Gabarre Sergio, Albareda Jorge, Gracia Luis, Puértolas Sergio, Ibarz Elena, Herrera Antonio
Department of Mechanical Engineering, University of Zaragoza, Zaragoza, Spain.
Department of Orthopaedic Surgery and Traumatology, Lozano Blesa University Hospital, Zaragoza, Spain; Aragón Health Research Institute, Zaragoza, Spain; Department of Surgery, University of Zaragoza, Zaragoza, Spain.
Injury. 2017 Nov;48 Suppl 6:S40-S46. doi: 10.1016/S0020-1383(17)30793-3.
Femoral shaft fractures are among the most severe injuries of the skeleton. They are associated with high morbidity and mortality. The most appropriate treatment depending on the type of fracture and location level should be chosen. A finite element model of the femur has been developed, analyzing various types of fractures in the subtrochanteric and diaphyseal supracondylar area, with several gap sizes, being stabilized with a single combination of screws for the intramedullary nail. The mechanical strength of the nail against bending and compression efforts was studied comparing two materials for the nail: stainless steel and titanium alloy. Beside the finite elements (FE) simulations, a clinical follow-up was carried out, considering a sample of 55 patients, 24 males, and 31 females, with mean age of 52.5 years. Localizations of fractures were 22 in the right femur and 33 in the left one, respectively. A good agreement between clinical results and the simulated fractures in terms of gap size was found. Non-comminuted fractures have a mean consolidation time of 4.1 months, which coincides with the appropriate mobility at fracture site obtained in the FE simulations, whereas comminuted fractures have a higher mean consolidation period estimated in 7.1 months, corresponding to the excessive mobility at fracture site obtained by means of FE simulations. The obtained results between both nail materials (stainless steel and titanium alloy) show a higher mobility when using titanium nails, which produce a higher rate of strains at the fracture site, amplitude of micromotions and bigger global movements compared to stainless-steel nails. Steel nails provide stiffer osteosyntheses than the titanium nails. In conclusion, anterograde locked nail is particularly useful in the treatment of a wide range of supracondylar fractures with proximal extension into the femoral diaphysis.
股骨干骨折是最严重的骨骼损伤之一。它们与高发病率和死亡率相关。应根据骨折类型和位置水平选择最合适的治疗方法。已经建立了股骨的有限元模型，分析了转子下和骨干髁上区域的各种类型骨折，具有几种间隙尺寸，并用髓内钉的单一螺钉组合进行固定。研究了两种钉材料（不锈钢和钛合金）的钉在抗弯曲和压缩力方面的机械强度。除了有限元（FE）模拟外，还进行了临床随访，考虑了55例患者的样本，其中男性24例，女性31例，平均年龄52.5岁。骨折部位分别为右股骨22例和左股骨33例。发现在间隙尺寸方面临床结果与模拟骨折之间有良好的一致性。非粉碎性骨折的平均愈合时间为4.1个月，这与有限元模拟中在骨折部位获得的适当活动度一致，而粉碎性骨折的平均愈合期估计较高，为7.1个月，对应于通过有限元模拟获得的骨折部位的过度活动度。两种钉材料（不锈钢和钛合金）之间获得的结果表明，使用钛钉时活动度更高，与不锈钢钉相比，钛钉在骨折部位产生更高的应变率、微动幅度和更大的整体运动。钢钉提供比钛钉更坚固的骨固定。总之，顺行锁定钉在治疗广泛的髁上骨折并向股骨干近端延伸方面特别有用。
