Objective: To investigate the correlation between the first tarsometatarsal joint (TMT1) sagittal mobility and hallux valgus (HV) combined with transfer metatarsalgia (TM). Methods: The weight-bearing CT (WBCT) imaging data of 111 HV patients (167 feet) who were treated at the Foot and Ankle Surgery Center, Beijing Tongren Hospital Affiliated to Capital Medical University from January 2018 to January 2020 were retrospectively analyzed. The patients underwent PedCAT WBCT scans of both feet, and the hallux valgus angle (HVA), intermetatarsal angle (IMA), plantar distance (PD), medial cuneiform-first metatarsal angle (CMA) and metatarsal protrusion distance (MPD) were measured using CubeVue software. PD and CMA were signs of TMT1 instability. Visual analogue scale (VAS) and foot and ankle ability measures (FAAM) scores were obtained. The patients were divided into TM group and non-TM group according to the presence of metatarsalgia. The TM group and the non-TM group were compared in terms of HVA, IMA, PD, CMA, MPD, VAS and FAAM. Correlations between PD, CMA and HVA, IMA, VAS, FAAM were analyzed using Spearman correlation. Results: Total of 111 cases were included in this study, there were 35 males and 76 females with a mean age of (57.7±14.1) years. The average values of HVA (37.9°±8.6°), IMA (17.9°±2.6°), CMA (2.1°±0.3°) and PD [(1.8±0.4) mm] in TM group were all significantly higher than those in the non-TM group [HVA (32.5°±9.1°), IMA (15.1°±3.4°), CMA (1.7°±0.3°) and PD (1.6±0.2) mm] (All P<0.001). There was no significant difference in MPD between the two groups (P=0.580). The TM group demonstrated a higher VAS score when compared with the non-TM group (P<0.001). The FAAM score of the TM group (54.1±11.8) was significantly lower than that in the non-TM group (66.2±11.4) (P<0.001). The results of Spearman correlation analysis showed that there was no correlation between PD and HVA, IMA and VAS score. There was a negative correlation between PD, CMA and FAAM score, and the difference was statistically significant (rs=-0.637, -0.254, both P<0.001); CMA was positively correlated with HVA, IMA, and VAS score (rs=0.603, 0.971, 0.269, all P<0.001). Conclusions: WBCT is helpful for the diagnosis of TMT1 sagittal instability. The severity of TMT1 sagittal instability is positively correlated with hallux valgus and TM. The TMT1 instability may play an important role in the pathogenesis of hallux valgus.
目的： 探讨第一跖楔关节（TMT1）矢状不稳与拇外翻合并转移性跖骨痛（TM）的相关性。 方法： 回顾性分析2018年1月至2020年1月期间于首都医科大学附属北京同仁医院足踝外科中心就诊的111例拇外翻患者（167足）的负重CT影像学资料。患者接受PedCAT负重CT扫描双足，使用CubeVue软件测量拇外翻角（HVA）、第一、二跖骨间角（IMA）、跖骨抬高距离（PD）、内侧楔骨-第一跖骨关节面角（CMA）及跖骨突出距离（MPD），其中PD及CMA作为TMT1不稳的征象。对患者进行视觉模拟评分（VAS）及足踝功能测试（FAAM）评分。根据临床检查有无TM将患者分为TM组及非TM组，比较两组间HVA、IMA、PD、CMA、MPD、VAS及FAAM的差异。使用Spearman相关性分析PD、CMA和HVA、IMA、VAS及FAAM的相关性。 结果： 最终纳入111例患者（167足），其中男35例，女76例，年龄（57.7±14.1）岁。TM组中HVA（37.9°±8.6°）、IMA（17.9°±2.6°）、CMA（2.1°±0.3°）、PD［（1.8±0.4）mm］，均高于非TM组［HVA（32.5°±9.1°）、IMA（15.1°±3.4°）、CMA（1.7°±0.3°）、PD为（1.6±0.2）mm］（均P<0.001）。TM组及非TM组MPD差异无统计学意义（P=0.580）。TM组VAS评分高于非TM组（P<0.001）。TM组FAAM评分为（54.1±11.8）分，低于非TM组的（66.2±11.4）分（P<0.001）。Spearman相关分析显示，PD与HVA、IMA及VAS评分无相关性（均P>0.05）；PD、CMA与FAAM评分呈负相关（rs=-0.637、-0.254，均P<0.001）；CMA与HVA、IMA及VAS评分呈正相关（rs=0.603、0.971、0.269，均P<0.001）。 结论： 负重CT有助于TMT1矢状不稳的诊断，TMT1矢状不稳程度与拇外翻严重程度及TM具有相关性，TMT1不稳对拇外翻病理变化有重要作用。.