Abstract
The authors evaluated the anterior-posterior radiographic assessment on weight bearing position at conventional extension, flexion of 15°, 30° and 45°in 18 patients (26 joints) with osteoarthritis of the knee. Their average age was 67 years (53-83 years), 6 men 12 women, average femoro-tibial angle of 179.5° (162-193°).
The joint widths in the middle and shortest portions of the medial joint were markedly narrower in flexion position at 15°, and significantly narrower at 30° than in the extension position.
The joint widths in the shortest portion of the lateral joint were significantly narrower in flexion positions at 30°, and 45°than in the extension position. However, there was no significant difference between flexion and extension in the middle portion of the lateral joint in the same position.
The differences in femoro-tibial angles between various flexed and extended knees in flexion at 15°was smaller than that at 30°and 45°.
The authors suggest that 15°of flexion was effective to assess narrowed joint spaces because patients with osteoarthritis mainly have varus deformity. Further evaluation of a comparative study of the view using flexion in a large number of cases is required.
