非典型Wassel Ⅵ型复拇畸形的手术治疗

Treatment of atypical Wassel type VI thumb duplication

目的探讨儿童非典型WasselⅥ型复拇畸形的手术治疗方法。方法回顾性分析2008年5月至2012年3月收治的4例非典型Wassel Ⅵ型复拇畸形的临床资料。其中，男2例，女2例；年龄11个月～3．5岁，平均1．8岁；左侧3例，右侧1例。切除桡侧拇指，保留其掌骨，将发育不全的尺侧拇指的掌骨远端嫁接于桡侧拇指掌骨，交叉克氏针固定，大鱼际肌止点缝合于尺侧拇指近节指骨桡背侧，术后拇外展石膏托固定。骨折愈合后拔出克氏针，拇指外展弹性支具固定3个月。结果术中发现4例均存在尺侧拇指掌骨明显发育不良，近端缺如；桡侧拇指发育不良，指间关节尺偏，2例无屈曲功能。大鱼际肌均附着于桡侧拇指近节指骨基底桡侧。术后随访12-46个月，平均26个月。术后骨折愈合慢，于8～12周拔出克氏针。根据Tada等制定的标准评价：4例均为优。结论非典型Wassel Ⅵ型复拇畸形罕见，手术方法与Wassel Ⅵ型截然不同。掌骨嫁接和大鱼际肌止点移位是手术治疗的关键。

Objective To explore an effective treatment for atypical Wassel type VI thumb duplication. Methods Four pediatric cases of atypical Wassel type VI thumb duplication were studied retrospectively. There were 2 males and 2 females with an average age of 1.8 （11/12-3.5） years. Three cases were left-sided and one right-sided. During operation, after resection of radial digit, ulnar digit was transported to the top of radial metacarpal bone and fixed with pinning. And end point of thenar was shifted to the base of proximal phalanx. Fixation with plaster was applied and Kirschner wire removed after fracture healing. Brace was used for fixation and thumb abduction maintained for about 3 months. Results The intraoperative findings revealed that ulnar metacarpal-like bone was remarkably hypoplastic. Radial metacarpal-like bone was shorter than normal metacarpal and interphalangeal joint had ulnar deviation. Two patients had a lack of extensor tendon. The end point of thenar was attached to the base of radial proximal phalanx. All patients were followed up for an average of 26 （12-46） months. There was delayed metacarpal union and Kirschner wire was removed at 8-12 weeks. According to the Tada standard, all patients were excellent. Conclusions Atypical Wassel type VI thumb duplication is rare. And its treatment is completely different from that of Wassel type VI. Metacarpal bone transportation and end point of thenar shift are key points for the treatment of atypical Wassel type VI thumb duplication..