Department of Orthopaedic Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, No.138, Sheng-Li Road, Tainan City, 70428, Taiwan.
Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan.
J Orthop Surg Res. 2019 May 27;14(1):157. doi: 10.1186/s13018-019-1209-7.
The optimal insertion angle for suture anchor insertion has long been of great interest. Although greater tuberosity decortication is commonly performed during rotator cuff repair, the effect of decortication on the suture anchor insertion angle remains unclear. The purpose of this study was to compare the pullout strength of threaded suture anchors inserted at 45° and 90° in decorticated and non-decorticated synthetic bone models.
Two kinds of synthetic bones were used to simulate the decorticated and non-decorticated conditions, for which 40 metallic suture anchors were used. Anchors were inserted at 45° and 90° in both decorticated and non-decorticated models and tested under cyclic loading followed by load-to-failure testing. The number of completed cycles, ultimate failure load, and failure modes was recorded.
In the decorticated model, the ultimate failure load of anchors inserted at 45° (67.5 ± 5.3 N) was significantly lower than that of anchors inserted at 90° (114.1 ± 9.8 N) (p < 0.001). In the non-decorticated model, the ultimate failure load of anchors inserted at 45° (591.8 ± 58 N) was also significantly lower than that of anchors inserted at 90° (724.9 ± 94 N) (p = 0.003). Due to the diverse failure modes in the non-decorticated model, specimens with a failure mode of suture anchor pullout were analyzed in greater detail, with results showing a significantly larger pullout strength for anchors inserted at 90° (781.6 ± 53 N) than anchors inserted at 45° (648.0 ± 43 N) (p = 0.025).
Regardless of decortication, the pullout strength of anchors inserted at 90° was greater than those inserted at 45°. The clinical relevance is that inserting suture anchors at 90° is recommended due to the significantly larger ultimate failure load in both decorticated and non-decorticated bones.
缝线锚钉的最佳插入角度一直备受关注。虽然在肩袖修复过程中通常会进行更大结节的骨皮质剥离，但骨皮质剥离对缝线锚钉插入角度的影响尚不清楚。本研究旨在比较在去皮质和非去皮质合成骨模型中以 45°和 90°插入带螺纹缝线锚钉的拔出强度。
使用两种合成骨模拟去皮质和非去皮质条件，共使用 40 枚金属缝线锚钉。在去皮质和非去皮质模型中，以 45°和 90°的角度插入锚钉，并在循环加载后进行直至失效的测试。记录完成的循环次数、最终失效载荷和失效模式。
在去皮质模型中，以 45°插入的锚钉的最终失效载荷（67.5±5.3 N）明显低于以 90°插入的锚钉（114.1±9.8 N）（p<0.001）。在非去皮质模型中，以 45°插入的锚钉的最终失效载荷（591.8±58 N）也明显低于以 90°插入的锚钉（724.9±94 N）（p=0.003）。由于非去皮质模型中的失效模式多样，因此更详细地分析了以缝线锚钉拔出为失效模式的标本，结果显示以 90°插入的锚钉的拔出强度（781.6±53 N）明显大于以 45°插入的锚钉（648.0±43 N）（p=0.025）。
无论是否去皮质，以 90°插入的锚钉的拔出强度均大于以 45°插入的锚钉。临床意义在于，由于在去皮质和非去皮质骨中，最终失效载荷均明显更大，因此推荐以 90°插入缝线锚钉。
