The effect of early motion on tibial tunnel widening after anterior cruciate ligament replacement using hamstring tendon grafts

Abstract

Purpose: The purpose of this study was to evaluate the hypothesis that early motion increases tibial tunnel enlargement in patients who underwent anterior cruciate ligament (ACL) replacement with hamstring autograft.

Type of study: Cohort analytic study.

Methods: All patients in this study had received a doubled semitendinous and gracilis graft. Grafts were secured in place with an implant-free technique. Two groups of patients were evaluated. Group A consisted of 35 patients who underwent isolated ACL replacement and whose rehabilitation protocol included early motion. Group B consisted of 20 patients who underwent combined arthroscopic meniscal repair and ACL replacement. Partial weight bearing and restriction of range of motion for 6 weeks was recommended for these patients. The only 2 variables between the groups were the meniscal repair and the postoperative rehabilitation. Patients were evaluated clinically and radiographically at 3, 6, and 12 months postoperatively. After correction for radiographic magnification, the tibial tunnel was measured at distal (T1), middle (T2), and proximal (T3) locations on both anteroposterior and lateral views.

Results: At 1-year follow-up evaluations, tunnel enlargement was significantly higher in the group with early motion, in both the anteroposterior and lateral views, in all but one location (anteroposterior, T1). The enlargement was greater in the mid-portion (T2) of the tunnel in both groups. The mean percentage was 45.92% for group A and 23.34% for group B ( P <.05) in the anteroposterior view, and 48.14% for group A and 24.47% for group B ( P <.05) in the lateral view. No correlation was found between tunnel enlargement and clinical results or between tunnel enlargement and joint laxity measured by a KT-1000 arthrometer.

Conclusions: Our study confirms that early motion increases the amount of tibial tunnel enlargement after anterior cruciate ligament replacement with hamstring autograft. This may have an impact on future rehabilitation protocols.

Level of evidence: Level II.