Gonsalves Mishka N, Jankovits Daniel A, Huber Michael L, Strom Adam M, Garcia Tanya C, Stover Susan M
Mishka Gonsalves, DVM, Animal Specialty Group, 4641 Colorado Blvd., Los Angeles, CA 90039, United States, Phone: +1 818 244 7977, Fax: +1 818 507 9418, E-mail:
Vet Comp Orthop Traumatol. 2016 Sep 20;29(5):353-60. doi: 10.3415/VCOT-15-06-0097. Epub 2016 Jul 21.
To compare the biomechanical properties of simulated humeral condylar fractures reduced with one of two screw fixation methods: 3.0 mm headless compression screw (HCS) or 3.5 mm cortical bone screw (CBS) placed in lag fashion.
Bilateral humeri were collected from nine canine cadavers. Standardized osteotomies were stabilized with 3.0 mm HCS in one limb and 3.5 mm CBS in the contralateral limb. Condylar fragments were loaded to walk, trot, and failure loads while measuring construct properties and condylar fragment motion.
The 3.5 mm CBS-stabilized constructs were 36% stiffer than 3.0 mm HCS-stabilized constructs, but differences were not apparent in quality of fracture reduction nor in yield loads, which exceeded expected physiological loads during rehabilitation. Small residual fragment displacements were not different between CBS and HCS screws. Small fragment rotation was not significantly different between screws, but was weakly correlated with moment arm length (R² = 0.25).
A CBS screw placed in lag fashion provides stiffer fixation than an HCS screw, although both screws provide similar anatomical reduction and yield strength to condylar fracture fixation in adult canine humeri.
比较两种螺钉固定方法之一复位模拟肱骨髁上骨折后的生物力学特性：3.0毫米无头加压螺钉（HCS）或采用拉力方式置入的3.5毫米皮质骨螺钉（CBS）。
从9具犬类尸体上收集双侧肱骨。在一侧肢体用3.0毫米HCS对标准化截骨进行固定，在对侧肢体用3.5毫米CBS进行固定。对髁部骨折块施加行走、小跑和破坏载荷，同时测量固定结构特性和髁部骨折块的运动情况。
3.5毫米CBS固定的结构比3.0毫米HCS固定的结构刚度大36%，但在骨折复位质量和屈服载荷方面差异不明显，屈服载荷超过了康复期间预期的生理载荷。CBS和HCS螺钉固定时小的残余骨折块移位无差异。螺钉之间小骨折块的旋转无显著差异，但与力臂长度呈弱相关（R² = 0.25）。
采用拉力方式置入的CBS螺钉比HCS螺钉提供更坚固的固定，尽管两种螺钉在成年犬肱骨髁上骨折固定时都能提供相似的解剖复位和屈服强度。
