Objective: To investigate the clinical and imaging characteristics of distal tibiofibular synostosis in postoperative ankle fractures and its effects on the ankle mobility. Methods: The clinical and imaging data of 47 patients with distal tibiofibular synostosis treated surgically from October 1991 to June 2013 were analyzed retrospectively. There were 30 males and 17 females, aged from 15 to 68 years with a mean age of (39±13) years. The original fracture types, internal fixation profiles, imaging features of distal tibiofibular synostosis were recorded. Ankle range of motion (ROM) and complications at the last follow-up were also evaluated.The ROMs of healthy and fractured sides were compared with paired sample rank test. Results: The patients were followed up for 3 to 204 months (mean 25.4 months). Of the patients, 34(72.4%) were ankle fractures, 7(14.9%) were distal tibiofibular fractures, 1(2.1%) was tibiofibular shaft fracture, 2(4.3%) were tibial shaft fractures associated with lateral malleolus fracture and the resting 3(6.4%) were Pilon fractures. In patients with ankle fractures, 76.5%(26/34) of the synostosis occurred at the distal tibiofibular syndesmosis, while 23.5%(8/34) at the proximal of the tibiofibular sydesmosis; in patients with distal tibiofibular fracture, 85.7%(6/7) of the tibiofibular synostoses occurred at the fracture sites. The synostosis occurred at the level of syndesmotic screws in 8 patients (88.9%, 8/9) fixed with distal tibiofibular syndesmotic screws. And synostosis occurred at the sites of the distal locking screws in all (3/3) of the patients fixed with intramedullary nails. At the last follow-up, the active plantarflexion, active dorsiflexion and passive dorsiflexion in the affected side was 0°(0°, 5°), 2°(0°, 5°), 5°(0°, 10°) less than those in the healthy side, respectively (Z=-3.493, -4.491, -5.130, all P<0.05).During the follow-up, 4 patients complained of lateral ankle discomfort with no impact on daily life. Conclusions: Post-operative distal tibiofibular synostosis mainly occurs at the sites of fractures, distal tibiofibular syndesmotic screw sites and the sites of the distal locking screws of tibial intramedullary nails. ROM of the injured ankle decreases in comparison with that at the contralateral side, although no obvious symptoms are observed and no intervention needed.
目的： 探讨下肢骨折术后胫腓远端骨性连接的临床、影像学特点及其对踝关节活动度的影响。 方法： 对1991年10月至2013年6月北京积水潭医院收治的47例下肢骨折术后出现胫腓远端骨性连接患者的临床和影像学资料进行回顾性分析。其中男30例，女17例；年龄15~68岁，平均（39±13）岁。记录患者的原始骨折类型，内固定方式，胫腓远端骨性连接的影像学特点。此外，记录末次随访时踝关节的活动度及术后并发症。患侧和健侧踝关节活动度对比采用配对样本秩和检验。 结果： 47例患者，术后平均随访25.4个月（3~204个月），其中踝关节骨折34例（72.3%），胫腓骨远端骨折7例（14.9%），胫腓骨骨干骨折1例（2.1%），胫骨干骨折合并外踝骨折2例（4.3%），Pilon骨折3例（6.4%）。在踝关节骨折患者中，76.5%（26/34）胫腓间骨性连接发生在下胫腓联合部位，23.5%（8/34）在下胫腓联合近端；在胫腓骨远端骨折患者中，85.7%（6/7）骨性连接位于骨折线水平；在行下胫腓螺钉固定的患者中，88.9%（8/9）骨性连接位于下胫腓螺钉的置钉水平；在行胫骨髓内针固定的患者中，骨性连接均位于远端锁钉水平。末次随访时，与健侧相比，患侧踝关节活动度主动跖屈较健侧减小0°（0°, 5°），主动背伸减小2°（0°, 5°），被动背伸减小5°（0°, 10°），双侧差异均有统计学意义（Z=-3.493、-4.491、-5.130，均P<0.05）。随访期间，4例诉患侧踝部不适，但对日常生活无明显影响。 结论： 骨折术后胫腓远端骨性连接多发生在骨折线部位、下胫腓螺钉部位、胫骨髓内针远端锁钉部位。与健侧相比，患侧踝关节活动度下降，但不会引起明显症状和功能障碍，无需干预。.
Keywords: Ankle mobility; Distal tibiofibular synostosis; Radiographic characteristics.