Analysis of Growth after Transphyseal Anterior Cruciate Ligament Reconstruction in Children

Background: Pediatric transphyseal anterior cruciate ligament reconstruction (ACLR) bears several advantages and is widely used. The main concern is the risk of growth disturbance. Our purpose was to investigate the incidence and risk factors of growth disturbance in skeletally immature patients who underwent transphyseal ACLR. We hypothesized that this procedure would generate neither clinically relevant limb length discrepancy (LLD) nor axis deviation. Methods: This prospective, consecutive, single-center series included skeletally immature patients who underwent primary transphyseal ACLR using semitendinosus tendon autograft, with a 2-year follow-up bone length standing radiograph of both lower limbs from pelvis to ankle in anterior posterior view. Lower limb length, mechanical axis deviation (MAD), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) were measured. The definition of postoperative growth disturbance was defined as ≥10 mm for LLD or ≥3 degrees for axis deviation in comparison to the contralateral lower limb. Predictive variables included age at surgery, gender, side, and diameter of bone tunnels. Student or Mann-Whitney test was used for numerical variables, and Chi-square test or Fisher exact test was used for categorical variables. P values <0.05 were considered statistically significant. Results: Fifty consecutively treated patients were included. Forty-seven patients (31 boys, 16 girls) with a mean age of 13.2 years (range, 9 to 16) at the time of surgery were available for analysis. Six patients had an LLD of at least 10 mm. Twenty-five patients had a difference in MPTA of a least 3 degrees (range, 5 to 8). Sixteen patients had a difference in LDFA of a least 3 degrees (range, 4 to 9). No patients presented with a clinical deformity or related symptoms. Regarding coronal alignment, there was no statistical difference in mechanical axis deviation, LDFA, or MPTA. Gender, side, age, and bone tunnel diameter did not influence growth disturbance. Conclusions: Transphyseal pediatric ACLR generated a high rate of growth disturbances (leg length discrepancy and axis deviation) although none clinically relevant. Mild proximal tibial axis deviation in patients operated on near skeletal maturity should be further investigated. Level of Evidence: Level III. Study design: Case-control study.