An adjustable humeral cutting guide for defining a cutting plane for a saw in a bone in which a positioning structure is located includes a clamp, a saw guide, and an orientable coupling. The clamp is configured to be secured to the positioning structure. The saw guide includes a slot formed therein sized to receive a saw and limit the saw to cutting in a specific plane. The orientable coupling is mounted to the clamp and the saw guide. The orientable coupling is configured to adjust the saw guide at a selectable anterior/posterior angle and a selected medial/lateral angle.