Calkins M S, Zych G, Latta L, Borja F J, Mnaymneh W
University of Miami School of Medicine, Department of Orthopaedics and Rehabilitation, Florida.
Clin Orthop Relat Res. 1988 Feb;227:152-63.
Measurements of the percentage of remaining posterior acetabulum on computed tomography (CT) scan (the Acetabular Fracture Index) in posterior fracture dislocations of the hip were evaluated to determine the stability of the joint. All hips with less than 34% of the remaining posterior acetabulum were unstable. Hips with greater than 55% were stable. Between these values, hips were either stable or unstable. A statistical analysis demonstrated highly significant differences in the average remaining posterior acetabulum between the stable and unstable group. These findings were based on a review of 26 patients with posterior fracture dislocations of the hip (Epstein Type I-IV injuries) combined with CT scan analysis. The clinical status of hip stability was correlated with the Acetabular Fracture Index, and this provided the basis for the study. A simple linear measurement of the remaining posterior acetabulum on CT (the Approximate Acetabular Fracture Index) can be done easily by a physician, and this closely approximates the true remaining acetabular arc. Seven of ten unstable hips in 31 Epstein Type I-V patients showed femoral head subluxation of 0.5 mm or more on CT scan, whereas none of the 21 stable hips had demonstrable subluxation. Risk analysis provided a means of predicting hip stability for individual patients.
通过计算机断层扫描（CT）测量髋关节后脱位时髋臼后壁剩余部分的百分比（髋臼骨折指数），以评估关节的稳定性。所有髋臼后壁剩余部分少于34%的髋关节均不稳定。剩余部分大于55%的髋关节则稳定。在这两个数值之间的髋关节，其稳定性不定。统计分析显示，稳定组与不稳定组的髋臼后壁平均剩余量存在显著差异。这些发现基于对26例髋关节后脱位（爱泼斯坦I-IV型损伤）患者的回顾，并结合CT扫描分析得出。髋关节稳定性的临床状况与髋臼骨折指数相关，这为该研究提供了依据。医生可轻松在CT上对髋臼后壁剩余部分进行简单的线性测量（近似髋臼骨折指数），该测量结果与真实的髋臼剩余弧长非常接近。在31例爱泼斯坦I-V型患者中，10例不稳定髋关节中有7例在CT扫描上显示股骨头半脱位0.5毫米或以上，而21例稳定髋关节中无一例有明显半脱位。风险分析为预测个体患者的髋关节稳定性提供了一种方法。
