APM outcomes in patients presenting mechanical symptoms, meniscus tear
The outcomes after arthroscopic partial meniscectomy (APM) do not appear to be superior to placebo surgery in patients without knee osteoarthritis but with symptoms of a degenerative medial meniscus tear, according to 2-year data from a recent study.
A total of 146 patients (aged 35 to 65 years) with knee symptoms consistent with degenerative medial meniscus tear and no knee osteoarthritis were randomized to receive either APM or placebo surgery.
The between-group difference in the change from baseline in the Western Ontario Meniscal Evaluation Tool (WOMET) and Lysholm knee scores and knee pain after exercise at 24 months after surgery was assessed as the primary study outcome. Secondary outcomes were the frequency of unblinding of the treatment-group allocation, participants' satisfaction, impression of change, return to normal activities, the incidence of serious adverse events and the presence of meniscal symptoms in clinical examination. Two subgroup analyses were performed to evaluate the outcome on those with mechanical symptoms and those with unstable meniscus tears.
An intention-to-treat analysis found no significant between-group differences in the mean changes from baseline to 24 months in the following outcomes: WOMET score (27.3 in the APM group vs 31.6 in the placebo-surgery group; between-group difference, −4.3; 95 percent CI, −11.3 to 2.6), Lysholm knee score (23.1 vs 26.3, respectively; between-group difference, −3.2; −8.9 to 2.4) and knee pain after exercise (3.5 vs 3.9, respectively; between-group difference, −0.4; −1.3 to 0.5).
Results were similar for the secondary outcomes and within the analysed subgroups, with no statistically significant differences seen between the two groups.
APM is one of the most commonly performed orthopaedic operations and is frequently carried out in middle-aged and older patients with knee symptoms and degenerative knee disease. Several studies have reported that APM provides treatment benefit over conservative treatment or placebo surgery in patients who fail conservative treatment, as well as in subgroups of those with so-called mechanical symptoms of the knee or those with unstable meniscal tear. [Am J Sports Med 2013;41:2333–9; Arthroscopy 2014;30:659–60; N Engl J Med 2014;370:1260; BMJ 2014;348:g2382; Int Orthop 2015;39:769–75]
The present data, however, provide no evidence to support the prevailing ideas that patients presenting with mechanical symptoms or certain meniscus tear characteristics or those who have failed initial conservative treatment are more likely to benefit from APM, researchers said.