Department of Surgery, Western University, Roth | McFarlane Hand and Upper Limb Centre Bioengineering Laboratory, St. Joseph's Health Care, London, ON, Canada.
Schulich School of Medicine & Dentistry, Western University, Roth | McFarlane Hand and Upper Limb Centre Bioengineering Laboratory, St. Joseph's Health Care, London, ON, Canada.
J Shoulder Elbow Surg. 2014 Apr;23(4):463-9. doi: 10.1016/j.jse.2013.11.026. Epub 2014 Feb 20.
The optimal articular shape for distal humeral hemiarthroplasty has not been defined because of a paucity of data quantifying the morphology of the normal distal humerus. This study defines the osseous anatomy and anatomic variability of the distal humerus using 3-dimensional imaging techniques.
Three-dimensional surface models were created from computed tomography scans obtained from 50 unpaired human cadaveric elbows. Geometric centers of the capitellum and the trochlear groove defined the anatomic flexion-extension axis. A coordinate system was created, and the distal humerus was sectioned into 100 slices along this axis. The C line was defined as the line of best fit connecting the geometric centers of each of the slices.
The anatomic flexion-extension axis of the distal humerus was found to be an average of 1° ± 1° from the C line (range, 0°-3°) in the coronal plane and 2° ± 1° (range, 0°-7°) in the transverse plane. The average trochlear width was 22 ± 3 mm, and the average trochlear height was 18 ± 2 mm. The mean width of the capitellum was 17 ± 2 mm; the height was 23 ± 2 mm (P < .001).
The difference in the capitellum width and height demonstrates that the capitellum is ellipsoid, not spherical. A data bank of humeral dimensions may be used for the development of future distal humeral hemiarthroplasty implants. A more anatomic implant may optimize kinematics and maximize contact area, thus minimizing contact stresses on the native ulna and radius.
由于缺乏量化正常肱骨远端形态的资料，因此尚未确定肱骨远端半关节成形术的最佳关节形状。本研究使用三维成像技术定义了肱骨远端的骨骼解剖结构和解剖变异性。
从 50 个未配对的人体尸体肘部获得的计算机断层扫描创建了三维表面模型。肱骨头和滑车沟的几何中心定义了解剖屈伸轴。创建了一个坐标系，并沿该轴将肱骨远端分为 100 个切片。C 线定义为连接每个切片的几何中心的最佳拟合线。
发现肱骨远端的解剖屈伸轴在冠状面平均偏离 C 线 1°±1°（范围为 0°-3°），在横断面上平均偏离 C 线 2°±1°（范围为 0°-7°）。滑车的平均宽度为 22±3mm，平均滑车高度为 18±2mm。肱骨小头的平均宽度为 17±2mm；高度为 23±2mm（P<0.001）。
肱骨小头的宽度和高度的差异表明，肱骨小头呈椭圆形，而不是球形。肱骨尺寸数据库可用于未来肱骨远端半关节成形术植入物的开发。更符合解剖结构的植入物可以优化运动学并最大化接触面积，从而最小化对原生尺骨和桡骨的接触应力。
