发育性髋关节脱位闭合复位后股骨头坏死自然演变过程的临床及实验观察

Clinical and experimental observation on the natural processes of the femoral head avascular necrosis in DDH patients after close reduction

目的 探讨发育性髋关节脱位闭合复位术后股骨头坏死的自然演变过程。方法 单侧髋关节脱位闭合复位术后出现股骨头坏死的患儿22例,平均复位年龄10.5月（5~23月）。K＆M分型II型11例,III型8例,IV型3例。平均随访3.5年（2.5~5.5年）,采用股骨头高度同骺线宽度比（Height-Wild Ratio,HWR）计算股骨头修复百分比。同时观察了异常应力髋关节发育不良动物模型中,去除应力前后股骨头的形态变化及其修复情况。结果 22例患儿,在去除外固定架后自然负重的情况下,股骨头形态均有不同程度的修复。22例患儿坏死侧股骨头同健侧对比,从（24.7±5.26）%修复至（80.3±17.9）%。出现股骨头坏死后随访≤2年（n=10）股骨头高宽比（HWR）修复为（72±2.7）%;随访〉2年（n=12）股骨头HWR修复（81.2±9.4）%。其中II型（n=11）HWR修复（78.3±4.2）%;III型（n=8）HWR修复（74.1±6.9）%;IV型（n=3）HWR修复（59.3±7.7）%。造模动物的股骨头形态学观察结果显示,随应力时间延长股骨头形态改变越显著,去除应力后均有不同程度修复。去除应力越早,日后发育越接近正常形态的股骨头。结论 发育性髋关节脱位闭合复位后股骨头坏死在自然负重状态下具有逐步修复的趋势;出现股骨头坏死后可以继续随访2~4年,以发挥DDH患儿股骨头自我修复的最大潜能。

Objective To explore the natural processes of the femoral head avascular necrosis in patients developmental dislo -cation of the hips （ DDH） after close reduction .Methods Twenty-two DDH patients with single dislocation hip who presented femoral head avascular necrosis after close reduction were enrolled in this study .The average age was 10.5 months ranged from 5 to 23 months . Based on Kalamchi＆amp;MacEwen classification ,there were 11 cases with K＆amp;M type II ,8 cases with K＆amp;M type III ,and 3 cases with type IV.The average follow-up was 3.5 years ranged from 2.5 years to 5.5 years.Height-Wild Ratio （HWR） of femoral head was used to calculate percentage of recovery .In the mean time ,we also observed the morphologic feature in hip dysplasia animal model .Results In the 22 patients,the morphology of necrosis femoral head had all recovered partially with natural body weight loading after releasing brace.Compared with normal side,HWR of femoral head was changed from （24.7 ±5.26）%to （80.3 ±17.9）%.The HWR recov-ery was （72 ±2.7）%（n =10） when followed up for less than 2 years while HWR recovery was （81.2 ±9.4）%（n =12） when followed up for more than 2 years.Moreover,HWR recovery was （78.3 ±4.2）%in the type II patients,（74.1 ±6.9）% in the type III and （59.3 ±7.7）%in the type IV.In animal model,we observed that the shape of femoral head changed dramatically in abnormal stress loading,somehow the morphology of the femoral head recovered partially after stress overloading removed .Conclusion The avas-cular necrosis of femoral head has capability to recover partially in DDH close reduction with natural body weight loading after releasing brace.The patients could be followed-up for 2~4 years after occurrence of femoral head necrosis in order to the patients play the big-gest potential for femoral head self healing .