Discoid lateral meniscus: diagnosis and results of arthroscopic treatment.

We evaluated the results of arthroscopic meniscectomy in patients with discoid lateral menisci of the knee. Discoid lateral menisci were detected in 308 patients, of whom 197 (124 males, 73 females; mean age 34.5 years, range 6-67) were clinically, radiologically, and arthroscopically found to be symptomatic and underwent partial meniscectomy. The average period between injury and operation was 13.2 months (range 6-52). The results were evaluated according to the Ikeuchi and Lysholm criteria. The mean follow-up was 57.8 months (range 24-138). The most common complaints were pain (66%) and joint line tenderness (61%). Widening of lateral joint space was the most common radiological finding (25%). The confirmation of diagnosis by magnetic resonance imaging was not congruent with arthroscopic results for some patients (31%). According to the Ikeuchi criteria, the results were excellent in 110 patients (56%), good in 53 (27%), fair in 26 (13%), and poor in 8 (4%). On the other hand, according to the Lysholm scale, the results were excellent in 119 patients (60%), good in 57 patients (29%), fair in 16 (8%), and poor in five (3%) patients. Clinical and radiological findings were not congruent with arthroscopic results for all patients. Therefore arthroscopic evaluation has more value for discoid lateral meniscus. Moreover, tear pattern and degenerative changes in lateral compartment may effect outcomes without relation to the type of surgery. We concluded that arthroscopic partial meniscectomy should be the preferred method for the surgical treatment for discoid lateral menisci, due to it's minimal traumatic effects, possibilities of early mobilization, a lower complication rate, and easy and short rehabilitation period.