Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY.
Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, NY.
J Hand Surg Am. 2021 May;46(5):368-376. doi: 10.1016/j.jhsa.2020.12.015. Epub 2021 Mar 23.
This study evaluated the biomechanics of Geissler IV (G4) wrists in cadavers and compared them with intact specimens after multiple ligament sectioning to create scapholunate instability. It also evaluated carpal motion changes after sectioning of the lunotriquetral interosseous ligament (LTIL).
Eight cadaver wrists determined to be G4 arthroscopically were tested using a wrist joint motion simulator. The LTIL was then sectioned, and carpal motion was recorded again. Carpal motions were compared with 37 normal wrists after sectioning of the scapholunate interosseous ligament and other ligaments to create a G4 wrist.
Carpal motion of the 37 normal wrists after ligamentous sectioning was similar to motion of the 8 specimens noted to be G4. These wrists did not demonstrate subluxation of the scaphoid that may occur after ligament sectioning. After sectioning of the LTIL, there were significant changes in lunate and triquetral motion.
These findings support the hypothesis that sectioning multiple ligaments in normal wrists to create scapholunate instability causes average motion comparable to that seen in G4 wrists. Ligamentous sectioning can cause a range of scaphoid instability. Lunotriquetral interosseous ligament sectioning in native G4 wrists caused greater changes in triquetral than scaphoid range of motion.
Patients with arthroscopically determined G4 lesions have an incompetent SLIL and scapholunate instability but do not necessarily have scapholunate dissociation and subluxation. Cadaver studies that evaluate instability by sectioning specific intact wrist ligaments are similar to the G4 specimens and thus are a good approximation of naturally occurring wrist instability. The functionality of secondary stabilizers not seen arthroscopically may explain the differences in motion. Geissler IV wrists and ligament-sectioned wrists are points on the spectrum of carpal instability, which is determined by the extent of damage to multiple ligamentous structures.
本研究评估了尸检中 Geissler IV（G4）腕关节的生物力学，并将其与在多条韧带切断后形成舟月骨不稳定的完整标本进行比较。还评估了切断月三角骨间韧带（LTIL）后腕骨运动的变化。
使用腕关节运动模拟器测试了 8 个经关节镜检查确定为 G4 的尸体腕关节。然后切断 LTIL，并再次记录腕骨运动。将腕骨运动与 37 个正常腕关节（在切断舟月骨间韧带和其他韧带后形成 G4 腕关节）进行比较。
在切断韧带后，37 个正常腕关节的腕骨运动与 8 个被确定为 G4 的标本的运动相似。这些腕关节没有发生可能在韧带切断后发生的舟骨半脱位。切断 LTIL 后，月骨和三角骨运动有明显变化。
这些发现支持以下假说：在正常腕关节中切断多条韧带以形成舟月骨不稳定会导致与 G4 腕关节相似的平均运动。韧带切断可引起多种程度的舟骨不稳定。在天然 G4 腕关节中切断 LTIL 会导致三角骨运动范围比舟骨运动范围更大的变化。
关节镜检查确定的 G4 病变患者的 SLIL 和舟月骨不稳定，但不一定有舟月骨分离和半脱位。通过切断特定的完整腕关节韧带来评估不稳定的尸体研究与 G4 标本相似，因此是自然发生的腕关节不稳定的良好近似值。在关节镜下未观察到的次要稳定器的功能可能解释了运动的差异。G4 腕关节和韧带切断腕关节是腕骨不稳定谱上的两个点，这取决于多个韧带结构损伤的程度。
