Transfemoral Prosthetic Socket Production in Sierra Leone

Introduction: Prosthetic devices are life-improving for individuals with TF amputations, but their accessibility often relies on the expertise of prosthetists and is limited in LMICs. Current study addressed the need to reduce the operator dependency by streamlining the TF hybrid socket manufacturing workflow. This was achieved by developing a data-supported standardized hybrid brim set and a simplified method to measure the distal stump volume and digitally design the distal socket part. Method: This developmental study consisted of three phases. In Phase 1, an analysis of existing hybrid brim dimensions was conducted, focusing on brim characteristics like the distance between the center of the tuber support and the lateral wall (approximated skeletal ML distance) in relation to its circumference. This analysis aimed to identify any correlations between the circumference of the brim and other important brim dimensions, to define a scaling procedure. Phase 2 covered the development of a data-supported brim set based on the scaling procedure of Phase 1, and Phase 3 focused on the establishment of a simplified method to measure distal stump volume used for digital socket design and was finalized with TF socket fitting. Results: Phase 1 included 13 hybrid brims and revealed a correlation (p=0.0003, R2 = 0.717) between the brim circumference and the approximated skeletal ML dimension which functioned as the foundation for the scaling procedure applied in Phase 2 to develop the data-supported brim set. Promising brim fitting results were yielded on 8 (5 males) participants with room for improvement on the medial and anterior trimlines. Phase 3 successfully developed a simplified method to measure distal stump volume, and digitally transform these into a distal socket design. Valuable insights were obtained regarding the shape of the socket design during the full TF socket fitting on 2 (1 male) participants. Discussion: The TF socket workflow was streamlined with a data-supported brim set and a simplified method to measure distal stump volume that relies on just a few measurements, eliminating the need for locating specific anatomical landmarks. Limitations included a small brim dataset and limited generalizability to LMIC populations. Further research should involve diverse population and consider additional factors influencing socket effectiveness by going through the full rehabilitation process. In addition, the data-supported brim set can be further enhanced by analyzing more brim shapes in relation to user characteristics. The study's clinical relevance lies in its potential to implement the TF socket workflow in automated software, reducing operator dependency and increasing accessibility, especially in LMICs.