No increase in adverse events with lateral extra-articular tenodesis augmentation of anterior cruciate ligament reconstruction – Results from the stability randomized trial

OBJECTIVES: Results from the Stability Study suggest that adding a lateral extra-articular tenodesis (LET) to a hamstring tendon autograft reduces the rate of anterior cruciate ligament reconstruction (ACLR) failure in high-risk patients. The purpose of this study is to report adverse events over the 2-year follow-up period and compare groups (ACLR alone vs. ACLR + LET). METHODS: Stability is a randomized clinical trial comparing hamstring tendon ACLR with and without LET. Patients aged 14-25 years with an ACL deficient knee were included. Patients were followed and adverse events documented (type, actions taken, resolution) with visits at 3, 6, 12, and 24 months postoperatively. Adverse events were categorized as none, minor medical, minor surgical, contralateral ACL rupture, or graft rupture. Patient reported outcome measures (PROMs) collected at each visit included the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee Score (IKDC), and ACL Quality of Life Questionnaire (ACL-QOL). RESULTS: In total, 618 patients were randomized (mean age 18.9 years, 302 (49%) male). Forty-five patients (7%) suffered graft rupture; 34 (11%) in the ACLR group compared to 11 (4%) in the ACLR + LET group (RRR = 0.67, 95% CI 0.36 to 0.83, p < 0.001). There were no differences in effusion or infection rates between groups. The ACLR + LET group experienced an increased number of hardware removals (10 vs. 4). Overall, the rate of minor medical events (11%), minor surgical events (7%), and ipsilateral or contralateral ACL tears (10%) were low considering the high-risk patient profile. Increasing severity of adverse events was associated with lower PROMs at 24 months post-operative. Patients in the ACLR + LET group reported greater degree of pain at 3 months only. There were no clinically significant differences in range of motion between groups. CONCLUSIONS: The addition of LET to hamstring tendon autograft ACLR in young patients at high risk of re-injury resulted in a statistically significant reduction in graft rupture. While the addition of LET may increase rates of hardware irritation, there was no significant increase in overall rates of minor medical adverse events, minor surgical events, or overall re-operation rates. The concerns regarding complications associated with a LET did not materialize in this study. LEVEL OF EVIDENCE: Level I.