[The effect of axis pedicle and intra-axial vertebral artery on C 2 pedicle screw placement].

Objective: To investigate the influence of axis pedicle and intra-axial vertebral artery (IAVA) alignment on C 2 pedicle screw placement by measuring the data of head and neck CT angiography. Methods: The 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 C 3 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 C 2 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 C 2 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. Results: The rate of C 2 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 C 2 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. Conclusion: Vertebral 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.

[Comparative study on the effectiveness of improved and traditional Kirschner wire tension band fixation in treatment of type C patellar fractures].

OBJECTIVE: To compare the effectiveness of improved and traditional Kirschner wire tension band fixation in treatment of type C patellar fractures. METHODS: Between 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. RESULTS: The 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) ( χ 2=6.611, P=0.010). CONCLUSION: Compared 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.

[Surgical treatment strategy for the "shell" phenomenon after thoracolumbar fracture].

Objective: To explore the surgical treatment strategy of the vertebral "shell" after thoracolumbar fracture, and provide clinical reference for the intervention and treatment of "shell". Methods: Between June 2015 and January 2017, 53 patients with high risk of vertebral "shell" after thoracolumbar fracture surgery were enrolled in a prospective study according to the selection criteria. All patients were randomly divided into two groups according to the order of treatment, 27 cases in the treatment group were treated with short-segment fixation combined with vertebral reconstruction, 26 cases in the control group were treated with short-segment fixation. There was no significant difference in gender, age, injury cause, Denis classification, fracture segment, the degree of injured vertebra compression, bone mineral density, and American Spinal Cord Injury Association (ASIA) classification between the two groups ( P>0.05). The degree of injured vertebra compression, visual analogue scale (VAS) score, and Oswestry disability index (ODI) score at preoperation, immediate after operation, and last follow-up were calculated and compared between the two groups. The "shell" phenomenon and surgery complications were observed at the same time. Results: All patients were followed up 12-18 months with an average of 14.4 months. There were 5 cases of "shell" phenomenon in the treatment group and 4 cases of nonunion at last follow-up, 23 cases of "shell" phenomenon in the control group and 19 cases of nonunion at last follow-up; there was a significant difference between the two groups ( P<0.05). In the treatment group, 1 case had incision fat liquefaction and 4 cases had bone cement leakage; in the control group, 2 cases had screw loosening and 1 case had unilateral connecting rod rupture; there was no significant difference in the incidence of complications between the two groups ( χ2=0.504, P=0.478). The degree of injured vertebra compression, VAS score, and ODI score were significantly improved in both groups at immediate after operation and last follow-up ( P<0.05). There was no significant difference in the degree of injured vertebra compression between the two groups at immediate after operation ( P>0.05), but which was significantly higher in the control group than that in the treatment group at last follow-up ( P<0.05). Except that the ODI score of the control group was significantly higher than that of the treatment group at last follow-up ( P<0.05), there was no significant difference in VAS score and ODI score between the two groups at the other time points ( P>0.05). Conclusion: The treatment of thoracolumbar fracture with short-segment fixation combined with injured vertebral reconstruction can effectively prevent the "shell" phenomenon, which is conducive to maintaining the height of injured vertebral and improving the long-term function. The effectiveness is satisfactory.

[Effectiveness comparison between minimally invasive surgery and traditional open reduction internal fixation in treatment of unstable distal radial fractures].

