Hojo Junya, Omokawa Shohei, Iida Akio, Ono Hiroshi, Moritomo Hisao, Tanaka Yasuhito
Department of Orthopedic Surgery, Heisei Memorial Hospital, Nara Medical University, Nara, Japan.
Department of Hand Surgery, Nara Medical University, Nara, Japan.
J Hand Surg Am. 2019 Apr;44(4):336.e1-336.e6. doi: 10.1016/j.jhsa.2018.06.019. Epub 2018 Aug 16.
To assess the wrist joints of healthy volunteers in extended and loaded states versus the unloaded state by using computed tomography (CT) to analyze the in vivo 3-dimensional movements in the distal radioulnar joint (DRUJ).
The dominant arms of 9 volunteers with healthy wrists were studied. We mounted a compression device onto the elbows in an inverted position. A 0-kg and 7-kg load each was applied during low-dose radiation CT imaging and a bone model was produced. We marked the insertion sites for the 4 radioulnar ligaments stabilizing the DRUJ: palmar superficial radioulnar ligament (PS-RUL), dorsal superficial radioulnar ligament (DS-RUL), dorsal deep radioulnar ligament (DD-RUL), and palmar deep radioulnar ligament (PD-RUL). Using Marai's method, each ligament was virtualized and the length of each simulated ligament was measured. We also computed the 3-dimensional displacement and corresponding rotation of the distal ulna where it comes into contact with the radius in the sigmoid notch.
The lengths of palmar ligaments (PS-RUL and PD-RUL) increased significantly under loaded conditions, and although not significant, the length of dorsal ligaments (DS-RUL and DD-RUL) tended to increase. When the wrist was loaded, the ulna rotated toward the open palmar side.
The length of simulated radioulnar ligaments increased when the wrist joint was loaded in an extended position. This kinematic movement of DRUJ separation under a loading condition is different from physiological active movement.
The 3-dimensional kinematic analysis revealed that palmar radioulnar ligaments were stretched during axial loading, suggesting that a tear of the palmer ligament can result from a fall on an outstretched hand.
通过计算机断层扫描（CT）评估健康志愿者在伸展和负重状态下与非负重状态下的腕关节，以分析桡尺远侧关节（DRUJ）的体内三维运动。
对9名腕关节健康志愿者的优势手臂进行研究。我们将一个压缩装置倒置安装在肘部。在低剂量辐射CT成像期间分别施加0 kg和7 kg的负荷，并生成骨模型。我们标记了稳定DRUJ的4条桡尺韧带的附着点：掌侧浅桡尺韧带（PS-RUL）、背侧浅桡尺韧带（DS-RUL）、背侧深桡尺韧带（DD-RUL）和掌侧深桡尺韧带（PD-RUL）。使用Marai方法，将每条韧带虚拟化为三维模型并测量每条模拟韧带的长度。我们还计算了尺骨远端在乙状切迹处与桡骨接触点的三维位移和相应旋转。
在负重条件下，掌侧韧带（PS-RUL和PD-RUL）的长度显著增加，背侧韧带（DS-RUL和DD-RUL）的长度虽无显著增加，但有增加趋势。当手腕负重时，尺骨向手掌开放侧旋转。
当腕关节在伸展位负重时，模拟桡尺韧带的长度增加。这种负重条件下DRUJ分离的运动学变化不同于生理性主动运动。
三维运动学分析显示，轴向负重时掌侧桡尺韧带被拉伸，提示手掌着地摔倒可能导致掌侧韧带撕裂。
