Function and complications after endoprosthetic replacement of knee bone-forming tumors exposed to radiotherapy and multiagent chemotherapy

Abstract

We discuss analysis of function outcome and complications in 65 patients undergoing endoprosthetic knee replacement for osteosarcoma after radiotherapy and multiagent chemotherapy. Specifically, we found that multiagent chemotherapy caused a periprosthetic infection in 7.7% of cases. Major complications of radiotherapy included periprosthetic infection (27.3%), bone fracture at the site of endoprosthesis stem implantation (27.3%), aseptic loosening of stem (18.2%) and in 9.1% of patients a post-radiation skin ulcer was observed. Strategies for eliminating complications of periprosthetic infection included: removal of the endoprosthesis, installation of a metal-cement spacer followed by repeated joint endoprosthesis replacement. Then metal osteosynthesis was performed with cover plates and cable grip in case of bone fractures at the site of endoprosthesis stem implantation. A revision knee replacement surgery was performed in case of aseptic loosening of stem; removal of ulcer, removal of necrotic tissue, wound revision, and wound closure by means of muscle reposition with the subsequent free skin grafting was carried out during removal of postradiation ulcer. Hip amputation or disarticulation of the thigh was carried out in case of recurrence; multiagent chemotherapy with metastasioctomy was performed in case of metastases in lung.