应力调控型带锁髓内钉治疗股骨骨折的应力水平研究

Treatment of femoral fractures with stress-controlled auto-compression locking nails

目的探讨应力调控型带锁髓内钉（SCALN）治疗股骨骨折后应力水平的变化。方法采集12具成人新鲜尸体股骨标本，模拟Panjabi方法制作股骨中段横断骨折模型，将标本分为三组（每组3个标本），分别采用SCALN、第一代自动加压带锁髓内钉（ALN）和普通带锁髓内钉（GK钉）固定，均进行系统生物力学性能测试、应力遮挡分析和应力水平测量，并进行比较。结果与ALN、GK钉相比，SCALN应力-应变关系值分别小14％和18％（P〈0．05）；应力遮挡率分别小10％和66％（P〈0．05）。SCALN刚柔结合弹性动态固定使股骨断端应力水平接近生理性，且手术操作方便。结论SCALN在有效控制骨折端弯、扭、剪、旋有害应力的同时，解决了临床上坚强内固定骨折断端无应力传导的问题，是当前新一代股骨骨折优良的髓内固定器械。

Objective To study the stress changes at the fracture ends in treatment of femoral fractures with stress-controlled auto-compression locking nails （SCALN） . Methods Twelve femoral specimens from fresh adult cadavers were collected. The transverse femoral fracture models were created in the specimens by Panjabi method and randomized into 3 groups which were fixated with SCALN, ALN （auto-compression locking nail） and GK（Gross-Kempf） After fixation, tests of biological mechanics, stress-shielding analysis and t of stresses were performed systemically. Results were compared among the 3 groups. Results Compared with ALN and GK nails, the strain-stress ratio of SCALN was 14% and 18% smaller respectively, and the stress-shielding rate of SCALN 10% and 66% smaller respectively（ P 〈 0.05） . Under SCALN fixation, the stress at the femoral fracture ends approximated the normal level. Conclusion SCALN is a good intramedullary fixator for femoral fractures, because on the one hand it can effectively control such harmful stresses as bending, twisting, shearing and rotating, and on the other hand it can maintain normal stress conduction at the fracture ends under firm internal fixation.