Clinical, radiologic and arthroscopic assessment and treatment of bilateral discoid lateral meniscus.

The purpose of the study is to evaluate clinical, radiologic and arthroscopic features of bilateral discoid lateral meniscus and to assess the outcome of arthroscopic meniscectomy. Among the 177 arthroscopies performed for discoid lateral meniscus between January 1993 and January 2004, 12 were bilateral. The clinical and radiologic evaluation was done from the records. The type of discoid meniscus, the type of tear was assessed arthroscopically. All patients underwent arthroscopic meniscectomy. Patients were followed up for a minimum period of 2 years. All patients had pain as presenting symptom. Eight patients presented with bilateral knee pain and four patients developed pain in the opposite knee after the affected knee was treated. The classically described thud was present in 11 knees. The widening of the joint space was found in 13 knee radiographs; 14 knees had complete type, nine had incomplete type and one had ring type of discoid lateral meniscus on arthroscopic evaluation; 20 knees involving 10 complete types, all incomplete types and ring type of discoid lateral meniscus showed obvious meniscal tears. The remaining four meniscus showed softening of a portion of the meniscus. Underlying intra-substance tear was visualized arthroscopically in the softened areas on saucerisation. All but one discoid menisci underwent arthroscopic partial central meniscectomy. When followed up for an average period of 32.6 months 19 knees showed excellent results and 5 knees good results. Possibility of bilaterality should be suspected in discoid lateral meniscus. Softening of meniscus denotes underlying intra-substance tear. This finding has not been described in the literature so far. Arthroscopic partial meniscectomy gives good results in symptomatic bilateral discoid meniscus. This to our knowledge is the largest series of bilateral discoid lateral menisci.