Partial Transphyseal Anterior Cruciate Ligament Reconstruction: Clinical, Functional, and Radiographic Outcomes

Abstract

Background: With a steadily increasing rate of anterior cruciate ligament (ACL) injury and reconstruction in the pediatric population, disagreement remains regarding the optimal reconstruction technique for patients with ACL injury and ≥2 years of growth remaining.

Purpose: This study aims to quantify the incidence of linear and angular growth disturbance of adolescents undergoing partial transphyseal ACL reconstruction (ACLR) while assessing graft failure rates, reoperation rates, and functional outcomes in the population.

Study design: Case series; Level of evidence, 4.

Methods: Consecutive patients undergoing partial transphyseal ACLR by 2 surgeons were retrospectively reviewed. Radiographic outcomes, including bilateral limb length, mechanical axis deviation (MAD), mechanical lateral distal femoral angle (MLDFA), and medial proximal tibial angle (MPTA), were measured on long standing anterior-posterior view radiographs postoperatively. Growth disturbance was defined as ≥1-cm leg length discrepancy, ≥1-cm difference in MAD, or 5° difference in MLDFA or MPTA as compared with the nonoperative side and as MAD, MLDFA, or MPTA outside the established range of reference values. Clinical outcomes, including graft failure and reoperation, were recorded at each follow-up visit. Pediatric International Knee Documentation Committee (Pedi-IKDC) scores were collected electronically after last follow-up.

Results: Twenty-four patients (mean ± SD age, 12.3 ± 0.9 years; 79.2% male) with a mean follow-up of 31.5 ± 17.1 months met inclusion criteria for the study. Overall postoperative growth disturbance incidence was 16.7% (4 of 24), but the incidence of growth disturbance was 66.7% (2 of 3) for those patients with >5 years of growth remaining. Seven patients (29.2%) required reoperation, most frequently for hardware removal. Two patients (8.3%) had graft failure with subsequent revision ACL reconstruction. One patient underwent bilateral medial distal femur hemiepiphysiodesis for genu valgum that was present before ACLR, but no other patients required guided growth procedures. In the subset of patients who completed a Pedi-IKDC questionnaire, the mean score was 94.8 ± 5.3.

Conclusion: Overall, partial transphyseal ACLR has good functional outcomes and graft failure and reoperation rates, comparable with those seen with transphyseal and all-epiphyseal techniques. While postoperative growth disturbance occurred in 16.7% of the cohort, the severity was mild and well tolerated without necessitating secondary procedures. There is a high rate of growth disturbance of patients with >5 years of growth remaining (66.7%). Partial transphyseal ACLR represents a valid recommendation for adolescent patients with ACL injury and ≤5 years of growth remaining.

Keywords: ACL reconstruction; adolescent ACL; pediatric ACL; physeal-sparing; transphyseal.