Summary

Anatomic refinement of triangle technique of double bundle MCL reconstruction improves knee stability close to the normal knee

Abstract

Background

Understanding anatomy of MCL (medial collateral ligament) and POL (posterior oblique ligament) has lead to refinement in tunnel position and attachments of both the bundles in double bundle MCL reconstruction technique using ipsilateral hamstring tendons. This “anatomic equivalent triangle technique” closely mimics the anatomic double bundle reconstruction technique; hence can improve the medial stability in reconstructed knees.

Hypothesis

The postoperative medial stability of the knee that underwent MCL reconstruction by this technique may not be significantly different from that of the noninjured knee.
STUDY DESIGN:
Case series; Level of evidence, 4.

Methods

A total of 25 patients with chronic combined ACL and MCL injuries were operated with ACL and MCL reconstruction at our institution between 2013 and 2015. Twenty two of the 25 patients were clinically evaluated at least 1 year after surgery. Opposite leg hamstring tendons were used for anatomic single bundle ACL reconstruction; whereas same side hamstrings were used for MCL reconstruction by 3 incision percutaneous approach similar to triangle configuration but in anatomic locations close to double bundle anatomic reconstruction.
A single femoral side tunnel was created at the center joining medial epicondyle and gastrocnemius tubercle and fixation was achieved by IntraFix (Mitek) to keep both the bundle of graft separated similar to the anatomic double bundle technique. For MCL, the distal hamstrings insertion was left intact on tibia and it was augmented with an anchor 12 mm distal to joint line. For POL, the tibial insertion was created in the posteromedial corner of tibia which was fixed with bioscrew with knee in extended position.
The International Knee Documentation Committee (IKDC) evaluation form and Lysholm score were used to evaluate postoperative knee function. Anteroposterior knee laxity was examined with a KT-2000 arthrometer. To assess objective medial instability, we performed a stress radiograph examination under valgus stress with the knee at 20° of flexion.

Results

At the final follow-up, 1 patient showed a loss of knee extension of more than 5°. Three patients revealed a loss of knee flexion of 6° to 15° and 1 patients of 16° to 25°. Lysholm scores averaged 95.2 points. In the IKDC evaluation, 10 patients were graded as A and 12 were graded as B. In the stress radiograph examination, the mean medial joint opening improved from 7.5 ± 1.6 mm in the preoperative stage to 1.1mm ± 0.8 mm at follow-up. There was no significant difference in the medial joint opening between reconstructed and intact knees.

Conclusion

Medial side reconstruction for chronic combined ACL-MCL deficient knees can be safely performed using ipsilateral hamstring tendon autografts with anatomic equivalent triangle technique, and the clinical outcome with a minimum 1-year follow-up was favorable with satisfactory stability.