Five-year MRI follow-up of growth-related complications after ACL reconstruction in children and adolescents

Background: Growth-related complications are a concern in skeletally immature patients undergoing anterior cruciate ligament reconstruction (ACLR). Reported outcomes of growth disturbances following ACLR in this population are heterogeneous. Purpose: We hypothesized that transphyseal ACLR performed with a standardized technique results in mild radiological, but clinically non-significant growth disturbances. Methods: This single-center study prospectively enrolled 50 patients with open growth plates undergoing transphyseal ACLR. Magnetic resonance imaging of the operated knee was performed preoperatively and at 6, 12, 24, and 60 months postoperatively. Growth-related outcomes included tibial and femoral physeal-diaphyseal angles in coronal and sagittal planes, Harris growth arrest line deviation, focal physeal bone bridge formation, physeal violation by tunnels, skeletal maturity, and premature physeal closure. Growth disturbances were also evaluated clinically. Results: Sixteen patients completed the 60-month follow-up. Eighty-seven point five percent had reached skeletal maturity by then. Physeal–diaphyseal angles remained stable over time, with no significant differences between preoperative and 60-month measurements (medial tibial physeal angle, p -value = 0.20; lateral femoral physeal angle, p -value = 0.91; posterior tibial physeal angle, p -value = 0.16; posterior femoral physeal angle, p -value = 0.30). Angular deviations (≥ ±5°) were identified in 37.5% of cases, but were minimal (max −6° and + 5°) and clinically insignificant. Bone bridges were observed in three patients (18.8%) and resolved spontaneously. No premature physeal closure or Harris growth arrest line deviation was identified. Mean physeal violation was minimal. Significance of Study: This study supports the safety of transphyseal ACLR in skeletally immature patients. Conclusions: Transphyseal ACLR in skeletally immature patients appears to be associated with minimal physeal injury and a low risk of clinically relevant growth disturbances. Level of Evidence: IV, Retrospective case series of prospectively enrolled patients.