Objective: To compare the effectiveness of minimally invasive percutaneous internal fixation and traditional open reduction via Henry approach and internal fixation in the treatment of unstable distal radial fractures. Methods: Fifty-six patients with unstable distal radial fractures that met the selection criteria between October 2013 and December 2014 were randomly divided into minimally invasive group (26 cases) and traditional group (30 cases). They were treated with oblique T-shaped locking plate internal fixation via minimally invasive percutaneous approach or traditional Henry approach. There was no significant difference in gender, age, side, causes of injury, fracture classification, and time from injury to operation between 2 groups ( P>0.05). The length of incision, operation time, intraoperative blood loss, hospitalization time, and fracture healing time were recorded in 2 groups. The difference of the length of the radial styloid process, the volar tilting angle, and the ulnar inclining angle between at 3 months postoperatively and preoperation were compared between 2 groups. The visual analogue scale (VAS) score, the percentage of the lateral wrist flexion and extension range, forearm rotation, and the hand grip strength (recorded as FS%, FR%, and HG% , respectively) were compared between 2 groups at 4 weeks and 3 months postoperatively. The wrist function was evaluated through the disability of arm-shoulder-hand (DASH) scores at 3 months postoperatively. Results: The length of incision, operation time, intraoperative blood loss, and hospitalization time in minimally invasive group were significantly less than those in traditional group ( P<0.05). The incisions of 2 groups were all achieved primary healing. All patients were followed up 10-16 months (mean, 12.6 months). There was no radial artery injury, screw too long, or screw entering the joint space. In minimally invasive group, 1 patient had the symptoms of median nerve irritation after operation, and recovered completely at 1 month; in traditional group, there were 2 cases of tendon irritation after operation. There was no significant difference in the fracture healing time, the difference of the length of the radial styloid process, the volar tilting angle, and the ulnar inclining angle between at 3 months postoperatively and preoperation between 2 groups ( P>0.05). At 4 weeks after operation, the VAS score in minimally invasive group was significantly less than that in traditional group, and the FS%, FR%, and HG% were significantly higher than those in traditional group ( P<0.05). There was no significant difference in above indicators between 2 groups at 3 months after operation ( P>0.05). The DASH score in minimally invasive group was significantly less than that in traditional group at 3 months after operation ( t=-5.308, P=0.000). The patient's aesthetic evaluation of postoperative wound in minimally invasive group was better than in traditional group. Conclusion: For treatment of unstable distal radial fractures, the metacarpal minimally invasive internal fixation has the advantages of smaller wound, incisional concealment, and quicker recovery of wrist joint.

[Imaging study of "shell" phenomenon of thoracolumbar fractures after posterior reduction].

Objective: To analyze the imaging characteristics of vertebral "shell" phenomenon of thoracolumbar fractures after posterior reduction and to explore the relationship between vertebral "shell" and fracture healing. Methods: Between January 2013 and December 2015, the clinical data of 116 patients with thoracolumbar fractures treated with posterior pedicle screw-rod system reduction and internal fixation were analyzed retrospectively. There were 72 males and 44 females, aged 22-66 years (mean, 43 years). Injury causes were traffic accident in 24 cases, falling from height in 54 cases, bruise in 38 cases. Fracture segment located at T 11 in 5 cases, T 12 in 38 cases, L 1 in 52 cases, L 2 in 21 cases. There were 51 cases of compressive fracture and 65 cases of burst fracture. The sagittal Cobb angle ranged from 8 to 27°, with an average of 15°. Degree of preoperative spinal compression ranged from 20% to 75%, with an average of 44%. Bone density measurement showed that normal bone mass in 30 cases, bone loss in 40 cases, osteoporosis in 41 cases, and severe osteoporosis in 5 cases. The number, pathological characteristics, and imaging regularity of the vertebral "shell" phenomenon were observed and analyzed by logistic regression. Results: All patients were followed up 11-18 months with an average of 13 months. A total of 72 cases of vertebral "shell" phenomenon mainly located in the vertebral anterior column and the end plate near the weak area (54/72, 75.0%). Most of them were in the irregular shape (50/72, 69.5%). The vertebral fracture line was related to the shape of the vertebral body and the displacement of the vertebral body after reduction. The outcome of the "shell" can be divided into disappeared type, reduced type, and collapse type, the volume of vertebral "shell" and its outcome were the risk factors for vertebral fracture healing. Conclusion: The incidence of vertebral "shell" and nonuion of thoracolumbar fractures after posterior reduction are high. The main influencing factors are vertebral "shell" outcome and size.

[Effectiveness comparison of suspension fixation plus hinged external fixator and double plate internal fixation in treatment of type C humeral intercondylar fractures].

