Radiographic study of Kinematic total knee arthroplasty.

One thousand sixty-nine consecutive cemented Kinematic Condylar total knee arthroplasties performed by one group of orthopaedists were studied. The maximum follow-up period was 7 years. Most patients had rheumatoid arthritis or osteoarthritis, and the average patient age was 67 years (range, 12-90 years). Aseptic revisions for loosening were required for only one tibial component and six patella components. Average postoperative flexion was 2.5-107 degrees. The preoperative to postoperative change in range of flexion was not affected by the tilt angle of the tibial component in the sagittal plane. With the use of external alignment guides, the average postoperative alignment was ideal but the standard deviation was high; the standard deviation and the extremes were lower when intramedullary guides were used. There was a 14% incidence of femoral radiolucency and a 30% incidence of tibial radiolucency, which increased only slightly with time. Most radiolucencies on the tibial side were small and restricted to the extreme edges; rarely did radiolucency occur around the central peg. More than one half of the thicker radiolucencies occurred adjacent to wedge-shaped bone defects that were filled with cement.