Mechanical Symptoms and Arthroscopic Partial Meniscectomy in Patients With Degenerative Meniscus Tear: A Secondary Analysis of a Randomized Trial.

BACKGROUND: Recent evidence shows that arthroscopic partial meniscectomy (APM) offers no benefit over conservative treatment of patients with a degenerative meniscus tear. However, patients who report mechanical symptoms (sensations of knee catching or locking) may benefit from APM.

OBJECTIVE: To assess whether APM improves mechanical symptoms better than sham surgery.

DESIGN: Randomized, patient- and outcome assessor-blinded, sham surgery-controlled, multicenter trial. (ClinicalTrials.gov: NCT00549172).

SETTING: 5 orthopedic clinics in Finland.

PATIENTS: Adults (aged 35 to 65 years) with a degenerative medial meniscus tear and no knee osteoarthritis.

INTERVENTION: APM or sham surgery.

MEASUREMENTS: Patients' self-report of mechanical symptoms before surgery and at 2, 6, and 12 months after surgery.

RESULTS: 70 patients were randomly assigned to APM, and 76 were assigned to sham surgery. Thirty-two patients (46%) in the APM group and 37 (49%) in the sham surgery group reported catching or locking before surgery; the corresponding numbers at any follow-up were 34 (49%) and 33 (43%), with a risk difference of 0.03 (95% CI, -0.06 to 0.12). In the subgroup of 69 patients with preoperative catching or locking, the risk difference was 0.07 (CI, -0.08 to 0.22).

LIMITATION: Analyses were post hoc, and the results are only generalizable to knee catching and occasional locking because few patients reported other types of mechanical symptoms.

CONCLUSION: Resection of a torn meniscus has no added benefit over sham surgery to relieve knee catching or occasional locking. These findings question whether mechanical symptoms are caused by a degenerative meniscus tear and prompt caution in using patients' self-report of these symptoms as an indication for APM.

PRIMARY FUNDING SOURCE: Academy of Finland.