ObjectiveTo explore the application value of thin CT angiography (CTA) of pedicle sagittal plane of axis for preoperative evaluation planning pedicle screw placement.MethodsBetween February 2016 and August 2017, 34 patients (68 pedicles) who underwent thin CTA scan before posterior axial surgery were retrospectively analyzed. The vertebral artery development was statistically analyzed. The continuous layers of transverse process hole pedicle height more than or equal to 4 mm (f) were measured and read. The axial fixation methods, clinical manifestations of vertebral artery and spinal cord injury and the bone union of fractures or implants were recorded. Postoperative results of pedicle screws were evaluated by CT scan.ResultsThe right sides of 8 cases and the left sides of 18 cases were dominant vertebral arteries, and equilibrium was reached in 8 cases; f>9 layers were found in 16 pedicles,f=9 layers in 27 pedicles, f=8 layers in 17 pedicles, and f<8 layers in 8 pedicles. The 43 pedicles off≥9 layers used pedicle screw fixation; in the 17 pedicles of f=8 layers, 16 used pedicle screw fixation, and the other one used laminar screw fixation; in the 8 pedicles of f<8 layers, 4 used pedicle screw fixation, and the other 4 used laminar screw fixation. A self-defined pedicle screw grading system was used to evaluate the excellence, and the result showed that,f>9 layers: 14 pedicles were class A, 2 were class B, none was class C;f=9 layers: 16 pedicles were class A, 7 were class B, 4 were class C; f=8 layers: 3 pedicles were class A, 5 were class B, 8 were class C; f<8 layers: none was pedicles class A or class B, 4 were class C. The other 4 lamina screws fixation didn’'t invade the spinal canal. One case of pedicle class C showed clinical manifestations of mild dizziness and drowsiness. The patients were followed up for 6-11 months with an average of (8±3) months, and the fracture or bone graft fusion were observed after 6 months of following-up.ConclusionBased on preoperative CTA thin layer scanning, through measuring and reading continuous layers of transverse process hole pedicle height more than or equal to 4 mm, can effectively judge the security of axial pedicle screws in order to subsequently choose the reasonable operation methods so as to improve success rate and decrease surgical risk.
ObjectiveTo investigate the distance between the screw-out point and the middle sacral artery, and evaluate the safety when the S1 pedicle screw placed by the three cortical fixation techniques.MethodsFrom March to June 2018, randomized CT scan data of 98 adult pelvic angiography were selected to measure the distance from the middle sacral artery to the anterior edge of the vertebral body (a) and the distance from the middle sacral artery to the midline of the vertebral body (b). S1 screw entry point was set as the intersection of lines where extension of S1 facet joint inferior margin and lateral margin cross over. Introversion angles of 10, 15, 20, and 25° were used; the distance between the screw insertion point and the middle sacral artery (d) was measured.ResultsThe middle sacral artery was usually located on the left side of the upper endplate plane of S1. The distance a was (5.40±2.95) mm in 49 males and (4.43±2.32) mm in 49 females, and the difference between the males and females was not statistically significant (t=1.818, P=0.72). The distance b was (12.07±5.42) mm in 45 males and (14.12±4.88) mm in 48 females, and the difference between the males and females was not statistically significant (t=–1.914, P=0.59). The distance d was (12.67±6.00), (9.40±5.17), (7.50±3.76), and (8.10±3.64) mm when the nail was placed at a common internal inclination of 10, 15, 20, and 25°. The differences in the distance d at a common internal inclination of 10° vs. 15°, 10° vs. 20°, 10° vs. 25°, and 15° vs. 20° were all statistically significant (t=16.828, 11.609, 6.073, 6.254; P<0.008 3); there was no statistically significant difference in that at 15°vs. 25°, or 20° vs. 25° (t=2.034, –1.723; P>0.05).ConclusionBy analyzing the relationship between the middle sacral artery and the upper endplate plane of the S1 vertebra, the risk of middle artery injury is small while the biomechanical stability of the screw is increased when using the Lenham method.
