Discoid medial meniscus of both knees: A case report

BACKGROUND: Discoid meniscus is a congenital anomaly that typically affects the lateral meniscus. The appearance of the discoid medial meniscus in both knees is extremely rare, with an incidence of only 0.012%. CASE SUMMARY: Our patient was a 30-year-old female. Under no obvious predisposing causes, she began to experience pain in both knees, which worsened while walking and squatting. The pain was aggravated after exercise, and joint flexion and extension activities were accompanied by knee snapping. Apley’s test was positive on physical examination, and there was a pressing pain in the medial articular space. Plain radiographs of both knees revealed no obvious abnormalities in the bilateral knee joint space. Partial meniscectomy as well as menisci reformation were performed on both knees under arthroscopy. Under the guidance of rehabilitation, the patient’s range of motion in both knees returned to normal without pain and knee snapping. CONCLUSION: This study showed that the clinical manifestations of the discoid medial meniscus injury are identical to those of the conventional medial meniscus injury, and arthroscopic surgery is effective.