Four Risk Factors for Arthrofibrosis in Tibial Spine Fractures: A National 10-Site Multicenter Study.

BACKGROUND: Tibial spine fractures (TSFs) are relatively rare pediatric injuries. Postoperative arthrofibrosis remains the most common complication, with few studies having examined factors associated with its development. PURPOSE: To identify risk factors for arthrofibrosis and required MUA or lysis of adhesions in the largest known cohort of patients with TSFs. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This was a multicenter study of 249 patients ≤18 years old who had a TSF between January 2000 and February 2019. Patients were separated into cohorts based on whether they developed arthrofibrosis, defined as a 10° deficit in extension and/or 25° deficit in flexion at postoperative 3 months or a return to the operating room for manipulation under anesthesia (MUA) and/or lysis of adhesions. RESULTS: A total of 58 (23.3%) patients developed postoperative arthrofibrosis, with 19 (7.6%) requiring a return to the operating room for MUA. Patients with arthrofibrosis were younger (mean ± SD, 11.3 ± 2.7 vs 12.3 ± 2.8 years; P = .029). They were more likely to have a nonsport, trauma-related injury (65.4% vs 32.1%; P < .001) and a concomitant ACL injury (10.3% vs 1.1%; P = .003). Those with arthrofibrosis had longer operative times (135.0 vs 114.8 minutes; P = .006) and were more likely to have been immobilized in a cast postoperatively (30.4% vs 16.6%; P = .043). In multivariate regression, concomitant anterior cruciate ligament (ACL) injury (odds ratio [OR], 20.0; P = .001), traumatic injury (OR, 3.8; P < .001), age <10 years (OR, 2.2; P = .049), and cast immobilization (OR, 2.4; P = .047) remained significant predictors of arthrofibrosis. Concomitant ACL injury (OR, 7.5; P = .030) was additionally predictive of a required return to the operating room for MUA. CONCLUSION: Surgeons should be cognizant of arthrofibrosis risk in younger patients with concomitant ACL tears and traumatic injuries not resulting from athletics. Furthermore, postoperative immobilization in a cast should be avoided given the high risk of arthrofibrosis. Concomitant ACL injury is associated with a higher return to the operating room for MUA.