Conundrum of mechanical knee symptoms: signifying feature of a meniscal tear?

Abstract

BackgroundMechanical knee symptoms are often considered important in the decision to perform knee arthroscopy on the suspicion of a meniscal tear. We investigated if presence of a meniscal tear at knee arthroscopy in adults is associated with presence of preoperative self-reported mechanical knee symptoms.MethodsWe used data from Knee Arthroscopy Cohort Southern Denmark (KACS). KACS consists of patients aged 18 years or older referred to knee arthroscopy on the suspicion of a meniscal tear at four recruiting hospitals between 1 February 2013 and 31 January 2015. Of 1259 invited patients, 908 (72%) replied to the baseline questionnaire. With 91 patients excluded, the study sample consisted of 641 and 176 patientswithandwithouta meniscal tear confirmed at surgery, respectively. Exposure was meniscal tear as determined by the knee surgeon during arthroscopy. Main outcomes were preoperative mechanical knee symptoms defined as self-reported catching/locking or self-reported inability to straighten knee fully.Results55% of all patients reported symptoms of catching/locking and 47% were unable to straighten their knee fully. Preoperative mechanical symptoms were equally prevalent in patientswithandwithouta meniscal tear (prevalence ratio catching/locking 0.89, 95% CI 0.77 to 1.03, and inability to straighten knee fully, prevalence ratio 1.02, 95% CI 0.84 to 1.23).InterpretationPatient-reported mechanical symptoms were equally common irrespective of presence or absence of a meniscal tear in patients undergoing arthroscopy for suspicion of a meniscal tear. Our findings suggest that mechanical knee symptoms have a limited value when considering indication for meniscal surgery.Trial registration numberNCT01871272; Results.