Summary
Early results from the New Zealand ACL Registry demonstrate lower revision rates when performing a combined ACL reconstruction using BTB or hamstring autograft with a lateral extra-articular procedure
Abstract
Introduction
The addition of a lateral extra-articular procedure (LEAP) in primary anterior cruciate ligament (ACL) reconstruction is one of the latest surgical techniques aimed to address rotational instability. Orthopaedic registries have made significant contributions to the improvement of patient outcomes through their ability to detect inferior results associated with specific surgical techniques. The aim of this study was to present the early results of combined ACL reconstruction with a LEAP from the New Zealand ACL Registry.
Methods
Prospective data recorded in the New Zealand ACL Registry were analyzed. Primary ACL reconstructions performed between May 2014 and June 2022 were included, allowing for a minimum follow-up of six months. Only cases using bone-patellar tendon-bone (BTB) or hamstring tendon autografts were analyzed. The primary outcome measure was revision ACL reconstruction. The secondary outcome measures included the Marx activity score and the Knee Injury Osteoarthritis Outcome Score (KOOS). Outcome analysis was stratified by graft type and compared between isolated ACL reconstruction (iACLR) versus combined ACL reconstruction with a LEAP (ACLR+LEAP). Statistical analysis was performed through a Chi-square test for binary outcomes and Mann-Whitney U test for continuous outcomes.
Results
A total of 13735 primary ACL reconstructions were analyzed in which 491 had a LEAP. In the BTB cohort (n = 3874), 3584 underwent iACLR and 290 underwent ACLR+LEAP. There were zero revisions in patients who underwent an ACLR+LEAP with a BTB autograft, compared to 96 revisions in patients who underwent iACLR with a BTB autograft (crude rate = 2.7%, 0.7 revisions per 100 person-years). In the hamstring tendon autograft cohort (n = 9861), 9660 underwent iACLR and 201 underwent ACLR+LEAP. Only 3 patients who underwent ACLR+LEAP with a hamstring tendon autograft underwent a revision (crude rate = 1.5%, 0.5 revisions per 100 person-years) when compared to 468 patients who underwent iACLR with a hamstring tendon autograft (crude rate 4.8%, 1.1 revisions per 100 person-years, p = 0.03). In both the BTB and hamstring cohorts, similar Marx activity scores (Figure 1, p>0.05) and KOOS scores (Figure 2 and 3, p>0.05) were reported at 2-year follow-up when comparing iACLR and ACLR+LEAP.
Discussion And Conclusion
Early data from the New Zealand ACL Registry demonstrates promising results with combined ACLR+LEAP. In the BTB cohort, there were no revisions in patients who underwent a combined ACLR+LEAP during the study period. In patients with a hamstring tendon autograft, the addition of a LEAP was associated with a lower revision rate. Similar PROM scores were reported at 2-year follow-up between iACLR and ACLR+LEAP.