老年骨质疏松症对人工髋关节置换影响的实验研究

目的从生物力学角度探讨老年骨质疏松者对人工髋关节置换的影响及其治疗对策。方法采集30具新鲜股骨标本，DEXA骨密度仪测试每个标本干骺端、颈部、Ward三角区及大转子区的骨密度，将骨质疏松标本进行骨水泥和非骨水泥假体安装，测定其生物力学性能变化。结果老年骨质疏松程度的增加，假体置换后股骨上方应变呈增加的趋势。随着骨密度的增加，假体近端和远端微动随之减少，关节假体的初始稳定性显著增加。结论老年骨质疏松对人工关节假体的置换影响是明显的。老年骨质疏松患者采用骨水泥固定假体其松动率可下降30％～40％，临床上要求假体安装须精确匹配，骨水泥调制合理、厚度适中，以减少松动的发生率。

The Influence of Osteoporosis on Total Hip Arthroplasty for the Aged Patients

Objective To study the influence of osteoporosis on total hip arthroplasty for the aged people by biomechanical methods.Methods The bone mineral density was measured at metaphyseal, femoral neck, ward triangle and the great trochanteric region with DEXA in 30 fresh cadavers. All osteoporotic samples were divided into two groups and treated by cemented or non- cemented prostheses,respectively. The biomechanic property changes were examined. Results The strain became worse in the prosthesis - inserted samples with the increase of severity of osteoporosis. When bone mineral density increased, the micro - motion decreased at both the proximal and distal part, and the prosthesis thus had a better initial stability. Conclusion Osteoporosis in the aged people has obvious influence on the stability of hip prosthesis. The loosening rate can be decreased by 30 % -40 % in the cemented prosthesis, compared with the non- cemented ones. Clinically, the precise prosthesis- bone match, meticulous preparation of the cement and optimal thickness of cement mantle are necessary for the reduction of loosening rate.