Tunnel enlargement after arthroscopic anterior cruciate ligament reconstruction: comparison of bone-patellar tendon-bone and hamstring autografts.

Bone tunnel enlargement associated with anterior cruciate ligament (ACL) reconstruction has recently become a topic of interest in the literature. This association was examined, along with the effect of femoral and tibial tunnel enlargement on the clinical results of ACL reconstruction performed with either bone-patellar tendon-bone (BPTB) or hamstring (HST) autografts. Forty-six patients underwent arthroscopic ACL reconstruction (23 receiving BPTB autograft and 23 HST) between March 1999 and July 2001. Thirty patients (13 receiving BPTB autograft and 17 HST) completed the last clinical and radiologic evaluations and were included in the study. The mean age of patients in the HST group was 29.8 years (range 18-39) and that in the BPTB group was 27.6 years (range 20-37). The mean follow-up period was 24.6 months (range 12-36) in HST group and 18.5 months (range 12-40) in BPTB group. The effect of tunnel enlargement on the clinical results was evaluated by comparing preoperative and postoperative Lysholm, Tegner, and International Knee Documentation Committee scores and ligament laxity measurements between and within the groups. Postoperative femoral and tibial tunnel diameters in both groups were significantly larger than their corresponding preoperative tunnel diameters. In an intergroup evaluation, the enlargement of the tibial tunnel was similar in both groups (P=.556), but the femoral tunnel diameter was significantly larger in the HST group than in the BPTB group (P>.001). Preoperative laxity of the knees significantly improved after the operations in both groups, but no difference between the groups was evident at the final follow-up visit. No correlation between tunnel widening and the clinical results of the BPTB and HST procedures was observed.