An Open-Source Apparatus for Standardized Static Biomechanical Testing of Hip Implants

This article presents the design, construction, and validation of an open-source apparatus for biomechanical testing of hip implants. The device enables controlled axial loading of implant constructs, addressing common limitations in terms of cost, complexity, and adaptability. The design emphasizes reproducibility, using widely available components and specimen-specific 3D-printed alignment tools, while ensuring high accuracy in load application and displacement measurement. The apparatus replicates physiological stance-phase loading (1.00× body weight (BW) axial, ~1.55× BW abductor, ~2.47× BW joint compression forces). The displacement values obtained by the validated finite element model and the Digital Image Correlation (DIC) technique on cadaveric specimens were compared and a mean displacement difference of 0.17 mm ± 0.09 mm was observed. Detailed build instructions and step-by-step operating protocols are provided, along with access to open-source CAD files. This work aims to facilitate broader access to customized biomechanical testing solutions for orthopedic research and education.