Hand and Upper Limb Centre, St. Joseph's Health Care, 268 Grosvenor St., London, Ontario, Canada.
J Shoulder Elbow Surg. 2013 Sep;22(9):1242-7. doi: 10.1016/j.jse.2013.02.013. Epub 2013 May 2.
As more anatomic asymmetric radial head implants emerge, it is necessary to determine the optimal landmarks to ensure correct rotational orientation. The bicipital tuberosity and distal radius are possible bony landmarks that can be used for rotational alignment of asymmetric prostheses; however, they have not been validated. The purpose of this study was to evaluate the reliability of the bicipital tuberosity and distal radius as rotational landmarks for orientation of asymmetric radial head prostheses.
Measurements were made from computer tomography scans of 50 elbows in order to determine the rotational relationships between the radial head, bicipital tuberosity, biceps tendon footprint, and distal radius.
The maximum radial head diameter was oriented 65° ± 28° from the bicipital tuberosity, 119° ± 38° from the biceps tendon footprint, 82° ± 29° from the radial styloid, and 76° ± 28° from the volar surface of the distal radius. All of these landmarks had a significantly greater variance than a proposed acceptable clinical tolerance of 10° (P < .001).
The results demonstrate that the measured landmarks show no consistent rotational relationship with the maximum diameter of the radial head. In order to maximize the utility of more anatomic asymmetric radial head implant systems, further studies are necessary to identify more reliable rotational landmarks to ensure optimal implant positioning.
随着越来越多的解剖非对称桡骨小头植入物的出现，有必要确定最佳的标志点，以确保正确的旋转方向。肱二头肌结节和桡骨远端是可能的骨性标志点，可用于不对称假体的旋转对线；然而，它们尚未得到验证。本研究的目的是评估肱二头肌结节和桡骨远端作为旋转标志点用于定向非对称桡骨小头假体的可靠性。
对 50 个肘部的计算机断层扫描进行测量，以确定桡骨头、肱二头肌结节、肱二头肌肌腱止点和桡骨远端之间的旋转关系。
桡骨头最大直径与肱二头肌结节的夹角为 65°±28°，与肱二头肌肌腱止点的夹角为 119°±38°，与桡骨茎突的夹角为 82°±29°，与桡骨远端掌面的夹角为 76°±28°。所有这些标志点的方差都明显大于建议的 10°临床可接受公差（P<0.001）。
结果表明，所测量的标志点与桡骨头的最大直径之间没有一致的旋转关系。为了最大限度地利用更多解剖非对称桡骨小头植入物系统，有必要进一步研究以确定更可靠的旋转标志点，以确保最佳植入物定位。
