Hayami Naoki, Omokawa Shohei, Iida Akio, Kraisarin Jirachart, Moritomo Hisao, Mahakkanukrauh Pasuk, Shimizu Takamasa, Kawamura Kenji, Tanaka Yasuhito
Department of Orthopedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara City, Nara Prefecture, Japan.
Department of Hand Surgery, Nara Medical University, 840 Shijo-cho, Kashihara City, Nara Prefecture, Japan.
BMC Musculoskelet Disord. 2017 Nov 21;18(1):470. doi: 10.1186/s12891-017-1829-1.
Isolated radial head dislocation is a rare injury with an unclear pathomechanism, and the treatment is controversial. The purpose of the present study was to investigate the biomechanical contributions of the annular ligament, quadrate ligament, interosseous membrane, and annular ligament reconstructions to proximal radioulnar joint stability.
Five fresh frozen cadaveric upper extremities were amputated above the elbow and solidly fixed on a customized jig. Radial head dislocation was reproduced by sequential sectioning of ligamentous structures and passive mobility testing. Radial head displacement during mobility testing was measured with an electromagnetic tracking device in three forearm rotation positions. The data were compared among different sectioning stages and between two types of simulated ligamentous reconstruction.
Lateral displacement of the radial head significantly increased in the neutral forearm rotation after annular ligament sectioning (46 ± 10%, p < 0.05). After quadrate ligament sectioning, we found significant posterior (67 ± 36%, p < 0.05) and lateral (74 ± 24%, p < 0.01) displacement in neutral forearm rotation and pronation. Significant radial head displacement was found in all directions and in all forearm positions after sequential sectioning of the proximal half of the interosseous membrane. Anatomical annular ligament reconstruction stabilized the proximal radioulnar joint except for anterior laxity in neutral forearm rotation (15 ± 6%, p < 0.05). The radial head with Bell Tawse procedure was significantly displaced in all directions.
The direction of radial head instability varied depending on the degree of soft tissue sectioning and specific forearm rotation. Anterior radial head dislocation may involve more severe ligament damage than other types of dislocation. Anatomical annular ligament reconstruction provided multidirectional radial head stability.
单纯桡骨头脱位是一种罕见损伤，其发病机制尚不清楚，治疗方法存在争议。本研究的目的是探讨环状韧带、方形韧带、骨间膜及环状韧带重建对近端桡尺关节稳定性的生物力学贡献。
将5具新鲜冷冻尸体的上肢在肘部上方截断，并牢固固定在定制夹具上。通过依次切断韧带结构并进行被动活动度测试来重现桡骨头脱位。在三个前臂旋转位置使用电磁跟踪装置测量活动度测试期间的桡骨头位移。对不同切断阶段以及两种模拟韧带重建之间的数据进行比较。
切断环状韧带后，在前臂中立旋转位时桡骨头的外侧位移显著增加（46±10%，p<0.05）。切断方形韧带后，在前臂中立旋转位和旋前位时，我们发现桡骨头有显著的向后（67±36%，p<0.05）和外侧（74±24%，p<0.01）位移。依次切断骨间膜近端一半后，在所有方向和所有前臂位置均发现桡骨头有显著位移。解剖学环状韧带重建使近端桡尺关节稳定，但在前臂中立旋转位时有前侧松弛（15±6%，p<0.05）。采用贝尔·陶斯手术的桡骨头在所有方向均有显著位移。
桡骨头不稳定的方向因软组织切断程度和特定的前臂旋转而异。桡骨头前脱位可能比其他类型的脱位涉及更严重的韧带损伤。解剖学环状韧带重建提供了多方向的桡骨头稳定性。
