胸腰段钉棒系统内固定术后断钉原因分析

Causes analysis of pedicle screw breakage after internal fixation of thoracolumbar spinal fracture

目的：分析椎弓根螺钉术后断钉的原因。方法分析45例胸腰段骨折患者术后10例发生断钉的骨折类型、术中操作、产品设计、螺钉负荷、椎弓根螺钉置入情况、术后活动情况以及术后预防措施。结果10例术后断钉患者中,术后1个月复查时发现断钉2例,术后4-6个月复查时发现断钉7例,术后30个月复查时发现断钉1例。 T11断钉1例,T12断钉4例,L1断钉3例,L2断钉2例。未减压24例（其中含Chance骨折3例）中断钉4例,减压未植骨5例中断钉3例；减压植骨16例（其中含骨折脱位型4例）中断钉3例。45例中椎弓根螺钉预留骨界面过长4例中断钉3例。结论骨折类型与植骨、术中操作、撑开后螺钉负荷过大、术后活动不当、内固定取出过迟为螺钉断裂的主要原因。

Objective To analyse the causes of breakage of pedicle screw after internal fixation of thoracolumbar spi-nal fracture. Methods In all 45 cases of spinal fractures,there were 10 cases of pedicle screw breakage after the in-ternal fixation of thoracolumbar spinal fracture,which were studied by analysis classification of fracture, operational skills, design of the internal fixation system, load of the pedicle screw, the placement of the pedicle screw, precau-tion measures after operation and function exercise. Results Among 10 cases of breakage of pedicle screw,2 cases were found screw breakage in 1 month after operation,7 cases were found between 4-6 months and 1 case was found in 30 months after operation. 1 case of pedicle screw breakage occurred at T11 , 4 cases of pedicle screw breakage at T12 , 3 cases of pedicle screw breakage at L1 , 2 cases of pedicle screw breakage at L2 . 24 cases were without decom-pression（ including 3 cases of Chance fractures） , among these, 4 cases were found screw breakage;5 cases were de-compression without bone graft, among these, 3 cases were found screw breakage;16 cases were decompression and bone graft（including 4 cases with fracture-dislocation）, among these, 3 cases was found screw breakage. In this group the pedicle screws above the bone interface were too long in 4 cases, among these, 3 cases was found screw breakage. Conclusions The main causes of pedicle screw breakage include the classification of fracture, operational skills, placement of the pedicle screw, function exercise and too late to take out the screws.