Patient selection method
Inclusion criteria include the following: (a) back and waist pain, limited activity; (b) MRI showed fresh vertebral compression fractures, vertebral bone metastases or Kummell disease; (c) CT scan diagnosed as thoracolumbar flexion compression fractures, Denis type A-D ; (d) Asia Grade E; (e) 18 years and older; (f) the responsible vertebral body of patient was a single segment.
Exclusion criteria include the following: (a) patients with other fractures; (b) patients with bone cement allergy; (c) patients with nerve injury and progressive aggravation; (d) patients with osteomyelitis and epidural cyst; (e) patients with coagulation dysfunction.
80 patients with kyphoplasty from January 2019 to December 2020 were selected and divided into experimental group (n = 40) and control group (n = 40) according to different treatment methods.
All operations were performed by the chief surgeon of spine surgery. All patients were treated with local infiltration anesthesia . All patients were in prone position, with pillows on the chest and ilium . The pedicle of the responsible vertebral body was located and marked by C-arm fluoroscopy. The 10'a clock and 2'a clock positions of the pedicle shadow on both sides of the responsible vertebral body were used as puncture points. The experimental group was punctured with a new puncture needle with a diameter of 4.0 mm (Fig. 1), and the puncture points by C-arm fluoroscopy was good, Maintain the appropriate lateral tilting angle and upper tilting inclination angle, continue to knock the needle inward, C-arm fluoroscopy showed that the needle tip had reached the medial edge of pedicle shadow in the anterior and posterior position, and the needle tip had reached the posterior edge of vertebral body in the lateral position, continue to knock the needle inward for 3mm, removed the inner core of the needle, and had established the working channel. The bone drill was inserted into the working channel on both sides to expand the bone channel in the vertebral body, and then the balloon was placed to expand. The edge of the balloon was close to the upper and lower endplates, reached the cortex around the vertebral body, or the vertebral fracture was restored,and the expansion was stopped. Appropriate PMMA was injected through the working channel (Fig. 2, 3).
The diameter of the puncture needle in the control group was 3.0 mm. After removing the inner core of the puncture needle, the guide needle was put in first, then the puncture needle cannula was removed, and then the expansion cannula and the working cannula were inserted along the guide needle to establish the working channel. The tip of the working cannula was 3mm in front of the posterior cortex of the vertebral body under C-arm fluoroscopy. Finally, the expansion cannula and guide needle were removed, and the working channel was established. The remaining operations was the same as the experimental group.
All patients wear waist circumference by nurse guided to walk 2 hours after operation and change wound dressing on time.
All patients were followed up for at leat 12 months after treatment. The operation time and intraoperative blood loss of all patients were recorded. Intraoperative blood loss = (preoperative hemoglobin - postoperative hemoglobin) / preoperative hemoglobin × 100%. VAS pain score standard  was used to evaluate the improvement of pain. From 0 to 10 points, the higher the score, the more obvious the pain. VAS scores before operation, 2h, 4h and 48h after operation were recorded. The vertical height of the anterior edge of the upper and lower endplates in the median sagittal plane of the vertebral body was measured by lateral X-ray film . The ratio of anterior height of injured vertebral body = (anterior height of injured vertebral body / average height of anterior edge of upper and lower vertebral body of injured vertebral body) × 100%. The anterior height of injured vertebral body was recorded before operation, 3 days after operation and the last follow-up. The vertical height of the middle of the upper and lower endplates in the median sagittal plane of the vertebral body was measured by lateral X-ray film. The ratio of middle height of injured vertebral body = (middle height of injured vertebral body / average height of middle of upper and lower vertebral body of injured vertebral body) × 100%. The middle height of injured vertebral body was recorded before operation, 3 days after operation and the last follow-up.The angle between the extension lines of the upper and lower endplates in the median sagittal plane of the vertebral body was measured by lateral X-ray film. The wedge angle of injured vertebral body was recorded before operation, 3 days after operation and the last follow-up . The number of C-arm fluoroscopy during the operation and the total cost of the operation were recorded.
SPSS 26.0 was used for data analysis. The measurement data were expressed by mean ± standard deviation. For intergroup comparison, variance homogeneity F test was used first, then independent sample t / t' test was used, and paired sample t test was used for intragroup comparison. The count data were expressed by the number of cases and percentage, and the comparison of counting data was performed by chi-square test. Test level α = 0.05, bilateral test.