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° ± 4.76°; CR: 6.25° ± 3.13°; p = 0.001). The range of motion (ROM) (PS: 105.19° ± 15.56°; CR: 93.29° ± 15.09°; p = 0.001) as well as the deficit after six months (PS: 23.56° ± 19.73°; CR: 37.57° ± 23.33°; p = 0.003) between patients with PS and CR-TKA were significantly different. Gender (male vs. female PS/CR) and age (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: 31.03; p = 0.009) and WOMAC score (mean ranks: 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.

Background: Total hip arthroplasty (THA) is a widely performed procedure to alleviate pain and restore function in patients with advanced hip osteoarthritis. Despite extensive research, the question of sex disparities remains inconclusive, with studies showing comparable or different clinical outcomes. Methods: A prospective analysis was conducted on 167 patients who underwent total hip arthroplasty (THA) between 06/2022 and 06/2023 at a university hospital to analyses sex-specific outcomes. Demographic data, the mobility, the use of walking aids, pre- and postoperative range of motion, pain and the HHS (Harris Hip Score) after six months were collected and analysed. Data analyses were conducted with SPSS Version 29.0. Results: The mean age of the patients was 66.9 ± 10.5 with a percentage of women (w) of 60.5%. After six months the range of motion between the sexes was significantly different with more motion deficits for men (m). For example, women revealed a significantly greater total range of motion (ranks: 70.8 vs. 92.6; p = 0.001) with a higher degree (°) of hip flexion ((w) 103.0° ± 7.5° vs. (m) 98.2° ± 7.4°; p = 0.001) and internal rotation ((w)13.3° ± 6.8° vs. (m) 8.9° ± 6.6°, p = 0.001). The pain in both sides was significantly reduced six months after surgery (rest: 2.2 ± 0.9 vs. 0.6 ± 1.5; movement: 7.3 ± 1.1 vs. 1.6 ± 2.4; for both p = 0.001) but no sex difference could be found. The gait pattern and stair climbing ability were better in men ( p = 0.008; p = 0.037), but no significant differences in postoperative satisfaction or quality of life could be detected ( p = 0.671; p = 0.409). The combination of a stem with a low offset and cups larger than 55 mm showed better results in the Harris Hip Score (HHS) (mean: 86.9 ± 10.7 vs. 95.3 ± 4.0; p = 0.001), what can be considered an advantage for men. Conclusions: This study shows sex differences in the range of motion and mobility in everyday life. Although the female sex showed better mobility, no differences in satisfaction or quality of life were found six months after surgery. However, the combination of stem and cup size seems to have a relevant influence on postoperative outcome, especially in men.