Hip arthroplasty trial systems and associated medical devices, methods, and kits

Hip arthroplasty trial systems (1, 100, 300, 500, 700) and associated medical devices (10, 110, 310, 510, 710), methods (200, 900, 1000), and kits (1100) are described that can be utilized in situ to complete a femoral head trial. An example embodiment of a hip arthroplasty trial system (1) includes a medical device (10) and a femoral stem (20). The medical device (10) has a head member (12), a spacer (14), a shaft (16), and a locking member (18). The spacer (14) is disposed within the head member (12) and is moveable from a first position to a second position. The shaft (16) is disposed within the head member (12) and contacts the femoral stem (20). The shaft (16) is moveable from a first position to a second position. Movement of the shaft (16) from the first position to the second position moves the spacer (14) from its first position to its second position. The locking member (18) is disposed within the head member (12) and releasably attaches the shaft (16) to the head member (12).