부산대학교 도서관

Background Fixation of pathological long bones with telescopic intramedullary rods is well known to be a technically challenging procedure even in specialist centres, with a high complication rate due to rod migration, hardware failure, nonunion or malunion. However there is very little guidance in the literature regarding salvage treatment options when failure occurs. Aim We demonstrate a surgical technique that can be used for salvage treatment of both femoral and humeral complex nonunions following Fassier-Duval (FD) rodding in a child with osteogenesis imperfecta (OI). Case description A 13 year-old girl with OI type VIII presented sequentially with nonunion and deformity of the femur then the humerus following previous FD rods in those segments. The femur was also complicated with metallosis between the steel rod and an overlying titanium plate. Both segments were treated with pseudarthrosis debridement, removal of metalwork and stabilisation with hydroxyapatite (HA)-coated flexible intramedullary nails, with temporary Ilizarov frame to provide enough longitudinal and rotational stability to allow immediate weight-bearing. The femur Ilizarov frame was removed after 64 days, and the femur remained straight and fully healed at 2.5 years. The frame time for the humerus was 40 days, complete union was achieved and upper limb function restored and maintained at 9 months. Discussion The transphyseal telescopic rod is the traditional implant of choice in terms of treating fractures and stabilising osteotomies for deformity in OI. However, it does not provide enough torsional or longitudinal stability by itself to allow early weight-bearing which is detrimental to bone healing in this vulnerable patient group. The incidence of delayed union or nonunion at osteotomy site in telescopic rod application is not negligible: up to 14.5-51.5 %. Although the technique we have shown in this case may not be applied to all complex OI patients, we believe that the combination of flexible intramedullary nails and Ilizarov frame provides a favourable environment for bone healing in complex or revision cases. As a secondary learning point the initial revision surgery to the left femur demonstrated the perils of using a steel rod and a titanium plate in a biologically active environment which in this case lead to metallosis and lysis. Conclusion We found the technique of HA-coated flexible intramedullary nails combined with the Ilizarov frame effective in the salvage of failed telescopic rods in both femur and humerus and feel this technique can be used as a salvage option in similar cases worldwide. This case also demonstrates the perils of using different metals in combined internal fixation.