Assessment of tibiofemoral position in total knee arthroplasty using the active flexion lateral radiograph.

This study is a retrospective comparative cohort radiographic analysis of 114 consecutive patients who underwent posterior cruciate retaining (PCR) total knee arthroplasty (TKA), medial and patellofemoral compartment bicruciate retaining arthroplasty (BCR), or bicruciate substituting (BCS) TKA. In an effort to obtain a quantitative measurement of both anteroposterior (AP) tibiofemoral position and active knee flexion we have routinely taken post-operative lateral radiographs in a position of maximal active flexion. Passive range of motion (PRoM) after TKA was significantly greater than pre-operative passive range of motion for each cohort (p<0.