ObjectiveTo compare the effectiveness of improved and traditional Kirschner wire tension band fixation in treatment of type C patellar fractures.MethodsBetween January 2017 and January 2019, 26 patients with type C patellar fractures were treated with improved Kirschner wire tension band fixation (group A), and 24 patients were treated with traditional Kirschner wire tension band fixation (group B). There was no significant difference in gender, age, injury cause, disease duration, and side and type of fracture between 2 groups (P>0.05). The operation time, intraoperative blood loss, the visual analogue scale (VAS) scores at 1 and 3 days after operation, the fracture healing time, and the occurrence of complications (skin irritation of Kirschner wires, failure of internal fixation, fracture reduction loss) were recorded, and the knee function was evaluated by Lysholm scoring standard in 2 groups.ResultsThe operation time in group A was significantly less than that in group B (t=−4.742, P=0.000). There was no significant difference in the intraoperative blood loss and VAS scores at 1 and 3 days after operation between 2 groups (P>0.05). All incisions healed by first intention. All patients were followed up 8-15 months, with an average of 11 months. The fracture healing time was (3.3±0.6) months in group A and (3.2±0.6) months in group B, showing no significant difference (t=0.589, P=0.559). At last follow-up, the knee joint function was evaluated according to Lysholm scoring standard. And there were 15 cases of excellent, 8 cases of good, and 3 cases of fair, with an excellent and good rate of 88.5% in group A; there were 8 cases of excellent, 7 cases of good, 7 cases of fair, and 2 cases of poor, with an excellent and good rate was 62.5%. The difference between 2 groups was significant (Z=2.828, P=0.005). The internal fixators were removed after the fracture healed in 2 groups. At last follow-up, no skin irritation of Kirschner wires occurred in group A, but 3 cases in group B. X-ray films reexamination showed that 5 cases of internal fixation failure and no fracture reduction loss were found in group A, while 9 cases of internal fixation failure and 1 case of fracture reduction loss in group B. The incidence of complications in group A was 19.2% (5/26), which was significantly lower than that in group B (54.2%, 13/24) (χ2=6.611, P=0.010).ConclusionCompared with the traditional Kirschner wire tension band fixation, the improved Kirschner wire tension band fixation in treatment of type C patellar fracture can shorten the operation time, reduce the incidence of complications, and benefit the functional recovery of knee joint.
Objective To explore the clinical effect of occipital-cervical fusion and its impact on cervical curvature, and preliminarily study the causes of postoperative dysphagia. Methods The data of 24 patients who underwent occipito-cervical fusion in the Fourth People’s Hospital of Zigong between January 2014 and December 2018 were retrospectively analyzed, including 13 males and 11 females, aged 33-82 years, with an average age of (58.3±13.3) years. Among them, there were 14 cases of atlas fractures, 6 cases of atlantoaxial fractures, 1 case of intraspinal canal space-occupying lesion, 2 cases of chronic atlantoaxial dislocation with spinal cord compression, and 1 case of instability caused by inflammatory diseases. Japanese Orthopedic Association (JOA) score and Visual Analogue Scale (VAS) score were used to evaluate neurological function and pain of patients preoperatively and postoperatively. Occipito-cervical angle (O-C2) and lower cervical angle (C2-C7) were measured to evaluate the preoperative and postoperative angle changes in patients. The causes of postoperative dysphagia were analyzed. Results All the 24 patients were followed up for 8-50 months (26.3 months on average). The mean JOA score increased from 11.6±1.5 before surgery to 15.4±1.2 at the last follow-up, and the mean VAS score decreased from 6.4±1.1 before surgery to 2.0±0.6 at the last follow-up; the differences between the two time points were statistically significant (P<0.001). The bone graft fusion rate was 95.8% (23/24). The mean O-C2 angle decreased from (16.5±7.6)° before surgery to (14.7±4.5)° at the last follow-up, with no statistical significance (P=0.395). The mean angle of C2-C7 increased from (9.4±5.5)° before surgery to (16.3±3.5)° at the last follow-up, and the difference was statistically significant (P<0.001). Two patients developed postoperative dysphagia, possibly due to fusion in a flexion position. Conclusion Occipito-cervical fusion has reliable efficacy in treating occipito-cervical instability, with a high fusion rate and a low incidence of complications, but it will change the physiological curvature of upper and lower cervical vertebra, and fusion in a flexion position may cause postoperative dysphagia.
