Humeral lengthening and deformity correction with the multiaxial correction system

Limb lengthening for humeral length discrepancy is typically accomplished using a traditional monolateral external fixator frame or an Ilizarov-type device, which have distinct shortcomings for the correction of concomitant deformity and application to the upper extremity, respectively. A new monolateral frame, the multiaxial correction (MAC) system, provides advantage over other monolateral frames and Ilizarov-type devices for humeral lengthening and may achieve similar outcomes. The purpose of this study was to report on the use of the MAC system for limb lengthening in pediatric patients, each with humeral length discrepancy and deformity. Surgical technique for applying the frame to the humerus is described briefly. A retrospective review of all pediatric patients with humeral length discrepancy treated with the MAC system by one orthopedic surgeon at a major teaching hospital was performed. Clinical data, operative records, and radiographs were reviewed for each patient. A total of three humeri in three children were lengthened over a 3-year period. There were two girls and a boy, with a mean age of 10.3 ± 1.9 years. Etiologies for their discrepancies were osteomyelitis and posttraumatic physeal arrest. Mean initial humeral length discrepancy was 9.4 ± 2.3 cm. All patients had proximal varus deformities, which were partially corrected during treatment. Mean lengthening was 6.5 ± 0.8 cm, and mean healing index was 27.1 ± 4.1 days/cm. Mean follow-up was 23.0 ± 9.9 months. There were no major complications. In conclusion, the MAC system is well suited to the correction of humeral length discrepancies and associated humeral deformities in children. Level of evidence: level IV case series.