Meniscus Allograft Transplantation for Discoid Lateral Meniscus: Clinical Comparison Between Discoid Lateral Meniscus and Nondiscoid Lateral Meniscus

Purpose: This study was performed to compare the clinical results of meniscus allograft transplantation (MAT) after total meniscectomy in torn discoid lateral meniscus (DLM) and nondiscoid lateral meniscus (NLM). Methods: We conducted a retrospective study of 36 patients who underwent MAT. The discoid and nondiscoid groups consisted of 16 and 20 patients, respectively. The mean follow-up period was 32 months. We checked range of motion (ROM), visual analog scale (VAS) score, International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Tegner activity score for clinical evaluation; magnetic resonance imaging (MRI) was checked for objective evaluation. Results: The mean last follow-up VAS score, IKDC subjective score, Lysholm score, Tegner activity score, and subjective satisfaction of the patient were not significantly different between the discoid group and the nondiscoid group. The ROM of the discoid group was significantly decreased compared with that of the nondiscoid group (P <.05). Follow-up MRI was performed in 17 patients (9 from the discoid group and 8 from the nondiscoid group). Mean extrusion of the graft was 2.0 mm in the discoid group and 2.4 mm in the nondiscoid group (P = .344). Relative percentage of extrusion (RPE) was 22.8% in the discoid group and 22.7% in the nondiscoid group (P = .519). Conclusions: According to the minimal 2-year follow-up observations, MAT in patients with a torn discoid meniscus is an effective method for reducing the pain caused by meniscal deficiency and improving the function of the knee joint.