Shanmugam Rukmanikanthan, Jian Chong Yin Chyi Chong Shyh, Haseeb Amber, Aik Saw
Department of Orthopaedic Surgery (NOCERAL), Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
J Orthop Surg (Hong Kong). 2018 May-Aug;26(3):2309499018802511. doi: 10.1177/2309499018802511.
Metacarpal bone fractures constitute 10% of all fractures. Unstable metacarpal fractures require surgical intervention, which poses danger to flexor tendon either due to bicortical drilling or construct of the implant. Unicortical locking plate fixation may be the solution to preventing flexor tendon injury. Studies have compared locking and compression plates. However, in these studies, the biomechanical properties were tested using the static loading method. This study looks into cyclical loading that is more representative of in vivo conditions, particularly for early rehabilitation. We compared the biomechanical strength of the unicortical locking plate and bicortical compression plate system in a transverse metacarpal fracture, tested with cyclical loading and torsion.
Twenty pieces of fourth-generation, biomechanical testing grade, left third metacarpal composite bones were used. Resin was used to create the holding block at both ends of the bone. An oscillating saw with 0.8 mm thick saw blade was used to osteotomize the metacarpal sawbones to create a midshaft transverse metacarpal fracture model. Ten pieces were fixed with a 2.0 mm titanium locking plate via unicortical screw purchase and 10 were fixed with a 2.0 mm, four holes, titanium dynamic compression plate, bicortical purchase of screws. They were subjected to cyclic load to failure testing three-point bending and torsion.
There were no significant difference in stiffness and cyclic three-point bending to failure between the unicortical locking plate group and the bicortical compression plate group. The bicortical compression plate group is stiffer and has a higher cyclic bending load to failure as compared to the unicortical locking plate group.
Unicortical locking plate fixation of metacarpal fracture can be reliably applied clinically to produce a strong and stable construct that allows early mobilization of the joints. This will not only reduce the complication rate of metacarpal plating, but also improve the functional outcome of the hand.
掌骨骨折占所有骨折的10%。不稳定掌骨骨折需要手术干预，而双皮质钻孔或植入物的构建都可能对屈肌腱造成危险。单皮质锁定钢板固定可能是预防屈肌腱损伤的解决方案。已有研究比较了锁定钢板和加压钢板。然而，在这些研究中，生物力学性能是使用静态加载方法进行测试的。本研究探讨了更能代表体内情况的循环加载，特别是对于早期康复而言。我们比较了单皮质锁定钢板和双皮质加压钢板系统在掌骨横行骨折中的生物力学强度，采用循环加载和扭转进行测试。
使用20块第四代生物力学测试级别的左侧第三掌骨复合骨。用树脂在骨的两端制作固定块。使用带有0.8毫米厚锯片的摆动锯将掌骨锯骨截骨，以创建中轴掌骨横行骨折模型。10块用2.0毫米钛锁定钢板通过单皮质螺钉固定，10块用2.0毫米四孔钛动力加压钢板通过双皮质螺钉固定。对它们进行循环加载至失效测试，包括三点弯曲和扭转。
单皮质锁定钢板组和双皮质加压钢板组在刚度和循环三点弯曲至失效方面无显著差异。与单皮质锁定钢板组相比，双皮质加压钢板组更硬，循环弯曲失效载荷更高。
掌骨骨折的单皮质锁定钢板固定可在临床上可靠应用，以产生坚固稳定的结构，允许关节早期活动。这不仅会降低掌骨钢板固定的并发症发生率，还会改善手部的功能结果。
