Biomechanical advantages of dual over single iliac screws in lumbo-iliac fixation construct

摘要: The development of iliac screws has provided a markedly easier way for spino-pelvic instrumentation than the classical Galveston technique. However, high rates screw loosening and breakage are usually reported, especially in cases where bilateral single used. Therefore, there is need exploring more stable fixation techniques. Thus, objective this study was to compare biomechanical effects dual on stability L3-iliac construct under total sacrectomy condition. In study, L2-pelvic specimens were harvested from seven fresh human cadavers. After biomechanically testing intact state simulated by L3-L5 pedicle fixation, destabilization introduced sacrectomy. Upon destabilization, screw-rod reconstructions performed four different techniques as follows: (1) short (Single-Short); (2) long (Single-Long); (3) screws, placed upper lower columns (Dual-UL); (4) all column (Dual-Lower). These sequentially preformed same specimen, lengths 70 130 mm, respectively. Biomechanical material machine 800 N compression 7 Nm torsion loading modes evaluate stiffness. compression, stiffness constructs Single-Short, Single-Long, Dual-UL, Dual-Lower 73, 76, 98, 108% state, No significant differences detected between Single-Short Single-Long (P = 0.589) compressive these two significantly Dual-UL 0.05). torsional other three groups < For lumbo-illiac reconstruction after sacrectomy, even use single, do not help restoring local provide much higher technique should be preferred treating unstable situation caused