Functional outcome of double-bundle anterior cruciate ligament reconstruction

Abstract Background/Purpose The anterior cruciate ligament (ACL) is one of the most frequently injured ligaments in the knee joint and is generally treated by surgical reconstruction. A possible reason for the unsatisfactory nature of this reconstruction is that the complex function of the ACL is not reproduced by the traditional ACL reconstruction procedure, which replicates only a single bundle rather than the two separate bundles that form the original ACL. It has been suggested that re-establishment of the double-bundle anatomy of the ACL is crucial for obtaining a better restoration of the normal biomechanics of the knee and improving the knee's rotatory stability. The purpose of this study was to evaluate the authors' current double-bundle ACL reconstruction technique and assess the various functions of the anteromedial and posterolateral bundles. Methods Patients were assessed for instability and laxity after a mean follow-up of 16 months (range, 12–26 months). The range of motion was measured and compared with the opposite normal knee. Clinical evaluation was performed using the modified Lysholm scoring scale, the Tegner activity scale, and the International Knee Documentation Committee (IKDC) rating system. Results The study included 20 patients, 15 males and five females, with a mean age of 22.7 years (range, 18–29 years) at the time of surgery. Following the procedure described by Yasuda et al, double-bundle ACL reconstruction, which anatomically reproduces the anteromedial and posterolateral bundles using hamstring tendon grafts, was performed on patients under general anesthesia. The clinical results for the Lysholm rating system were good to excellent, being 71 points preoperatively and 94 postoperatively. The IKDC rating was 65% preoperatively and 92% postoperatively. All patients showed a negative pivot shifting test. Conclusion The ACL not only is the primary restraint on anterior tibial translation but also contributes considerably to normal knee kinematics. Our study showed that the four-tunnel double-bundle ACL reconstruction provides significant advantages in terms of anterior and rotational stability as well as objective IKDC. The subjective measurement of postoperative functional results using either the Lysholm or the IKDC rating system revealed a promising outcome after a short follow-up period.