Re-alignment and intramedullary rodding of the humerus and forearm in children with osteogenesis imperfecta: revision rate and effect on fracture rate.

PURPOSE: Intramedullary rodding is indicated for patients with osteogenesis imperfecta (OI) to manage deformity and help treat recurrent fractures. Historically, the focus of intramedullary stabilisation has been the lower extremity. Here we report our experience of intramedullary rodding of the humerus and forearm in children with OI and its impact on the fracture rate of those bone segments.

PATIENTS AND METHODS: This is a retrospective chart review of all OI patients who have undergone re-alignment and intramedullary rodding of the humerus or forearm between October 1994 and February 2016. Patient demographics, surgical information, complications and pre-operative and post-operative fracture rates were gathered.

RESULTS: A total of 45 upper extremity segments (26 humeri, 19 forearms) were rodded at an average age of 8.7 years (3.1 to 19.2). Of these, 15 (33.3%) of the bone segments required a return to the operating room at a mean 30.8 months (1 to 90) post-operatively. Fracture data was available for 24 of the bone segments. The average number of pre-operative and post-operative fractures was 3.58 (SD 2.84) and 0.46 (SD 0.72) respectively. The average pre-operative and post-operative fracture rates were 0.87 fractures/year (SD 0.47) and 0.10 fractures/year (SD 0.16) respectively.

CONCLUSION: In this OI population, re-alignment and rodding appeared to reduce the fracture rate of the humerus and forearm. Among our population, one third returned to the operating room and one fifth required revision to a new intramedullary implant. This data may help families better understand the potential outcomes of upper extremity realignment and rodding and its effect on the rate of upper extremity fractures.