Sixty-six patients undergoing a total knee arthroplasty with anterior referenced Zimmer® NexGen® LPS prosthesis and ninety-one with posterior referenced Tornier® HLS Noetos® were divided into two groups according to the prosthetic model used and retrospectively compared. PCOR was calculated as the quotient of the distance between the posterior condylar border and the tangent to the posterior cortex of the femoral diaphysis, and the distance between the posterior condylar border and the tangent to the anterior cortex of the femoral diaphysis. PCOR was determined preoperatively and postoperatively and compared within each group and between both groups.
An increase in the PCOR (P < 0.0001) following surgery was observed in both anterior referencing and posterior referencing models. No difference was noted when the postoperative PCOR was compared between both groups (P = 0.61).
Both anterior and posterior referencing prosthesis lead to a similar increase of the PCOR following total knee arthroplasty.
Level IV.