Joint arthrodesis and arthroplasty

An implantable fixation system for fusing a joint between a first bone and a second bone. The system may include an intramedullary nail and an anchor. The intramedullary nail may include a standoff and a compression bolt. The system may be implanted across the joint along an intramedullary trajectory. The length of the system may be adjustable to provide compressive force between the anchor and the compression bolt. The system may be implanted across a tibiotalar joint with the anchor positioned in the sinus tarsi. A spacing member may be inserted between the two bones and the fixation system implanted to extend through an opening in the spacing member. The spacing member may be anatomically shaped and/or provide deformity correction. An ankle arthroplasty system may include a tibial plate, a talar plate, and a bearing insert. The plates may be anchored to the tibia and talus along a single trajectory. The ankle arthroplasty system may be revisable to a fusion system.