发育性髋关节脱位儿童与正常儿童软骨性髋臼前倾角的MRI研究

MRI measurement of cartilaginous acetabular anteversion in DDH and normal children

[目的]通过MRI观察发育性髋关节脱位（developmental dislocation of hip,DDH）患儿病变髋软骨性髋臼是否存在过度前倾,测量不同年龄组正常儿童的软骨性髋臼前倾角（articaginous acetabular anteversion,CAA）并分析其发育演变。[方法]回顾性收集55例DDH儿童和222例正常儿童的髋关节MRI影像学资料。病例组：男22例,女33例;年龄6-60个月,平均19个月。共有73例脱位髋、9例半脱位髋、10例发育不良髋和18例未受累髋。对照组：男132例,女90例;年龄3个月-15岁,平均6.2岁。共444例正常髋,并以患者年龄（岁）为单位分为15个亚组。通过MRI测量各组髋关节的CAA,统计学分析对比病例组和对照组以及对照组各组间CAA是否存在统计学差异。[结果]DDH儿童脱位与半脱位髋关节的CAA均大于未受累髋关节和正常儿童髋关节的CAA,差异具有统计学意义（P〈0.05）。DDH儿童脱位髋关节CAA大于发育不良髋关节的CAA,差异具有统计学意义（P〈0.05）。正常对照组儿童髋关节CAA在不同年龄组间不存在相关性（r〈0,P〉0.05）。所有病例均未发现髋臼后倾现象。[结论]DDH儿童脱位与半脱位髋关节的CAA是存在过度前倾的;正常的CAA在人们出生时就已完全形成,并且不随年龄的增长而发生明显改变。作者认为CAA更能反映髋臼的真实前倾角,采用MRI对DDH患儿的软骨结构进行评估可用于指导DDH的术式选择。

[Objective] To observe whether the cartilaginous acetabular anteversion（ CAA） on dislocated hips presented excessive anteversion in developmental dislocation of the hip（ DDH） using MRI. And to observe the CAA in normal children with different ages using MRI and analyze its development and growth. [Methods] Fifty-five patients with DDH were retrospectively reviewed,including 33 girls and 22 boys with an average age of 19 months（ range 6 to 60 months）. In all,73 dislocated hips,9 subluxated hips,10 dysplasia hips and 18 unaffected hips were enrolled in the present study. A total of 222 children were involved in the normal control group,including 90 girls and 132 boys with an average age of 6. 2 years months（ range 3 months to 15 years）. In all,444 normal hips were divided into 15 groups according to age. The CAA of all hips were respectively measured using MRI. The data were statistically analyzed. [Results] The CAA both on the dislocated and subluxated hips in DDH were larger than that both on the unaffected hips in DDH and normal hips（ P〈0. 05）. The CAA in the dislocated hips were larger than that in the dysplasia hips（ P〈0. 05）. The correlation of CAA with the age was not presented in the normal group（ P〈0. 05）. None retroverted acetabulum was found in all hips. [Conclusion] The CAA was significant increasing on the dislocated and subluxated hips in DDH. The normal CAA has fully formed at birth,and there are not obvious fluctuation at different age groups. We think CAA on the basis of MRI measurement reflect the true acetabular anteversion in DDH,MRI can be used to evaluate deformity of the cartilage before operation which is helpful for guiding the surgical process.