Omid Reza, Heckmann Nathanael, Wang Lawrence, McGarry Michelle H, Vangsness C Thomas, Lee Thay Q
Department of Orthopaedic Surgery, University of Southern California Keck School of Medicine, Los Angeles, CA, USA.
Orthopaedic Biomechanics Laboratory, VA Long Beach Healthcare System, Long Beach, CA, USA.
J Shoulder Elbow Surg. 2015 Oct;24(10):1635-43. doi: 10.1016/j.jse.2015.02.008. Epub 2015 Apr 3.
The purpose of this study was to characterize the biomechanical effects of the lower trapezius transfer and to compare it with the latissimus dorsi transfer in a cadaveric model of a massive posterosuperior rotator cuff tear.
Eight cadaveric shoulders were tested at 0°, 30°, and 60° of shoulder abduction. Range of motion, humeral rotational position due to muscle loading, joint reaction forces, and kinematics were measured. All specimens were tested in 4 conditions: intact, massive posterosuperior cuff tear, lower trapezius transfer, and latissimus dorsi transfer. A repeated-measures analysis of variance was used for statistical analysis.
Internal rotation due to muscle loading increased with massive cuff tear compared with the intact condition (P < .05). The latissimus transfer corrected this change at 0° abduction, whereas the trapezius transfer corrected this at all abduction angles. The massive cuff tear decreased glenohumeral joint compression forces at all abduction angles; these forces were restored by the lower trapezius transfer (P < .05). At maximum humeral internal rotation and 0° of abduction, the humeral head apex shifted superiorly and laterally with massive cuff tear (P < .05); this shift was more closely restored to intact values by the trapezius transfer compared with the latissimus transfer (P < .05).
The lower trapezius transfer is superior to the latissimus transfer at restoring native glenohumeral kinematics and joint reaction forces in our cadaveric model. It may be a promising treatment option for patients with a massive irreparable rotator cuff tear.
本研究的目的是描述下斜方肌转移的生物力学效应，并在巨大后上盂唇撕裂的尸体模型中与背阔肌转移进行比较。
对8具尸体肩部在肩关节外展0°、30°和60°时进行测试。测量活动范围、肌肉负荷引起的肱骨旋转位置、关节反应力和运动学。所有标本在4种情况下进行测试：完整、巨大后上盂唇撕裂、下斜方肌转移和背阔肌转移。采用重复测量方差分析进行统计分析。
与完整状态相比，巨大盂唇撕裂时肌肉负荷引起的内旋增加（P <.05）。背阔肌转移在0°外展时纠正了这种变化，而下斜方肌转移在所有外展角度均纠正了这种变化。巨大盂唇撕裂在所有外展角度均降低了盂肱关节压缩力；下斜方肌转移恢复了这些力（P <.05）。在肱骨最大内旋和0°外展时，巨大盂唇撕裂时肱骨头顶点向上和向外移位（P <.05）；与背阔肌转移相比，下斜方肌转移使这种移位更接近恢复到完整值（P <.05）。
在我们的尸体模型中，下斜方肌转移在恢复盂肱关节自然运动学和关节反应力方面优于背阔肌转移。对于巨大不可修复的盂唇撕裂患者，它可能是一种有前景的治疗选择。
