Abstract: A method for determining the transverse axis for flexion of a condylar ended bone comprises the steps of: conducting a computer tomographic (CT) scan from the end of the condyles inwardly, transverse to the transverse axis of the limb (or extremity) with the joint flexion plane facing forwardly. One then selects the CT slice image exhibiting maximum epicondylar width and establishes a line between the epicondyles at the widest extent. A line is then established joining the posterior condylar tangents on the CT image. Measured lines are established from the posterior condylar tangent line at right angles to the said line between said epicondyles; and then the transverse axis of motion as referenced from the transepicondylar line is obtained.