Ahmad Christopher S, DiSipio Catherine, Lester Jonathon, Gardner Thomas R, Levine William N, Bigliani Louis U
Center for Shoulder, Elbow, and Sports Medicine, Department of Orthopaedic Surgery, Columbia University, New York, New York, USA.
Arthroscopy. 2007 May;23(5):537-41. doi: 10.1016/j.arthro.2006.12.030.
The anatomic and biomechanical factors that influence distal migration of the long head of the biceps tendon (LHBT) after biceps tenotomy procedures are currently not known. This study evaluates the morphology of the proximal LHBT and the force required to cause the biceps to drop distally after tenotomy.
Fourteen human fresh-frozen cadaveric shoulders (mean age, 63.6 years) were inspected and placed into diseased and healthy LHBT groups. Diseased tendons showed degenerative changes of fraying, splitting, or hypertrophy, whereas healthy tendons were opaque and intact. The humerus was fixed and the LHBT was detached from the glenoid. The biceps tendon inferior to the bicipital groove was secured to the head of a materials testing device. Force data were recorded to pull the LHBT through the bicipital groove. The tendons were then frozen and cut into 5-mm sections. Digital pictures were taken perpendicular to the sections, and imaging software was used to measure the cross-sectional areas and tendon morphology.
Of the LHBTs, 7 were diseased and 7 were healthy. The force required to simulate a dropped biceps deformity was significantly greater in the diseased tendons than in the healthy tendons (mean, 33.03 +/- 10.46 N v 21.61 +/- 9.1 N; P < .05). The maximum tendon cross-sectional area was also larger in the diseased tendons than in the healthy tendons (mean, 91.29 +/- 39.33 mm2 v 63.93 +/- 19.77 mm2; P = .1). Diseased tendons had broader cross-sectional dimensions (flattening) than healthy tendons (mean, 16.39 +/- 1.50 mm v 10.97 +/- 1.48 mm; P < .05).
This study shows that diseased tendons with greater flattening have increased force required to travel through the bicipital groove.
These data help explain the clinical observation that cosmetic deformity may not result after biceps tenotomy in tendons with disease causing hypertrophy and flattening.
目前尚不清楚在肱二头肌肌腱切断术后影响肱二头肌长头肌腱（LHBT）向远侧移位的解剖学和生物力学因素。本研究评估了LHBT近端的形态以及肌腱切断术后使肱二头肌向远侧下垂所需的力。
检查14个新鲜冷冻的人体尸体肩部（平均年龄63.6岁），并将其分为病变LHBT组和健康LHBT组。病变肌腱表现出磨损、撕裂或肥大等退行性改变，而健康肌腱不透明且完整。固定肱骨，将LHBT从关节盂上分离。将肱二头肌沟下方的肱二头肌肌腱固定在材料测试装置的头部。记录使LHBT穿过肱二头肌沟的力数据。然后将肌腱冷冻并切成5毫米的切片。拍摄垂直于切片的数码照片，并使用成像软件测量横截面积和肌腱形态。
14条LHBT中，7条为病变肌腱，7条为健康肌腱。模拟肱二头肌下垂畸形所需的力在病变肌腱中显著大于健康肌腱（平均分别为33.03±10.46 N和21.61±9.1 N；P<.05）。病变肌腱的最大肌腱横截面积也大于健康肌腱（平均分别为91.29±39.33 mm²和63.93±19.77 mm²；P = 0.1）。病变肌腱的横截面积尺寸（变扁平）比健康肌腱更宽（平均分别为16.39±1.50 mm和10.97±1.48 mm；P<.05）。
本研究表明，变扁平程度更大的病变肌腱穿过肱二头肌沟所需的力增加。
这些数据有助于解释临床观察结果，即在因疾病导致肥大和扁平的肌腱进行肱二头肌肌腱切断术后可能不会出现外观畸形。
