THE NATURAL-HISTORY OF MENISCAL TEARS IN ANTERIOR CRUCIATE LIGAMENT INSUFFICIENCY

We reviewed the meniscal status of 176 consecutive patients undergoing anterior cruciate ligament reconstruction acutely (less than 6 weeks from injury), subchronically (6 weeks to 12 months from injury), and chronically (more than 12 months from injury). The commonest tear was the single longitudinal vertical split of the medial meniscus. There was an increasing incidence of meniscal tears as the injury became more chronic, with a significant (P < 0.001) increase in medial meniscal tears; the incidence of lateral meniscal tears remained relatively constant. Seventy-five (43%) of the patients had one or both menisci repaired. Acutely, repair was performed more frequently on the medial meniscus than the lateral (80% versus 24%, respectively). All repaired menisci had single longitudinal tears unstable to probing. The incidence of repair dropped to 46% in the medial meniscus and 14% in the lateral meniscus in the chronic stage. Nineteen (25%) of these 75 patients (26 menisci) underwent a check arthroscopy at a minimum of 6 months from repair. All 21 medial menisci and all 5 lateral meniscal tears had healed; however, 1 lateral meniscus had torn along the line of the sutures. At an average followup of 40 months, 92% of the repaired menisci were still in situ and 8% that had required resection were related to the recurrence of anterior cruciate ligament instability. This study highlights the increasing incidence of meniscal injury in chronic anterior cruciate ligament insufficiency with the meniscal tears becoming more complex and therefore less amenable to suture. We recommend that patients with anterior cruciate ligament instability be investigated for repairable meniscal tears and that ligament stabilization of the knee and meniscal sutures be considered early.