ObjectiveTo investigate the effectiveness of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) assisted with microscope in treatment of lumbar spondylolisthesis. MethodsBetween January 2011 and June 2012, 52 patients with lumbar spondylolisthesis underwent MI-TLIF assisted with microscope. There were 29 males and 23 females with an average age of 46 years (range, 32-67 years). The median disease duration was 3.2 years (range, 3 months to 6 years). There were 38 cases of lumbar isthmic spondylolisthesis and 14 cases of degenerative spondylolisthesis; 12 cases had stenosis secondary to lumbar spondylolisthesis. The affected segments were L4, 5 (29 cases) and L5, S1 (23 cases). According to the Meyerding evaluating system, 24 cases were classified as degree I and 28 cases as degree Ⅱ. The visual analogue scale (VAS) score and Oswestry disability index (ODI)were used for clinical assessment, and the clinical effects were also analyzed by Macnab criterion at last follow-up. The radiographic data were used to evaluate reduction of spondylolisthesis, including slipping degree, slipping angle, and intervertebral space height. The fusion rate was assessed by Suk criterion. ResultsThe operations were performed successfully in all patients. No dural tear or cerebrospinal fluid leakage occurred during operation. The average operation time was 105 minutes; the average intraoperative blood loss was 225 mL; the average postoperative drainage volume was 75 mL; and the average hospitalization days were 5.5 days. Superficial infection of incision occurred in 1 case and was cured after change dressing, and primary healing of incision was obtained in the others. All patients were followed up 12-26 months (mean, 18 months). No loosening, breakage, and displacement of pedicle screw and no Cage dislocation occurred by X-ray films after operation. The lumbar spondylolisthesis all got good correction. The three-dimensional CT showed continuous bone trabecula between centrums. The VAS score, ODI, and the slipping degree, slipping angle, and intervertebral space height were significantly improved at last follow-up when compared with preoperative ones (P<0.05). According to Macnab criterion at last follow-up, the results were excellent in 20 cases, good in 29 cases, and fair in 3 cases; the excellent and good rate was 94.2%. According to Suk criterion for fusion, 49 cases obtained complete fusion and 3 cases got possible fusion. ConclusionAs long as indications are seized, MI-TLIF assisted with microscope is safe and reliable for treatment of lumbar spondylolisthesis (Meyerding dergee I or Ⅱ), and it has the advantage of less injury, less blood loss, less complications, and definite short-term effectiveness.
ObjectiveTo explore the effectiveness percutaneous monoaxial screw combined with polyaxial pedical screw for treating thoracolumbar fracture by comparing with simple polyaxial pedicle screw fixation. MethodsBetween January 2012 and June 2014, 56 cases of thoracolumbar fractures were treated by percutaneous pedicle screw fixation, the clinical data were retrospectively analyzed. Of 56 cases, 30 were treated with percutaneous monoaxial screw combined with percutaneous polyaxial pedical screw fixation (group A), 26 patients with only percutaneous polyaxial pedicle screw fixation (group B). There was no significant difference in gender, age, body mass index, injury causes, time from injury to admission, involved segments, fracture type, and preoperative American Spinal Injury Association (ASIA) stage, visual analogue scale (VAS), the anterior height of the injured vertebrae, Cobb angle, and sagittal index between 2 groups (P>0.05). The operation time, intraoperative blood loss, and complications were recorded and compared between the 2 groups. The VAS score was used to evaluate the improvement of the pain. The sagittal kyphosis Cobb angle, the anterior height of the injured vertebrae, sagittal index, and the average correction (difference between 3 days after oeration and preoperation) and loss degrees (difference between last follow-up and 3 days after operation) were measured on the X-ray films at preoperation, 3 days after operation, and last follow-up. ResultsIncision healing at stage I was obtained, no related complications occurred. The operation time and intraoperative blood loss showed no significant difference between 2 groups (P>0.05). The patients were followed up 20-42 months (mean, 32 months) in group A and 21-44 months (mean, 30 months) in group B. VAS score of group A was significantly lower than that of group B at 3 days after operation (t=-2.277, P=0.027), but no significant difference was found at last follow-up (t=-0.289, P=0.774). X-ray examination showed good position of internal fixation, with no broken nails or exit of nail. There were significant differences in the anterior height of the injured vertebrae, Cobb angle, and sagittal index between at preoperation and at 3 days and last follow-up, and between at 3 days and last follow-up in 2 groups (P<0.05). The anterior height of the injured vertebrae, Cobb angle, and sagittal index of group A were significantly better than those of group B at 3 days and last follow-up (P<0.05), and correction degree were significantly higher than those of group B (P<0.05), but loss degree was not significant between 2 groups (P>0.05). ConclusionPercutaneous monoaxial screw combined with polyaxial pedicle screw fixation is better than simply polyaxial pedicle screw in effects of treating thoracolumbar fracture under the premise of strictly holding indications.