Transphyseal anterior cruciate ligament reconstruction in adolescents with substantial remaining growth causes temporary growth arrest resulting in subclinical leg-length discrepancy

The purpose of the present study was to investigate the characteristics of growth disturbances in patients with remaining growth after transphyseal anterior cruciate ligament (ACL) reconstruction who were confirmed to have no definite postoperative physeal abnormalities on magnetic resonance imaging (MRI). Forty adolescents (mean age 15.6 ± 1.0 years [range 12.2–16.8], mean follow-up 2.7 ± 0.7 years [range 2.0–5.5 years]), who underwent transphyseal ACL reconstruction and were confirmed to have no focal physeal disruptions on follow-up MRIs 6 to 12 months after the operation, were retrospectively evaluated. The patients were grouped according to the leg-length growth of the uninjured side, measured on scanograms, obtained before surgery, and at the final follow-up. Leg-length discrepancies (LLD) at the last follow-up were greater in patients with leg growth ≥4 cm than in those with leg growth <4 cm (5.3 ± 9.0 mm vs −0.3 ± 4.2 mm, P = .033); however, no significant difference was observed between subgroup patients with leg growth of 4 to 6 cm or ≥6 cm (5.6 ± 10.4 mm vs 4.8 ± 7.0 mm, P = .958). On multivariate analysis, leg growth was a significant predictive factor for the final LLD (P = .030). Adolescents with additional leg-length growth after transphyseal ACL reconstructions presented with greater LLDs (as shown in the <4 cm vs ≥4 cm groups), but they also presented a ceiling effect (as shown in the 4–6 cm vs ≥6 cm subgroups). Transphyseal ACL reconstructions appeared to cause temporary growth arrest/disturbances in patients with substantial remaining growth which then resumed resulting in clinically insignificant LLDs.