Background: The restoration of posterior femoral translation has
been shown to be an important factor in enhancing knee flexion after total
knee arthroplasty. The purpose of this study was to compare the ranges of
motion associated with standard and high-flexion posterior stabilized total
knee prostheses in patients managed with simultaneous bilateral total knee
Methods: Fifty patients (mean age, sixty-eight years) received a
standard fixed-bearing knee prosthesis in one knee and a high-flexion
fixed-bearing knee prosthesis in the contralateral knee. Two patients were
men, and forty-eight were women. At a mean of 2.1 years postoperatively, the
patients were assessed clinically and radiographically with use of the
knee-rating systems of the Knee Society and The Hospital for Special
Results: The mean postoperative Hospital for Special Surgery knee
score was 90 points for the knees treated with the standard fixed-bearing
prosthesis and 89.4 points for those treated with the high-flexion prosthesis.
At the time of the final follow-up, the knees with the standard prosthesis had
a mean range of motion of 135.8° (range, 105° to 150°) and those
with a high-flexion prosthesis had a mean range of motion of 138.6°
(range, 105° to 150°) (p = 0.41). No knee had aseptic loosening,
revision, or osteolysis.
Conclusions: After a minimum duration of follow-up of two years, we
found no significant differences between the groups with regard to range of
motion or clinical and radiographic parameters, except for posterior femoral
Level of Evidence: Therapeutic Level II. See Instructions
to Authors for a complete description of levels of evidence.