Summary

The most important finding of the present study was that there were no significant differences in the knee stability and clinical results after bicruciate reconstruction between those with and those without collateral ligament surgery. These results showed that reconstruction of bicruciate MLKIs with repair or reconstruction of associated collateral ligament injuries improves clinical outcomes.

Abstract

Introduction

Several procedures for combined rupture of both anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in multiple ligament knee injuries (MLKIs) have been reported. However, the clinical outcome of these treatments remains controversial. Biomechanical studies have established that injuries to the posteromedial corner (PMC) or the posterolateral corner (PLC) of the knee worsen the deleterious effects of tears in both cruciate ligaments. Based on the previous studies, the purpose of the present study is to evaluate clinical results of MLKIs undergoing simultaneous bicruciate reconstruction with an associated collateral ligament repair/reconstruction when needed. We have proposed the following hypothesis: postoperative knee stability and clinical outcomes that underwent simultaneous bicruciate reconstruction would be comparable to those that underwent bicruciate reconstruction with collateral ligament surgery.

Methods

A retrospective study was conducted with forty-one patients (41 knees) who sustained unilateral MLKIs with both combined ACL and PCL rupture. According to anatomic MLKI classification, MLK 2 and MLK 3 were enrolled in this study. Fifteen cases required both simultaneous ACL and PCL reconstruction, and the others had the following additional surgical treatment; At the time of cruciate ligament reconstruction, 14 of cases required posteromedial corner (PMC) reconstruction, 8 cases required posterolateral corner (PLC) reconstruction. 5 cases were treated with an initial PMC or PLC prior to the cruciate ligament reconstruction. One of these underwent PMC reconstruction at the 2nd stage for residual valgus laxity. Then, we divided the cases into two groups based on surgical procedures: In group I, 15 patients underwent only bicruciate reconstruction. In group II, 26 patients underwent bicruciate and PMC or PLC reconstruction/repair. The patients were examined at 2 years or more after surgery. Statistical analyses were made using the paired t-test, the Mann-Whitney U test and the Chi square test. The significance level was set at p=0.05.
RESULT:
The side-to-side difference in the total anteroposterior translation, and the relative position on the anterior and posterior stress radiographs significantly improved postoperatively in both groups (group I: p=0.0115, p=0.0007, group II: p=0.0004, p<0.0001). In the valgus and varus stress tests, the medial and lateral joint opening significantly improved postoperatively in group II (p<0.0001, p=0.0093). Anterior, posterior, valgus and varus stress radiographs showed no significant differences in comparison with that in the uninjured knee. There were no significant differences in the postoperative anteroposterior laxity, and the medial and lateral joint opening between the groups. The Lysholm score, the IKDC evaluation, all subscales of the KOOS, the Tegner score, and the isokinetic peak torque of quadriceps and hamstring muscles significantly improved postoperatively in both groups (p<0.0003). Each clinical parameter did not differ between the two groups. 3 patients who had acute intraarticular infections were treated by arthroscopic synovectomy within 2 weeks postoperatively and performed continuous irrigation treatment without the graft removal.

Discussion

The most important finding of the present study was that there were no significant differences in the postoperative knee stability and clinical outcomes between bicruciate reconstruction and bicruciate and collateral ligament reconstruction/repair groups. MLKI along with bicruciate ligament rupture (MLK 2 and MLK 3) can be safely performed using autografts. The Lysholm overall clinical scores were favorable, and the postoperative knee stability was found to be good without a loss of knee extension of more than 5°. These results showed that reconstruction of bicruciate MLKIs with repair or reconstruction of associated collateral ligament injuries improves clinical outcomes.