Transepiphyseal Anterior Cruciate Ligament Reconstruction in Pediatric Patients: Surgical Technique

Abstract

The prevalence of anterior cruciate ligament (ACL) tears in children and adolescents is relatively low due to anatomic and biomechanical factors that predispose skeletally immature knees to bone injury rather than ligament tears.17 Nevertheless, ACL tears in this age group appear to be increasing.1,7,8,12,14-16,18 Management of these injuries presents a unique challenge; evidence in the literature indicates that the outcome of nonoperative treatment of ACL tears in skeletally immature patients is poor.1,9,11,14,15 Conversely, surgical intervention may cause iatrogenic physeal injury, which can result in leg-length discrepancy or angular deformity.6,11,13,14 Management decisions are complicated by deficiency in the basic science on physeal response to injury and by the limitations of the clinical studies that document surgical treatment for ACL insufficiency in children and adolescents. Despite these uncertainties, a rational approach based on current understanding of normal growth and development can be implemented.2-5 This article describes a technique for transepiphyseal reconstruction of the ACL using autogenous hamstring tendon grafts. The procedure adheres to the generally accepted principles of ACL replacement in adults, but theoretically minimizes the risk of physeal injury by not transgressing either the tibial or femoral physis. The decision as to whether to use this procedure to treat an ACL tear in a child or adolescent can be based on estimates of the relative risk of physeal injury (high, intermediate, or low), which can be determined by assessing the patient’s skeletal and physiological age. The consequences of iatrogenic physeal injury may be severe in children who have a great deal of growth remaining and insignificant in teenagers who have minimal growth remaining in the distal femur and proximal tibial physes. The central issue in treatment of ACL tears in the pediatric age group is the patient’s skeletal age, which determines the potential risk of injurious consequences. The most common method of estimating skeletal age is by comparing an anteroposterior radiograph of the patient’s left hand and wrist with the age-specific radiographs in the Greulich and Pyle Atlas.10 Physiological age can be classified according to Tanner’s staging of sexual maturation.19 Prepubescent patients are categorized in Tanner stages I and II of development, pubescent patients are in Tanner stage III, late pubescent in Tanner stage IV, and postpubescent patients are in Tanner stage V.3-5 The success of transepiphyseal ACL reconstruction, with meniscal repair, without evidence of growth disturbance, supports a recommendation for aggressive treatment of these injuries.2-5 Transepiphyseal replacement is recommended for prepubescent patients in Tanner stage I or II of development, including boys younger than 12 years and girls younger than 11 years; these patients are at high risk of growth disturbance if physeal injury occurs. Pubescent Tanner stage III patients, including boys 13 to 16 years of age and girls 12 to 14 years of age, are at intermediate risk. Transepiphyseal replacement is also recommended in early Tanner stage III patients because the threshold of safety for transphyseal drilling is currently unknown.