ObjectiveTo explore the feasibility of the clinical application of individualized simulated S1 pedicle screw.MethodsThe data of patients with lumbar disease diagnosed and treated in the Fourth People’s Hospital of Zigong from May 2017 to April 2019 were retrospectively analyzed. According to the preoperative individualized design of the S1 pedicle screw placement path, the patients were divided into individualized screw placement group and traditional screw placement group. The distance D between the screw tip and the endplate of the S1, the angle α of the screw in the plane of the dysplasia and the lumbar pedicle of the L5, the angle of oblique angle β, the number of screws of 35 and 40 mm in length, and the screw loosening rate (followed-up within 1 year) in the two groups were analyzed.ResultsA total of 59 patients were enrolled in this study, 31 in the individualized screw placement group and 28 in the traditional screw placement group. The differences in the distance D between the screw tip and the endplate of the S1 [(2.61±0.82) vs.(4.13±1.51) mm; t=-5.718, P<0.001], the angle α of the screw in the plane of the dysplasia and the lumbar pedicle of the L5 [(9.31±3.52) vs. (13.53±4.78)°; t=-5.646, P<0.001], the angle of oblique angle β [(15.73±6.04) vs. (10.65±5.09)°; t=3.022, P=0.004], the proportion of using screw models [40 mm in length: 56 vs. 8; 35 mm in length: 6 vs. 48; χ2=68.539, P<0.001], and the screw loosening rate followed-up within 1 year [3.22% vs. 16.07%; χ2=5.774, P<0.001] were statistically significant between the individualized screw placement group and the traditional screw placement group.ConclusionsPreoperative individualized design of the pedicle screw of the S1 pedicle screw can be used in clinical practice. The biomechanical stability of the S1 pedicle screw can be improved and the sagittal balance can be achieved.
In the variation of vertebral artery in artery groove, high-riding vertebral artery is the most common. High-riding vertebral artery can affect the choice of internal fixation device for upper cervical spine surgery, and may lead to serious complications such as vertebral artery injury and even death. In recent years, great progress has been made in the concept, incidence, diagnostic techniques, classification and impact on upper cervical spine surgery of high-riding vertebral artery. This review summarizes the above contents in order to improve clinicians’ understanding of high-riding vertebral artery, and provide a reference for timely diagnosis of high-riding vertebral artery, make an appropriate plan for upper cervical cervical spine surgical fixation, and reduce surgical complications.
Objective To investigate the influence of axis pedicle and intra-axial vertebral artery (IAVA) alignment on C2 pedicle screw placement by measuring the data of head and neck CT angiography. MethodsThe axis pedicle diameter (D), isthmus height (H), isthmus thickness (T), and IAVA alignment types were measured in 116 patients (232 sides) who underwent head and neck CT angiography examinations between January 2020 and June 2020. Defined the IAVA offset direction by referencing the vertical line through the center of C3 transverse foramen on the coronal scan, it was divided into lateral (L), neutral (N), and medial (M). Defined the IAVA high-riding degree by referencing the horizontal line through the outlet of the C2 transverse foramen, it was divided into below (B), within (W), and above (A). The rate of pedicle stenosis, high-riding vertebral artery, and different IAVA types were calculated, and their relationships were analysed. Simulative C2 pedicle screws were implanted by Mimics 19.0 software, and the interrelation among the rates of pedicle stenosis, high-riding vertebral artery, IAVA types, and vertebral artery injury were analyzed. ResultsThe rate of C2 pedicle stenosis was 33.6% (78/232), and the rate of high-riding vertebral artery was 35.3% (82/232). According to the offset direction and the degree of riding, IAVA was divided into 9 types, among which the N-W type (29.3%) was the most, followed by the L-W type (19.0%) and the L-B type (12.9%), accounting for 60.9%. The vertebral artery injury rate of simulative implanted C2 pedicle screws was 35.3% (82/232). The vertebral artery injury rate in patients with pedicle stenosis and high-riding vertebral artery was significantly higher than that who were not (P<0.001). The rate of pedicle stenosis, high-riding vertebral artery, and vertebral artery injury were significantly different among IAVA types (P<0.001), and M-A type was the most common. ConclusionVertebral artery injury is more common in pedicle stenosis and/or high-riding vertebral artery and/or IAVA M-A type. Preoperative head and neck CT angiography examination has clinical guiding significance.