Abstract
We compare the postoperative outcomes and range of motion between NexGen LPS® and NexGen LPS-FLEX® knee prostheses. We operated on 27 knees of 20 patients, using LPS TKA and 21 knees of 15 patients using LPS-FLEX TKA, and compared their knee scores, and range of motion at one year postoperatively. The LPS group preoperative knee score was 10.9±10.4 (SD), versus 93.4±6.9 at one year postoperatively, and the LPS-FLEX group scored 26.0±12.8 (SD), versus 91.6±10.2 ±at one year postoperatively. The LPS group preoperative maximum flexion angle was 86.6±24.7 (SD) degrees, versus 120.0±12.3 degrees at one year postoperatively, and the LPS-FLEX group was 117.6±14.4 (SD) degrees, versus 130.2±13.4 (SD) degrees at one year postoperatively. The relative improvement in maximum flexion angle at one year postoperatively was 159.8±97.7% in LPS group, versus 111.3±5.2% in the LPS-F group. When we compared the cases with 110 degrees or more of flexion before operation (in the LPS group 6 knees (average=118.3± 9.8 degrees) and in the LPS-F group 18 knees (average= 122.5±8.6degrees) ), the postoperative flexion angle was 133.3±8.3 degrees in LPS group versus 134.2±9.1 degrees in the LPS-F group; the relative improvement was 113.2±9.0% in the LPS group, versus 109.8±7.6% in the LPS-F group. Among these cases of 110 degree or more of flexion before operation, there was no significant difference between the two groups in flexion angle at one year postoperatively. The cases which achieved 140 degrees or more of postoperative flexion angle were 1 knee in the LPS group, and 3 knees in the LPS-FLEX group.
