Range of motion of standard and high-flexion cruciate retaining total knee prostheses.

Recently, use of high-flexion design was introduced in cruciate-retaining (CR) total knee prostheses. The purpose of this study was to prospectively compare the ranges of motion (ROMs) of 89 knees with standard and 87 knees with high-flexion CR total knee prostheses. Differences in age, gender, diagnosis, preoperative ROM of the knee, and Knee Society Score between the 2 groups were not statistically significant. At 12-month follow-up, average ROM was 112.0 degrees +/- 12.6 degrees for standard, and 115.3 degrees +/- 13.4 degrees for high-flexion CR prosthesis (P = .101). To our knowledge, this is the first report on the ROM with the high-flexion CR total knee prosthesis. Using the technique of anterior referencing for femoral component sizing and using a fixed 7 degrees slope for the tibial component, we found no significant differences between groups with regard to ROM, clinical, or radiographic parameters.