Akimoto Koji, Ochiai Nobuyasu, Hashimoto Eiko, Sasaki Yasuhito, Nojima Daisuke, Kajiwara Daisuke, Matsuura Yusuke, Sasaki Yu, Yamaguchi Takeshi, Kijima Takehiro, Ohtori Seiji
Department of Orthopaedic Surgery, Chiba University After Graduate School of Medicine, Japan.
Department of Orthopaedic Surgery, Chiba University After Graduate School of Medicine, Japan.
J Orthop Sci. 2020 Jan;25(1):96-103. doi: 10.1016/j.jos.2019.02.007. Epub 2019 Mar 8.
Massive rotator cuff tears have a high rate of re-injury because of severe fatty infiltration. Our data showed that injuries proximal to the suprascapular nerve may be one cause of massive rotator cuff tears. The purpose of this study was to evaluate, using a rat model, how brachial plexus injury associated with a massive rotator cuff tear influences healing of the rotator cuff repair.
Seventy Sprague-Dawley rats were divided into three groups: rotator cuff tear with BP injury (DT group) (n = 28), rotator cuff tear without brachial plexus injury (T group) (n = 28), and a sham-operated group (n = 14). In the DT group, the rotator cuff tear was made and repaired 4 weeks after brachial plexus ligation. The gross assessment (evaluated the wet weight), biomechanical testing (evaluated the yield stress and the Young's modulus) and histological analyses (using the Bonar scale) were performed at baseline in the sham group, and at 4 and 12 weeks postoperatively in the DT and T groups (n = 7/group/time).
Mean wet weight and yield stress were significantly lower in the DT group than in the T group. Additionally, the mean Young's modulus was significantly higher in the DT group than in the T group. Histologically, greater tendon degeneration was observed around the musculotendinous junction in the DT group than in the T group.
The gross, biomechanical and histological data show that the repaired rotator cuff tendon with brachial plexus injury in rats does not heal as well as a repaired tendon without an accompanying brachial plexus injury. This suggests that more proximal neuropathy is one risk factor for re-tear of a repaired rotator cuff tendon.
由于严重的脂肪浸润，巨大肩袖撕裂的再损伤率很高。我们的数据表明，肩胛上神经近端的损伤可能是巨大肩袖撕裂的原因之一。本研究的目的是使用大鼠模型评估与巨大肩袖撕裂相关的臂丛神经损伤如何影响肩袖修复的愈合。
70只Sprague-Dawley大鼠分为三组：伴有臂丛神经损伤的肩袖撕裂组（DT组）（n = 28）、不伴有臂丛神经损伤的肩袖撕裂组（T组）（n = 28）和假手术组（n = 14）。在DT组中，在臂丛神经结扎4周后制造肩袖撕裂并进行修复。在假手术组的基线时，以及在DT组和T组术后4周和12周进行大体评估（评估湿重）、生物力学测试（评估屈服应力和杨氏模量）和组织学分析（使用博纳尔量表）（每组/每次n = 7）。
DT组的平均湿重和屈服应力显著低于T组。此外，DT组的平均杨氏模量显著高于T组。组织学上，DT组在肌腱-肌肉连接处周围观察到比T组更严重的肌腱退变。
大体、生物力学和组织学数据表明大鼠中伴有臂丛神经损伤的修复后的肩袖肌腱愈合情况不如不伴有臂丛神经损伤的修复后的肌腱。这表明更近端的神经病变是修复后的肩袖肌腱再次撕裂的一个风险因素。
