Objective To investigate the stability and feasibility of using absorbable screws during Bernese periacetabu-lar osteotomy.Methods A retrospective analysis was conducted on a 36 year-old woman diagnosed with developmental dysplasia of the hip,who had undergone Bernese periacetabular osteotomy.Finite element analysis was used to simulate the stability of the acetabulum under loads of 10％,20％,50％,and 100％of the patient's weight.The structural stiffness of the pelvis and the maxi-mum equivalent stress on the absorbable screws were observed under different conditions,including whether the acetabular bone block and the ilium were in contact,whether 3 or 4 screws were used,and whether a graft(including fibular cortical bone and PEEK grafts)was used.Results The structural stiffness of the pelvis fixed with four screws increased by 67％-94％compared to that with three screws.After using a graft,the structural stiffness of the pelvis increased by 50％-83％.As the load increased,the maximum equivalent stress on the screws also increased.When the acetabular bone block and the ilium had no contact,no graft was used,and only three screws were used for fixation,the maximum equivalent stress could reach 518.9 MPa,while this value dropped to 61％when four screws were used(318.7 MPa).When the acetabular bone block and the ilium were in contact,the maxi-mum equivalent stress was about 12％of that when there was no contact,regardless of the number of screws used.When a cortical bone graft or a PEEK graft was used,the maximum equivalent stress could drop to 21％-26％of that without a graft.When the screw strength was 130 MPa,a load of 20％of body weight was applied,and only three screws were used without a graft,the equiv-alent stress could exceed the strength of the screw;if four screws were used,the equivalent stress was slightly higher than the strength of the screw when a load of 50％of body weight was applied.However,when a graft was used(either cortical bone or PEEK),even when a load of 100％of body weight was applied,the equivalent stress was slightly lower than the strength of the screw.Conclusion Absorbable screws can provide sufficient stability for Bernese periacetabular osteotomy.The contact between the acetabular bone block and the ilium,an increase in the number of screws,and the use of grafts(cortical bone and PEEK grafts)can further improve stability.Therefore,absorbable screws have broad application prospects in Bernese periacetabular osteotomy.
关键词
截骨术/可吸收性植入物/有限元分析/应力,物理
Key words
Osteotomy/Absorbable implants/Finite element analysis/Stress,mechanical
维普
万方数据