Lieber R L, Pontén E, Burkholder T J, Fridén J
Department of Orthopaedics, University of California, San Diego, USA.
J Hand Surg Am. 1996 Jul;21(4):612-8. doi: 10.1016/S0363-5023(96)80012-8.
Sarcomere length was measured intraoperatively on five patients undergoing tendon transfer of the flexor carpi ulnaris (FCU) to the extensor digitorum communis (EDC) for radial nerve palsy. The most significant result was that the absolute sarcomere length and sarcomere length operating range of the FCU increased after transfer into the EDC (p < .001). Preoperatively, with the wrist fully extended and fingers flexed, FCU sarcomere length was 4.22 +/- .24 microns and decreased to 3.19 +/- .05 microns as the wrist was fully flexed. This represented an overall sarcomere length range of 1.03 microns. After the tendon transfer using standard recommended techniques, all sarcomere lengths were significantly longer (p < .001). Specifically, sarcomeres were 0.74 +/- .14 microns longer with the muscle in its fully lengthened position (4.96 +/- .43 microns with the wrist and digits flexed) and 0.31 +/- .16 microns longer with the FCU in the fully shortened position (3.50 +/- .06 microns with the wrist and digits extended). At these sarcomere lengths, the FCU muscle was predicted to develop relatively high force only during movement involving synergistic wrist flexion and finger extension. Under the conditions of the procedures performed, the transferred FCU muscle was predicted to produce maximum force over the range of about 30 degrees of wrist flexion and 0 degree of finger flexion to 70 degrees of wrist extension and 90 degrees of finger flexion. While this is acceptable, a more desirable result was predicted to occur if the muscle was transferred at a longer length. In this latter case, greater stretch of the FCU during transfer (increasing sarcomere length to about 5 microns) was predicted to improve the transfer. The more highly stretched FCU was predicted to result in maximum force as the wrist and fingers progressed from about 60 degrees of wrist extension and 0 degree of finger flexion to 80 degrees of wrist extension and 70 degrees of finger flexion. These results quantify the relationship between the passive tension chosen for transfer, sarcomere length, and the estimated active tension that can be generated by the muscle. The results also demonstrate the feasibility of using intraoperative laser diffraction during tendon transfer as a guide for optimal placement of the transferred muscle.
对5例因桡神经麻痹而接受尺侧腕屈肌（FCU）转位至指总伸肌（EDC）肌腱转位手术的患者，术中测量了肌节长度。最显著的结果是，FCU转位至EDC后，其绝对肌节长度和肌节长度操作范围增加（p < 0.001）。术前，腕关节完全伸展且手指屈曲时，FCU肌节长度为4.22±0.24微米，当腕关节完全屈曲时，肌节长度降至3.19±0.05微米。这代表肌节长度的总体范围为1.03微米。使用标准推荐技术进行肌腱转位后，所有肌节长度均显著变长（p < 0.001）。具体而言，肌肉处于完全拉长位置时（腕关节和手指屈曲时为4.96±0.43微米），肌节长0.74±0.14微米，FCU处于完全缩短位置时（腕关节和手指伸展时为3.50±0.06微米），肌节长0.31±0.16微米。在这些肌节长度下，预计FCU肌肉仅在涉及协同性腕关节屈曲和手指伸展的运动中产生相对较高的力量。在所进行手术的条件下，预计转位的FCU肌肉在腕关节屈曲约30度且手指屈曲0度至腕关节伸展70度且手指屈曲90度的范围内产生最大力量。虽然这是可以接受的，但如果肌肉在更长的长度下转位，预计会出现更理想的结果。在后一种情况下，预计转位过程中FCU更大程度的拉伸（将肌节长度增加至约5微米）会改善转位效果。预计当腕关节和手指从腕关节伸展约60度且手指屈曲0度进展至腕关节伸展80度且手指屈曲70度时，拉伸程度更高的FCU会产生最大力量。这些结果量化了转位时选择的被动张力、肌节长度与肌肉可产生的估计主动张力之间的关系。结果还证明了在肌腱转位过程中使用术中激光衍射作为转位肌肉最佳放置指导的可行性。
