Department of Orthopaedic Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California, U.S.A.
Orthopaedic Biomechanics Laboratory, Congress Medical Foundation, Pasadena, California, U.S.A.
Arthroscopy. 2021 Apr;37(4):1117-1125. doi: 10.1016/j.arthro.2020.11.054. Epub 2020 Dec 8.
To biomechanically characterize superior capsule reconstruction (SCR) using fascia lata allograft, double-layer dermal allograft, and single-layer dermal allograft for a clinically relevant massive irreparable rotator cuff tear involving the entire supraspinatus and 50% of the infraspinatus tendons.
Eight cadaveric specimens were tested in 0°, 30°, and 60° abduction for (1) intact, (2) massive rotator cuff tear, (3) SCR using fascia lata, (4) SCR using double-layer dermis, and (5) SCR using single-layer dermis. Superior translation and subacromial contact pressure were measured. Statistical analysis was conducted using repeated measures ANOVA or paired t test with P < .05.
Massive rotator cuff tear significantly increased superior translation of the humeral head at all abduction angles (P < .05). At 0° abduction, all SCR conditions significantly decreased superior translation compared with the massive tear but did not restore translation (P < .05) to intact. Fascia lata and double-layer dermis SCR restored superior translation to intact at 30° and 60° of abduction, but single-layer dermis did not. Subacromial contact pressure at 0° of abduction significantly decreased with SCR with fascia lata and double-layer dermis compared with tear. At 30°, all SCR conditions significantly decreased subacromial contact pressure. Single-layer dermis graft thickness significantly decreased more than fascia lata during testing (P = .02).
For SCR tensioned at 20° glenohumeral abduction, all 3 graft types may restore superior translation and subacromial contact pressure depending on the glenohumeral abduction angle; fascia lata and double-layer dermis may be more effective than single-layer dermis.
If a dermal graft is to be used for SCR, consideration should be given to doubling the graft for increased thickness and better restorative biomechanical properties, which may improve clinical outcomes following SCR.
为了生物力学特征的优越性胶囊重建（SCR）使用阔筋膜移植物，双层真皮移植物和单层真皮移植物的临床相关的巨大不可修复的肩袖撕裂涉及整个冈上肌和 50%的冈下肌腱。
8 个尸体标本在 0°、30°和 60°外展角下进行测试，包括（1）完整，（2）巨大肩袖撕裂，（3）使用阔筋膜移植物的 SCR，（4）使用双层真皮移植物的 SCR，和（5）使用单层真皮移植物的 SCR。测量肩峰上表面的翻译和肩峰下接触压力。采用重复测量方差分析或配对 t 检验进行统计学分析，P<.05。
巨大肩袖撕裂显著增加了所有外展角度的肱骨头的翻译（P<.05）。在 0°外展角，所有 SCR 条件与巨大撕裂相比显著减少了肩峰上表面的翻译，但没有恢复到完整（P<.05）。阔筋膜和双层真皮 SCR 在 30°和 60°外展时恢复了完整的肩峰上表面翻译，但单层真皮没有。与撕裂相比，阔筋膜和双层真皮 SCR 在 0°外展时的肩峰下接触压力显著降低。在 30°时，所有 SCR 条件都显著降低了肩峰下接触压力。在测试过程中，单层真皮移植物的厚度比阔筋膜移植物显著减少（P=.02）。
对于在 20°盂肱关节外展角拉紧的 SCR，所有 3 种移植物类型都可以根据盂肱关节外展角度恢复肩峰上表面的翻译和肩峰下接触压力；阔筋膜和双层真皮可能比单层真皮更有效。
如果要使用真皮移植物进行 SCR，应考虑增加移植物的厚度，以获得更好的恢复生物力学特性，这可能会改善 SCR 后的临床效果。
