Department of Orthopaedic Surgery, University of Connecticut, Farmington, Connecticut, USA.
Department of Orthopaedic Sports Medicine, Technical University, Munich, Germany.
Am J Sports Med. 2019 May;47(6):1441-1450. doi: 10.1177/0363546519833990. Epub 2019 Apr 9.
The concept of dynamic anterior shoulder stabilization (DAS) combines a Bankart repair with the additional sling effect of the long head of the biceps (LHB) tendon to treat anterior glenohumeral instability. This surgical technique was created to close the gap between the indications for isolated Bankart repair and those requiring bone transfer techniques.
To biomechanically investigate the stabilizing effects of the DAS technique in comparison with the standard Bankart repair in different defect models.
Controlled laboratory study.
Twenty-four fresh-frozen cadaveric shoulders (mean ± SD age, 60.1 ± 8.6 years) were mounted in a 6 degrees of freedom shoulder testing system. With cross-sectional area ratios, the rotator cuff muscles and LHB tendon were loaded with 40 N and 10 N, respectively. Anterior and inferior glenohumeral translation was tested in 60° of abduction and 60° of external rotation (ABER position) while forces of 20 N, 30 N, and 40 N were applied to the scapula in the posterior direction. Total translation and relative translation in relation to the native starting position were measured with a 3-dimensional digitizer. Maximal external rotation and internal rotation after application of 1.5-N·m torque to the humerus were measured. All specimens went through 4 conditions (intact, defect, isolated Bankart repair, DAS) and were randomized to 1 of 3 defect groups (isolated Bankart lesion, 10% anterior glenoid defect, 20% anterior glenoid defect). The DAS was performed by transferring the LHB tendon through a subscapularis split to the anterior glenoid margin, where it was fixed with an interference screw.
Both surgical techniques resulted in decreased anterior glenohumeral translation in comparison with the defect conditions in all defect groups. As compared with isolated Bankart repair, DAS showed significantly less relative anterior translation in 10% glenoid defects at translation forces of 20 N (0.3 ± 1.7 mm vs 2.2 ± 1.8 mm, P = .005) and 30 N (2.6 ± 3.4 mm vs 5.3 ± 4.2 mm, P = .044) and in 20% glenoid defects at all translation forces (20 N: -3.2 ± 4.7 mm vs 0.8 ± 4.1 mm, P = .024; 30 N: -0.9 ± 5.3 mm vs 4.0 ± 5.2 mm, P = .005; 40 N: 2.1 ± 6.6 mm vs 6.0 ± 5.7 mm, P = .035). However, in 20% defects, DAS led to a relevant posterior and inferior shift of the humeral head in the ABER position and to a relevant increase in inferior glenohumeral translation. Both surgical techniques did not limit the rotational range of motion.
In the context of minor glenoid bone defects, the DAS technique demonstrates less relative anterior translation as compared with an isolated Bankart repair at time zero.
The new DAS technique seems capable of closing the gap between the indications for isolated Bankart repair and bone transfer techniques.
动态前肩稳定术（DAS）的概念结合了 Bankart 修复术和肱二头肌长头肌腱（LHB）的附加吊带效应，用于治疗前盂肱关节不稳定。这项手术技术的创建是为了弥合单纯 Bankart 修复术和需要骨转移技术的适应证之间的差距。
在不同的缺损模型中，从生物力学角度比较 DAS 技术与标准 Bankart 修复术的稳定效果。
对照实验室研究。
24 个新鲜冷冻的尸体肩部（平均年龄±标准差，60.1±8.6 岁）安装在一个 6 自由度肩部测试系统中。使用横截面积比，分别以 40 N 和 10 N 的力加载冈上肌和 LHB 肌腱。在 60°外展和 60°外旋（ABER 位置）下测试盂肱关节的前向和下向移位，同时在后方向上向肩胛骨施加 20 N、30 N 和 40 N 的力。使用三维数字化仪测量总移位和相对于原始起始位置的相对移位。在向肱骨施加 1.5-N·m 扭矩后测量最大外旋和内旋。所有标本均经历 4 种条件（完整、缺损、单纯 Bankart 修复、DAS），并随机分为 3 个缺损组（单纯 Bankart 病变、10%前盂唇缺损、20%前盂唇缺损）。DAS 通过将 LHB 肌腱从前锯肌劈开转移到前盂唇边缘，然后用干扰螺钉固定。
与所有缺损组的缺损状态相比，两种手术技术均导致盂肱关节前向移位减少。与单纯 Bankart 修复相比，DAS 在 10%的盂唇缺损时，在 20 N（0.3±1.7 mm 比 2.2±1.8 mm，P=.005）和 30 N（2.6±3.4 mm 比 5.3±4.2 mm，P=.044）时，相对前向移位明显减少，在 20%的盂唇缺损时，在所有的移位力时（20 N：-3.2±4.7 mm 比 0.8±4.1 mm，P=.024；30 N：-0.9±5.3 mm 比 4.0±5.2 mm，P=.005；40 N：2.1±6.6 mm 比 6.0±5.7 mm，P=.035）。然而，在 20%的缺损中，DAS 导致 ABER 位置下肱骨头的明显后下移位，并导致下盂肱关节移位增加。两种手术技术均不限制旋转活动范围。
在较小的盂唇骨缺损情况下，与单纯 Bankart 修复相比，DAS 技术在即刻时表现出较小的相对前向移位。
新的 DAS 技术似乎能够弥合单纯 Bankart 修复术和骨转移技术之间的适应证差距。
