OBJECTIVETo explore the clinical outcome of unilateral pedicle screw fixation plus single cage interbody fusion through spatium intermuscular of multifidus by Quadrant system.

METHODSFrom April 2008 to April 2009, 47 patients underwent unilateral pedicle screw fixation plus single cage interbody fusion through spatium intermuscular of multifidus. There were 22 males and 25 females with the mean age of 58.2 years (range, 46-74 years). Among them 12 cases had far-lateral lumbar disc herniation, 7 cases had post-discectomy recurrence, and 28 cases had degenerative instability. Thirty-seven cases were treated with lumbar interbody fusion through transforaminal approach, 10 cases through posterior approach. After surgery, the radiography was carried out to demonstrate the fusion status, and the Nakai criterion was used for assessment.

RESULTSThe average skin incision length was 3.2 cm (range, 3.0 to 3.5 cm), the average operative time was 90 min (range, 70 to 160 min), and the average blood loss was 130 ml (range, 90 to 360 ml). All cases were followed up for 8 - 20 months (average 13.6 months). Postoperative radiography showed no evidence of instrument failure, and 43 cases got bone fusion, 4 cases got suspicious fusion. At final followed-up the average leg pain VAS decreased from 7.4 ± 1.1 preoperatively to 2.4 ± 1.3 postoperatively, the average low back pain VAS decreased from 6.7 ± 1.3 preoperatively to 1.8 ± 1.5 postoperatively. According to Nakai criterion, 31 cases were rated as excellent, 11 cases as good, and 5 cases as fair with the total excellent and good rate of 89.4%.

CONCLUSIONSUnilateral pedicle screw fixation plus single cage interbody fusion through spatium intermuscular of multifidus has some advantages of minimal invasiveness, less blood loss, less complications and reliable curative effect. It is a satisfactory lumbar fusion method under suitable indication.