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Twenty-six comminuted distal femur fractures treated with a lateral condylar buttress plate were followed up until fracture union or implant revision (mean follow-up, 26 months). Mean postoperative angle (medial distal femoral angle immediately after surgery) was 96 degrees, and mean final angle (angle at fracture healing or implant revision) was 91 degrees (P = .06). Distal femoral angle decreased 5 degrees or less in 15 patients, 6 degrees to 10 degrees in 8 patients, and more than 10 degrees in 3 patients. Final distal femoral angle was 90 degrees or less in 13 of the 26 fractures: 38% of these 13 fractures required reconstruction for nonunion, malunion, or knee arthrosis. The lateral condylar buttress plate, which is not a fixed-angle device, allowed more than 5 degrees of varus collapse to occur in 42% of the comminuted distal femur fractures.

Radiographically distinguishable screws were centered 5 mm below the articular surface in the anterior and posterior halves of the tibial plateau in 8 fresh-frozen cadaveric knees. X-rays were taken with the knees in 0 degrees, 10 degrees, 20 degrees, 40 degrees, and 60 degrees of flexion. The screws were positioned relative to each other and to the articular surface. The posterior slope of the tibial plateau was measured from a lateral x-ray. Full extension of the knee caused the anterior screw to appear inaccurately placed--superior to the posterior screw in all 8 knees and intra-articular in 5 of these knees. In 6 cases, the screws appeared collinear and accurately subchondral on the x-ray taken with the knee in 10 degrees of flexion. In the other 2 cases, the screws were super-imposed on each other on the x-ray taken with the knee in 20 degrees of flexion. In all 8 cases, the knee's being in more than 20 degrees of flexion caused the anterior screw to inaccurately appear inferior to the posterior screw on x-ray. Anteroposterior x-rays assessing the position of screws or wires in the tibial plateau should be taken with the knee in 10 degrees of flexion, rarely in 20 degrees, to achieve accurate assessment. Radiographic evaluation of tibial plateau hardware with the knee in full extension or in more than 20 degrees of flexion will produce inaccurate results.