Cautious surgery for discoid menisci.

This retrospective study reviewed the outcomes of 43 knees in 38 patients with discoid menisci treated from 1977 to 1989. Patients underwent either no treatment, trimming, or subtotal or total resection. Approximately 40% of patients who underwent meniscectomy or partial meniscectomy had a fair or poor rating after an average follow-up of 6.5 years. Pathology demonstrating mucoid fibrinous degeneration within the discoid meniscus was found in many cases, showing abnormal meniscal tissue. Only one third of these knees had symptoms of locking, and only 20 (63%) of 32 had a positive arthrogram, demonstrating the diagnostic difficulties encountered with the discoid meniscus. Patients with a discoid meniscus who are symptomatic should undergo arthroscopy. A partial meniscectomy should be performed to achieve a smooth meniscus and a strong, stable peripheral rim.