Intercalary Diaphyseal Endoprosthetic Reconstruction.

Intercalary endoprosthetic devices are a diaphyseal segmental reconstructive option for both primary tumors and skeletal metastases, most used for pathological fractures or failure of internal fixation. Numerous designs have been employed with varying success. These implants require adequate quality and length bone stock, both proximal and distal, to be employed. Alternative reconstructions may include vascularized fibula autograft, allograft reconstruction, acute shortening, and fixation with cement spacer augmentation with planning staged procedures. The reported functional results and complication profile of intercalary endoprostheses are acceptable, but their use is carefully considered, as aseptic loosening remains one of the most common risks for failure. Although successful at short follow-up, these devices are often used for patients with segmental destruction or tumor involvement of the upper extremity, particularly in cases with metastatic bone disease or myeloma. In this review, we discuss the numerous designs, indications and contraindications, alternative options, biomechanics, reported results, and complications.