RESULTS OF MODULAR MEGAPROSTHESIS (LINK MEGASYSTEM C) IN TREATMENT OF METASTATIC DISEASE

Abstract

The treatment of bone metastases is usually palliative and aims to achieve adequate control of pain, to prevent and resolve compression of the cord in lesions of the spine and to anticipate or stabilise pathological fractures in the appendicular skeleton. In selected cases the complete resection of an isolated bone metastasis may improve the survival of the patient. During recent decades, the life expectancy of patients affected with metastatic carcinoma has improved considerably because of advances in chemotherapy, immunotherapy, hormonal treatment and radiotherapy. This improvement requires greater reliability in the reconstructive procedure in order to avoid mechanical failure during prolonged survival of the patient. The author experience with modular megaprosthesis by Link (megasystem C) allowed us to present a rapid, effective and functional solution.

From June 2001 to December 2007 225 patients have been operated with a megaprosthesis C for tumoral resection. The new megaprosthesis C by Link represents a wide-ranging system that can afford a large variety of reconstructions in the inferior limb, from very short replacement of 5 cm in proximal femur, to a total femur and proximal tibia replacement. Modularity is represented by 1 cm increase in length. The different options of cemented and not cemented stem may be used with intraoperative decision. In cemented stem a rough collar seals the osteotomy and prevents polyethylene debris from entering the femoral canal by inducing a scar tissue around the stem entrance (so-called purse-string effect). Moreover in patients with solitary lesions and very good prognosis an allograft-prosthesis composite can be performed with improved clinical results on walking and function. Of the 225 patients that underwent tumoral resection and reconstruction with a modular megaprosthesis approximately 43% (97 cases) were operated for metastatic disease. Among these cases 55 cases were proximal femoral recontructions, 39 cases were distal femoral reconstructions and 3 cases were proximal tibial reconstructions. All cases were performed with cemented stems. We experienced a 7% of postoperative infections, 2% of dislocations of proximal femoral prosthesis and 3% of mechanical failures. While infections and dislocation rates were in the average for this surgery, mechanical failures seemed relatively high. However in patients with relatively long resections and muscle deficiency the mechanical stress exerted on the prosthesis can explain this kind of mechanical failure.