Objective: To compare the effectiveness of suspension fixation plus hinged external fixator with double plate internal fixation in the treatment of type C humeral intercondylar fractures. Methods: Between January 2014 and April 2016, 30 patients with type C (Association for the Study of Internal Fixation, AO/ASIF) humeral intercondylar fractures were treated. Kirschner wire suspension fixation plus hinged external fixator was used in 14 cases (group A), and double plate internal fixation in 16 cases (group B). There was no significant difference in gender, age, injury cause, disease duration, injury side, and type of fracture between 2 groups ( P>0.05). Results: There was no significant difference in operation time and hospitalization stay between 2 groups ( P>0.05). But the intraoperative blood loss in group A was significantly less than that in group B ( P<0.05); the visual analogue scale (VAS) score at 1 day and 3 days after operation in group A were significantly less than those in group B ( P<0.05). Primary healing of incision was obtained in all patients of 2 groups, and no surgery-related complications occurred. The patients were followed up 6-24 months (mean, 12.3 months) in group A and 6-24 months (mean, 12.8 months) in group B. The self-evaluation satisfaction rate was 85.7% (12/14) in group A and was 81.2% (13/16) in group B at 3 months after operation, showing no significant difference ( χ2=0.055, P=0.990). Based on the improved Gassebaum elbow performance score at 6 months after operation, excellent and good rate of the elbow function was 78.6% (excellent in 5 cases, good in 6 cases, fair in 2 cases, and poor in 1 case) in group A and was 81.2% (excellent in 6 cases, good in 7 cases, fair in 2 cases, and poor in 1 case) in group B, showing no significant difference between 2 groups ( χ2=0.056, P=0.990). Heterotopic ossification occurred at 3 months after operation in 1 case of each group respectively. The X-ray films showed bony union in all cases; no loosening or breakage of screw was observed. The bone union time showed no significant difference between 2 groups ( t=-0.028, P=0.978). The time of internal fixation removal, the intraoperative blood loss, and VAS score at 1 day and 3 days after operation in group A were significant better than those in group B ( P<0.05). Conclusion: The suspension fixation plus hinged external fixator and double plate internal fixation for the treatment of type C humeral intercondylar fractures have ideal outcome in elbow function. But the suspension fixation plus hinged external fixator is better than double plate internal fixation in intraoperative blood loss, postoperative VAS score, and time of internal fixation removal.

[CLINICAL RESEARCH OF INDIVIDUAL PERCUTANEOUS CANNULATED SCREWS FIXATION FOR TREATMENT OF Herbert TYPE Ib SCAPHOID FRACTURE].

OBJECTIVE: To investigate the effectiveness of individual percutaneous cannulated screws fixation of computer-assisted design combined with three-dimensional (3D) guide plate by comparing with cast immobilization and open internal fixation for treatment of Herbert type Ib scaphoid fracture. METHODS: Between January 2010 and June 2015, 56 patients with fresh Herbert type Ib scaphoid fracture were treated with cast immobilization in 16 cases (external fixation group), with open reduction and internal fixation in 20 cases (open reduction group), and with individual percutaneous cannulated screws fixation of computer-assisted design combined 3D guide plate in 20 cases (minimal invasion group). There was no significant difference in gender, age, injury cause, side, disease duration, and classification of fractures between groups P>0.05).The time of bone union, bone nonunion rate, return-to-work time, wrist range of motion (ROM), and Mayo function score were recorded and compared. RESULTS: Primary healing of incision was obtained in open reduction group and minimally invasion group, without related complications. The cases were followed up 10-24 months (mean, 16.6 months). The time of bone union and return-to-work time of minimal invasion group were significantly shorter than those of the other 2 groups (P<0.05), and the rate of bone nonunion was significantly lower than that of the other 2 groups (P<0.05). At last follow-up, the wrist ROM of minimal invasion group[(104.40±3.46)°] was significantly larger than that of external group[(94.20±2.42)°] and open reduction group[(96.40±2.66)°] (P<0.05). According to Mayo function score, the results were excellent in 6 cases, good in 5 cases, fair in 2 cases, and poor in 3 cases in external fixation group, with an excellent and good rate of 69%; the results were excellent in 9 cases, good in 7 cases, fair in 2 cases, and poor in 2 cases in open reduction group, with an excellent and good rate of 80%; the results were excellent in 16 cases, good in 3 cases, and fair in1 case in minimal invasion group, with an excellent and good rate of 95%; there was significant difference in excellent and good rate among groups (P<0.05). CONCLUSIONS: Individual percutaneous cannulated screws fixation of computer-assisted design combined with 3D guide plate has satisfactory effectiveness in the treatment of Herbert type Ib scaphoid fractures, with the advantages of mini-invasion, high accuracy, high rate of bone union, less complication, early return-to-work time.