Focal fibrocartilaginous dysplasia (FFCD) of the distal ulna is a rare benign lesion resulting in progressive radiocapitellar dislocation, limb deformity and limitation in function. This study reported our experience with 10 cases and it aimed to determine a reasonable strategy for diagnosis and treatment. Ten cases treated from 2010 to 2018 in our department were retrospectively reviewed. The diagnosis was based on imaging features. All patients underwent lesion excision in the early stage and five patients required ulna lengthening in the second stage. The radiographic and functional outcomes were analyzed and reported. The median age at diagnosis was 32 months (range, 6-36 months). The median age at the time of surgery was 34 months (range, 10-40 months). The median clinical and radiographic follow-up period was 37 months (range, 24-50 months). The ulna was shortened by an average of 31 mm (range, 27–35 mm). There was no new radial head dislocation after lesion excision. For five cases of radial head dislocation, the median elbow varus angle before ulnar lengthening was 20° and it decreased to 5° after ulnar lengthening. Supination and pronation of the elbow increased from 50°-10° to 70°-30°. We believe that early excision of the lesion can prevent radiocapitellar joint dislocation in patients with FFCD of the ulna. Ulna lengthening can correct limb deformity and improve the range of motion.

尺骨远端局灶性纤维软骨发育不良（FFCD）是一种罕见的良性病变，可导致进行性桡骨头脱位、肢体畸形和功能限制。本研究报告了我们对10例病例的经验，旨在确定合理的诊断和治疗策略。回顾性分析我科2010年至2018年收治的10例病例。诊断基于影像学特征。所有患者早期均接受病灶切除术，5例患者第二期需进行尺骨延长术。分析并报告放射学和功能结果。诊断时的中位年龄为 32 个月（范围 6-36 个月）。手术时的中位年龄为 34 个月（范围：10-40 个月）。中位临床和影像学随访期为 37 个月（范围 24-50 个月）。尺骨平均缩短 31 毫米（范围：27-35 毫米）。病灶切除后未出现新的桡骨头脱位。5例桡骨头脱位患者，尺骨延长前肘关节正中内翻角为20°，尺骨延长后降至5°。肘部的旋后和旋前从50°-10°增加到70°-30°。我们认为，早期切除病变可以预防尺骨 FFCD 患者的桡小头关节脱位。尺骨延长可以矫正肢体畸形并改善运动范围。