Allograft and Autograft Transphyseal Anterior Cruciate Ligament Reconstruction in Skeletally Immature Patients: Outcomes and Complications

Abstract

The purpose of the study was to evaluate outcomes, graft failure rates, and complications after transphyseal soft-tissue allograft and autograft anterior cruciate ligament (ACL) reconstruction (ACLR) in patients with open growth plates. Twenty-nine skeletally immature athletes (30 knees) with a mean age of 13.9 years (range, 9 to 16 years) underwent transphyseal ACLR (22 with quadrupled hamstring autograft and 8 with tibialis anterior allograft). Of the patients, 5 were Tanner stage I, 17 were Tanner stage II, and 7 were Tanner stage III. Outcomes included KT-1000 (MEDmetric, San Diego, CA) measurements and International Knee Documentation Committee (IKDC), Cincinnati, and Lysholm scoring. Radiographs were evaluated for asymmetrical physeal closure, growth arrest lines, and knee alignment. The mean outcomes scores, excluding the 5 graft failures, were 91.8 points for the IKDC score, 93.0 points for the Cincinnati score, and 91.5 points for the Lysholm score at a mean of 4 years' follow-up (range, 24 to 84 months). The 95% confidence intervals for the differences were-27.7 to-18.0 for the IKDC score,-26.4 to-12.1 for the Cincinnati score, and-20.1 to-6.4 for the Lysholm score. One hundred percent of patients ultimately returned to their prior level of sports, but only 76% maintained that level at most recent follow-up. The mean KT-1000 side-to-side difference at most recent follow-up was 0.4 mm (SD, 1.3 mm; range,-2 to 3 mm) (n= 25). Evaluation at a minimum of 2 years postoperatively showed 4 patients with Harris growth arrest lines and 1 genu valgum deformity that spontaneously corrected at latest follow-up. For the remaining 29 knees, there was a mean side-to-side difference of 1.3° (range, 0° to 4°) in the radiographic tibiofemoral angle and 0.2 cm (range, 0 to 1 cm) for clinical leg-length measurements. Sports-related graft failure occurred at a mean of 24 months after ACLR in 16.7% of patients (37.5% with allografts [3 of 8] v 9% with autografts [2 of 22], P= .10). In 5 patients (16.7%), a contralateral ACL injury was sustained. Transphyseal ACLR in patients with open growth plates resulted in a high rate of return to sports with a low rate of growth arrest and deformity at a mean of 4 years' follow-up. Harris growth arrest lines and a case of genu valgum deformity that spontaneously corrected, however, were observed. Graft failure rates and contralateral ACL tears were not insignificant in this young patient population. Level IV, therapeutic case series.