Vahey J W, Wegner D A, Hastings H
Orthopaedic Specialists of Nevada, Las Vegas 89106, USA.
J Hand Surg Am. 1998 Jul;23(4):673-81. doi: 10.1016/s0363-5023(98)80054-3.
Extensor lag is a common sequella of proximal phalangeal fractures. Proximal phalangeal fractures frequently lead to extensor tendon dysfunction via adhesions and phalanx malunion with angulation and/or shortening. The primary purpose of this study was to quantify the influence of proximal phalangeal angulation and shortening on proximal interphalangeal (PIP) joint extension by examining the effect of isolated proximal phalangeal bone to extensor digitorum communis tendon discrepancy on PIP joint lag. The secondary goal was to determine the reserve of the extensor digitorum communis to overcome the PIP joint lag. A proximal phalangeal bone-extensor tendon discrepancy results in either a PIP lag or a potential lag that must be compensated for by another system, such as by overpull of the extrinsic extensor or by the pull of the intrinsics. Six cadaveric middle fingers were used, proximal phalangeal malunions were simulated, and the extensor lag was measured radiographically. A linear relationship between extensor tendon lengthening and the resulting PIP lag was observed. Similarly, a linear relationship between proximal phalangeal shortening and the lag was observed. For both, the average slope was 12 degrees of lag/mm of bone-tendon discrepancy. For average apex palmar angulations of 16 degrees, 27 degrees, and 46 degrees, PIP lags of 10 degrees, 24 degrees, and 66 degrees, respectively, resulted. The extensor tendon reserve was 2 to 6 mm. The sagittal bands became tight at the limits of the extensor tendon reserve. The results of this study quantify the importance of re-establishing the bone-tendon relationship for proximal phalangeal fractures.
伸肌滞后是近节指骨骨折常见的后遗症。近节指骨骨折常通过粘连以及伴有成角和/或短缩的指骨畸形愈合导致伸肌腱功能障碍。本研究的主要目的是通过检查孤立的近节指骨与指总伸肌腱差异对近端指间（PIP）关节滞后的影响，来量化近节指骨成角和短缩对PIP关节伸展的影响。次要目标是确定指总伸肌克服PIP关节滞后的储备能力。近节指骨与伸肌腱的差异会导致PIP关节滞后或潜在滞后，这必须由另一个系统来代偿，例如通过外在伸肌的过度牵拉或内在肌的牵拉。使用了六具尸体的中指，模拟近节指骨畸形愈合，并通过放射学测量伸肌滞后。观察到伸肌腱延长与由此产生的PIP关节滞后之间存在线性关系。同样，也观察到近节指骨短缩与滞后之间存在线性关系。对于两者，平均斜率均为每毫米骨-肌腱差异12度滞后。对于平均掌侧成角分别为16度、27度和46度的情况，PIP关节滞后分别为10度、24度和66度。伸肌腱储备为2至6毫米。在伸肌腱储备极限时，矢状带会变紧。本研究结果量化了重建近节指骨骨折骨-肌腱关系的重要性。
