Short-term Patient-Reported Outcomes After Primary Anterior Cruciate Ligament Reconstruction With and Without Lateral Extra-articular Tenodesis: A Matched-Cohort Analysis From the Swedish Knee Ligament Registry

Background: Despite reduced graft failure rates reported in randomized controlled trials comparing anterior cruciate ligament reconstruction (ACL-R) with and without lateral extra-articular tenodesis (LET), the impact of LET on postoperative patient-reported outcomes (PROs) remains poorly defined. Purpose: To compare short-term PROs, as well as anterior cruciate ligament (ACL) revision rates and clinical failure rates (defined as Knee injury and Osteoarthritis Outcome Score [KOOS] Quality of Life [QoL] value <44) between patients undergoing primary ACL-R with and without concomitant LET. Study Design: Cohort study; Level of evidence, 3. Methods: Data were extracted from the Swedish Knee Ligament Registry for all patients undergoing primary ACL-R between January 1, 2005, and June 25, 2025. Patients who underwent ACL-R + LET were matched to patients who underwent ACL-R without LET using 1:4 matching based on age, sex, body mass index, graft type, time from injury to reconstruction, and concomitant meniscal and cartilage injury status. The primary outcomes were KOOS values at the 1- and 2-year follow-ups. Secondary outcomes included revision ACL-R and clinical failure within 1 and 2 years. Categorical variables were compared using Fisher exact or chi-square tests, continuous variables were compared using Fisher nonparametric permutation tests, and within-group KOOS changes were compared using Wilcoxon signed-rank tests. Adjusted 1- and 2-year KOOS Symptoms comparisons for baseline differences and outcomes were interpreted relative to published minimal clinically important difference thresholds. Results: After matching, the final cohort consisted of 870 patients: 174 in the ACL-R + LET group and 696 in the ACL-R group. There were no significant between-group differences in KOOS 4 (mean of the Symptoms, Pain, Sports and Recreation, and QoL subscales) scores at the 1-year (77.7 ± 15.2 for ACL-R + LET vs 78.8 ± 14.9 for ACL-R) or 2-year (79.9 ± 16.7 for ACL-R + LET vs 80.7 ± 13.4 for ACL-) follow-up ( P > .5). Both groups demonstrated significant within-group improvements in KOOS 4 scores from baseline through the 2-year follow-up (all P ≤ .002). ACL revision rates at 2 years were 2.3% and 2.4% in the ACL-R + LET and ACL-R groups, respectively. Rates of clinical failure at 2 years were similar between groups (25.5% for ACL-R + LET vs 25.6% for ACL-R; P > .99). Conclusion: In this matched-cohort registry study, the addition of LET to primary ACL-R did not demonstrate superior short-term PROs at 1 or 2 years postsurgery.