Burkhart Timothy A, Khadem Mehrdad, Wood Thomas J, Dunning Cynthia E, Degen Ryan, Lanting Brent A
Lawson Health Science Institute, Canada; Department of Mechanical and Materials Engineering, Western University, 1151 Richmond Rd, London, ON N6A 3K7, Canada.
Department of Mechanical and Materials Engineering, Western University, 1151 Richmond Rd, London, ON N6A 3K7, Canada.
Clin Biomech (Bristol). 2019 Oct;69:34-38. doi: 10.1016/j.clinbiomech.2019.06.017. Epub 2019 Jun 28.
Total hip arthroplasty complications are associated with mechanical loosening of the acetabular component, which may be attributed to the type of fixation used (press fit, trans-cortical screws, cancellous screws). Therefore, the purpose of this study was to compare trans-cortical and cancellous screws to press fit for fixation of the acetabular shell.
Five cadaveric pelvis specimens were hemisected (N = 10) at the sacroiliac joint. Each hemi-pelvis was initially tested with a press fit cup followed by the left and right pairs being randomized to either a cancellous or trans-cortical screw condition. Each fixation was tested by applying a load to a rod inserted into the centre of the acetabular cup at 0.5 mm/s, until failure occurred. The failure force, failure moment, and the rotation angle of the cup at failure were calculated.
The cups fixated with a trans-cortical screw failed at a significantly greater mean [SD] force (1046.20 [386.52] N). The trans-cortical screws also significantly increased the angle of failure 46.29 (16.90) ° compared to the press-fit cups (6.73 [4.59] °). Finally, there was a significant increase in the failure moment, such that, the trans-cortical condition failed at a mean (SD) moment of 53.75 (16.24) Nm compared to 9.59 (1.85) Nm and 32.15 (18.16) Nm for the press fit and cancellous (p = 0.044) conditions, respectively.
The acetabular shells that were fixated with trans-cortical screws provide greater stability compared to the press-fit cups or cancellous screws.
全髋关节置换术的并发症与髋臼组件的机械性松动有关，这可能归因于所使用的固定类型（压配、经皮质螺钉、松质骨螺钉）。因此，本研究的目的是比较经皮质螺钉和松质骨螺钉与压配用于髋臼杯固定的效果。
将5个尸体骨盆标本在骶髂关节处半切（N = 10）。每个半骨盆最初用压配杯进行测试，然后将左右两半随机分为松质骨螺钉或经皮质螺钉固定组。通过以0.5毫米/秒的速度向插入髋臼杯中心的杆施加负荷来测试每种固定方式，直至失败。计算失败力、失败力矩以及失败时髋臼杯的旋转角度。
用经皮质螺钉固定的髋臼杯在平均[标准差]力（1046.20 [386.52]牛）下显著更高时失败。与压配杯（6.73 [4.59]°）相比，经皮质螺钉还显著增加了失败角度，达到46.29（16.90）°。最后，失败力矩有显著增加，经皮质固定组在平均（标准差）力矩53.75（16.24）牛米时失败，而压配组和松质骨固定组分别为9.59（1.85）牛米和32.15（18.16）牛米（p = 0.044）。
与压配杯或松质骨螺钉相比，用经皮质螺钉固定的髋臼杯提供了更大的稳定性。
