2017 年 36 巻 4 号 p. 435-439
Objective: We have developed a posterior-stabilized (PS) total knee prosthesis designed for Japanese patients (ACTIYAS®, Kyocera Medical, Japan), and started clinical trials from 2010. Herein we report our two-year results of ACTIYAS® compared with those of the NexGen® LPS-Flex (Zimmer Biomet, USA), another high-flexion PS prosthesis, which is the most popular prosthesis.
Methods: All cases requiring primary total knee arthroplasty (TKA) were due to osteoarthritis (OA). Patients with rheumatoid arthritis were excluded from this study. The group receiving the ACTIYAS® prosthesis (group A) consisted of 94 cases (141 knees), with a mean age of 76 years, and with surgery performed from November 2010 to August 2012 inclusive. The group receiving the NexGen® LPS-Flex (group B) consisted of 82 cases (120 knees), with a mean age 75 years, who underwent surgery from January 2007 to December 2008, inclusive. We evaluated the groups’ Knee Society Scores (KSS), the range of motion (ROM) preoperatively, on the day of discharge, 3, 6, 12, and 24 months postoperatively. Knee satisfaction level and hospitalization period were also evaluated.
Result: KSS at one year postoperatively was significantly improved compared with the preoperative score in both group A and B, respectively. The ROM change in group A was −4.6/125, −6/108, −4.2/118, −3.0/122, −2.3/124, and−1.9/126, while in group B it was −5.2/127, −5.5/112, −3.1/122, −2.3/124, −1.0/128, and−1.1/128, preoperatively, on the day of discharge, postoperatively at 3, 6, 12, and 24 months, respectively. Though the ROM of group B at 12 month was better than that of group A, there was no significant difference regarding KSS at each period between the two groups. Group A had a significantly higher level of knee satisfaction (85.4 points) than group B (80.6 points), respectively (P<0.01). There was a shortened hospitalization period in group A (22.9 days) than in group B (25.3 days), respectively (P<0.01).
Conclusion: ACTIYAS® achieved better patient satisfaction and was associated with a shorter hospital stay compared to the LPS-Flex posterior-stabilized total knee prosthesis.
