To investigate to what extent the higher risk of tibiofemoral radiographic osteoarthritis (TFROA) in females vs. males can be explained by knee malalignment. Using data from Multicenter Osteoarthritis Study (MOST) and Osteoarthritis Initiative (OAI), we examined the relation of sex to the incident medial and lateral TFROA and performed mediation analyses to assess to what extent varus and valgus malalignments account for sex differences in the incident medial or lateral TFROA. Of the 3462 knees without medial and lateral TFROA in MOST, the 7-year risks of medial and lateral TFROA were 16.9% and 10.0% in females, and 15.8% and 4.2% in males, respectively. Females had 2.31-fold (95% confidence interval [95% CI]: 1.73 to 3.08) higher incident lateral TFROA than males, and the relative risk (RR) of the indirect effect of sex on lateral TFROA through valgus malalignment was 1.15 (95% CI: 1.09 to 1.20), accounting for 23% of its total effect on lateral TFROA. In OAI (n = 3095 knees), females had 1.54-fold (95% CI: 1.15 to 2.04) higher incident lateral TFROA than males, and RR of the indirect effect of sex on lateral TFROA through valgus malalignment was 1.10 (95% CI: 1.04 to 1.21), accounting for 26% of its total effect on lateral TFROA. No apparent sex difference in the incident medial TFROA was found in MOST (RR = 1.05, 95% CI: 0.89 to 1.25) or OAI (RR = 1.02, 95% CI: 0.84 to 1.19). Females had a higher risk of developing lateral TFROA than males; however, valgus malalignment only modestly explained such a difference.

中文翻译：

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排列不正对性别与胫股骨关节炎发病风险关系的中介作用


旨在调查女性与男性相比，胫股骨放射骨关节炎 (TFROA) 的风险较高在多大程度上可以用膝关节排列不良来解释。使用多中心骨关节炎研究 (MOST) 和骨关节炎倡议 (OAI) 的数据，我们检查了性别与事件内侧和外侧 TFROA 的关系，并进行中介分析，以评估内翻和外翻畸形在多大程度上解释了事件内侧的性别差异或横向 TFROA。在 MOST 的 3462 个没有内侧和外侧 TFROA 的膝关节中，女性 7 年内侧和外侧 TFROA 的风险分别为 16.9% 和 10.0%，男性为 15.8% 和 4.2%。女性的外侧 TFROA 发生率比男性高 2.31 倍（95% 置信区间 [95% CI]：1.73 至 3.08），并且性别通过外翻畸形对外侧 TFROA 产生间接影响的相对风险 (RR) 为 1.15 (95 % CI：1.09 至 1.20），占其对外侧 TFROA 总影响的 23%。在 OAI（n = 3095 膝）中，女性的外侧 TFROA 发生率比男性高 1.54 倍（95% CI：1.15 至 2.04），性别通过外翻畸形对外侧 TFROA 的间接影响的 RR 为 1.10（95% CI） ：1.04 至 1.21），占其对横向 TFROA 总影响的 26%。在 MOST（RR = 1.05，95% CI：0.89 至 1.25）或 OAI（RR = 1.02，95% CI：0.84 至 1.19）中未发现发生内侧 TFROA 的明显性别差异。女性患外侧 TFROA 的风险高于男性；然而，外翻畸形只能适度地解释这种差异。