Clinical Outcome of Unilateral and Bilateral Pedicle Screw Fixation Plus Single Cage Interbody Fu-sion through Spatium Intermuscalare of Muhifidus by Quadrant System for Ddiscogenic Low Back Pain

Abstract：Objective To investigate the clinical outcome of unilateral and bilateral pedicle screw fixation plus single cage interbody fusion through spatium intermuscalare of muhifidus by Quadrant system for discogenic low back pain. Methods Be-tween December 2009 and August 2012,60 patients presenting with discogenic low back pain of singal segment underwent ped-icle screw fixation plus single cage interbody fusion through spatium intermuscalare of muhifidus by Quadrant system. 32 cases underwent a unilateral pedicle screw fixation with intervertebral body fusion( group A ),while 28 cases underwent bilateral pedicle screw fixation with intervertebral body fusion(group B). There were 38 males and 22 females with the mean age of 40. 5 years( range,30~55 years). There were 35 cases of L4~5 fusion,20 cases of L5 S1 fusion and 5 cases of L3~4 fusion. The op-erative time,intraoperative blood loss,complications and the cost were observed. VAS score system was used to evaluate the pre-and post-operative back pain. The clinical outcomes were assessed by the MacNab method and the fusion rates was evalua-ted by the literature method. Results The average operative time was 85. 5 min in group A,120 min in group B;the average intraoperative blood loss was 120 mL in group A,250 mL in group B. The average cost in group A was 20 000 RWB and 35 000 RMB in group B. The blood loss,operation time and cost between two groups showed remarkable difference(P<0. 05). Preop-erative VAS score between two groups showed no significant difference(P>0. 05). After an follow-up of 25. 3 months(range, 8~36 months),VAS score between two groups at final follow-up showed no significant difference(P>0. 05). The excellent rate and bone fusion rate between two groups showed significant difference(P>0. 05). Conclusion Unilateral and bilateral pedicle screw fixation plus single cage interbody fusion through spatium intermuscalare of muhifidus are both optional for disco-genic low back pain. Unilateral pedicle screw fixation has advantages of minimal invasiveness,less blood loss,less cost,less complications and reliable curative effect. It is a satisfactory operative method for discogenic low back pain.