ObjectiveTo investigate the clinical application of three-dimensional (3D) printing technique combined with a new type of thoracic pedicle screw track detector in thoracic pedicle screw placement.MethodsAccording to the characteristics of thoracic pedicle and common clinical screw placement methods, a new type of thoracic pedicle screw track detector was independently developed and designed. The clinical data of 30 patients with thoracic vertebrae related diseases who underwent posterior thoracic pedicle screw fixation between March 2017 and January 2020 were retrospectively analysed. Among them, there were 18 males and 12 females with an average age of 56.3 years (range, 32-76 years). There was 1 case of thoracic disc herniation, 4 cases of thoracic canal stenosis, 2 cases of ossification of posterior longitudinal ligament of thoracic vertebra, 16 cases of thoracic trauma, 2 cases of thoracic infection, and 5 cases of thoracic canal occupation. Three-dimensional CT of the thoracic vertebra was routinely performed preoperatively, and the model of the patient’s thoracic vertebra was reconstructed and printed out. With the assistance of the model, preoperative simulation was performed with the combination of the new type thoracic pedicle screw track detector, and detected no nails after critical cortical damage. During operation, one side was randomly selected to use traditional hand screws placement (control group), and the other side was selected to use 3D printing technique combined with new type thoracic pedicle screw track detector to assist thoracic pedicle screws placement (observation group). The single screw placement time, adjustment times of single screw, and blood loss during screw placement were compared between the two groups. The accuracy of screw placement in the two groups was evaluated according to postoperative CT imaging data.ResultsThe single screw placement time, adjustment times of single screw, and blood loss during screw placement in the observation group were significantly less than those in the control group (P<0.05). Postoperative CT examination showed that the observation group had 87 screws of grade 1, 3 screws of grade 2, and the acceptable screw placement rate was 100% (90/90); the control group had 76 screws of grade 1, 2 screws of grade 2, 11 screws of grade 3, and 1 screw of grade 4, and the acceptable screw placement rate was 86.7% (78/90); showing significant difference in screw placement between the two groups (χ2=12.875, P=0.001). All patients were followed up 6-18 months, with an average of 11.3 months. There was no complication of vascular, nerve, spinal cord, or visceral injury, and screws or rods broken, and no patient was revised.ConclusionThe 3D printing technique combined with the new type of thoracic pedicle screw track detector assisted thoracic pedicle screw placement is convenient, and significantly improves the accuracy and safety of intraoperative screw placement, and overall success rate of the surgery.
ObjectiveTo investigate the effectiveness of synchronous unilateral percutaneous kyphoplasty (PKP) in the treatment of double noncontiguous thoracolumbar osteoporotic vertebral compression fracture (OVCF). MethodsBetween December 2018 and September 2020, 27 patients with double noncontiguous thoracolumbar OVCF were treated by synchronous unilateral PKP. There were 11 males and 16 females, with an average age of 75.4 years (range, 66-92 years). The fractures were caused by falls in 22 cases and sprains in 5 cases. The time from injury to hospital admission was 0.5-7.0 days, with an average of 2.1 days. The fractured vertebrae located at T9 in 2 cases, T10 in 3 cases, T11 in 10 cases, T12 in 15 cases, L1 in 12 cases, L2 in 6 cases, L3 in 4 cases, and L4 in 2 cases. The volume of bone cement injected into each vertebral body, operation time, and intraoperative fluoroscopy times were recorded. Anteroposterior and lateral X-ray films of thoracolumbar spine were taken to observe the anterior height of the injured vertebra, the Cobb angle of kyphosis, and the diffusion and good distribution rate of bone cement in the thoracolumbar spine. Visual analogue scale (VAS) score and Oswestry disability index (ODI) were used to evaluate the pain and functional improvement. ResultsAll operations completed successfully. The operation time was 34-70 minutes, with an average of 45.4 minutes. The intraoperative fluoroscopy was 21- 60 times, with an average of 38.6 times. The volume of bone cement injected into each vertebral body was 2-9 mL, with an average of 4.3 mL. All patients were followed up 6-21 months, with an average of 11.3 months. X-ray film reexamination showed that the anterior height of the injured vertebra and Cobb angle at each time point after operation were significantly improved than those before operation (P<0.05), and there was no significant difference between different time points after operation (P>0.05). The distribution of bone cement was excellent in 40 vertebral bodies, good in 13 vertebral bodies, and poor in 1 vertebral body, and the excellent and good rate was 98.1% (53/54). The pain of all patients significantly relieved or disappeared, and the function improved. The VAS score and ODI at each time point after operation were significantly lower than those before operation (P<0.05), and there was no significant difference between different time points after operation (P>0.05).ConclusionFor the double noncontiguous thoracolumbar OVCF, the synchronous unilateral PKP has the advantages of simple puncture, less trauma, less intraoperative fluoroscopy, shorter operation time, satisfactory distribution of bone cement, etc. It can restore the height of the vertebral body, correct the kyphotic angle, significantly alleviate the pain, and improve the function.