Imaging evaluation of transerve process placement of lumbar pedicle screws in the operation of minimally invasive transforaminal lumbar interbody fusion

English Keywords:Transverse process placement  Pedicle screws  Imaging evaluation

English Abstract:

  【Abstract】 Objectives: To discuss transverse process placement of lumbar pedicle screws in the operation of minimally invasive transforaminal lumbar interbody fusion(MISTLIF) and imaging evaluation at postoperation. Methods: Retrospectively analysis was performed on 82 patients who underwent MISTLIF from January 2014 to December 2014 in our hospital. 40 patients， 18 cases of male, 22 cases of female, the average age was 55.4±5.0(46-67) years old, who were placed the lumbar pedicle screws by superior margin of transverse process root were in the treatment group; 42 patients, 20 cases of male, 22 cases of female, the average age was 56.2±5.5(47-70) years old, who were placed the pedicle screws by "∧" shape crest were in the control groups. The operation time and blood loss were all documented. All patients were followed up for 24.0±3.5 months postoperation, CT three dimensional reconstruction examined at 1 year follow-up. The position of pedicle screws was evaluated by Rao classification. The transverse and sagittal section angle of the pedicle screws were measured by CT scan. The cranial facet joint violation was also evaluated by the transverse section of CT scan. Results: There was no statistical significance between the two groups about age, gender or preoperative diagnosis(P>0.05). The average operation time of treatment group was 95.0±10.5min, the average blood loss was 120.0±11.2ml, the average operation time of control group was 150.0±10.5min, the average blood loss was 150.0±11.5ml, there was no statistical significance between the two groups about the blood loss(P>0.05), but there was statistical significance about the operation time(P<0.05). The position of pedicle screws in the treatment had no statistical significance of perforation ratio of pedicle between the two groups(P<0.05). There was no statistical significance of SSA between the two groups(P>0.05). However, the TSA had statistical significance(P<0.05). There was statistical significance of FJV between the two groups(P<0.05). Conclusions: The transverse process placement of pedicle screws technique can place the pedicle screws accurately with low cranial FJV rate and is appropriated to MISTLIF, comparing with the "∧" shape crest pedicle placement technique. However, the entrypoint is lateral to "∧" shape crest, the TSA should be added in the operation, in order to prevent perforation of lateral cortex of the pedicle.