43. LONG-TERM OUTCOMES FOLLOWING FREE VASCULARIZED FIBULA PHYSEAL TRANSFER FOR PROXIMAL HUMERUS ONCOLOGIC RECONSTRUCTION IN CHILDREN: AN INTERNATIONAL MULTI-INSTITUTIONAL STUDY

Abstract

PURPOSE: Vascularized fibula epiphyseal flap was first described in 1998 for proximal humeral reconstruction in children/infants. The authors aim to review their international, multi-institutional long-term outcomes. METHODS: An international, multi-institutional review (2004-2020) was conducted of patients <18 years of age undergoing free vascularized fibula epiphyseal transfer for proximal humeral reconstruction. Donor/recipient site complications, shoulder motion, pain, and final ambulatory status were reviewed. Growth of the transferred bone was assessed under the guidance of a pediatric musculoskeletal radiologist. RESULTS: Twenty-seven patients were included with a median age of 7 years (range 2-13 years). Average follow-up was 120 ± 87.4 months. There were two flap failures (7.4%). Recipient site complications included fracture (n=11, 40.7%), avascular necrosis of the fibula head (n=1, 3.7%), fibular head avulsion (n=1, 3.7%), infection (n=1, 3.7%), hardware failure (n=1, 3.7%). Operative fixation was necessary in one patient with a fracture. The case of infection necessitated fibula explantation 2 years post-operatively, and ultimately prosthetic reconstruction. Sixteen patients suffered peroneal nerve palsy (59.3%): thirteen of these cases resolved within a year (81% recovery), and 3 were permanent. One patient (3.7%) complained of upper extremity pain. Longitudinal growth was confirmed in all but 3 cases (n=24, 88.9%) at an average rate of 0.83 ± 0.25 cm/year. CONCLUSION: The vascularized fibula epiphysis for proximal humerus reconstruction in children preserves the potential for future growth and an articular surface for motion. Peroneal nerve palsy is common following harvest, although this is often transient. Future efforts should be geared towards reducing post-operative morbidity.