髋臼卵圆窝在实现术前预期髋臼杯外展角中的参考价值

  目的 探讨髋臼卵圆窝的解剖及影像学特点，评价其在实现术前预期髋臼杯外展角中的作用。方法 在16具正常成人骨盆标本上标记髋臼卵圆窝 中轴线，观察卵圆窝中轴线走行特点及其与卵圆窝顶和髋臼骨性边缘交点在标准骨盆正位X线片上的对应关系。通过模板测量观察预期外展角度的髋臼杯中轴线 与髋臼卵圆窝顶点之间的对应关系。于骨盆标本两侧髋臼施行生物髋臼杯植入术，一侧采用卵圆窝参照法，对侧采用髋臼定位器法，在标准骨盆正位X线片上比 较两侧手术前后髋臼杯外展角偏差的差异。结果 卵圆窝中轴与卵圆窝顶和髋臼骨性边缘的交点是较为恒定的解剖标志，在标准骨盆正位X线上分别对应髋臼顶部 关节面软骨下骨的内缘和外缘。髋臼卵圆窝顶点与40°±5°外展角度的髋臼杯中轴线密切相关。卵圆窝参照组手术前后髋臼杯外展角偏差为0.19° ±3.14°（-6°~5°），髋臼定位器组为2.75°±2.89°（-2°~8°），两组差异有统计学意义（t=－2.453，Ρ=0.027）。结论 对于患者髋臼解剖相对正常的 初次全髋关节置换，依据术前模板测量获得的预期髋臼杯位置与卵圆窝顶点的关系，可较精确地获得预期髋臼杯外展位置。

The use of acetabular fossa as a reference for achieying the anticipated inclination of the acetabular cup

Objective To discuss the anatomical and radiographic characteristics of acetabular fossa, and evaluate their value as a reference for achieving the anticipated inclination of the acetabular cup. Methods Sixteen adult normal pelvic specimens were studied. Central axis of acetabular fossa and its intersection with fossa edge and acetabular rim were marked. The radiographic appearance of the two intersections was evaluated. With radiographic templating, the relationship between the top of acetabular fossa and the central axis of acetabular cup at anticipated inclination was identified. Implantation of cementless acetabular cup was performed bilaterally on the pelvic specimens. The acetabular fossa was used as a reference for implantation on one side, and the acetabular positioning device was used on the other side. The discrepancy of acetabular inclination was recorded before and after operation in the two groups. Results Intersection of central axis of acetabular fossa with fossa top edge and acetabular rim corresponded to the most medial and lateral aspect of acetabular sourcil respectively on standard anteroposterior pelvic radiograph. There was close correlation between most medial aspect of acetabular sourcil and central axis of the acetabular cup at anticipated inclination of 40°±5°. For the group of using acetabular fossa as reference, the mean difference of inclination was 0.19°±3.14° (-6°-5°) before and after operation, and the discrepancy was 2.75°±2.89 °(-2°-8°) for the control group. The difference between the two groups was statistically significant (t=－2.453, Ρ=0.027）. Conclusion In primary total hip replacement, if normal anatomy of acetabulum was found, the anticipated inclination of acetabular cup can be accurately obtained, based on the relationship between the top of acetabular fossa and anticipated inclination of acetabular cup on preoperative templating.