Objective: To investigate the impact of changes in the posterior tibial slope (PTS) in Oxford unicompartmental knee arthroplasty (OUKA) on the mid-term clinical outcomes of postoperative patients. Methods: This study was a follow-up study. The data of 135 patients (150 knees) who underwent OUKA at the China-Japan Friendship Hospital from January 2012 to January 2013 were analyzed retrospectively. The patients were followed-up for at least ten years. According to the changes in PTS of the medial tibial plateau before and after surgery, patients were divided into three groups: group A (PTS decreased by more than 5°), group B (PTS changed by 5° or less), and group C (PTS increased by more than 5°). The Knee Society Clinical Score (KSS-C), Knee Society Functional Score (KSS-F), Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and knee range of motion (ROM) among the three groups were compared at the last follow-up. Results: Prior to the final follow-up assessment, six patients expired, and an additional nine patients were lost to follow-up. A total of 120 patients (135 knees) were enrolled in this study (30 males and 90 females). The mean age was (66.29±8.62) years, and the follow-up time was (10.54±0.72) years. Group A consisted of 32 patients (34 knees), group B comprised 77 patients (90 knees), and group C included 11 patients (11 knees). One knee in group A suffered prosthesis loosening, and two knees in group C experienced postoperative bearing dislocation, one knee encountered bearing fragmentation. The incidence of postoperative complications differed significantly among the three groups (P<0.05). The preoperative OKS was (33.91±6.59) points, KSS-F was (43.46±8.99) points, KSS-C was (41.05±5.70) points and ROM was 115.23°±13.53°; after the surgery, they changed to (18.82±7.01) points, (81.51±7.34) points, (82.64±7.94) points, and 119.07°±8.62°, respectively, and all the differences were statistically significant (all P<0.001). In terms of postoperative outcomes, group A had an OKS of (21.44±8.46) points and a FJS of (63.83±11.40) points, group B had an OKS of (17.07±5.81) points and a FJS of (70.49±12.45) points, group C had an OKS of (25.09±5.07) points and a FJS score of (59.48±10.09) points; the differences among the three groups were all statistically significant (all P<0.05), but there were no significant differences in the postoperative KSS scores and ROM among the three groups (all P>0.05). Conclusions: After OUKA, better mid-term clinical outcomes are achieved when ΔPTS is<5°. Although the recommended central value for PTS in OUKA is 7° according to Oxford, it should be individualized, and it is recommended to consider the preoperative angle, with a change of less than 5° before and after surgery.
目的： 探讨Oxford膝关节单髁置换术（OUKA）胫骨后倾角（PTS）的变化对术后患者中期疗效的影响。 方法： 随访研究。回顾性分析2012年1月至2013年1月中日友好医院连续收治的135例（150膝）OUKA患者资料，随访至少10年时间。依据手术前后胫骨内侧平台PTS的变化值ΔPTS将患者分为3组：A组（后倾减小>5°）、B组（后倾变化≤5°）、C组（后倾增大>5°）。比较3组病例末次随访时膝关节学会临床评分（KSS-C）、膝关节学会功能评分（KSS-F）、牛津膝关节评分（OKS）、关节遗忘评分（FJS）及膝关节活动度（ROM）。 结果： 截至末次随访，6例患者死亡，9例患者失访，共纳入120例患者（135膝），男30例，女90例，年龄为（66.29±8.62）岁，随访时间为（10.54±0.72）年。其中，A组32例34膝，B组77例90膝，C组11例11膝。截至末次随访，A组1例出现假体松动，C组2例出现聚乙烯垫片脱位，1例出现垫片碎裂，3组并发症发生率差异有统计学意义（P<0.05）。术前OKS为（33.91±6.59）分，KSS-F为（43.46±8.99）分，KSS-C为（41.05±5.70）分，ROM为115.23°±13.53°，术后则分别为（18.82±7.01）分、（81.51±7.34）分、（82.64±7.94）分和119.07°±8.62°，差异均有统计学意义（均P<0.001）。术后A组OKS为（21.44±8.46）分，FJS为（63.83±11.40）分，B组分别为（17.07±5.81）分和（70.49±12.45）分，C组则分别为（25.09±5.07）分和（59.48±10.09）分，3组差异均有统计学意义（均P<0.05），但3组术后KSS评分、ROM差异均无统计学意义（均P>0.05）。 结论： OUKA手术前后，当ΔPTS<5°时，术后中期疗效更好，同时OUKA中PTS虽以Oxford推荐7°为中心，但要个体化，建议参考术前角度，手术前后变化最好不要超过5°。.