Bone-Anchored Prosthesis Implant Connectors, Fail-Safe Mechanisms, and Alignment

Background To successfully manage the clinical prosthetic care of bone-anchored prosthesis (BAP) users, it is important to know about the associated connector and fail-safe mechanisms used to attach the distal prosthetic components to the implant system. Across the currently available BAP implant systems, each has a specific connector component with unique design differences. Additionally, the alignment of the prosthetic components, especially the prosthetic knee center, is an important clinical care consideration, which has influence on gait efficiency, stability, and potentially on longevity of the BAP implant-bone interface. Methods A review of published descriptions of the various BAP implant systems and their associated prosthesis adapter components was conducted. Clinical experience and consensus concerning the alignment considerations of BAP were summarized. Results 1. Implant System Adapters: The prosthesis connector and fail-safe mechanisms are presented for Osseointegrated Prostheses for the Rehabilitation of Amputees, Integral Leg Prosthesis, Osseointegration Prosthetic Limb, OTN, Compress, and Percutaneous Osseointegration Prosthesis implant systems. 2. Alignment: Methodologies for alignment of the prosthetic knee and other components in the frontal, sagittal, and transverse planes involve skeletal and implant system alignment and individual patient anthropometrics. Conclusions Each implant system involved has its own associated prosthetic connector and fail-safe mechanisms, which are important for clinicians to recognize and become familiar with in treating patients with BAP. Alignment of the distal prosthetic components involves similar principles as traditional socket-worn prostheses, with additional opportunities to optimize joint centers and sensitivity to even minor misalignment. Clinical Relevance Statement This article provides a descriptive and visual resource for clinicians to understand the various BAP implant systems and their associated connector and fail-safe mechanisms. With the additional clinical experience–based alignment considerations, this manuscript contributes to the growing knowledge base of BAP systems and clinical care.