Park Kun Bo, Park Hui Wan, Lee Ki Seok, Joo Sun Young, Kim Hyun Woo
Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea.
J Bone Joint Surg Am. 2008 Aug;90(8):1712-21. doi: 10.2106/JBJS.G.00792.
Calcaneal lengthening osteotomy and extra-articular arthrodesis of the subtalar joint are two methods used for the correction of valgus deformity of the heel and forefoot abduction. The purpose of this study was to compare the operative results of these procedures in patients with cerebral palsy who were able to walk. We focused primarily on changes in radiographic parameters and how altered mobility of the subtalar joint by the two operative methods would modify pressure distribution over the plantar surface of the foot.
A total of eighty-one feet in forty-seven patients were included in the study. The mean age at the time of surgery was eight years and one month, and the mean follow-up period was thirty-nine months. The subjects were divided into two groups; Group I consisted of thirty-seven feet in twenty-two patients who underwent a calcaneal lengthening osteotomy, and Group II comprised forty-four feet in twenty-five patients who underwent an extra-articular subtalar arthrodesis. Preoperative and final follow-up radiographs and dynamic pedobarographs were used to evaluate the results.
The feet in both groups were found to be similarly deformed before surgery, by radiographic measurements and dynamic foot-pressure analysis. Both operative procedures led to improved radiographic indices; however, calcaneal pitch failed to improve after the subtalar arthrodesis. After surgery, the relative vertical impulse was decreased for the hallux, first metatarsal head, and medial aspect of the midfoot in both groups, while it was increased for the lateral aspect of the midfoot and calcaneus. On the other hand, postoperatively, the relative vertical impulse of the medial aspect of the midfoot was higher and the relative vertical impulse of the first through fourth metatarsal heads was lower in the group that had subtalar arthrodesis compared with the group that had a calcaneal lengthening osteotomy and the normal control subjects.
Extra-articular subtalar arthrodesis appears to be an effective means to achieve predictable correction of severe valgus deformity of the heel in patients with cerebral palsy who are able to walk; however, supination deformity of the forefoot remains and calcaneal equinus is not corrected. On the other hand, we believe that the calcaneal lengthening osteotomy is the treatment of choice because postoperative foot-pressure distribution more closely approximates the normal foot-pressure distribution.
跟骨延长截骨术和距下关节外关节融合术是用于矫正足跟外翻畸形和前足外展的两种方法。本研究的目的是比较这两种手术方法在能够行走的脑瘫患者中的手术效果。我们主要关注影像学参数的变化以及两种手术方法引起的距下关节活动度改变如何影响足底表面的压力分布。
本研究共纳入47例患者的81只足。手术时的平均年龄为8岁1个月，平均随访期为39个月。受试者分为两组；第一组包括22例患者的37只足，接受了跟骨延长截骨术，第二组包括25例患者的44只足，接受了距下关节外关节融合术。术前和末次随访的X线片及动态足底压力仪用于评估结果。
通过影像学测量和动态足压分析发现，两组足在术前的畸形程度相似。两种手术方法均使影像学指标得到改善；然而，距下关节融合术后跟骨倾斜度未改善。术后，两组的拇趾、第一跖骨头和足中部内侧的相对垂直冲量均降低，而足中部外侧和跟骨的相对垂直冲量增加。另一方面，与跟骨延长截骨术组和正常对照组相比，距下关节融合术组术后足中部内侧的相对垂直冲量较高，第一至第四跖骨头的相对垂直冲量较低。
距下关节外关节融合术似乎是一种有效的方法，可使能够行走的脑瘫患者足跟严重外翻畸形得到可预测的矫正；然而，前足旋后畸形仍然存在，跟骨马蹄足未得到矫正。另一方面，我们认为跟骨延长截骨术是首选治疗方法，因为术后足部压力分布更接近正常足部压力分布。
