Anterior cruciate ligament reconstruction in adolescents (Tanner stages 2 and 3)

Management of anterior cruciate ligament injuries in skeletally immature patients (in Tanner stages 2 and 3) is controversial. Conventional reconstruction used in adults can cause iatrogenic growth disturbance due to physeal damage, and studies that report long-term results using a specific technique are scarce. The aim of this study is to evaluate in a large series the mid- and long-term results of a partial transphyseal technique and define the safe percentage of lesions of the femoral growth plate.

Between 1989 and 2012, 42 adolescents at risk of growth disturbances (growth prediction of lower limbs >5 cm-Tanner 2, 3) underwent reconstruction of the anterior cruciate ligament using the semitendinosus and gracilis tendons. Growth characteristics of all the patients were assessed preoperatively, and the percentage of damage that would be produced in the femoral physis by the drilling of a 6-mm-diameter tunnel was determined. The technique used achieved graft fixation at both insertion sites, drilling the femoral physis and avoiding the tibial physis. We distinguished two groups: (a) long-term follow-up (mean 13 years 7 months, min 10.9, max 16.2) and (b) medium follow-up (mean 6 years 3 months, min 3.7, max 9.9). All knees were evaluated subjectively by history and objectively by KT2000 testing, and X-rays of both knees were compared for osteoarthritis using the Kellgren-Lawrence classification.

In group A (12 patients) one osteoarthritis grade 2, one instability, and ten good stability and function were observed. The mean KT2000 arthrometer values at 30 lb showed a difference of +2.4 mm (range 1-4 mm) between the operated and non-operated sides (p < 0.05). In group B (21 patients) no growth disturbance of the lower limbs, two failures (reinjury while participating in pivoting sports), and 19 good stability and function were observed. The mean KT2000 arthrometer values at 30 lb showed a difference of +1.9 mm (range 1-5 mm) between the operated and non-operated sides (p < 0.05). The average IKDC score of all the patients was 90 (min: 68, max: 97). None of the adolescents had consequences on growth after an eccentric damage passing tendons less than 7% on the frontal plane and of 1% on cross-sectional area of the femoral physis, and after an oblique tunnel passing 6-mm-diameter tendons of the tibial epiphyseal nucleus.

This study defines the possibility to perform a partial transphyseal intra-articular ACL reconstruction in patients in Tanner stages 2 and 3 that avoids tibial physis, involves the distal femoral physis, and produces good results at mid- and long-term follow-up without causing growth disturbances.

IV.