Obesity is linked to early tibial tray failure after primary total knee arthroplasty (TKA) for osteoarthritis (OA), especially in patients with preoperative varus. This study compared standard and stemmed tibiae TKAs in patients with class I and II obesity with varus deformity. Between April 2013 and June 2020, a prospective study was conducted including patients with end-stage OA, body mass index between 30 and 40 kg/m², and varus <15 degrees. Patients were randomly assigned to TKAs with either standard or long-stemmed tibiae and evaluated 5 years after surgery using the Knee Society Scoring (KSS). The knee society and modified radiographic evaluation systems were used for radiological evaluation. In total, 264 TKAs were performed in 264 patients (134 in the standard group and 130 in the stemmed group). The mean preoperative hip–knee–ankle angles for the standard and stemmed groups were 8.2 ± 3.2 degrees/varus and 9 ± 2.9 degrees/varus, respectively (p = 0.2), which improved to 5.1 ± 3 degrees/valgus and 5 ± 3.5 degrees/valgus after surgery (p = 0.52). There was no statistically significant difference between the objective KSS (92 vs. 92.9; p = 0.84) and the functioning KSS (73.4 vs. 74.8; p = 0.28). There were no aseptic loosening cases or radiographic differences. In-group analysis revealed significant outcomes differences in both groups if preoperative varus was >10 degrees irrespective of the stem design (p < 0.0001). Complications occurred in two patients; one with a late infection and one had a stem-related tibial fracture. Standard tibia TKAs yielded comparable results in obese patients to long-stemmed tibias. No aseptic tibial loosening was observed regardless of stem type, and worse clinical outcomes were associated with greater varus.

Clinical trial registry: registered at http://www.researchregistry.com (researchregistry5717).Level of Evidence II; a prospective randomized trial.

肥胖与骨关节炎 (OA) 初次全膝关节置换术 (TKA) 后早期胫骨托失效有关，尤其是术前内翻的患者。本研究比较了伴有内翻畸形的 I 级和 II 级肥胖患者的标准胫骨 TKA 和带柄胫骨 TKA。2013年4月至2020年6月期间，进行了一项前瞻性研究，纳入的患者为终末期骨关节炎、体重指数在30至40 kg/m ²之间、内翻<15度的患者。患者被随机分配接受标准胫骨或长柄胫骨的 TKA，并在术后 5 年使用膝关节协会评分 (KSS) 进行评估。膝关节协会和改良的放射学评估系统用于放射学评估。总共有 264 名患者接受了 264 次 TKA（标准组 134 名，干细胞治疗组 130 名）。标准组和带柄组的术前平均髋膝踝角度分别为 8.2 ± 3.2 度/内翻和 9 ± 2.9 度/内翻 ( p = 0.2)，改善至 5.1 ± 3 度/外翻和 5 ± 3.5 度/内 翻术后度数/外翻 ( p  = 0.52)。客观 KSS（92 vs. 92.9； p  = 0.84）和功能 KSS（73.4 vs. 74.8；p  = 0.28）之间没有统计学上的显着差异。没有无菌性松动病例或影像学差异。组内分析显示，如果术前内翻大于 10 度，则无论股骨柄设计如何，两组结果均存在显着差异 ( p  < 0.0001)。两名患者出现并发症；一名患有晚期感染，一名患有与干相关的胫骨骨折。标准胫骨 TKA 在肥胖患者中产生的结果与长柄胫骨相当。无论股骨柄类型如何，均未观察到无菌性胫骨松动，并且较差的临床结果与更大的内翻相关。

临床试验注册处： 注册于http://www.researchregistry.com(researchregistry5717)。证据级别II；一项前瞻性随机试验。