Optimal Design in Tumor Prostheses: Application of Extracortical Bone Bridging and Ingrowth Fixation Principle

Abstract

The utilization of custom-designed segmental bone and joint replacement prostheses in tumor surgery has been a viable option for quite some time [1–4]. However, the clinical results and prosthetic device performance still require improvements, especially in active patients with greater functional demands. The associated poor clinical results were mainly due to implant failure through fracture, loosening, dislocation, and infection. For conditions of massive bone defect, relatively smooth and straight cortex, and large bending torsional loads, traditional methods of implant fixation face a grim outlook in this class of bone and joint replacement. The lack of normal soft tissue coverage and constraint make the joint less stable, which contributes to poor functional results and increases the propensity of stem loosening. Other problems associated with custom prosthetic replacement include the lack of interchangeability, limited availability of the implant components at the time of surgery, improper size and dimension, length of time required for implant fabrication, and high cost.