ObjectiveTo investigate the security of pedicle screw fixation in fractured vertebra in treatment of thoracolumbar fractures by comparing with routine fixation cross fractured vertebra. MethodsA total of 101 cases of single segmental thoracolumbar fracture were selected between June 2008 and June 2011. Of them, 56 cases underwent pedicle screw fixation in fractured vertebra (group A), and 45 cases received routine fixation cross fractured vertebra (group B). There was no significant difference in gender, age, causes of injury, fracture type, fracture segment, Frankel grading, time of injury to operation, and the preoperative anterior vertebral height compression ratio and the canal occupation rate between 2 groups (P>0.05). There were 34 cases of junction fracture of pedicle and vertebra (type I), 2 cases of pedicle waist fracture (type Ⅱ), and 20 cases of junction fracture of pedicle and lamina (type Ⅲ) in group A. The position of fractured vertebral pedicle screw was observed; the anterior vertebral height compression ratio, canal occupation rate, and surgical complications were compared between 2 groups. ResultsA total of 103 pedicle screws were placed in 54 patients of group A, except 2 patients of type Ⅱ fracture; 96 screws were placed in the bone cortex completely and 7 screws deviated. The operation time of group A was significantly longer than that of group B (t=4.339, P=0.000), but there was no significant difference in intraoperative blood loss between 2 groups (t=-0.089, P=0.929). All 101 patients were followed up 6-16 months (mean, 8.5 months). The patients of 2 groups achieved nerve functional recovery. Fixation-related complications occurred in 1 case of 2 groups respectively, showing no significant difference (P=1.000). At last follow-up, according to Denis lumbago classification, 51 cases were rated as P1 level and 5 cases as P2 level in group A; 35 cases were rated as P1 level, 8 cases as P2 level, and 2 cases as P3 level in group B; and there was no significant difference between 2 groups (Z=-1.836, P=0.066). There was no significant difference between 2 groups in canal occupation rate at immediate after operation and at last follow-up (P>0.05), and in the anterior vertebral height compression ratio at immediate after operation (P>0.05), but the anterior vertebral height compression ratio of group B was significantly higher that of group A at last follow-up (P<0.05). ConclusionSingle segmental thoracolumbar fracture treated by pedicle screw fixation in fractured vertebra through posterior approach is safe and feasible according to different pedicle fracture types to guide fixation.
ObjectiveTo evaluate the clinical significance of individualized reference model of sagittal curves and navigation templates of pedicle screw by three-dimensional printing technique for thoracolumbar fracture with dislocation. MethodsBetween February 2011 and November 2013, 42 patients with thoracolumbar fracture and dislocation undergoing pedicle screw fixation were divided into 2 groups:traditional pedicle screw internal fixation by fluoroscopy assistant was used in 24 cases (control group), and individualized reference model of sagittal curves and navigation templates of pedicle screw were used in 18 cases (trial group). There was no significant difference in gender, age, injury causes, segment, degree of dislocation, and Frankel classification between 2 groups (P>0.05). The operation time, intraoperative blood loss, perspective times, and dislocation rate, sagittal angle recovery rate at different time were compared. The success rate of pedicle screw insertion, sagittal screw angle, and Frankel classification were compared. The angle between sagittal screws, difference of screw entry point at horizontal position, and difference of screw inclined angle were compared. ResultsThe operating time, intraoperative blood loss, and perspective times in trial group were significantly lower than those in control groups (P<0.05). All the patients were followed up 12-40 months (mean, 22 months). The dislocation rate at immediate after operation and last follow-up were significantly improved when compared with preoperative value in 2 groups (P<0.05). At immediate after operation and last follow-up, the dislocation rate and sagittal angle recover rate in trial group were significantly better than those in control group (P<0.05). There were significant differences in the one-time success rate, final success rate of pedicle screw insertion, and saggital screw angle between 2 groups (χ2=9.38, P=0.00; χ2=10.95, P=0.00; χ2=13.43, P=0.00). The angle between sagittal screws, difference of screw entry point at horizontal position, and difference of screw inclined angle in trail group were significantly less than those in control group (P<0.05). There was significant difference in the Frankel classification between 2 groups at last follow-up (Z=-1.99, P=0.04). ConclusionThe application of individualized reference model of sagittal curves and navigation templates of pedicle screw by three-dimensional printing technique for thoracolumbar fracture with dislocation has the advantages of shorter operation time, less intraoperative blood loss, better recovery of thoracolumbar dislocation, and better Frankel classification.
