Preliminary clinical study of anterior pedicle screw fixation for lower cervical spine injuries / 中华创伤杂志

ABSTRACT

Objective To investigate the preliminary clinical application of anterior pedicle screws in treatment of the lower cervical spine injuries. Methods The study involved 22 patients with lower cervical spine injuries treated with anterior pedicle screw technique from January 2009 to December 2011.X-ray and CT images of the patients were taken postoperatively to evaluate whether the position,orientation and length of the screws were appropriate and whether there involved pedicle cortex perforation,transverse foramen or spinal canal invasion.MRI was also performed to ascertain the situation of decompression,the formation of epidural hematoma and the degeneration of cervical spinal cord.The improvement of JOA score was compared statistically. Results All the patients were followed up for 3-36 months ( mean,15.5 months).A total of 44 anterior lower cervical screws were implanted and all screws were inserted smoothly.All the patients had bone healing after average 4.5 months,which showed no loosening,prolapse or breakage of the screws or no loosening of the plate.One patient showed hoarseness postoperatively,which was probably due to the long-term distraction of recurrent laryngeal nerve.The symptom disappeared at around three weeks after neurotrophic support.Two patients complained of dysphagia postoperatively,and were informed of keeping a soft diet.The symptom was remarkably alleviated after three months or so.The X-ray films indicated satisfactory position of the implanted screws.Before discharge,the transaxial CT images showed that two screws perforated the medial pedicle cortex ( 1 ° ) and that two screws perforated the lateral cortex (1 °) and affected the medial margin of the transverse foramen.Before discharge,the MRI indicated obvious alleviation of the anterior spinal cord compression in all patients and a small amount of anterior epidural hematoma in four patients,with no obvious spinal cord compression.At 12 months after operation,the MRI showed significant improvement of spinal cord degeneration in three patients.JOA score was increased from preoperative (8.5 ± 0.7) to ( 14.5 ± 0.8 ) before discharge (P ＜0.01 ).JOA score was (15.7 ±0.7) at six months postoperatively,which was significantly improved as compared with that before discharge. Conclusions Anterior pedicle screw fixation is a reliable and safe method for reconstruction of the anterior lower cervical injuries.Surgical indications should be strictly controlled in its clinical application.