Promising short-term results following selective bundle reconstruction in partial anterior cruciate ligament tears.

BACKGROUND

The different functions of the two anterior cruciate ligament (ACL) bundles have increased interest in tears of only one of these two bundles. The purpose of this study was to assess the outcome of selective reconstruction of an injured bundle of isolated anteromedial bundle (AMB) or posterolateral bundle (PLB) tears.

METHODS

Consecutive series of 147 ACL reconstructions was prospectively analyzed. Patients with partial ACL tears who underwent selective bundle reconstructions were studied. Stability was assessed with the Lachman, anterior-drawer and pivot-shift tests and KT-1000. Functional assessment was performed with Lysholm and Tegner questionnaires. The preoperative MRI was analyzed to detect differences from arthroscopic findings.

RESULTS

Twenty-eight patients (19%) were included. The minimum follow-up period was 30months. Eighteen had AMB and 10 PLB tears. Only 19% of their MRI's were categorized as partial ACL tears. The Lysholm score improved from 66.1/65.5 to 96.6/95.2 in the AMB/PLB groups, respectively (p<0.001). The same or no more than one level lower Tegner score was restored. The pivot-shift, Lachman and anterior-drawer tests were negative in all cases (p<0.001). Two reconstructed AMBs developed extension loss due to Cyclops lesions and were resolved surgically.

CONCLUSIONS

The technique provided excellent functional scores with normalized stability and a return to previous level of activity with a low rate of minor complications at a minimum 2.5years' follow-up. Arthroscopic examination was the most reliable tool for properly diagnosing and treating a condition observed in almost one out of every five ACL reconstructed knee in this series.

LEVEL OF EVIDENCE

Therapeutic case series; level 4.