An improved method for percutaneous pedicle screw implantation and the effect of the improvement on radiation exposure / 中华骨科杂志

ABSTRACT

Objective To introduce a new minimally invasive lumbar positioning system and its positioning method as well as conduct a prospective control study on the differences in positioning time,positioning frequency and radiation exposure dose between the new positioning method and the traditional positioning method.Methods 121 patients with lumbar disc herniation combined with lumbar instability and patients with thoracolumbar vertebral fracture admitted in our hospital from May 2010 to February 2013 were randomized into two groups.68 patients in Group A had undergone the traditional positioning method before and during operation.Among the 68 patients,41 were with single-segment lesion and 27 were with two-segment lesion.53 patients in Group B had undergone the new minimally invasive lumbar positioning system before and during operation.Among the 53 patients,34 were with single-segment lesion and 19 were with two-segment lesion.There were no significant differences in gender,age,course of disease and other general information between the two groups.The positioning time,positioning frequency and radiation dose of the two groups before and during operation were compared and statistically analyzed.Results The positioning time of Group A and Group B were 8.26±3.44 min and 3.51±1.82 min respectively; the positioning frequencies were 3.57 and 1.22; the accuracy were 60.8％ and 96.2％.For the patients with single-segment lesion,the positioning time before implanting two percutaneous pedicle screws during operation were 15.12±4.69 min and 5.51±1.32 min respectively and the positioning frequency were 6.47 and 2.45.For the patients with two-segment lesion,the positioning time before implanting three percutaneous pedicle screws during operation were 24.91±7.43 min and 8.84±2.32 min respectively and the positioning frequency were 11.72 and 3.69.Moreover,the radiation dose detected at neck,chest and wrist of the surgical staff in Group A were 3.09±0.24 Gy,4.23±0.71 Gy and 5.17±0.62 Gy and that detected in Group B were 1.38±0.47 Gy,2.69±0.33 Gy and 3.21±1.05 Gy.There were significant differences in positioning time,positioning frequency and radiation dose between Group A and Group B.Conclusion The minimally invasive spine positioning system and positioning method can simplify the operative procedures and largely reduce radiation exposure,which is characterized by high positioning accuracy,short positioning time,low fluoroscopy frequency and X-ray radiation dose.