Functional outcomes at mid-term follow-up after ACL reconstruction with lateral meniscus posterior root repair: comparison between radial tears and avulsions.

BACKGROUND: Lateral meniscus (LM) posterior root lesions are frequently associated with anterior cruciate ligament (ACL) injuries and may affect knee biomechanics. Although biomechanical differences between avulsion and radial tear patterns have been described, their clinical relevance remains unclear. This study aimed to determine whether lesion type influences functional outcomes and return to sport after ACL reconstruction with LM posterior root repair. HYPOTHESIS: No significant differences in postoperative functional outcomes were expected between lesion types. PATIENTS AND METHODS: A retrospective comparative study included 65 patients undergoing ACL reconstruction with associated LM posterior root repair. Thirty-one patients had avulsion-type lesions and 34 had radial tears. Functional outcomes were assessed at a mean follow-up of 51.0 months using IKDC, subjective knee value, ACL-RSI, and Tegner scores. Return-to-sport rates and levels were recorded. Multivariable linear regression analyses were performed to adjust for potential confounders. RESULTS: No significant differences in functional outcomes were observed between groups for IKDC (74.5 ± 14.1 vs 74.0 ± 15.4; p = 0.917), subjective knee value (86.5 ± 13.0 vs 89.0 ± 19.3; p = 0.127), ACL-RSI (76.5 ± 24.6 vs 77.7 ± 25.8; p = 0.776), or postoperative Tegner score (6.9 ± 2.5 vs 7.3 ± 2.3; p = 0.562). Return-to-sport rates were similar (83.9% vs 85.3%; p = 1.00). However, among patients who returned to sport, the distribution of return-to-sport level differed (p = 0.026), with a higher proportion of patients in the radial tear group returning to their pre-injury level. Multivariable analyses confirmed the absence of association between lesion type and functional outcomes. CONCLUSION: No statistically significant differences in mid-term patient-reported outcomes were observed between lesion types in this cohort after ACL reconstruction with LM posterior root repair. However, differences in return-to-sport level were identified and should be interpreted cautiously given the limited sample size. These findings should also be interpreted in light of the retrospective design and the absence of objective postoperative imaging and functional assessments. Further studies are required to determine whether clinically relevant differences exist between lesion types. LEVEL OF EVIDENCE: III; retrospective comparative study.