Skeletal Maturity Is Associated With Increased Meniscal and Chondral Pathology in Patients Under 21 Years of Age Undergoing Primary Anterior Cruciate Ligament Reconstruction Within 6 Months of Injury

Purpose

To compare injury profiles of meniscal and/or chondral injury in skeletally mature (SM) with immature (SI) patients undergoing primary anterior cruciate ligament reconstruction (ACLR).

Methods

Current Procedural Terminology code 29888 was queried from January 2012 to April 2020. Patients younger than 22 years who underwent primary ACLR within 6 months of injury were included. Exclusion criteria included age older than 22 years, treatment after 6 months, revision ACLR, concurrent osteotomy, or multiligamentous injury. All patients required a minimum 1-year follow-up. Demographics and intraoperative pathology were recorded. Data were analyzed for factors affecting intra-articular injury and stratified by sport.

Results

Of 927 patients (739 SM, 188 SI), the mean age was 16.63 and 14.00 years for the SM and SI cohorts, respectively (P < .001). There were more SM males (51.4%) compared to SI males (81.9%) (P < .001); however, in univariate analysis, sex did not significantly affect the rates of meniscal (P = .519) or chondral injury (P = .961). In total, 887 meniscal injuries were recorded (344 medial, 543 lateral) in 659 patients. SM sustained greater rates of medial meniscal tear (MMT) (P < .001) and underwent higher rates of partial meniscectomy (P = .022). Male sex conferred meniscal injury (95% confidence interval [CI], 0.43-0.81; P = .001). Body mass index prognosticated medial meniscal (95% CI, 1.01-1.06; P = .002) and medial chondral injuries (95% CI, 1.02-1.09; P < .001). Skeletal maturity was a superior predictor of intra-articular pathology than age for all outcomes: MMT (95% CI, 0.00-0.06; P = .002), lateral meniscal tear (95% CI, 0.00-0.75; P = .034), and chondral injury (95% CI, 0.00-0.49; P = .049). In sport subanalysis, soccer anterior cruciate ligament (ACL) injuries were most common (32.6%). Soccer and basketball athletes were more likely SM (P = .016, P = .003 respectively) with increased medial compartment pathology. Football ACL injuries occurred significantly in SI athletes (P = .001) via contact mechanisms (P = .025).

Conclusions

Skeletal maturity affects the meniscal and chondral injury profile in ACL-injured patients. SM patients have greater risk of sustaining concomitant meniscal injury, while chondral injury profile depends more on the mechanism of injury. Mechanism of injury and skeletal maturity status affect risk of sports-related ACL rupture and ACL-concurrent pathology in young patients. Patient-specific variables influence injury profiles within each sport. Skeletal maturity rather than age predicts concomitant intra-articular injury risk.

Level of Evidence

Level III, retrospective cohort study.