Anterior cruciate ligament injury in the skeletally immature.

Although ACL injuries in truly skeletally immature patients are relatively uncommon events, they are experienced more frequently than initially reported--especially in the adolescent population. Natural history data is limited but appears to mirror the natural history in adults with this injury if return to high-risk activity is allowed. Treatment of this injury presents unique challenges because of the substantial growth that occurs through the distal femoral and proximal tibial physes. The physiologic skeletal maturity of the patient must be determined prior to deciding treatment. Techniques of reconstruction include physeal sparing, partial transphyseal, and transphyseal methods. Reconstruction is recommended for any patient with an "ACL +" knee (a complete ACL tear and concomitant meniscal injury) or one who is non-compliant with a nonoperative treatment program and develops symptoms of persistent instability. Short-term outcomes of functional return postreconstruction appear promising, but study numbers are small and follow-up times relatively brief in truly immature patients. Long-term outcome studies are still needed.