Tibial Bone Transport with a Single Implant All-Internal Bone Transport Nail.

Abstract

A single implant all-internal magnet-driven bone transport (BT) intramedullary nail (BTN - NuVasive Specialized Orthopaedics, Inc.) has recently been introduced as a treatment method for segmental tibial bone defects. This innovation provides promise in the management of segmental bone defects as it negates numerous complications associated with circular external fixation and the need for multiple implants when considering hybrid plate assisted bone segment transport (PABST) constructs. Given the novelty of the BTN, description of the surgical application and patient outcome measures are scarce in the current literature. To date, we have treated four patients with an average age of 27 years (range: 19-44 years) using the BTN for segmental tibial defects ranging from 50-128 mm. We have accumulated data over an average follow up of 18.07 months (range: 12.96-25.13 months) demonstrating good patient tolerance of the device. Three patients successfully completed their treatment course with a calculated average bone healing index of 41.4 days/cm (range: 31.41-54.82 days/cm). One patient was noted to experience an asymptomatic docking site nonunion requiring subsequent surgery for nonunion repair. Implant-associated complications included symptomatic implant, axial malalignment, docking site nonunion, and External Remote Control technical malfunction. Injury-related complications were encountered and noted to include: superficial infection, wound dehiscence, peroneal tendonitis, and joint rigidity. In this study, the authors present a case series utilizing this implant to date and discuss our experiences with the BTN with reference to clinical indications, tibial bone preparation, BTN implantation, transport protocol, docking site procedure, and clinical/radiographic outcomes.