Davenport S R, Lindsey R W, Leggon R, Miclau T, Panjabi M
Department of Orthopaedic Surgery, University of Cincinnati School of Medicine, Ohio.
J Orthop Trauma. 1988;2(2):146-50.
The use of unicortical screws instead of bicortical screws in the extreme outer holes of dynamic compression plates (DCPs) has been recommended to minimize the stress riser effect at the end of the plates. The authors examined in vitro two groups of paired canine femurs after compression plates had been applied to the anterolateral diaphyseal surface bilaterally. Group I: intact paired femurs with bicortical peripheral screws in one DCP and unicortical peripheral screws in the other; Group II: osteotomized paired femurs again comparing unicortical and bicortical peripheral DCP screws. All specimens were torsion tested to failure and the torque, stiffness, energy, rotation, and failure fracture length were calculated. Unicortical screws did not enhance the torsional strength in either group, and significantly compromised stiffness, energy, and rotation in the osteotomized group. The only apparent benefit of unicortical peripheral screws in a DCP was a shorter, less comminuted fracture upon failure.
有人建议在动力加压钢板（DCP）最外侧的孔中使用单皮质螺钉而非双皮质螺钉，以尽量减少钢板末端的应力集中效应。作者对两组配对的犬股骨进行了体外研究，双侧股骨的骨干前外侧表面均应用了加压钢板。第一组：一对完整的股骨，一个DCP使用双皮质周边螺钉，另一个使用单皮质周边螺钉；第二组：截骨后的配对股骨，同样比较单皮质和双皮质周边DCP螺钉。所有标本均进行扭转试验直至破坏，并计算扭矩、刚度、能量、旋转角度和破坏骨折长度。单皮质螺钉在两组中均未提高扭转强度，且在截骨组中显著降低了刚度、能量和旋转角度。DCP中使用单皮质周边螺钉的唯一明显益处是破坏时骨折更短、粉碎程度更低。
