Schneeberger Alberto G, von Roll Andreas, Kalberer Fabian, Jacob Hilaire A C, Gerber Christian
Department of Orthopaedic Surgery, university of Zurich, Balgrist, Zurich, Switzerland.
J Bone Joint Surg Am. 2002 Dec;84(12):2152-60. doi: 10.2106/00004623-200212000-00005.
Retears after rotator cuff repairs occur relatively frequently and may compromise the functional result. The goal of this study was to analyze the mechanical properties following arthroscopic techniques for rotator cuff repair and to evaluate possible alternative techniques.
In the first part, five different bone anchors (the Revo screw; Mitek Rotator Cuff anchor, 5.0-mm Statak, PANALOK RC absorbable anchor, and 5.0-mm Bio-Statak) were tested in vitro under cyclic loading on five pairs of cadaveric shoulders. Then five types of arthroscopic tendon suturing instruments were tested on rotator cuff tendons. Finally, the arthroscopically performed mattress and modified Mason-Allen stitches, fixed with either the Revo screw or the Bio-Statak, were evaluated on ten pairs of human cadaveric shoulders.
The holding strengths of the various anchors were similar, ranging from 130 to 180 N, and approximated the holding strength of knotted number-2 suture materials. The fixation of the tested anchors yielded comparable values of stiffness except for one anchor, which showed significantly greater subsidence under cyclic load (p = 0.003). All tested, commercially available arthroscopic suturing devices were unsuitable for performing a modified Mason-Allen stitch on normal supraspinatus tendons. Modification of a commercially available suture punch with a longer needle allowed us to consistently perform a modified Mason-Allen stitch. The modified Mason-Allen stitch, which has shown favorable mechanical properties in open repairs of the rotator cuff, was not found to be stronger than the mattress stitch when performed arthroscopically and used with bone anchors. When the modified Mason-Allen stitch was fixed to one anchor, it was even weaker than a mattress stitch repaired with another anchor (168 versus 228 N). Unequal loading of the two suture branches due to the more rigid modified Mason-Allen stitch may be the reason for this difference.
Arthroscopic techniques for rotator cuff repair with use of the mattress stitch and bone anchors allow for a relatively solid fixation. The holding strength is not improved with use of the modified Mason-Allen stitch. Although a direct comparison with previous in vitro studies is not possible, the holding strength of open fixation techniques seems to be stronger. If rotator cuffs are subjected to high postoperative loading, open repair might be preferred to reduce the risk of a retear, until stronger arthroscopic fixation techniques are developed.
肩袖修复术后再撕裂相对常见，可能会影响功能恢复结果。本研究的目的是分析关节镜下肩袖修复技术后的力学性能，并评估可能的替代技术。
在第一部分中，对五对尸体肩部进行体外循环加载测试，使用五种不同的骨锚（Revo螺钉；Mitek肩袖锚钉、5.0毫米Statak、PANALOK RC可吸收锚钉和5.0毫米Bio-Statak）。然后对肩袖肌腱测试五种关节镜下肌腱缝合器械。最后，在十对人体尸体肩部上评估使用Revo螺钉或Bio-Statak固定的关节镜下褥式缝合和改良的梅森-艾伦缝合。
各种锚钉的握持强度相似，范围为130至180牛，接近2号打结缝合材料的握持强度。除一种锚钉外，测试锚钉固定后的刚度值相当，该锚钉在循环载荷下显示出明显更大的下沉（p = 0.003）。所有测试的市售关节镜缝合装置均不适合在正常冈上肌腱上进行改良的梅森-艾伦缝合。使用更长针的市售缝合冲头进行改良，使我们能够始终如一地进行改良的梅森-艾伦缝合。改良的梅森-艾伦缝合在肩袖开放修复中已显示出良好的力学性能，但在关节镜下使用骨锚进行缝合时，其强度并不比褥式缝合更强。当改良的梅森-艾伦缝合固定在一个锚钉上时，甚至比用另一个锚钉修复的褥式缝合更弱（168牛对228牛）。改良的梅森-艾伦缝合更僵硬，导致两个缝合分支受力不均，可能是造成这种差异的原因。
使用褥式缝合和骨锚的关节镜下肩袖修复技术可实现相对牢固的固定。使用改良的梅森-艾伦缝合并不能提高握持强度。尽管无法与先前的体外研究进行直接比较，但开放固定技术的握持强度似乎更强。如果肩袖术后承受高负荷，在开发出更强的关节镜固定技术之前，开放修复可能更可取，以降低再撕裂的风险。
