Summary

The combined ACL and ALL reconstruction in patients with hypermobility/knee hyperextension and ACL injury is an effective and safety solution and leads to good functional outcomes with no increase in complication rate

Abstract

Purpose

Hypermobility has been implicated as a contributing factor for ACL and
ACL graft injury in certain subpopulations. Recent studies have reported poor neuromuscular control and increased risk for ACL and ACL graft injury for patients with generalized hypermobility/joint laxity. The objective of this study is to evaluate the results of combined ACL and anterolateral ligament (ALL) reconstruction in patients with hypermobility/knee hyperextension and ACL injury. It was hypothesized that patients who underwent combined ACL and ALL reconstruction would exhibit less residual laxity and better clinical outcomes.

Methods

Two groups of patients were evaluated and compared retrospectively. Both groups consisted only of patients with hypermobility according to the Beighton criteria or more than 10 degrees of knee hyperextension. Patients in group 1 underwent anatomical intra-articular reconstruction of the ACL and patients in group 2 underwent anatomic intra-articular ACL reconstruction combined with ALL reconstruction. The presence of associated meniscal injury, ACL graft size, the subjective International Knee Documentation Committee (IKDC) and Lysholm functional outcome scores in the postoperative period, KT-1000 evaluation, the presence of residual pivot shift and graft rupture rate were evaluated.

Results

Ninety patients with hypermobility/knee hyperextension who underwent reconstruction of ACL injuries were evaluated. The mean follow-up was 29.6 +/- 6.2 months for group 1 and 28.1 +/- 4.2 months for group 2. There were no significant differences between groups regarding gender, duration of injury until reconstruction, follow-up time, ACL graft size or presence of associated meniscal injuries in the preoperative period. The mean age was 29.9 ± 8.1 years in group 1 and 27.0 ± 9.1 years in group 2 (p = 0.017). Regarding functional outcome scores, patients presented similar results on both the IKDC (84.3 +/- 9.8 vs 86.9 +/- 9.3; p = 0.46) and the Lysholm (86.3 +/- 7.8 vs 88.3 +/- 7.3; p = 0.41) evaluations. Patients in group 2 had better KT-1000 evaluation (2.3 +/- 1.4 vs 1.5 +/- 1.1; p = 0.02) and a lower pivot shift rate at physical examination, presenting 26.7% positivity versus 51.7% in the isolated ACL reconstruction (p = 0.02). Regarding re-ruptures, group 1 presented 13 (21.7%) cases, and group 2 presented one case (3.3%); p= 0.03.

Conclusion

The combined ACL and ALL reconstruction in patients with hypermobility/knee hyperextension is an effective and safety solution and leads to good functional outcomes with no increase in complication rate. The clinical relevance of this finding is the possibility to indicate this type of procedure when patients present with this condition.