Green Robert N, Donaldson Oliver W, Dafydd Meilyr, Evans Sam L, Kulkarni Rohit
Department of Orthopaedics, Northern Deanery, Newcastle-upon-Tyne, England.
Yeovil District Hospital, Yeovil, England.
Arthroscopy. 2014 Dec;30(12):1535-9. doi: 10.1016/j.arthro.2014.07.010. Epub 2014 Sep 11.
To assess the effect of the insertion angle and the angle of applied load on the pullout strength of screw-in suture anchors.
Screw-in metallic suture anchors were inserted into a 10-lb/cu ft synthetic cancellous bone block at 30°, 45°, 60°, and 90° to the surface. The suture pull angle was then varied in 30° increments between 0° and 180°. Five constructs were tested to failure (anchor pullout) for each combination of angles using a Zwick tensile testing machine (Zwick Roell, Ulm, Germany).
There were a total of 25 combinations. The greatest pullout strength was seen with a suture anchor inserted at 90° to the bone block with a pull angle of 90° to the bone (mean, 306 N; standard deviation [SD], 9 N). The weakest pullout strength was seen with a suture anchor inserted at 30° with the angle of pull at 120° (i.e., opposite to the direction of insertion of the anchor) (mean, 97 N; SD, 11 N). A simulated deadman's angle of 45° with an angle of pull of 150° produced a pullout strength of 127 N (SD, 4 N). The pullout strengths for each insertion angle were greatest when the angle of pull was similar to the angle of insertion (P < .0001, repeated-measures analysis of variance).
The angle of applied load to a suture anchor and the insertion angle significantly influence the biomechanical pullout strength of screw-in suture anchors. The insertion angle of the suture anchor should replicate the angle of applied load to ensure the optimum pullout strength.
The screw-in anchor insertion angle and angle of applied load may have an influence on pullout strength.
评估拧入式缝线锚钉的插入角度和施加载荷角度对其拔出强度的影响。
将拧入式金属缝线锚钉以与表面呈30°、45°、60°和90°的角度插入到密度为10磅/立方英尺的合成松质骨块中。然后将缝线牵拉角度在0°至180°之间以30°的增量进行变化。使用Zwick拉伸试验机（德国乌尔姆市的Zwick Roell公司）对每种角度组合进行五次构建测试直至失效（锚钉拔出）。
共有25种组合。当缝线锚钉与骨块呈90°插入且牵拉角度与骨呈90°时，拔出强度最大（均值为306 N；标准差[SD]为9 N）。当缝线锚钉以30°插入且牵拉角度为120°（即与锚钉插入方向相反）时，拔出强度最弱（均值为97 N；SD为11 N）。呈45°的模拟钝角且牵拉角度为150°时，拔出强度为127 N（SD为4 N）。当牵拉角度与插入角度相似时，每种插入角度的拔出强度最大（P < 0.0001，重复测量方差分析）。
施加于缝线锚钉的载荷角度和插入角度显著影响拧入式缝线锚钉的生物力学拔出强度。缝线锚钉的插入角度应与施加载荷角度一致，以确保最佳拔出强度。
拧入式锚钉的插入角度和施加载荷角度可能会对拔出强度产生影响。
