[SHORT-TERM EFFECTIVENESS OF PERCUTANEOUS PEDICLE SCREW GUIDED WITH PHOTOELECTRIC NAVIGATION FOR THORACOLUMBAR...

To investigate the short-term effectiveness of percutaneous pedicle screw (PPS) guided with photoelectric navigation for thoracolumbar fractures.

Between May 2013 and June 2015, the clinical data of 39 patients with thoracolumbar fractures in accordance with the selection criteria were retrospectively analyzed. The patients were divided into photoelectric navigation PPS group (trial group, 20 cases) and C-arm X-ray guidance PPS group (control group, 19 cases). There was no significant difference in gender, age, injury cause, fracture vertebrae, AO classification, operation time after injury, visual analogue scale (VAS) score, and vertebral compression ratio (VCR) between 2 groups (P > 0.05). The operation time, bleeding amount, perspective times, VAS score, and one-time success rate (OSR) of screw placement were recorded; VCR and endplate-screw angle (ESA) were measured; and pedicle-screw relationship (PSR) was assessed by Ringel's method in radiographic result.

Differences in operation time and bleeding amount were not significant between 2 groups (P > 0.05); perspective times of control group was significantly more than t hat of trial group (t=-15.658, P=0.000). The OSR of trial group (95.60%, 87/91) was significantly better than that of control group (86.75%, 72/83) (χ²=4.323, P=0.038). The patients were followed up 6-11 months (mean, 7.6 months) in trial group, and 7-11 months (mean, 7.8 months) in control group. No neurovascular complications associated with screw insertion occurred. Difference was not significant in VAS score at 7 days and 6 months after operation between 2 groups (P > 0.05), but VAS scores at 7 days and 6 months were significantly improved when compared with preoperative score in 2 groups (P < 0.05), and significant difference in VAS score was shown between at 7 days and 6 months in 2 groups (P < 0.05). VCR of trial group and control group were significantly improved to 94.75%±5.10% and 92.40%±5.09% at 6 months after operation from preoperative 71.97%±5.66% and 73.50%±5.97% (t=11.865, P=0.000; t=11.359, P=0.000), but there was no significant difference between 2 groups (t=1.442, P=0.158). ESA of trial group and control group were (1.82±1.13)° and (3.36±2.43)° at 6 months after operation, showing significant difference (t=5.421, P=0.000). At 6 months after operation, according to PSR classification, 83 screws rated as grade I, 6 as grade II, and 2 as grade III, and excellent and good rate of screw replacement was 97.80% in trial group; 54 screws were rated as grade I, 19 as grade II, 7 as grade III, and 3 as grade IV, and excellent and good rate of screw replacement was 87.95% in control group; difference was significant between 2?groups (χ²=18.347, P=0.000).

Application of photoelectric navigation can guide screws placement by the two-dimensional multi pl ane dynamic image, has better accuracy of screws position in thoracolumbar fractures, reduces the introperative X-ray perspective times, maintains good reduction of vertebral body, and achieves satisfactory effectiveness.