Chevalier Yan, Pietschmann Matthias F, Thorwächter Christoph, Chechik Ofir, Adar Eliyahu, Dekel Assaf, Müller Peter E
Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich, Germany.
Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich, Germany.
Clin Biomech (Bristol). 2018 Feb;52:41-48. doi: 10.1016/j.clinbiomech.2017.12.008. Epub 2017 Dec 18.
Failure after rotator cuff repair remains a major clinical problem and could be related to excessive pressures from the acromion. Previous studies with irreparable tears showed good clinical results of tendon healing with arthroscopic insertion of a protective biodegradable spacer balloon between the repaired tendon and the acromion. One hypothesis is that compression pressures on the repaired tendon will be reduced by the spacer. This cadaver study aimed to investigate the effects of this subacromial spacer on compression pressures over a repaired supraspinatus tendon in passive motion.
Rotator cuff tear and repair were performed in six fresh-frozen cadaveric shoulders, followed by insertion of a biodegradable subacromial spacer. Specimens were tested using a passive shoulder simulator for abduction-adduction, flexion-extension and internal-external rotations. A sensor positioned below the acromion was used to measure compression pressure changes through passive range of motion before and after placement of a subacromial spacer. Peak pressures were measured in adduction-abduction motion, near 90° abduction.
Both the mean and peak pressures in abduction-adduction were significantly reduced after insertion of the subacromial spacer (from mean 121.7 (SD 9.5) MPa to 51.5 (SD 1.2) MPa and from peak 1749.6 (SD 80.7) MPa to 535.1 (SD 27.6) MPa) (P<0.0001).
The reduced peak pressures and wider load distributions over the sensor during both passive abduction-adduction and flexion-extension motions suggest that the use of the spacer will lead to reduced wear of the repair in patients, and potentially prevent rotator cuff re-tear after surgical repair.
肩袖修复术后失败仍是一个主要的临床问题，可能与肩峰产生的过大压力有关。先前针对不可修复撕裂的研究表明，通过在修复的肌腱与肩峰之间关节镜下插入可生物降解的保护性间隔球囊，肌腱愈合取得了良好的临床效果。一种假设是，间隔物会降低修复肌腱上的压缩压力。本尸体研究旨在探讨这种肩峰下间隔物在被动运动中对修复的冈上肌腱上压缩压力的影响。
在六个新鲜冷冻的尸体肩部进行肩袖撕裂和修复，随后插入可生物降解的肩峰下间隔物。使用被动肩部模拟器对标本进行外展-内收、屈伸和内外旋转测试。在肩峰下方放置一个传感器，用于测量肩峰下间隔物放置前后在被动活动范围内的压缩压力变化。在接近外展90°的内收-外展运动中测量峰值压力。
插入肩峰下间隔物后，外展-内收的平均压力和峰值压力均显著降低（从平均121.7（标准差9.5）兆帕降至51.5（标准差1.2）兆帕，从峰值1749.6（标准差80.7）兆帕降至535.1（标准差27.6）兆帕）（P<0.0001）。
在被动外展-内收和屈伸运动期间，传感器上峰值压力降低且负荷分布更广泛，这表明使用间隔物将减少患者修复处的磨损，并可能防止手术修复后肩袖再次撕裂。
