RECONSTRUCTION OF DIAPHYSIS

Reconstruction of the diaphysis (intercalary procedure) after tumor removal is achieved with bone grafts or prosthetic implants, or both (see Plates 6-31 and 6-32). Grafting alternatives include the use of conventional dual fibular autografts, bone allografts, and vascularized fibular autografts.

Fibular Bone Grafts. Fibular autografts, combined with intramedullary rod or plate fixation, offer good stabilization but are weaker than the normal bone. Bone allograft is even more readily available and can also be combined with intramedullary rod or plate fixation. However, the distal osteosynthesis site can be a problem in terms of healing of the allograft to the adjacent host bone.

Transplantation with a vascularized fibular graft with microscopic arterial and venous anastomoses is a complex procedure requiring significantly longer operating time than other bone grafting techniques. It offers the potential of a viable graft that has the ability to heal, remodel, and hypertrophy much more rapidly than a conventional fibular graft. Usually placed within the medullary canal, this type of graft requires rigid fixation.

Prosthetic Implant. A segmental diaphyseal defect may be reconstructed using a porous prosthetic implant inserted into the medullary canal (see Plate 6-31). This reconstructive option is generally used for low-demand and morbid patients who would not tolerate a larger, lengthier allograft procedure or who have decreased life expectancies.

PSEUDARTHROSIS

Reconstruction with a pseudarthrosis (flail joint) can be performed after a radical resection of the acetabulum or scapula. Although functionally inferior to a painless arthroplasty or arthrodesis, it is superior to an arthroplasty or arthrodesis complicated by instability, pain, and infection. A pseudarthrosis requires only soft tissue reconstruction. The resultant joint is excessively mobile and has less stability.