【摘要】 背景:近年来,全髋关节置换的应用使大多患者初期都获得了满意的疗效,但临床上全髋置换后的并发症仍然是困扰医生和患者的一大难题,假体置入位置的优良成为评估置换效果的重要方面。目的:探究短柄假体不同置入位置对全髋关节置换效果的影响,为临床手术实施提供启示。方法:利用人体动力学软件进行完整周期的步态仿真,获得髋关节的承力条件;模拟短柄假体不同置入位置,即人体力线位置以及内、外偏3°,5°位置,建立其相应的全髋关节置换三维有限元模型,分析不同全髋关节置换模型中股骨、短柄的应力变化以及聚乙烯内衬的应变变化情况。结果与结论:①步态下髋关节的关节力和角度随时间呈周期性变化,约1.17 s为一个周期,在0.4 s左右关节合力达到峰值约700 N;②无论内外偏角度的大小,股骨小转子下方以及底端外侧的应力值均高于人体力线位置时的应力,内偏比外偏对股骨应力的影响更大;③股骨短柄的最大拉压应力在人体力线位时均比内、外偏时的应力值低;④以人体力线位为参考,聚乙烯内衬的最大压应变在外偏3°时最小,为2 198με;其他角度时的最大压应变均比人体力线位时大,其中内偏5°时最大达到了7 348με,是人体力线时的2.08倍,此角度下会加剧内衬的磨损;⑤提示在全髋关节置换过程中,不同假体置入位置会对股骨、假体和内衬的力学环境产生很大影响,在术中应该尽量保证假体处在与人体力线重合的位置。更多还原

【Abstract】 BACKGROUND: In recent years, total hip arthroplasty has been widely developed, and most patients have achieved satisfactory results at the initial stage. However, complications after total hip arthroplasty in clinical practice were still a major problem for doctors and patients, and the excellent implant position has become the key to evaluate the replacement effect. OBJECTIVE: To investigate the influence of different implant position of short-stemmed prosthesis on hip arthroplasty, and to provide guidance for doctors’ surgical implementation. METHODS: The full cycle gait simulation was carried out by using human dynamics software to obtain the load-bearing conditions of hip joint. The finite element model of hip joint replacement was established by simulating different implantation locations, that is, the position of human strength line and the position of internal and external deviation of 3° and 5°. The stress changes of femur and short-stemmed prosthesis and the strain changes of polyethylene liner in different total hip arthroplasty models were calculated and analyzed. RESULTS AND CONCLUSION:(1) In gait, the joint force and angle of the hip joint changed periodicity with time 1.17 s a period, and the total joint force reached a peak value of about 700 N at 0.4 s.(2) No matter how the angle of internal and external deviation changes, the stress value of the lower part of the lesser trochanter and the lateral end of the femur were higher than those of the position of the human physical line, and internal deviation had a greater impact on the stress of the femur than external deviation.(3) The maximum tensile and compressive stress of the prosthesis was lower than that of the internal and external deviation.(4) The maximum compressive strain of polyethylene liner was the smallest at 3° external deviation, reaching 2 198 με. The maximum compressive strain at other angles was higher than that at the human physical line. The maximum value reached 7 348 με at 5° internal deviation, which was 2.08 times as high as that of position of the human physical line, it would aggravate the liner wear.(5) In total hip arthroplasty, different implant position will have a great impact on the mechanical environment of femur, prosthesis and liner. During the operation, the prosthesis should be as close as possible to the human physical strength line.更多还原