Postoperative Radiographical Assessment of Prosthetic Replacement with Kotz Modular System

The radiographical assessment in 24 cases with endoprosthetic reconstruction after resection of bone and soft tissue tumors was reported according to the Rizzoli grading system and International Symposium of Limb Salvage (ISOLS) system. In roentgenographic changes, we made a comparison between Kotz modular femur and tibia reconstruction system (KMFTR) and Howmedica modular resection system (HMRS).The type of prosthesis did not significantly affect the pattern of bone remodelling and diaphyseal anchorage. On the ISOLS grading, the interface between the stem and bone was Fair or Poor in 20% at KMFTR and in 7% at HMRS. In addition, the average time of clear radiolucent line occurrence was later at HMRS than at KMFTR (KMFTR: 9.0 months, HMRS: 19.2 months). There was, however, no statistical significance in these results.HMRS was improved to address the problem of stress shielding. But our radiological results showed that it is not yet clear whether HMRS is the optimum prosthesis. Further experimental and clinical data are needed in order to improve results.