Hemiarthroplasty, where one side of a joint is replaced, is a minimally invasive procedure. It allows for the preservation of native tissue, though a significant ramification is accelerated cartilage wear when articulating with high stiffness materials that do not mimic the mechanical stiffness of the native tissue. An implant that employs a lattice design can significantly lower the stiffness of a solid structure whilst maintaining strength. This study was conducted to investigate the effect of implementing a porous internal lattice structure with a thin outer shell on the articular contact mechanics, using a radial head hemiarthroplasty. It was hypothesized that a porous internal lattice structure would reduce the effective stiffness of the implant, thus increasing hemiarthroplasty contact area and reducing contact stress relative to a solid implant. A BCC lattice was used to create the porous core of the implant surrounded by a 0.5 mm solid outer shell and was fabricated using polyamide PA2200 as the surrogate material. The lattice porosity of the radial head constructs was modified by increasing the size of the internal strut diameter (i.e., 0.4, 0.6, and 0.9 mm). A cadaveric study was performed to compare the contact mechanics of a native radial head, mid-modulus solid implant, and 65, 74, and 80%, porous implants under uniform compression over a 6-minute testing period. Contact area and stress were quantified using a Tekscan sensor interposed at the articulation. It was found that an internal lattice design can reduce articular stresses of a solid implant by approximately 40 – 65%. Future studies should further investigate the efficacy of a porous internal lattice structure using varying lattice designs, implant materials, and loading conditions to validate the effects on articular contact mechanics of hemiarthroplasty implants and ability to withstand physiologic loading conditions.