RESUMEN
Objective To explore the indication and the functional advantages of the high-flexion posterior stabilized (PS) rotating-platform mobile-bearing (RP-MB) total knee system. Methods A prospective randomized, controlled trial was performed. Osteoarthritis was the indicators for total knee arthroplasty.From Feb. 2009 to Apr. 2009, 75 patients (94 knees) were randomly assigned to to receive either a highflexion PS, RP-MB total knee system(PFC sigma RPF) or a standard one (PFC sigma RP). There were no statistical difference in the baselines, the preoperative scores of the Hospital for Special Surgery (HSS) and the knee range of motion (ROM) of both groups. The functional status were assessed with Hospital for Special Surgery and the ROM of the knee at the postoperative 1, 6, 12, 18 months. The satisfaction rates were assessed at the postoperative 18 months. The radiographic measurements were t assessed at the postoperative 3days and 3, 6, 12, 18 months. Results A total of 70 participants (87 knees) completed the 18-month followup. At the time of the final follow-up, the average Hospital for Special Surgery knee score was 92.4±5.0points in the standard group and 94.7±7.0 points in the high-flex ion group. The difference was not statistically significant(P ＞0.05). The average maximal flexion was 131.9±14 degrees in the high-flexion group and 123.0±15.3 degrees in the standard group. There was a statistical difference. But it was not enough to confirm our hypothesis that the difference should be higher than 10 degrees. Moreover, the satisfaction rate were 100% in both groups, and no statistical significant difference was found. Conclusion No significant differences were found between standard and high-flexion posterior-stabilized rotating-platform mobile-bearing total knee prostheses in terms of clinical outcomes or range of motion.