Various methods and apparatus for performing knee arthroplasty and unicondylar knee arthroplasty in particular, are known in the art. The known methods involve resection of the tibia and femur for fitting of trial tibial and femoral implants, respectively. Once the bone has been resected and the trial implants are secured in place, the surgeon then assesses the kinematics of the knee joint. At this stage, the surgeon may transect, elevate and/or release ligaments and other soft tissue structures to achieve the desired level of deformity correction, balance in the tension of relevant ones of the ligaments and other stabilising soft tissue structures, and an acceptable range of motion of the knee joint. Additional bone resection may also be required to achieve the desired outcome. This leads to an increase in operation time with an associated increase in the risk of surgery related complications. Moreover, such additional surgical intervention following fitting of the trial implants potentially leads to subsequent increased discomfort for the patient and increased healing times. Methods and apparatus for use in arthroplasty of a knee joint are exemplified in U.S. Pat. No. 5,171,244 and U.S. Pat. No. 5,520,695.