Perioperative and Follow-Up Analyses of Primary Posterior Stabilized and Cruciate Retaining Knee Arthroplasty

Background: Total knee arthroplasty (TKA) is a widely performed procedure to alleviate pain and restore function in patients with advanced knee osteoarthritis. Two common implant designs are cruciate-retaining (CR) and posterior-stabilized (PS) knees. Despite extensive research, the superiority of one design over the other remains inconclusive. Methods: A prospective analysis was conducted on 123 patients who underwent total knee arthroplasty (TKA) between June 2022 and June 2023 at a university hospital. Demographic data, mobility, the use of walking aids, pre- and postoperative range of motion and leg axis as well as surgical and systemic complications were collected and compared between CR and PS-TKA. Results: The mean age of the patients was 67.94 +/- 10.14 years and 65.9% were women. The time of operation was significantly different between PS- and CR-TKA (PS: 83.31 +/- 25.65 min; CR: 95.26 +/- 24.61 min; p = 0.011). The pre- to postoperative leg axis after six months was significantly different in both groups (PS: 7.06 degrees +/- 4.76 degrees; CR: 6.25 degrees +/- 3.13 degrees; p = 0.001). The range of motion (ROM) (PS: 105.19 degrees +/- 15.56 degrees; CR: 93.29 degrees +/- 15.09 degrees; p = 0.001) as well as the deficit after six months (PS: 23.56 degrees +/- 19.73 degrees; CR: 37.57 degrees +/- 23.33 degrees; p = 0.003) between patients with PS and CR-TKA were significantly different. Gender (male vs. female PS/CR) and age (<75 years vs. >75 years PS/CR) differences were shown for the ROM and flexion deficit after six months (p = 0.003; p = 0.005). For age, a significant difference was shown for the quality of life (mean ranks: <75 y: 47.96; >75 y: 31.03; p = 0.009) and WOMAC score (mean ranks: <75 y: 38.27; >75 y: 61.75; p = 0.001) after six months. Conclusions: This study shows the different outcomes for posterior-stabilized versus cruciate-retaining TKA with regard to time of surgery, range of motion, and flexion deficit after 6 months with PS-TKA yielding better results. The gender analyses revealed similar outcomes after six months between both arthroplasty groups, whereas the age analyses revealed significant differences. The standardized use of PS-TKA for the elderly is recommended.