Hip replacement surgery (hip arthroplasty) includes implantation of a distal stem into a femur of a patient, and implantation of a proximal body to connect to the distal stem. A practitioner uses a “trial” or “provisional” to determine a suitable size and configuration for the implantable proximal body, then selects a suitable proximal body from a set of differently sized and shaped proximal bodies. The trial adjusts discretely, as opposed to continuously, and has discrete settings that correspond to the sizes and configurations available in the set of implantable proximal bodies. In some examples, the trials are provided as a kit of parts, where each part in the kit is adjustable for height (i.e., the length of the femur). The parts in the kit can have different, fixed, values for offset (i.e., the lateral distance of the femur to the center of the femoral head in the acetabulum).