Catholic Institute for Applied Anatomy, Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul, 06591, Republic of Korea.
Department of Anatomy and Acupoint, College of Korean Medicine, Gachon University, Seongnam, 13120, South Korea.
J Anat. 2023 Sep;243(3):467-474. doi: 10.1111/joa.13868. Epub 2023 Mar 29.
Myofascial pain syndrome caused by myofascial trigger points is a musculoskeletal disorder commonly encountered in clinical practice. The infraspinatus muscle is the region most frequently involved in the myofascial pain syndrome in the scapular region. The characteristics of the myofascial trigger points are that they can be found constantly in the motor endplate zone. However, localizing myofascial trigger points within the motor endplate zone and establishing an accurate injection site of the infraspinatus muscle has been challenging because the anatomical position of the motor endplate zone of the infraspinatus muscle is yet to be described. Therefore, this cadaveric study aimed to scrutinize the motor endplate zone of the infraspinatus muscle, propose potential myofascial trigger points within the muscle, and recommend therapeutic injection sites. Twenty specimens of the infraspinatus muscle for nerve staining and 10 fresh frozen cadavers for evaluation of the injection were used in this study. The number of nerve branches penetrating the infraspinatus muscle and their entry locations were analyzed and photographed. Modified Sihler's staining was performed to examine the motor endplate regions of the infraspinatus muscle. The nerve entry points were mostly observed in the center of the muscle belly. The motor endplate was distributed equally throughout the infraspinatus muscle, but the motor endplate zone was primarily identified in the B area, which is approximately 20-40% proximal to the infraspinatus muscle. The second-most common occurrence of the motor endplate zone was observed in the center of the muscle. These detailed anatomical data would be very helpful in predicting potential pain sites and establishing safe and effective injection treatment using botulinum neurotoxin, steroids, or lidocaine to alleviate the pain disorder of the infraspinatus muscle.
肌筋膜触发点引起的肌筋膜疼痛综合征是临床实践中常见的一种肌肉骨骼疾病。肩胛区的冈下肌是肌筋膜疼痛综合征中最常受累的区域。肌筋膜触发点的特征是可以在运动终板区域内持续存在。然而，由于冈下肌运动终板区域的解剖位置尚未描述，因此定位肌筋膜触发点在运动终板区域内并确定冈下肌的准确注射部位一直具有挑战性。因此，这项尸体研究旨在仔细研究冈下肌的运动终板区域，提出肌肉内潜在的肌筋膜触发点，并推荐治疗性注射部位。本研究使用了 20 个用于神经染色的冈下肌标本和 10 个用于评估注射的新鲜冷冻尸体。分析并拍摄了穿透冈下肌的神经分支数量及其进入位置。对冈下肌的运动终板区域进行了改良的 Sihler 染色。神经进入点主要观察到在肌腹的中心。运动终板在冈下肌中均匀分布，但运动终板区域主要在 B 区确定，B 区约位于冈下肌近端 20-40%处。运动终板区域的第二常见发生部位是在肌肉中心。这些详细的解剖学数据对于预测潜在疼痛部位以及使用肉毒毒素、类固醇或利多卡因进行安全有效的注射治疗以缓解冈下肌疼痛障碍非常有帮助。
