Lyons R P, Kozin S H, Failla J M
U.S. Air Force, Aviano Air Force Base, Italy.
Am J Orthop (Belle Mead NJ). 1998 Nov;27(11):759-63.
This study sought to define the anatomic variations of the radial side of the thumb metacarpophalangeal joint and to assess the contributions of the radial structures to stability. In Part I, the radial side of the thumb metacarpophalangeal joint was studied in 31 cadavers, showing that the extensor pollicis brevis insertion was variable. In Part II, 13 additional hands were studied to evaluate the static restraints to rotation and subluxation, showing that variability in the amount of volar subluxation and pronation was possible in the intact thumb. This study showed that the radial collateral ligament and extensor pollicis brevis capsule collectively contribute to stability against rotation and volar subluxation. We found roentgenograms with a pure volar displacement force to be more helpful than pronation stress roentgenograms in showing metacarpophalangeal instability after injury. This instability may require surgery to repair the injured structures and restore the stability to varus stress and volar subluxation.
本研究旨在明确拇指掌指关节桡侧的解剖变异，并评估桡侧结构对稳定性的作用。在第一部分中，对31具尸体的拇指掌指关节桡侧进行了研究，结果显示拇短伸肌止点存在变异。在第二部分中，又对另外13只手进行了研究，以评估对旋转和半脱位的静态限制，结果表明在完整的拇指中，掌侧半脱位和旋前的程度存在变异是可能的。本研究表明，桡侧副韧带和拇短伸肌腱鞘共同有助于抵抗旋转和掌侧半脱位。我们发现，在显示损伤后掌指关节不稳定方面，单纯掌侧移位力的X线片比旋前应力X线片更有帮助。这种不稳定可能需要手术修复受损结构，并恢复对内翻应力和掌侧半脱位的稳定性。
