Characteristics of medial plica syndrome complicated with cartilage damage.

PURPOSE: This study was designed to evaluate the characteristics of patients with medial plica syndrome and associated cartilage damage.

METHODS: The study subjects included 44 patients with 57 knees arthroscopically diagnosed with medial plica syndrome. Subjects were divided into those with severe cartilage damage, defined as International Cartilage Research Society (ICRS) stage 2 or higher, and those with mild cartilage damage, defined as ICRS stage 1 or lower. Local findings, period from onset to surgery, arthroscopic findings, and postoperative results were compared in the two groups.

RESULTS: The shapes of the medial synovial plica were types C and D of the Sakakibara classification in the severe group, and types A, B, and C in the mild group. Patellar ballottement tended to be more common in the severe than in the mild group (P = 0.059). The duration from onset to surgery was significantly longer in the severe than in the mild group (29.0 vs. 11.6 months, P = 0.043). Postoperative results were significantly better in the mild than in the severe group (P = 0.0017).

CONCLUSIONS: The shape of the medial synovial plica and the duration between symptom onset and surgery were associated with cartilage damage. Surgical treatment should be considered when the medial synovial plica covers part of the anterior aspect of the medial femoral condyle or ruptures, or when pain persists over a long period, thus reducing the potential for cartilage damage.

LEVEL OF EVIDENCE: Level IV.