinical evidence supporting their use. A Cochrane review found that arthroscopic surgery is ineffective for unselected patients with knee osteoarthritis (Cochrane Database Syst Rev 2008 Jan 23;(1):CD005118), based partly on the findings of a randomized trial showing no significant improvement in pain or function scores with either arthroscopic debridement or arthroscopic lavage compared to placebo surgery (N Engl J Med 2002 Jul 11;347(2):81 full-text). Another randomized trial subsequently showed that the addition of arthroscopic surgery to physical and medical therapies did not improve function or pain scores in patients with moderate-to-severe knee osteoarthritis (N Engl J Med 2008 Sep 11;359(11):1097 full-text). More recently, a randomized trial in patients with meniscal tear and knee osteoarthritis showed that arthroscopic partial meniscectomy plus physical therapy did not improve symptoms more than physical therapy alone (N Engl J Med 2013 May 2;368(18):1675 full-text, seeDynaMed EBM Focus Volume 8, Issue 13).
However, the implications for patients without clearly established knee osteoarthritis have remained unclear. A recent randomized trial comparing meniscectomy to strengthening exercises in patients presenting with degenerative medial meniscus tear and no clear evidence of osteoarthritis (Kellgren-Lawrence grade 0-1) found no significant between-group differences in function, pain, or patient satisfaction scores (Am J Sports Med 2013 Jul;41(7):1565). Now, a randomized trial compares arthroscopic partial meniscectomy to sham surgery in patients with medial meniscus tear without knee osteoarthritis.
A total of 146 patients aged 35-65 years with symptomatic degenerative medial meniscus tear without knee osteoarthritis were randomized to arthroscopic partial meniscectomy vs. sham surgery and followed for 12 months. Postoperative care, including walking aids and instructions for graduated exercises, was identical for both groups, and all patients were instructed to take over-the-counter analgesics as required. Symptoms were assessed using the Lysholm and Western Ontario Meniscal Evaluation Tool (WOMET) scores, which both range from 0 to 100, with higher scores indicating less severe symptoms. Knee pain was assessed after exercise using a numeric rating scale with a range of 0 to 10, with higher scores indicating greater pain severity.
Both groups had a significant improvement from baseline in symptom and knee pain scores, but there were no significant between-group differences for these outcomes at 12 months. The mean improvement in the Lysholm score was 21.7 points with arthroscopic partial meniscectomy group vs. 23.3 points with sham surgery, with a difference of 11.5 points considered clinically meaningful. Similarly, the mean improvement in the WOMET score was 24.6 points with partial meniscectomy vs. 27.1 points with sham surgery, with a difference of 15.5 points considered clinically meaningful. The mean improvement in knee pain was 3.1 points with partial meniscectomy vs. 3.3 points with sham surgery, with a difference of 2 points considered clinically meaningful. There were also no significant differences in the rate of subsequent knee surgery, patient-reported satisfaction, patient-reported improvement, or serious adverse events.
Recent clinical evidence from randomized trials has consistently shown a lack of efficacy of arthroscopic surgeries for patients with knee osteoarthritis, including patients with meniscus tears. This trial extends those findings to patients with meniscus tears but without established knee osteoarthritis, showing no significant difference in symptom or pain scores between patients receiving arthroscopic partial meniscectomy and those receiving sham surgery. It should be noted that the Lysholm and WOMET scores used in this trial for symptom assessment are primarily focused on basic activities of daily living, and may not adequately describe high-level function as may be required for strenuous work or sports.
For more information, see the Meniscus tears topic in DynaMed.