The activated carbon with high specific surface area was prepared by carbonization with walnut shell as raw material and activation by potassium hydroxide.The surface of activated carbon was then modified by phenyltrimethoxysilane to prepare phenyl-bonded high specific surface area activated carbon adsorption material.The specific surface area and pore size distribution of phenyl-bonded activated carbon were measured by nitrogen adsorption method.The organic functional groups of the phenyl-bonded activated carbon, the chemical environment of the surface elements and the crystal structure were characterized by infrared spectroscopy, X-ray photoelectron spectroscopy and X-ray powder diffraction method.The volatile organic compounds (VOCs) in the air were absorbed by a sampling tube filled with the adsorption material prepared here, then desorbed into carbon disulfide solution and detected by gas chromatography.The saturated adsorption capacities of phenyl bonded activated carbon to 7 kinds of VOCs (ethanol, acetone, hexane, ethyl acetate, tetrahydrofuran, 1,2-dichloroethane, benzene) were in the range of 129-216 mg/g.In the range of 0.05-2.50 mg/mL, there was a good linear relationship between the peak height of the 7 components and the concentration, and the detection limits were in the range of 0.92-3.60 mg/m3.

Objective:To evaluate the efficacy of posterior subtotal vertebrectomy in the treatment of thoracolumbar vertebral refractures after vertebroplasty.Methods:A retrospective analysis was conducted in the 28 patients with refracture after percutaneous vertebroplasty(PVP) or percutaneous kyphoplasty(PKP) who had been treated at Department of Spinal Surgery, Henan Provincial People's Hospital from June 2017 to October 2019. They were 7 males and 21 females, with an average age of 62.4 years(from 61 to 76 years). A total of 28 vertebrae were involved, including 5 T11s, 9 T12s, 11 L1s and 3 L2s. Their previous operations were PKP in 17 cases and PVP in 11. After the spinous process, vertebral plate, articular process and transverse process were resected by posterior approach, the vertebral body, bone cement and upper and lower intervertebral discs were partially resected by trans-vertebral lateral approach. At the same time, nerve decompression was performed. Finally, the inter-vertebral support was fixated followed by the posterior screw-rod orthopedic fixation. The operation time and intraoperative bleeding volume were recorded. The cobb angles of kyphosis were compared on the X-ray films of the whole spine between preoperation and the last follow-up to evaluate correction. Functional improvement of the spine was evaluated by comparison of the visual analogue scale (VAS) and JOA(Japanese Orthopedics Association) scores between preoperation and the last follow-up.Results:The operation time averaged 182.1 min and intraoperative bleeding volume 996.2 mL. All the 28 patients were followed up for 8 to 29 months (mean, 19.8 months). No obvious neurological lesions or other serious complications were observed. The cobb angle was improved from preoperative 41.3°±10.3° to 6.4°±2.5° at the last follow-up, the VAS score from preoperative 7.3±1.8 to 2.5±1.0 at the last follow-up, and the JOA score from preoperative 8.4±2.3 to 21.3±2.5 at the last follow-up, showing a significant difference in all the comparisons ( P<0.05). Conclusion:The posterior subtotal vertebrectomy is effective for thoracolumbar vertebral refractures after vertebroplasty because it can remove bone cement, decompress the spinal canal, fuse the inter-vertebral graft and reconstruct the spinal stability in one stage.

Objective:To compare the effect of O-arm assisted and free-hand pedicle screw placement in the treatment of AO type C thoracolumbar fracture.Methods:A retrospective cohort study was used to analyze the clinical data of 34 patients with type C thoracolumbar fracture admitted to Henan Provincial People′s Hospital from January 2018 to June 2021, including 23 males and 11 females; aged 42-63 years [(50.4±7.4)years]. The fracture was located at T 11 in 4 patients, T 12 in 10, L 1 in 12, L 2 in 6, T 11~12/L 1 in 1 and T 12/L 1 in 1. Posterior reduction and internal fixation was carried out for all patients, of whom 18 were treated with O-arm assisted pedicle screw placement (navigation group) and 16 with free-hand pedicle screw placement (free-hand group). The operation time, single screw placement time, intraoperative bleeding volume, operation mode and screw placement accuracy were compared between the two groups. The kyphotic Cobb angle, visual analogue score (VAS) and American Spinal Injury Association (ASIA) score were compared between the two groups before operation, at 1 week after operation, at 3 months after operation and at the last follow-up. Postoperative complications were observed. Results:All patients were followed up for 12-29 months [(16.8±6.1)months]. There was no significant difference between the two groups in the operation time, intraoperative bleeding volume and operation mode (all P>0.05). The single screw placement time was (9.4±1.6)minutes in navigation group, but was (10.8±1.5)minutes in free-hand group ( P<0.05). The screw placement accuracy was 97.4% in navigation group, but was 81.5% in free-hand group ( P<0.01). The kyphotic Cobb angle and VAS had no significant differences between the two groups before operation (all P>0.05). The kyphotic Cobb angle in navigation group and free-hand group was (4.3±1.1)° and (5.9±1.1)° at 1 week after operation, (4.4±1.2)° and (5.7±1.3)° at 3 months after operation, and (4.4±1.2)° and (6.8±0.9)° at the last follow-up, decreased significantly from that before operation [(21.8±3.1)°, (22.2±3.2)°] (all P<0.01). The kyphotic Cobb angle in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The VAS in navigation group and free-hand group was (3.2±0.7)points and (4.1±0.7)points at 1 week after operation, (2.4±0.6)points and (3.0±0.8)points at 3 months after operation, and (1.8±0.9)points and (2.6±0.7)points at the last follow-up, decreased significantly from that before operation [(8.4±0.8)points, (8.3±0.9)points] (all P<0.01). The VAS in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The ASIA score showed no significant difference within and between the two groups before operation, at 1 week, 3 months after operation and at the last follow-up (all P>0.05). Postoperative incision infection occurred in 1 patient in both groups ( P>0.05). Implant failure such as loosening or displacement was not observed in navigation group, and only occurred in 2 patients in free-hand group ( P>0.05). Conclusion:Compared with free-hand pedicle screw placement, O-arm assisted pedicle screw placement in the treatment of AO type C thoracolumbar fracture has advantages of rapid and accurate screw placement, good reduction and notable pain relief.