ObjectiveTo investigate the accuracy of the two-dimension computer-aided surgery navigation system in the lumbar pedicle screw fixation on recombinant CT section after operation. MethodsBetween February 2011 and April 2013, 218 patients undergoing lumbar spinal pedicle screw fixation were divided into 2 groups:two-dimension computer-aided surgery navigation system was used in 95 cases (the navigation group) and X-ray fluoroscopy assistant technology in 123 cases (the fluoroscopy assistant group). There was no significant difference in age, gender, and type of disease between 2 groups (P>0.05). The mean operating time, blood loss volume, and fluoroscopy times, and the one-time success rate of pedicle screw implant were observed. The sagittal screw angle (SSA), the relationship between the pedicle cortex and screw, the accuracy rate of pedicle screw, and the sagittal angle on both sides (SBA) were observed. ResultsA total of 504 screws were inserted in navigation group, 432 (85.7%) were inserted successfully at first time and 472 (85.7%) were inserted successfully at end time. A total of 656 screws were inserted in fluoroscopy assistant group, 474 (72.3%) were successfully inserted at first time, and 563 (85.8%) were inserted successfully at end time. There were significant differences in the one-time success rate and final success rate of pedicle screw implant between 2 groups (χ2=30.19, P=0.00; χ2=18.16, P=0.00). There was no significant difference in the mean operating time and the blood loss volume of pedicle screw implant between 2 groups (t=0.88, P=0.38; t=1.47, P=0.14); but the fluoroscopy times of pedicle screw implant in navigation group 0.7±0.3 were significantly less than that in fluoroscopy assistant group 1.5±1.0 (t=-8.09, P=0.00). The SSA and SBA in navigation group[(3.7±0.9)° and (1.7±0.8)°] were significantly less than those in fluoroscopy assistant group[(6.0±1.7)° and (3.5±1.6)°] (t=-26.92, P=0.00; t=-22.49, P=0.00). ConclusionThe sagittal screw angle and accuracy of pedicle screw implant can be significantly improved using the two-dimension computer-aided surgery navigation system in lumbar posterior fixation.
ObjectiveTo evaluate the clinical significance of individualized reference model of sagittal curves by three-dimensional (3D) printing technique and computer-aided navigation system for lumbar spondylolisthesis. MethodsBetween February 2011 and October 2012, 66 patients with lumbar spondylolisthesis underwent posterior lumbar interbody fusion (PLIF) by traditional operation in 36 cases (control group) and by individualized reference model of sagittal curves by 3D printing technique and computer-aided navigation system in 30 cases (trial group). There was no significant difference in gender, age, disease duration, segment, type of disease, degree of spondylolisthesis, and preoperative the visual analogue scale (VAS) of low back pain and leg pain between 2 groups (P>0.05). The operation time, blood loss, fluoroscopy times, VAS score of low back pain and leg pain were compared between 2 groups; the sagittal screw angle (SSA), accuracy rate of pedicle screw, Taillard index, disc height recovery rate, and sagittal angle recovery rate were compared between 2 groups. ResultsThere was no significant difference in operation time and blood loss between 2 groups (P>0.05). But fluoroscopy times of control group were significantly higher than those of trial group (P<0.05). One case had radicular symptoms after operation in control group. The patients of 2 groups were followed up 24-36 months (mean, 26 months). The VAS scores of low back pain and leg pain at last follow-up were significantly better than pre-operative scores in 2 groups (P<0.05); VAS score of low back pain in trial group at last follow-up was significantly lower than that in control group (P<0.05). The accuracy rate of pedicle screw was 81.9% (118/144) in control group and 91.7% (110/120) in trial group, showing significant difference (χ2=5.25, P=0.03). There was significant difference in SSA between 2 groups at immediate after operation (t=-6.21, P=0.00). At immediate after operation and last follow-up, Taillard index, disc height recovery rate, and sagittal angle recovery rate in trial group were significantly better than those in control group (P<0.05). ConclusionPLIF by individualized reference model of sagittal curves by 3D printing technique and computer-aided navigation system can effectively correct spondylolisthesis, recover the lumbar sagittal angle and improve the VAS score of low back pain though it has similar operation time and blood loss to traditional PLIF.
