Crowe Ⅲ型髋关节发育不良人工全髋关节置换髋臼解剖重建与非解剖重建髋关节生物力学有限元分析

目的：应用有限元分析研究CroweⅢ型发育性髋关节发育不良(developmental dysplasia of the hip,DDH) 全髋关节置换(total hip arthroplasty,THA)髋臼解剖重建与非解剖重建髋关节的生物力学为临床THA髋臼解剖重建提供理论基础和实验依据。方法：选取1例因左侧Crowe Ⅲ型DDH伴终末期髋骨关节炎于2020年4月就诊并行左侧全髋关节置换的患者,女,57岁。术前、术后分别行骨盆CT平扫三维重建。在Mimics和3-Matic软件里建立14组髋臼杯不同前倾角、外展角、旋转中心高度模型并进行材料赋值,在Abaqus软件里设置边界和负载条件,计算并观察髋关节应力峰值和分布。结果：对于Crowe Ⅲ型DDH全髋关节置换术,当旋转中心解剖重建,髋臼杯外展角设置为40°时,髋臼杯前倾角5°~25°变化时,髋臼杯、聚乙烯内衬最低Von Mises值出现在前倾角20°;当旋转中心解剖重建,髋臼杯前倾角设置为15°时,髋臼杯外展角30°~55°变化时,髋臼杯、聚乙烯内衬最低Von Mises值出现在外展角35°;当髋臼杯前倾角设置为15°、外展角设置为40°时,旋转中心上移0~20 mm变化时,髋臼杯、聚乙烯内衬最低Von Mises值出现在旋转中心上移10 mm。在所有14组髋臼杯参数模型中,旋转中心解剖重建,髋臼杯前倾角15°、外展角35°时,髋臼、髋臼杯、聚乙烯内衬Von Mises值最低。结论：在Crowe Ⅲ型DDH全髋关节置换术中,建议解剖重建旋转中心,髋臼杯前倾角15°、外展角35°,同时进行髋臼外上方植骨并增加螺钉以进一步减少髋关节应力峰值。

Hip joint biomechanical analysis of the acetabular anatomical reconstruction and nonanatomical reconstruction in total hip arthroplasty for Crowe type Ⅲ developmental dysplasia of the hip by finite element method

Objective To analyze the hip joint biomechanics of the acetabular anatomical reconstruction and nonanatomical reconstruction in total hip arthroplasty (THA) for Crowe type Ⅲ developmental dysplasia of the hip (DDH) by finite element method,which provided theoretical foundation and experimental basis for the anatomical acetabular reconstruction during THA in clinical practice.

Methods One patient with left end-stage hip arthritis secondary to Crowe type Ⅲ DDH was selected in this study,who underwent total hip arthroplasty in the orthopedic department of the First Affiliated Hospital of Bengbu Medical College in April 2020. This patient was female,57 years old. The preoperative and postoperative three dimentional CT scan of the patient''s pelvis were performed. Fourteen acetabular cup models with different anteversion,inclination and rotation center height were established in Mimics and 3-Matic software. The boundary and load conditions were set in Abaqus software. The Von Mises and stress distribution of the hip joint were calculated and observed.

Results In the Crowe type Ⅲ DDH THA,if the hip rotation center was restored anatomically and the acetabular cup''s inclination was set as 40°,the cup''s anteversion varied from 5° to 25°,the lowest Von Mises value of acetabular cup and polyethylene liner occured in 20ånteversioin;if the hip rotation center was restored anatomically and the acetabular cup''s anteversion was set as 15°,the cup''s inclination varied from 35° to 55°,the lowest Von Mises value of acetabular cup and polyethylene liner occured in 35° inclination;if the acetabular cup''s anteversion and inclination were set as 15ånd 40°respectively,the up migration of hip rotaion center varied from 0 mm to 20 mm,the lowest Von Mises value of acetabular cup and polyethylene liner occured in 10 mm up migration. In all fourteen models,the Von Mises value of the acetabulum,acetabulum cup and polyethylene liner were lowest when the acetabular cup''s anteversion and inlcination were 15°,35° respectively,as well as the rotation center was restored anatomically.

Conclusion In total hip arthroplasty for Crowe type Ⅲ DDH,the anatomical restoration of hip rotation center with 15° anteversion and 35° inclination of the acetabular cup are suggested,bone graft above the acetabular cup and additional screws are recommended simultaneously to further reduce the Von Mises of hip joint.