摘要
目的通过髋臼的三维重建及基于此的解剖形态研究,就临床上假体安装前的髋臼同心扩锉准备方式时过度扩锉对臼窝前后壁骨量丧失和髋臼缘开口前倾角改变作一定量分析。方法选取40例成人髋臼标本,通过CT扫描、图像边界处理和定标,利用Pro/Engineer软件拟合出髋臼三维结构,再将其导入Unigrapics软件中,运用其集成的工具条和球体表面逼贴技术,对二种过度髋臼同心扩锉,即扩锉至Harris窝底或扩锉至髋臼内侧壁时,髋臼横断面开口扭转角度变化及髋臼后壁与前壁骨量丧失量作定量分析。结果(1)当髋臼同心扩大至Harris窝底时,髋臼横断面开口扭转角度在不同髋臼层面均发生变化,其中,髋臼上半部分最大前倾角度可增加4.83°;而髋臼下半部分开口前倾角度轻微减小。(2)髋臼同心扩大至Harris窝底时,髋臼后壁与前壁骨量丧失量平均为6.75mm和6.11mm。(3)当髋臼同心扩大至髋臼内侧壁时,髋臼横断面上半部分开口扭转角度进一步增大,最大前倾角度增加达8.55°;此时,髋臼后壁与前壁骨量丧失量也增加至平均9.54mm和9.56mm。结论髋臼同心扩挫虽能保持髋臼活动中心点不变,但过度扩锉仍可造成较明显的髋臼前后壁骨量丧失与前倾角度变化,不利于髋杯假体与骨面的牢固固定和正确置放。髋臼扩锉达到或超过Harris窝底深度以上应尽可能在临床应用中避免。
Objece Acetabular component failure has been proved to be the key factor affecting the long-term result of survival rate of TKR. Preparation of the acetabular for the component is the most important procedure for predicating the destiny of acatabular component. This study aimed to evaluate the side-effect of extensive concentric reaming for acetabular preparation in respect of bone loss of acetabulum rim and change of acetabular anteversion. Methods CT images of 40 normal adult bony acetabula were obtained and processed with the algorithm of histogram-threshold segmenting and Kirsh boundary detection to get a binary contour image. The contour of scanned acetabulum was then used for three-dimensional reconstruction with CAD software. With best-fit sphere of acetabulum bone joint surface technique, quantitative analyses have been done in computer imitating the concentric reaming for acetabulum. Two kinds of extensive concentric reaming for acatabular preparation were defined as reaming to the depth of reaching bottom of Harris forum or reaming until reaching the inner pelvic wall at medial side of acetabulum. Results （1） when it was done to the depth of reaching bottom of Harris forum, bone losses at anterior rim and posterior rim of acetabulum were estimated to average 6.75 mm and 6.11 mm respectively, and the acetabular anteversion was increased at upper half of acetabulum with maximum increase of 4.83° . （2） when it was done to the depth of reaching reaching the inner pelvic wall, bone losses at the anterior rim and posterior rim could reach to 9.54 mm and 9.56 mm thickness and acetabular anteversion at upper half of acetabulum further increased with maximum increase of 8.55° . Conclusion Although concentric reaming for acetabular would precisely maintain the normal hip kinematic center, extensive concentric reaming to the extent reaching or passing over the bottom of Harris forum could result in obvious bone losses at both anterior and posterior rims of acetabular bearing surface and alter the nature acetabular anteversion, which might compromise both the integration of acetabular component with bone surface and proper orientation of the component.
出处
《医用生物力学》
EI
CAS
CSCD
2006年第1期49-53,61,共6页
Journal of Medical Biomechanics
基金
上海市教育委员会高等学校科技基金(No.2000B14)
关键词
髋臼
扩锉
骨丧失
前倾角变化
三维重建
Acetabulum
Reaming
Bone loss
Change of anteversion
3-D Reconstruction
