Endoprosthetic reconstruction using a custom-made metallic megaendoprosthesis is one of the common modalities for the limb salvage operation. The new promising advance of material science, design and fabrication of the endoprosthesis enable an immediate rehabilitation program and provide a durable and functional limb. Thus a successful limb reconstruction is possible in the well-selected patients. In addition to the endoprosthesis-related increased stress, a limited soft tissue support and constraint after limb salvage procedure usually results in an increased incidence of complications, especially in the long term survivors. Some patients may even need revision of the endoprosthesis and, at times, amputation. The complications after oncological endoprosthectic reconstructions usually occur more frequent than the conventional primary total joint arthroplasty. Considering the characteristics of the surgical procedure and the high demands on the implants, such a relatively high frequency of complications is not unexpected. The common complications include wound necrosis, aseptic loosening, fatigue fracture, local osteolysis, joint contracture, dislodgement/dislocation, nerve or vascular injury, rotational deformity, leg length discrepancy, infection, periprosthectic fracture, etc. Some complications are encountered with other modality of limb salvage procedure, whereas the other endoprosthesis-related complications are endoprosthetic-unique and not uncommon. The major causes of such a relatively high endoprosthesis-related complications include (1) extensive excision of soft tissue, leading to change of biomechanical ergonomics, little soft tissue constraints or support for a long replacement segments, and decreased local defense to infection, (2) increased stress on the implants due to higher activity level in the youthful active individuals, relatively narrower medullary canals with less cancellous bone for fixation, (3) special needs for the stability resulting an increased mechanical constraints placed directly within the endoprosthesis, thus raising the local stress transferred to the prosthesis, and to the prosthesis-bone interface, (4) poor immunological, hematological, or nutritional status resulting from chronic oncologic diseases or chemotherapy. It in turn accelerates the wear processes of the components, induces the wear particulate disease and local osteolysis, as well as to cause the aseptic loosening eventually. Early detection and early correction of minor complications has an important role of preventing the major complications, thus reduces the necessity of reoperation, and at times, amputation. We will review these complications in this article.
Intra-articular soft-tissue sarcoma of the knee: Is extra-articular resection and tumor endoprosthetic reconstruction the solution? A retrospective report on eight cases
