新型双叶型肱骨近端锁定钢板的研制与生物力学研究

目的 研制新型双叶型肱骨近端锁定钢板以解决复杂肱骨近端骨折大、小结节的固定问题, 并通过生物力学实验评估其固定肱骨大、小结节的稳定性。方法 取12具新鲜冰冻带肩袖肌的肱骨标本，编号后随机分成A、B两组，建立相同的肱骨大、小结节骨折模型。其中，A组用新型双叶型肱骨近端锁定钢板固定；B组用肱骨近端锁定钢板系统（proximal humeral internal locking system，PHILOS）、缝线缝合固定，小结节同时加用1枚3.5 mm空心螺钉固定。分别对两组标本进行肩胛下肌、冈下肌及小圆肌、冈上肌牵拉实验及大、小结节抗拉实验测试。结果 肩胛下肌牵拉实验：A组在180 N拉力以及疲劳实验后位移均明显小于B组（P<0.05）。冈下肌及小圆肌牵拉实验：两组在150 N拉力以及疲劳实验后位移比较差异均无统计学意义（P>0.05）。冈上肌牵拉实验：两组在90 N拉力以及疲劳实验后位移比较差异均无统计学意义（P>0.05）。小结节抗拉实验：A组失效载荷明显大于B组，且A组失效位移明显小于B组（P<0.05）。大结节抗拉实验：两组在失效载荷、失效位移比较差异均无统计学意义（P>0.05）。 结论 该新型双叶型肱骨近端锁定钢板对肱骨小结节的固定效果较缝线+空心钉螺钉固定更坚强，具有能同时固定大、小结节的优势。研究结果为临床治疗复杂肱骨近端骨折提供新的选择。
Objective To design a novel double-leaf proximal humeral locking plate for fixing greater and lesser tuberosities in complex proximal humeral fractures, and evaluate its fixing stability by biomechanical tests. Methods Twelve fresh-frozen humerus specimens with intact rotator cuff were randomly divided into two groups (Group A and Group B) to establish the same greater and lesser tuberosities fracture models. Specimens in Group A were fixed with the double-leaf proximal humeral locking plate, while specimens in Group B were fixed with the proximal humeral internal locking system (PHILOS) and tension band suture, and a 3.5-mm cannulated screw was added to stabilize the lesser tuberosity. The tensile test on subscapularis, infraspinatus and teres, supraspinatus as well as the load-to-failure test on greater and lesser tuberosities were performed on specimens in two groups. Results For subscapularis tensile tests, displacements under 150 N tensile stretch and after fatigue test in Group A were both significantly smaller than those in Group B (P<0.05). For infraspinatus and teres tensile tests, there were no statistical differences between Group A and B in displacements under 150 N tensile stretch and after fatigue test (P>0.05). For supraspinatus tensile tests, there were no statistical differences between Group A and B in displacements under 90 N tensile stretch and after fatigue test (P>0.05). For load-to-failure tests on lesser tuberosity, the failure load in Group A was significantly greater than that in Group B (P<0.05), and the failure displacement in Group A was significantly smaller than that in Group B (P<0.05). For load-to-failure tests on greater tuberosity, there were no statistical differences between Group A and B in both the failure load and failure displacement (P>0.05). Conclusions Compared with the ordinary tension band suture plus cannulated screw for fixing lesser tuberosity, the novel double-leaf proximal humeral