Young C M, Rayan G M
Hand Surgery Section, Orthopedic Surgery Department, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
J Hand Surg Am. 2000 Nov;25(6):1107-13. doi: 10.1053/jhsu.2000.18495.
Forty-eight digits from 12 human adult fresh-frozen and formalin-preserved cadaveric hands were used to study the anatomy and biomechanics of the sagittal band (SB) and to investigate the mechanism of its injury. The SB was observed to be part of a complex retinacular system in proximity to the metacarpophalangeal (MCP) joint collateral ligaments and the palmar plate. Dynamic changes in SB fiber orientation were observed with different positions of the MCP and wrist joints. The fibers were perpendicular (0 degrees ) to the extensor tendon in neutral position, distally angulated 25 degrees at 45 degrees of MCP flexion, and 55 degrees with full flexion. Swan-Ganz catheter measurements were obtained deep to the SB in varying positions of the MCP joint. The average pressure generation was greatest (50 mm Hg) during full MCP joint flexion and least (30 mm Hg) during 45 degrees flexion. When MCP joint radial or ulnar deviation was added the average measurement was greatest (57) in neutral MCP position and least (35 mm Hg) in 45 degrees flexion. Serial sectioning of the ulnar SB produced no extensor tendon instability. Partial proximal but not distal sectioning of the radial SB produced tendon subluxation. Complete sectioning of the radial SB produced tendon dislocation. Wrist flexion increased tendon instability after radial SB sectioning. We conclude that (1) extensor tendon instability following SB disruption is most common in the long finger and least common in the small finger; (2) ulnar instability of the extensor tendon is due to partial or complete radial SB disruption, (3) the degree of extensor tendon instability is determined by the extent of SB disruption, (4) proximal rather than distal SB compromise contributes to extensor tendon instability, (5) great forces are inflicted on the SB while the MCP joint is in full extension or less frequently in full flexion, which may be the mechanism of its injury, and (6) wrist flexion contributes to extensor tendon instability after SB disruption and may exacerbate the severity of its injury.
使用来自12具成人新鲜冷冻和福尔马林固定尸体手的48个手指来研究矢状带（SB）的解剖结构和生物力学，并探究其损伤机制。观察到SB是一个复杂的支持带系统的一部分，靠近掌指（MCP）关节侧副韧带和掌板。随着MCP和腕关节处于不同位置，观察到SB纤维方向的动态变化。在中立位时，纤维与伸肌腱垂直（0度），在MCP屈曲45度时向远端成角25度，在完全屈曲时成角55度。在MCP关节的不同位置，在SB深部进行Swan-Ganz导管测量。在MCP关节完全屈曲时平均压力产生最大（50 mmHg），在45度屈曲时最小（30 mmHg）。当增加MCP关节桡偏或尺偏时，平均测量值在MCP中立位时最大（57），在45度屈曲时最小（35 mmHg）。尺侧SB的连续切片未导致伸肌腱不稳定。桡侧SB近端部分而非远端部分的切片导致肌腱半脱位。桡侧SB完全切片导致肌腱脱位。腕关节屈曲在桡侧SB切片后增加了肌腱不稳定。我们得出结论：（1）SB断裂后伸肌腱不稳定在示指最常见，在小指最不常见；（2）伸肌腱尺侧不稳定是由于桡侧SB部分或完全断裂；（3）伸肌腱不稳定的程度由SB断裂的程度决定；（4）SB近端而非远端受损导致伸肌腱不稳定；（5）在MCP关节完全伸展时或较少见地在完全屈曲时，SB会受到很大力量，这可能是其损伤机制；（6）腕关节屈曲在SB断裂后导致伸肌腱不稳定，并可能加重其损伤的严重程度。
