Arthroscopic partial meniscectomy in young patients with symptomatic discoid lateral meniscus: an average 10-year follow-up study

Abstract

Introduction: The aim of this study is to evaluate mid-to-long-term clinical and radiological outcomes after an arthroscopic partial meniscectomy for symptomatic discoid lateral meniscus (DLM) in young patients and to determine whether degeneration of the residual meniscus and articular cartilage progresses during the follow-up period using magnetic resonance imaging (MRI).

Materials and methods: We retrospectively reviewed patients aged ≤ 40 years at surgery who underwent arthroscopic partial meniscectomy for symptomatic DLM and were followed up for ≥ 5 years. Lysholm knee scores and reoperation rates were assessed as clinical outcomes. Factors that affect clinical outcomes were evaluated. Tapper-Hoover classification and femorotibial angle were used for radiological assessment. The degree of degeneration of articular cartilages and residual meniscus was evaluated using preoperative and follow-up MRIs.

Results: A total of 73 knees (66 patients) were enrolled. The mean follow-up period was 10.0 years. The mean follow-up Lysholm knee score was 84.2 ± 14.5, and the reoperation rate was 32.9%. Follow-up Lysholm knee scores were related to duration of symptoms prior to surgery (β = - 0.129, P = 0.003) and femorotibial angle at the last follow-up (β = 1.362, P = 0.045). On simple radiographs, progression of arthritis of the lateral compartment was observed in 68.5% (49 knees). In MRI analyses, degeneration of the residual meniscus progressed in 52.9% (34 knees) (P < 0.001), and significant changes in modified Yulish scores were observed in both lateral femoral and tibial condyles (P < 0.001, both condyles).

Conclusions: After an arthroscopic partial meniscectomy for symptomatic DLM, unfavorable clinical outcomes were shown in > 30% of the patients during a mean follow-up of 10.0 years. Clinical outcomes based on the patient-reported outcome measures were related to durations of symptoms prior to surgery and alignment at the last follow-up. In radiological and MRI assessments, progression of degeneration of articular cartilages in the lateral compartments of the knees and residual menisci was observed.

Keywords: Arthroscopic partial meniscectomy; Discoid lateral meniscus; Magnetic resonance imaging; Outcomes.