目的 探讨改良Chevron截骨术治疗拇外翻后对无症状扁平足的影响。 方法 回顾性分析2018年1月至2022年12月采用改良Chevron截骨术治疗拇外翻患者伴有或不伴有无症状扁平足的病例资料118例（120足），按Meary角将其分为无症状扁平足组49例（50足）和非扁平足组69例（70足），比较两组患者术前一般资料及术前与末次随访时获取的负重位足X线正位片距舟覆盖角（talonavicular coverage angle， TNCA）、距骨第二跖骨角（talus-second metatarsal angle，T2MT）、侧位片距骨第一跖骨角（Meary角）等影像资料的差异。 结果 两组患者术前一般资料比较差异无统计学意义（P > 0.05）。术前与末次随访影像资料组内比较：无症状扁平足组Meary角改善（P < 0.001），非扁平足组TNCA及T2MT均增加（P < 0.05）；组间比较：无症状扁平足组术前TNCA、T2MT及Meary角均差于非扁平足组（P < 0.05），末次随访TNCA、T2MT差异无统计学意义（P > 0.05），而无症状扁平足组Meary角仍明显低于非扁平足组（P < 0.05）。 结论 改良Chevron截骨对拇外翻伴有无症状扁平足患者的内侧纵弓改善明显，而对其外展改善较弱；对拇外翻不伴有扁平足患者的内侧纵弓无明显影响，但可引起其外展，而利于拇外翻的矫正。这表明改良Chevron截骨在矫正拇外翻的同时，对其无症状扁平足的足弓有一定的改善作用，不会加重扁平足。

Objective Investigation into the impact of modified Chevron osteotomy on asymptomatic flatfoot following hallux valgus correction. Methods A retrospective analysis was performed on 118 patients （120 feet） who underwent modified Chevron osteotomy for hallux valgus between January 2018 and December 2022. Based on the Meary angle， the patients were categorized into two groups： an asymptomatic flatfoot group （49 cases， 50 feet） and a non-flatfoot group （69 cases， 70 feet）. Preoperative general data and radiographic parameters were compared between the two groups at baseline and during the last follow-up. These parameters included the talonavicular coverage angle （TNCA）， talus-second metatarsal angle （T2MT） on weight-bearing anteroposterior foot radiographs， and the Meary angle on lateral radiographs. Results There were no significant differences in preoperative general data between the two groups （P > 0.05）. In the asymptomatic flatfoot group， the Meary angle demonstrated a improvement （P < 0.001） when comparing radiographic parameters intra-group between preoperation and the last follow-up. In the non-flatfoot group， TNCA and T2MT increased （P < 0.05）. Inter-group comparisons revealed that preoperatively， TNCA， T2MT， and the Meary angle were significantly worse in the asymptomatic flatfoot group compared to the non-flatfoot group （P < 0.05）. At the last follow-up， there were no significant differences in TNCA and T2MT between the two groups （P > 0.05）； however， the Meary angle remained significantly lower in the asymptomatic flatfoot group than in the non-flatfoot group （P < 0.05）. Conclusions The modified Chevron osteotomy significantly enhances the medial longitudinal arch in patients with hallux valgus and asymptomatic flatfoot， although its effect on correcting abduction is relatively limited. In patients with hallux valgus but without flatfoot， this procedure does not substantially alter the medial longitudinal arch； however， it can induce abduction， which aids in the correction of hallux valgus. This study confirms that the modified Chevron osteotomy effectively improves foot arch structure in asymptomatic flatfoot cases while addressing hallux valgus， without worsening the flatfoot condition.