Outcomes after anterior cruciate ligament reconstruction with versus without lateral extra‐articular tenodesis: A propensity‐matched cohort study

PURPOSE: Lateral extra-articular tenodesis (LET) has gained increasing use as an adjunct to anterior cruciate ligament reconstruction (ACLR) to improve rotational stability and reduce graft failure. However, concerns remain regarding its potential impact on postoperative morbidity and longer-term joint outcomes. This study aimed to compare postoperative complications, healthcare utilisation and osteoarthritis risk between patients undergoing isolated ACLR and ACLR with LET. METHODS: A retrospective cohort study was conducted using the TriNetX research network. Patients undergoing primary ACLR with or without LET were identified using CPT. After applying the exclusion criteria, 1:1 propensity score matching was performed, yielding 5021 patients per cohort. Early outcomes at 3 and 6 months included arthrofibrosis-related procedures, wound complications, opioid use, rehabilitation utilisation, emergency room visits and hospital readmissions. Short-term outcomes at 1-2 years included subsequent ACLR and meniscal surgery. Mid-term outcomes at 5 years included knee osteoarthritis. A young high-risk subgroup aged 12-25 years was analysed for 1- and 2-year outcomes. Odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. RESULTS: ACLR/LET was associated with higher odds of arthrofibrosis-related procedures at 3, 6 and 12 months, including at 1 year (3.4% vs. 2.1%; OR 1.65, 95% CI 1.29-2.11; p < 0.001). The LET cohort also had higher odds of wound complications and hospital readmissions at 3 and 6 months, with greater early opioid and rehabilitation utilisation. At 2 years, ACLR/LET was associated with higher hazards of arthrofibrosis-related procedures (HR 2.01; p < 0.001) and subsequent meniscal surgery (HR 1.25; p < 0.05), but not subsequent ACLR. ACLR/LET was also associated with higher hazards of ICD-coded knee osteoarthritis in the primary 5-year analysis (HR 2.24, 95% CI 1.76-2.85; p < 0.001) and the 1-year landmark analysis (HR 2.57; p < 0.001). In the young subgroup, ACLR/LET was associated with lower odds of subsequent ACLR at 1 year. CONCLUSIONS: In this propensity-matched retrospective study, ACLR with LET was associated with increased early postoperative morbidity, higher hazards of subsequent meniscal surgery and ICD-coded knee osteoarthritis, and no significant reduction in subsequent ACL reconstruction in the primary 2-year time-to-event analysis. Given the retrospective design and potential residual confounding by indication, these findings should be interpreted as associations rather than definitive causal effects of LET augmentation. These results highlight the importance of careful patient selection and counselling when considering LET during ACLR. LEVEL OF EVIDENCE: Level III.