Gordon Karen D, Duck Teresa R, King Graham J W, Johnson James A
Bioengineering Research Laboratory, Hand and Upper Limb Centre, St. Joseph's Health Care London, and Department of Medical Biophysics, Faculty of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.
J Orthop Trauma. 2003 Apr;17(4):285-9. doi: 10.1097/00005131-200304000-00007.
To quantify the mechanical properties of subchondral bone of the radial head, with special interest in the regional variations in bone stiffness and strength.
Transverse subchondral cancellous bone slices obtained from the proximal radial head were subjected to indentation tests.
Biomechanics laboratory with a servohydraulic materials testing machine.
Thirteen previously frozen, cadaver proximal radii of mean age 69 +/- 9 years.
The mean indentation modulus and local yield strength were calculated for the anteromedial (AM), anterolateral (AL), posteromedial (PM), and posterolateral (PL) quadrants of the radial head.
There were no differences in mean indentation modulus across all 4 quadrants (AL, 55.56 +/- 16.20 MPa; AM, 53.48 +/- 20.67 MPa; PM, 49.20 +/- 18.31 MPa; PL, 49.96 +/- 14.97 MPa) (P > 0.05). The AM quadrant had higher local yield strength than the PL and PM quadrants, as did the AL compared with the PL quadrant (AL, 24.89 +/- 8.52 Mpa; AM, 28.39 +/- 10.52 Mpa; PM, 23.01 +/- 6.99; PL, 20.62 +/- 4.83 MPa) (P < 0.05). This suggests that the high frequency of radial head fractures in the AL quadrant is likely not due to the local strength of cancellous bone. Rather, the location of fracture may be influenced by the composite strength or the mechanisms of loading at the radiocapitellar and proximal radioulnar joints. The modulus results suggest that similar screw purchase can be achieved in all areas of the radial head during internal fixation of fractures. These results may also influence implant design and fixation. This study was limited to an older population and may not be representative of a younger population.
量化桡骨头软骨下骨的力学性能，特别关注骨刚度和强度的区域差异。
对从桡骨头近端获取的横向软骨下松质骨切片进行压痕试验。
配备伺服液压材料试验机的生物力学实验室。
13个先前冷冻的尸体近端桡骨，平均年龄69±9岁。
计算桡骨头前内侧（AM）、前外侧（AL）、后内侧（PM）和后外侧（PL）象限的平均压痕模量和局部屈服强度。
所有4个象限的平均压痕模量无差异（AL，55.56±16.20兆帕；AM，53.48±20.67兆帕；PM，49.20±18.31兆帕；PL，49.96±14.97兆帕）（P>0.05）。AM象限的局部屈服强度高于PL和PM象限，AL象限与PL象限相比也是如此（AL，24.89±8.52兆帕；AM，28.39±10.52兆帕；PM，23.01±6.99；PL，20.62±4.83兆帕）（P<0.05）。这表明AL象限桡骨头骨折的高发生率可能并非由于松质骨的局部强度。相反，骨折位置可能受桡肱关节和近端桡尺关节处的复合强度或加载机制影响。模量结果表明，在骨折内固定期间，桡骨头的所有区域均可实现相似的螺钉把持力。这些结果也可能影响植入物设计和固定。本研究仅限于老年人群，可能不代表年轻人群。
