High Rate of Recurrent Meniscal Tear and Lateral Compartment Osteoarthritis in Patients Treated for Symptomatic Lateral Discoid Meniscus: A Population-Based Study

BACKGROUND: Little is known about the natural history of a surgically treated symptomatic lateral discoid meniscus. The goals of this study were to describe the rate and factors associated with recurrent lateral meniscal tears and progression to symptomatic lateral compartment osteoarthritis (OA) in patients surgically treated for a symptomatic lateral discoid meniscus. HYPOTHESIS: Patients with surgically treated lateral discoid meniscus have a high incidence of meniscal retear and progression to lateral compartment OA. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A large geographic database was reviewed to identify and confirm patients presenting with symptomatic lateral discoid meniscus between 1998 and 2015. Charts were reviewed to document treatment and outcomes at a minimum clinical follow-up of 2 years. RESULTS: A total of 59 patients (27 females, 32 males) with a mean age of 25.7 years (range, 4.0-66.0 years) underwent surgical management of a discoid lateral meniscus and were evaluated for a mean of 5.6 years (range, 2.0-23.7 years). Of these, 48 (82%) patients underwent partial lateral meniscectomy, with 24 patients undergoing concurrent saucerization. Eleven (18%) underwent meniscal repair. Tear-free survival following surgery was 41% at 8 years. Progression to symptomatic lateral compartment OA was 50% at 8 years. Young age (hazard ratio, 0.96; 95% CI, 0.93-0.99; P = .01) and open growth plates (hazard ratio, 3.19; 95% CI, 1.15-8.88; P = .03) were associated with increased incidence of postoperative retear. Older age at diagnosis and body mass index ≥30 kg/m(2) were associated with increased risk of progression to lateral compartment OA on final radiographs. CONCLUSION: Patients with a surgically treated lateral discoid meniscal tear had a high rate of recurrent meniscal tear (59% at 8 years). Approximately 50% of surgically treated patients developed symptomatic lateral compartment OA at 8 years from diagnosis.