Budoff Jeffrey E, Lin Cheng-Li, Hong Chih-Kai, Chiang Florence L, Su Wei-Ren
Department of Orthopaedic Surgery, University of Texas, Houston, TX, USA.
Department of Orthopaedic Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
J Shoulder Elbow Surg. 2016 Jun;25(6):967-72. doi: 10.1016/j.jse.2015.10.022. Epub 2016 Jan 14.
Coracoacromial ligament (CAL) excision and acromioplasty increase superior and anterosuperior glenohumeral translation. It is unknown how much of an increase in rotator cuff force production is required to re-establish intact glenohumeral biomechanics after these surgical procedures. We hypothesized that, after CAL excision and acromioplasty, an increase in rotator cuff force production would not be necessary to reproduce the anterosuperior and superior translations of the intact specimens.
Nine cadaveric shoulders were subjected to loading in the superior and anterosuperior directions in the intact state after CAL excision, acromioplasty, and recording of the translations. The rotator cuff force was then increased to normalize glenohumeral biomechanics.
After CAL excision at 150 and 200 N of loading, an increase in the rotator cuff force by 25% decreased anterosuperior translation to the point where there was no significant difference from the intact specimen's translation. After acromioplasty (and CAL excision) at 150 and 200 N, an increase in the rotator cuff force of 25% and 30%, respectively, decreased superior translation to the point where there was no significant difference from the intact specimen's translation.
At 150 to 200 N of loading, CAL excision and acromioplasty increase the rotator cuff force required to maintain normal glenohumeral biomechanics by 25% to 30%.
After a subacromial decompression, the rotator cuff has an increased force production requirement to maintain baseline glenohumeral mechanics. Under many circumstances, in vivo force requirements may be even greater after surgical attenuation of the coracoacromial arch.
Basic Science Study; Biomechanics.
喙肩韧带（CAL）切除及肩峰成形术会增加肱盂关节向上及前上方的平移。目前尚不清楚在这些手术操作后，需要增加多少肩袖肌力才能重建完整的肱盂关节生物力学。我们假设，在CAL切除及肩峰成形术后，无需增加肩袖肌力即可重现完整标本的前上方及上方平移。
对9具尸体肩部在完整状态下、CAL切除后、肩峰成形术后进行向上及前上方加载，并记录平移情况。然后增加肩袖肌力以使肱盂关节生物力学正常化。
在CAL切除后，加载150 N和200 N时，肩袖肌力增加25%可使前上方平移减少至与完整标本平移无显著差异的程度。在肩峰成形术（及CAL切除）后，加载150 N和200 N时，肩袖肌力分别增加25%和30%可使上方平移减少至与完整标本平移无显著差异的程度。
在150至200 N的加载下，CAL切除及肩峰成形术使维持正常肱盂关节生物力学所需的肩袖肌力增加25%至30%。
肩峰下减压术后，肩袖需要增加肌力以维持肱盂关节力学基线。在许多情况下，喙肩弓手术减弱后，体内的肌力需求可能更大。
基础科学研究；生物力学。
