Hullfish Todd J, O'Connor Kathryn M, Baxter Josh R
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA.
PeerJ. 2019 Apr 23;7:e6788. doi: 10.7717/peerj.6788. eCollection 2019.
The purpose of this study was to characterize the short-term effects of Achilles tendon ruptures on medial gastrocnemius. We hypothesized that the fascicles of the medial gastrocnemius muscle of the injured Achilles tendon would be shorter and more pennate immediately following the injury and would persist throughout 4 weeks post-injury. B-mode longitudinal ultrasound images of the medial gastrocnemius were acquired in 10 adults who suffered acute Achilles tendon ruptures and were treated non-operatively. Ultrasound images were acquired during the initial clinical visit following injury as well as 2 and 4 weeks following this initial clinical visit. Resting muscle structure was characterized by measuring fascicle length, pennation angle, muscle thickness, and muscle echo intensity in both the injured and contralateral (control) limbs. Fascicle length was 15% shorter ( < 0.001) and pennation angle was 21% greater ( < 0.001) in the injured muscle compared to the uninjured (control) muscle at the presentation of injury (week 0). These differences in fascicle length persisted through 4 weeks after injury ( < 0.002) and pennation angle returned to pre-injury levels. Muscle thickness changes were not detected at any of the post-injury visits (difference < 4%, > 0.026). Echo intensity of the injured limb was 8% lower at the presentation of the injury but was not different compared to the contralateral muscle at 2 and 4 weeks post-injury. Our results suggest that Achilles tendon ruptures elicit rapid changes in the configuration of the medial gastrocnemius, which may explain long-term functional deficits.
本研究的目的是描述跟腱断裂对腓肠肌内侧头的短期影响。我们假设，受伤跟腱的腓肠肌内侧头肌束在受伤后即刻会更短且更羽状化，并在受伤后4周内持续存在。对10例急性跟腱断裂且接受非手术治疗的成年人获取了腓肠肌内侧头的B型纵向超声图像。在受伤后的初次临床就诊时以及初次临床就诊后的2周和4周获取超声图像。通过测量受伤侧和对侧（对照）肢体的肌束长度、羽状角、肌肉厚度和肌肉回声强度来表征静息肌肉结构。在受伤时（第0周），与未受伤（对照）肌肉相比，受伤肌肉的肌束长度短15%（<0.001），羽状角大21%（<0.001）。这些肌束长度的差异在受伤后4周内持续存在（<0.002），羽状角恢复到受伤前水平。在任何受伤后的就诊中均未检测到肌肉厚度变化（差异<4%，>0.026）。受伤肢体在受伤时的回声强度低8%，但在受伤后2周和4周时与对侧肌肉无差异。我们的结果表明，跟腱断裂会引起腓肠肌内侧头形态的快速变化，这可能解释了长期的功能缺陷。
