Larsen Christopher G, Sleasman Brian, Chudik Steven C
Stritch School of Medicine, Loyola University Chicago, Chicago, Illinois, USA.
Orthopedic Surgery and Sports Medicine Teaching and Research Foundation, Westmont, Illinois, USA.
Orthop J Sports Med. 2017 Sep 1;5(9):2325967117725293. doi: 10.1177/2325967117725293. eCollection 2017 Sep.
The standard of care for plating displaced midshaft clavicle fractures has been 6 cortices of purchase on each side of the fracture. The use of locking plates and screws may afford equivalent biomechanical strength with fewer cortices of purchase on each side of the fracture.
To compare the biomechanical and clinical performance of 3- versus 2-screw constructs for plating displaced midshaft clavicle fractures.
Controlled laboratory study/cohort study; Level of evidence, 3.
Lateral fragments of simulated midshaft fractures in 10 pairs of cadaveric clavicles were randomly assigned to plate fixation with either 3 nonlocking screws or 2 locking screws. Cyclic tensile loads were applied along the long axis of the clavicle. The constructs were then loaded to failure with pullout forces applied parallel to the long axis of the screws. Additionally, clinical outcomes of patients who had midshaft clavicle fractures that were surgically repaired were retrospectively identified and compared; 21 patients were treated with 3-screw constructs and 20 with 2-screw constructs.
Biomechanically, there were no significant differences for cyclic displacement, stiffness, yield load, or ultimate load between groups. Forces required for screw pullout were considerably higher than physiologic forces experienced by a healing clavicle in vivo. Clinically, there were no significant differences in American Shoulder and Elbow Surgeons, Constant, visual analog scale, and Single Assessment Numeric Evaluation scores; complications; or mean time to union. Additionally, we found that the plates used in the 2-screw group were consistently shorter.
Plate fixation of displaced midshaft clavicle fractures with 4 cortices of purchase with 2 locking screws demonstrated no significant differences biomechanically when compared with fixation with 6 cortices of purchase and 3 nonlocking screws. Clinically, there were no significant differences in outcomes or complications seen in patients receiving 2- or 3-screw constructs.
Clinical benefits of using the 3-screw construct for plate fixation include decreased surgical exposure, morbidity, and cost, and the use of shorter and noncontoured straight plates eliminates the extra time and technical difficulty associated with matching longer contoured plates to the complex morphology of the clavicle.
锁定钢板治疗中段锁骨骨折的标准是骨折两侧各有6层皮质骨的把持。使用锁定钢板和螺钉在骨折两侧所需的皮质骨把持层较少时，可能具有同等的生物力学强度。
比较使用3枚螺钉与2枚螺钉固定技术治疗移位中段锁骨骨折的生物力学和临床效果。
对照实验室研究/队列研究；证据等级为3级。
将10对尸体锁骨模拟中段骨折的外侧骨折块随机分组，分别采用3枚非锁定螺钉或2枚锁定螺钉进行钢板固定。沿锁骨长轴施加循环拉伸载荷。然后沿螺钉长轴方向施加拔出力直至试件破坏。此外，回顾性分析并比较接受手术治疗的中段锁骨骨折患者的临床疗效；21例患者采用3枚螺钉固定技术治疗，20例患者采用2枚螺钉固定技术治疗。
生物力学方面，两组间的循环位移、刚度、屈服载荷或极限载荷无显著差异。螺钉拔出所需的力远高于愈合中的锁骨在体内所承受的生理力。临床方面，美国肩肘外科医师学会评分、Constant评分、视觉模拟评分和单项评估数值评定法评分、并发症或平均愈合时间均无显著差异。此外，我们发现2枚螺钉组使用的钢板始终较短。
与采用6层皮质骨把持和3枚非锁定螺钉固定相比，采用4层皮质骨把持和2枚锁定螺钉固定移位中段锁骨骨折在生物力学上无显著差异。临床方面，接受2枚或3枚螺钉固定技术治疗的患者在疗效或并发症方面无显著差异。
使用3枚螺钉固定技术进行钢板固定的临床益处包括减少手术暴露、发病率和成本，并且使用较短的非塑形直板消除了将较长的塑形钢板与锁骨复杂形态相匹配所需的额外时间和技术难度。
