Modified minimally invasive method of lumbar pedicle screw placement without facet joint capsule stripping

English Keywords:Minimally invasive  Pedicle  Internal fixation  Operative approach

English Abstract:

  【Abstract】 Objectives: To compare the clinical results between a new pedicle screw placement without stripping facet joint capsule and conventional posterior midline approach in lumbar posterior surgery. Methods: From March 2008 to December 2011, 210 patients underwent single segment fusion and instrumentationwith pedicle screw system. According to the patient′s operation date on odd or even number, the patients were divided into 2 groups: groups A(100 case) including 56 males and 44 females, with an age of 48.4±0.7 years underwent traditional PLIF(stripping from the midline to the outside of the bilateral facet); groups B(110 cases) including 63 males and 47 females, with an age of 47.3±0.9 years underwent modified PLIF method(stripping from the midline to the medial side of facet joint for protection of the facet joint capsule). The data included operation time, intraoperative blood loss, postoperative volume of drainage, accuracy of pedicle screw placement. Results: The operation time of group A was 143±12min, while that of group B was 120±13min, which showed significant difference(P<0.05). The intraoperative blood loss of group A and B was 280±10ml and 170±7.5ml respectively, which showed significant difference(P<0.05). The postoperative volume of drainage of group A and B was 216±10ml and 125±8ml respectively, which showed significant difference(P<0.05). No significant difference was noted in terms of the age, sex and the accuracy of pedicle screw placement between 2 groups(P>0.05). The mean follow-up was 19 months, the fusion rate was 96.0% and 93.6% in group A and B, which showed no significant difference(P＞0.05). Conclusions: Compared with conventional posterior median approach of lumbar pedicle screw fixation, the modified method with facet joint capsule intact is a new minimally invasive technique, which is of time saving and blood loss decreasing.