Empirical Assessment of Biocompatibility and Mechanical Properties of Locally Available Polymers for Low-Cost Prosthetic Socket Fabrication in Nigeria

Prosthetic socket fabrication in Nigeria relies predominantly on imported thermoplastic materials at costs that are prohibitive for most amputees, and evaluation of locally available and lower-cost polymers for prosthetic socket applications addresses a critical access barrier. This study empirically assesses the biocompatibility and mechanical properties of four locally available and importable low-cost polymer materials as candidate materials for prosthetic socket fabrication in Nigeria, comparing them against a polypropylene reference standard commonly used in orthopaedic applications. Materials assessed include high-density polyethylene, polyvinyl chloride, acrylonitrile butadiene styrene, and cross-linked low-density polyethylene, all sourced through Nigerian industrial polymer suppliers. Mechanical testing following ISO 10328 prosthetic component testing principles evaluated tensile strength, flexural modulus, impact resistance, and fatigue life under cyclic loading conditions simulating prosthetic socket use in a seventy-kilogram ambulating user. Biocompatibility assessment followed ISO 10993 guidance, including cytotoxicity testing using L929 murine fibroblast cell viability assay, skin sensitization assessment using the mouse ear swelling test equivalent, and extract preparation for systemic toxicity screening. Results show that HDPE and cross-linked LDPE demonstrated mechanical properties closest to the polypropylene reference standard, with adequate tensile strength and impact resistance. ABS showed superior flexural stiffness but significantly lower impact resistance, limiting its suitability for active users. Cytotoxicity and sensitization tests confirmed acceptable biocompatibility for all four materials after removal of manufacturing additives by solvent washing treatment. The study identifies cross-linked LDPE as the most promising locally available low-cost prosthetic socket material. Keywords: prosthetic socket, biocompatibility, mechanical properties, low-cost materials, Nigeria.