Mechanical knee symptoms: indicators for meniscal tears?
This study found that 55% of patients report mechanical knee symptoms (catching/ locking) and 47% report not being able to fully extend the knee before arthroscopic partial meniscectomy (APM).
However, this reporting frequency did not differ between patients with and without meniscal tears seen on arthroscopy. The authors warn that the presence of mechanical symptoms may not necessary be attributable to the meniscal tear, even if seen in magnetic resonance imaging (MRI).
Consensus statements and guidelines advice against using arthroscopy for degenerative meniscal tears, but this procedure is still commonly performed when mechanical symptoms are present and a meniscal tear is confirmed by MRI. Moreover, mechanical symptoms are found in a range of other knee conditions such as ACL tears and synovial inflammation. A recent trial found no difference in outcomes between middle-aged and older patients with degenerative meniscal tears who underwent either APM or placebo APM.
A total of 641 and 176 patients with and without a meniscal tear confirmed at surgery, respectively, were eligible for the study. The Knee injury and Osteoarthritis Outcome Score (KOOS) corresponding subitems were used to determine the presence of knee locking/ catching and of inability to fully extend the knee. The presence of meniscal tears was determined by the surgeon during arthroscopy.
The similar prevalence of these symptoms in patients with and without meniscal tears questions the specificity of mechanical symptoms for meniscal tears and whether these should constitute an indication for arthroscopic surgery.
Expert opinion by José Pedro Correia
This study's findings once again highlight the lack of association between structural changes and self-reported symptoms.
A really interesting study that challenges established clinical practice and should alert all those dealing with such cases to treat the person and not the tear.
> From: Thorlund et al., Br J Sports Med 53 (2019) 299-303 (Epub ahead of print). All rights reserved to The Author(s). Click here for the online summary.