Summary

In patients with combined ACL-MCL instability, simultaneous reconstruction of the ACL and MCL, with semitendinosus (ACL) and gracilis (MCL) autografts can significantly improve the stability and functional outcomes, without compromising range of motion.

Abstract

Background

In cases of combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries, non-operative treatment of the MCL lesion may lead to valgus instability, rotatory instability and/or failure of the reconstructed ACL. Several procedures for MCL reconstruction using a hamstring tendon graft have been reported, however, the use of gracilis tendon in isolation for a reconstruction, has not been described.

Purpose

To present a case series of 14 patients who underwent simultaneous ACL-MCL reconstruction using semitendinosus (ACL) and gracilis (MCL) autografts, with a 2- to 5-year follow-up.

Methods

14 patients underwent simultaneous ACL-MCL reconstruction for ACL-MCL injury and/or instability between Jan 2017 and June 2020. Both acute (<6 weeks) and chronic injury patterns were addressed with the same surgical procedure and meniscal lesions were treated in the same setting. Patients with additional ligament injuries, cartilage lesions and limb malalignment were excluded. Anatomic single bundle ACL reconstruction was done using a triplicate or quadrupled semitendinosus autograft. Anatomic MCL reconstruction was done using a gracilis autograft trying to recreate the superficial MCL (SMCL) and the posterior oblique ligament (POL) fibres. It was fixed on the femur and the distal tibia with an adjustable loop and on the proximal tibia with a suture anchor (SMCL) and a bio-interference screw (POL). All patients were available for follow-up for at least 2 years. The International Knee Documentation Committee (IKDC) evaluation form, Lysholm scores, valgus opening on stress radiographs, anterior drawer, and range of motion (ROM) were assessed both preoperatively and postoperatively.

Results

The postoperative medial knee opening (side-to-side difference) was significantly reduced to 2.7 ± 0.6 mm (range, 2.2 to 4.6 mm) compared with 8.0 ± 0.8 mm (range, 7.1 to 9 mm) preoperatively (p < 0.01). Preoperatively, a grade III anterior drawer was seen in all patients. 2 patients had a grade II drawer and none had grade III instability at the last follow-up. The mean IKDC subjective score improved overall from 48.4 ± 9.0 preoperatively to 85.7 ± 11.2 at the last follow-up (p < 0.01). Postoperative ROM (0-128*±6*) was not significantly different from preoperative ROM (0-134*±7*), excluding two patients. One patient had hyperextension of 12* before surgery, which she had regained at 2 year follow-up. One patient had a decrease in flexion range after surgery, preoperative ROM 0-126* to postoperative ROM 0-96* at last follow up.

Conclusion

In patients with combined ACL-MCL instability, simultaneous reconstruction of the ACL and MCL, with hamstring autografts can significantly improve the stability and functional outcomes, without compromising range of motion.