Fig. 1

Measurement of the posterior condylar offset (PCO, a) and posterior condylar offset ratio (PCOR, a/b) based on true lateral preoperative and postoperative knee radiographs. a distance in millimeters from the tangent of the femoral diaphysis posterior cortex to the posterior condylar margin; b distance in millimeters from the posterior condylar border to the tangent of the femoral diaphysis anterior cortex