SALVAGE RESECTION-ARTHRODESIS OF THE KNEE JOINT FOLLOWING MEGAPROSTHETIC FAILURE USING MICROVASCULARIZED FIBULA

Introduction: Megaprosthetic failures around the knee and especially those who are infection-related are difficult to manage. Although most of these cases are effectively managed with a two-stage prosthetic revision, selected cases eventually require sacrifice of the knee joint. The authors present their experience with knee-arthrodesis using a vascularized fibula and allograft reinforcement. Materials and Methods: Between 1998 and 2002, eight patients with failed knee prosthesis were referred for resection-arthrodesis; all patients had at least two previous revision attempts using a spacer or a new implant. Knee-arthrodesis included resection of the distal femur and proximal tibia and reconstruction with a free micro-vascularized fibular graft and allograft reinforcement. Fibular grafts were harvested with a large musculocutaneous flap to facilitate soft-tissue coverage and monitor flap viability. Following surgery, patients were kept non-weight-bearing for 3 months. Radiographs were performed 6 and 12 weeks postoperatively to establish fibular graft incorporation. If healing had progressed satisfactorily, weight-bearing was gradually allowed. Results: At the most recent follow-up’ all eight patients had a stable and painless reconstruction, associated with radiological evidence of solid fibular graft union. The latter was typically observed between 6 to 12 weeks from surgery. Complications included one emergent surgery for anastamotic rupture in one patient and surgical debridement with skin grafting of musculocutaneous flap necrosis in another patient. Conclusions: Knee-arthrodesis using microvascularized fibula and allograft reinforcement is a safe and reliable salvage procedure in end-stage failures of megaprosthetic knee implants.