tailieunhanh - báo cáo hóa học:" The effect of abductor muscle and anterior-posterior hip contact load simulation on the in-vitro primary stability of a cementless hip stem"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học quốc tế đề tài : The effect of abductor muscle and anterior-posterior hip contact load simulation on the in-vitro primary stability of a cementless hip stem | Park et al. Journal of Orthopaedic Surgery and Research 2010 5 40 http content 5 1 40 éHMÌ JOURNAL OF ORTHOPAEDIC oo SURGERY AND RESEARCH RESEARCH ARTICLE Open Access The effect of abductor muscle and anterior-posterior hip contact load simulation on the in-vitro primary stability of a cementless hip stem Youngbae Park 41 Carolyne Albert42 Yong-San Yoon 1 Goran Fernlund3 Hanspeter Frei4 and Thomas R Oxland5 Abstract Background In-vitro mechanical tests are commonly performed to assess pre-clinically the effect of implant design on the stability of hip endoprostheses. There is no standard protocol for these tests and the forces applied vary between studies. This study examines the effect of the abductor force with and without application of the anterior-posterior hip contact force in the in-vitro assessment of cementless hip implant stability. Methods Cementless stems VerSys Fiber Metal were implanted in twelve composite femurs which were divided into two groups group 1 N 6 was loaded with the hip contact force only whereas group 2 N 6 was additionally subjected to an abductor force. Both groups were subjected to the same cranial-caudal hip contact force component times body weight BW and each specimen was subjected to three levels of anterior-posterior hip contact load 0 to BW walking and to BW stair climbing . The implant migration and micromotion relative to the femur was measured using a custom-built system comprised of 6 LVDT sensors. Results Substantially higher implant motion was observed when the anterior-posterior force was compared to the lower anterior-posterior load levels particularly distally and in retroversion. The abductor load had little effect on implant motion when simulating walking but resulted in significantly less motion than the hip contact force alone when simulating stair climbing. Conclusions The anterior-posterior component of the hip contact load has a significant effect on the axial .