Objective To investigate the clinical significance of applicating posterior internal fixation for regulating spinal curvature in thoracolumbar compression fractures. Methods Between May 2006 and May 2009, 63 patients with thoracolumbar compression fractures were treated, and the clinical data were retrospectively analyzed. Among them, 33 patients received traditional posterior internal fixation in control group; 30 patients underwent posterior internal fixation with spinal curvature correction under C-arm X-ray device in trial group. There was no significant difference in age, gender, cause of injury, injured segment, grade of fracture, and time from injury to operation between 2 groups (P gt; 0.05). The Cobb angle, height of injured vertebral body, and disc height were measured by X-ray examination; loosening and breakage of internal fixation were observed and compared between 2 groups. The recovery rate was calculated according to pre- and post-operative visual analogue scale (VAS) and Oswestry disability index (ODI) scores for each patient. Results All cases were followed up 20-45 months (mean, 31 months). The postoperative VAS score, ODI, Cobb angle, height of injured vertebral body, and disc height were improved significantly when compared with preoperative values in 2 groups (P lt; 0.05). At last follow-up, VAS and ODI scores of trial group were significantly better than those of control group (P lt; 0.05); loss of Cobb angle was (2.1 ± 1.7)° in trial group and (4.2 ± 3.2)° in control group, showing significant difference (t=1.457, P=0.000); loss of disc height was (1.4 ± 1.2) mm in trial group and (3.4 ± 2.3) mm in control group, showing significant difference (t=9.336, P= 0.000); loss of height of injured vertebral body was 1.8% ± 0.6% in trial group and 5.4% ± 2.1% in control group, showing significant difference (t=3.435, P=0.000). Broken screw and loosening screw occurred in 1 case of control group, respectively (6.1%), but no broken or loosening screw in trial group, showing significant difference (P=0.000). Conclusion Application of posterior internal fixation for regulating spinal curvature has a good clinical effectiveness. The postoperative spinal curvature, the height of injured vertebral body, and disc height can be improved significantly and low back pain can be recovered satisfactorily. The modified technique is also effective in reducing broken and loosening incidence of the fixation system.
Objective To investigate the relationship between the volume of bone-graft and fusion efficacy in posterior lumbar interbody fusion and internal fixation of spondylolisthesis. Methods Between May 2004 and June 2007, 79 patients with spondylolisthesis were treated with posterior lumbar interbody fusion and internal fixation. The patients were randomly divided into 3 groups according to the volume of bone-graft for interbody fusion: group A (n=27), 5 bone granules/ cm3 on average; group B (n=26), 11 bone granules/cm3 on average; and group C (n=26), 25 bone granules/cm3 on average. There was no significant difference in gender, age, disease duration, affected segment, and the degree of vertebral slip among 3 groups (P gt; 0.05). The volume of bone-graft, the fusion rate, the loss of intervertebral height, and the incidence of internal fixation failure were compared among 3 groups. Results All cases were followed up 24-43 months (mean, 35 months). There were significant differences in volume of bone-graft among 3 groups (P lt; 0.05). There was no significant difference in total volume of bone-graft and Cage height among 3 groups (P gt; 0.05). The Oswestry disability index (ODI) and visual analogue scale (VAS) scores of low back pain and leg pain at last follow-up were significantly decreased when compared with preoperative scores in 3 groups (P lt; 0.05); but no significant difference was found among 3 groups (P gt; 0.05). The fusion rate was significantly higher in group B than in groups A and C, and in group A than in group C at 1 and 2 years after operation (P lt; 0.05). The change values of the intervertebral height were (2.2 ± 1.4), (0.8 ± 1.3), and (2.3 ± 1.6) mm respectively in groups A, B, and C; it was significantly lower in group B than in groups A and C (P lt; 0.05). The degree of vertebral slip at immediately after operation and last follow-up was significantly improved when compared with preoperative one in 3 groups (P lt; 0.05); the loss of vertebral slip in group B was significantly lower than that in groups A and C at last follow-up (P lt; 0.05). After operation, nail breaking occurred in 1 case (3.7%) of group C at 1 year, depinning in 1 case (3.8%) of group A at 2 years, and no nail breaking or depinning in group B. There was no significant difference in the incidence of internal fixation failure among 3 groups (χ2=3.950, P=0.604). Conclusion The application of bone-graft with middle volume (11 bone granules/cm3 on average) in internal fixation and posterior lumbar interbody fusion has a good imageology outcome, which can increase the fusion rate and decrease the loss of intervertebral height.