Reconstruction of the anterior cruciate ligament alone in the treatment of a combined instability with complete rupture of the medial collateral ligament. A prospective study.

In a prospective study, 14 patients with a complete rupture of both the anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) were treated by reconstruction of the ACL alone. The torn MCL was not addressed. The initial instability was documented clinically and by stress radiographs (20 kp) taken under anaesthesia. The postoperative management involved immediate mobilization and partial weight bearing for 6-8 weeks. Follow-up examination at an average of 14 months demonstrated excellent results in 11 cases, good in 2 cases, and fair in 1 case. With the exception of one residual anterior tibial translation of 8 mm, all knees showed almost normal stability in the frontal and sagittal plane, with full range of motion. These result confirm that ACL reconstruction utilizing the patellar tendon alone is sufficient in the treatment of combined instability due to ACL and MCL injuries.