Objective To investigate the short-term effectiveness of percutaneous pedicle screw (PPS) guided with photoelectric navigation for thoracolumbar fractures. Methods 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. Results 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). Conclusion 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.
ObjectiveTo investigate the reconstruction mode selection of acetabular bone defect and the effect on the acetabular cup position in cementless total hip arthroplasty (THA). MethodsA retrospective analysis was made on the clinical data of 78 patients (78 hips) with acetabular bone defect according to the selection criteria who underwent THA between February 2008 and February 2014. In 39 cases having acetabular posterosuperior bone defect with defect area less than 30%, impaction bone grafting was performed (group A); in 24 cases having acetabular posterosuperior bone defect with defect area of 30%-50%, structural bone or tantalum block grafting was performed (group B); in 10 cases having acetabular medial wall bone defect with defect area less than 30%, impaction bone grafting was performed (group C); and in 5 cases having acetabular medial wall bone defect with defect area of 30%-50%, titanium mesh combined with impaction bone grafting was performed (group D). There was no significant difference in gender, age, and side between groups A and B, and between groups C and D (P>0.05). The acetabular abduction angle, anteversion, the horizontal and vertical distances of actual and true rotation center after operation were compared. ResultsThe patients were followed up 7-25 months. Prosthesis loosening occurred in 2 cases of group A, sciatic nerve injury and hip joint dislocation in 1 case of group B, respectively. At immediate after operation and last follow-up, there was no significant differences in the horizontal or vertical distance of actual and the true rotation center between groups A and B (P>0.05); significant difference was found in the horizontal distance between groups C and D (P<0.05), but no significant difference in the vertical distance (P>0.05). Difference was statistically significant in the acetabular abduction angle and anteversion between groups A and B (P<0.05), but difference was not significant between groups C and D (P>0.05). ConclusionIn patients with acetabular posterosuperior bone defect, reconstruction methods will have effect on acetabular abduction and anteversion; early acetabulum prosthesis loosening may be associated with too large acetabular abduction angle and inappropriate reconstruction methods. In patients with acetabular medial wall bone defect, the vertical distances of rotation center will shift upward in varying degrees, and reconstruction methods have effect on the horizontal distances of rotation center.
ObjectiveTo investigate the application value of acetabular centralization technology for correction of leg-length inequality in total hip arthroplasty (THA). MethodsBetween June 2001 and January 2012, 147 cases of abnormal acetabular center were treated. Of them, 68 cases underwent routine THA (control group), and 79 cases underwent acetabular reconstruction by fossae ovalis oriented centralized technology in THA (test group). There was no significant difference in gender, age, side, pathogeny, acetabular rotation center indexs, difference of relative and absolute leg-length, and Harris score between 2 groups before operation (P>0.05). The hip joint function was evaluated by Harris score; the difference of relative leg-length was measured by tape; the difference of absolute leg-length and the horizontal and vertical distances of actual and true rotation center were also measured on the X-ray films by software. ResultsThe patients were followed up 8-26 months (mean, 8.3 months) in the test group, and 6-33 months (mean, 9.7 months) in the control group. Sciatic nerve injury occurred in 2 cases (1 in each group, respectively), lower extremity deep venous thrombosis in 7 cases (3 in test group and 4 in control group), and hip joint dislocation in 2 cases (control group); the other patients had no related complications. The difference of relative leg-length and Harris score in test group were significantly better than in control group (P<0.05), and significant difference was also found when compared with preoperative one in 2 groups (P<0.05). The horizontal and vertical distances of actual and the true rotation center in test group was significantly better than those in control group at immediate after operation on the X-ray films (P<0.05); and significant differences were also found when compared with preoperative ones in 2 groups (P<0.05). At 6 months after operation, the absolute leg-length difference in test group was significantly better than that in control group (P<0.05); and significant difference was also found when compared with preoperative one in 2 groups (P<0.05). ConclusionThe fossae ovalis oriented acetabular centralized technology in THA can significantly correct abnormal hip center of rotation, thus reduce the relative and absolute leg-length inequality and improve the life quality of the patients.