重度先髋脱位全髋置换术中肢体延长长度的探讨

目的探讨全髋关节置换术(total hip arthroplasty,THA)治疗重度先天性髋关节脱位(developmental dys-plasia hip,DDH)时下肢可以延长的安全范围。方法基础研究部分:20只狗建立后肢延长后神经、血管损伤模型,通过神经电生理、组织学和血流动力学的方法,了解其神经损伤和血管损伤与牵拉的关系。临床研究部分:29例(32髋)重度DDH患者,26髋行单纯THA手术,6髋行THA、粗隆下截骨术。术后采用Harris评分、肌电图、血管超声等方法检查神经血管损伤,平均随访6个月。结果动物实验:延长长度超过肢体原有长度6%时,神经电生理有所表现,未发生血管损伤。临床试验:29例患者术前Harris评分为(32.98±8.51)分,术后随访6周,28例患者(脱漏1例)Harris评分为(91.26±3.57)分,肢体延长长度(3.3±1.15)cm,最长延长5.9 cm。有5例出现神经传导速度减慢,6例出现感觉神经传导减慢,4例延长超过下肢长度6%的患者均出现感觉及运动神经传导异常、肌电图未见自发电位,3例患者在术后出现肢体麻木,复诊时症状消失;血管损伤均未发生。结论 THA手术治疗重度DDH时,肢体延长不超过下肢长度的6%是安全的。

Leg Extension in Total Hip Arthroplasty for the treatment of Developmental Dysplasia Hip

Objective To investigate the accepted range of the extension for the leg in the operation of total hip arthroplasty（THA） to treat the serious developmental dysplasia hip（DDH）.Methods The Basic Study Part：Extend 20 dogs′ hind limbs to set the models of the injury of bloods and nerves.Use the Electrophysiologial and histological methods to explore the relationship between the injury of bloods and nerves and the extension of the hind limbs.The Clinical Study Part：There are 29 patients,32 hips,who catch serious DDH.There are 26 hips receive single THA,and 6 hips receive THA and femoral osteotomy.Score before and after surgery,electromyogram,vascular ultrasound are used to test the operational effect and the damnification of the blood vessels and the nerves.And every patient was followed 6 month.Results Animal experience show that when the length of the prolong is more than the 6%of the original lower limbs the EMG change will happen and the vascellum damage will not happen.Clinical trial shows the 29 patients′ score of Harris before the operation is（32.98±8.51）（means and standard deviation）,and the 28 patients′（one is lost） score of Harris,6 month after the operation,is（91.26±3.56）（means and standard deviation）.The length of the limb prolong is（3.3±1.14） cm（means and standard deviation）,and the greatest is 5.9 cm.5 patients catch the slower of the motor nerves conduct speed.6 patients catch the slower of the sensory nerves conduct speed.Hurt of the motor and sensory nerves could be found in all the 6 patients whose length of the limb prolong is more than 6%and no spontaneous potential in the EMG.There are 3 patients feeling the limb is less comfortable after the operation and all the symptom disappear when the return visit.No evidence of the damage to the blood verssel was found.Conclusion It is safe to prolong the limb less than the 6%of limbs′ length in the surgery of the THA in serious DDH cases.