A method prepares an ankle joint of a patient for replacement. The patient includes a tibia (20) having a medial portion (22), a talus (40), and an ankle (10) having a medial portion. The method employs a cutting alignment apparatus (50) including a first portion external to the patient and a second portion, and surgically prepares and exposes the medial portion of the ankle for replacement. The second portion of the cutting alignment apparatus is coupled to the tibia, and a cutting guide (90) is disposed with respect to the cutting alignment apparatus. The medial portion of the tibia is detached, a portion of the tibia proximate the talus is cut, and a portion of the talus proximate the tibia is cut. An ankle prosthesis (100) is installed to the ankle, and the medial portion of the tibia is reattached.