Long Term Results of Epiphyseal Transplant in Distal Radius Reconstruction in Children.

Abstract

Replacement of osseous defect, restoration of joint function, and restoration of longitudinal growth are the 3 main reconstructive issues that need to be addressed when the physis and epiphysis are damaged in a skeletally immature individual. Failure in achieving these objectives leads to severe deformity and functional impairment, which significantly compromises the quality of life of young patients. Because of its biological and morphological characteristics, the proximal fibula epiphyseal transfer has proven to be an excellent option in limb salvage surgery in pediatric oncologic cases meeting all the reconstructive requirements. Between 1992-2006, 8 children with a mean age of 7.3 years (range 4-11 years old) diagnosed with malignant bone tumor of the distal radius underwent tumor resection and immediate microsurgical reconstruction of the distal part of the radius with vascularized proximal fibular transfer, which included the physis and a variable length of the diaphysis. The anterior tibial vascular network supplied all of the grafts. One patient died to lung metastasis, 3.5 years after surgery; a second patient was lost at follow-up. The remaining 6 patients were periodically followed up both clinically, measuring range of motion, grip strength and the sensation of the hand, and by means of standard x rays, bone scan and CT scan. The mean follow-up was 13.2 years (range, 8-22 years). All the transfers survived and underwent fusion at the recipient site. In our experience the fibular growth expected after the transplant, ranges between 0.7 and 1.4 cm per year. In this series growth arrest occurred in only one patient after trauma. Serial radiographs and CT scans revealed progressive remodeling over time of the new articular surface. The functional result was rated as excellent in all but the one patient, in whom the distal portion of the ulna had to be resected because of tumor invasion. No major complication occurred at the recipient site. Peroneal nerve palsy occurred at the or site in 3 patients. The palsy was transient in 2 patients, but it persisted in one. No instability of the knee joint was observed. Our long-term results confirm that a vascularized transfer of the proximal fibula provides a reliable and durable reconstruction of the distal radius in children. Even after 22 years, the reconstructed joint resulted to be free of pain and degenerative changes thus maintaining a nearly normal range of motion. The described procedure is therefore highly recommended in case of distal radius reconstruction in growing children.