Comparison Of Cortical Bone Trajectory Screws And Traditional Pedicle Screws In The Treatment Of Patients With Single-level Lumbar Degenerative Disease And Osteoporosis

ObjectiveTo investigate and compare the clinical outcomes of cortical bone trajectory(CBT)screws+PLIF and pedicle screw(PS)+PLIF in treatment of patients with single-level lumber degenerative disease and osteoporosis,and provide basis for the operation planning.MethodsBased on the preset inclusion and exclusion criteria,this retrospective analysis included 60 patients(Department of Orthopaedics,the First Affiliated Hospital of Zhengzhou University)who underwent single-segment posterior lumbar interbody fusion(PLIF)from February 2017 to September 2019.CBT+PLIF was applied in 30 patients(Group CBT)and PS+PLIF was applied in 30 patients(Group PS).All cases were followed up for at least 24 months.Frontal and lateral X-ray of lumbar spine were obtained at 5 days after surgery.CT scan is obtained at 5 days and 24 months after surgery.Frontal and lateral X-ray of lumbar spine and the radiograms in flexion and extension were obtained at 3,6,12 and 24 months after surgery.The baseline data,surgery duration,intra-operative blood loss,length of incision,operative complications,incidence of adjacent cranial facet joint violation(FJV),fusion rate at 24 months postoperatively,visual analogue scale(VAS)and Oswestry disability index(ODI)at preoperative and 2 years postoperatively were recorded and compared.ResultsThere were no statistically significant differences in age,gender,Body mass index(BMI),bone mineral density,surgical level,VAS and ODI scores before the surgery between the two groups(P>0.05).The operative duration of group CBT and group PS was(127.7 ± 15.1)min and(122.7± 20.0)min respectively,but the difference was not statistically significant(P>0.05).The intra-operative blood loss of group CBT was(75.7 ± 38.4)ml,which was less than that of group PS(135.3 ± 46.6)ml;the incision length of group CBT and group PS were(6.0±0.8)cm and(8.7 ± 1.1)cm,respectively,leading to a statistically significant difference(P<0.05).The incidence of FJV in group CBT and group PS were 15.0%(9/60)and 56.7%(34/60),respectively,with a statistically significant difference(P<0.01).No screw implant failure or screw tunnel fracture was noted,and no vascular or nerve damage was found in any patient.Because of the poor fixation strength,one case in group PS end up using bone cement augmented pedicle screws.ODI and VAS scores at 24 months after surgery decreased significantly than those before the surgery(P<0.05),but no statistical difference was found between the two groups(P>0.05).The lumbar fusion was achieved in every patient at 24 months after the surgery.No screw looseness,detachment or cutting is found,and the screws,connecting rods and cages are all in good position.Conclusion1.The application of CBT+PLIF in treatment of patients with single-level lumber degenerative disease and osteoporosis can provide great short-term clinical outcomes and high fusion rate which have no significant differences with PS+PLIF.2.CBT is a minimally invasive surgery and can reduce the incidence of adjacent cranial FJV,which is worthy of clinical application.