Luckenbill Daniel B, Iossi Mike F, George Whitney Alyssa M, Miller Danielle, Crosby Lynn A, Goswami Tarun
Boonshoft School of Medicine, Wright State University, Dayton, OH 45435, USA.
Department of Biomedical Engineering, Orthopaedic Surgery, Sports Medicine and Rehabilitation, Wright State University, Dayton, OH 45435, USA.
Bioengineering (Basel). 2022 Feb 16;9(2):76. doi: 10.3390/bioengineering9020076.
The purpose of the study was to evaluate the force and torque required to dissociate a humeral head from the unimplanted modular total shoulder replacement system from different manufacturers and to determine if load and torque to dissociation are reduced in the presence of bodily fluids. Impingement, taper contamination, lack of compressive forces, and interference of taper fixation by the proximal humerus have all been reported as possible causes for dissociation. Experimental values determined in this research were compared with literature estimates of dissociation force of the humeral head under various conditions to gain more understanding of the causes of recurrent dissociations of the humeral head. This study examined biomechanical properties under dry and wet conditions under clinically practiced methods. Mean load to dissociation (1513 N ± 508 N) was found to be greater than that exerted by the activities of daily living (578 N) for all implants studied. The mean torque to dissociation was (49.77 N·m ± 19.07 N·m). Analysis of correlation coefficients and -values (α = 0.05) did not show any significant correlation between dry/bovine, dry/wet, or wet/bovine for load, displacement, or torsional stiffness in the majority of tests performed. Wetting the taper with water or bovine serum did not reduce the dissociation force to a statistically significant degree. Torque and lack of compressive forces at the rotator cuff may be the cause of dissociation at values less than those of activities of daily living. Torque data are provided by this study, but further research is needed to fully appreciate the role of torque in recurrent dissociations.
本研究的目的是评估将肱骨头与不同制造商的未植入模块化全肩关节置换系统分离所需的力和扭矩，并确定在存在体液的情况下分离所需的负载和扭矩是否会降低。撞击、锥度污染、缺乏压缩力以及肱骨近端对锥度固定的干扰都被报道为可能导致分离的原因。将本研究确定的实验值与文献中各种条件下肱骨头分离力的估计值进行比较，以更深入了解肱骨头反复分离的原因。本研究采用临床实践方法，研究了干燥和潮湿条件下的生物力学特性。对于所有研究的植入物，发现平均分离负载（1513 N±508 N）大于日常生活活动所施加的负载（578 N）。平均分离扭矩为（49.77 N·m±19.07 N·m）。在大多数测试中，对相关系数和P值（α = 0.05）的分析表明，在负载、位移或扭转刚度方面，干燥/牛血清、干燥/潮湿或潮湿/牛血清之间没有任何显著相关性。用水或牛血清湿润锥度并没有使分离力降低到具有统计学意义的程度。肩袖处的扭矩和缺乏压缩力可能是导致分离的原因，其值低于日常生活活动的值。本研究提供了扭矩数据，但需要进一步研究以充分了解扭矩在反复分离中的作用。
