[Mid-term outcomes of unilateral pedicle screw fixation with lumbar interbody fusion for lumber degenerative diseases].

Objective To evaluate the mid-term clinical outcomes of unilateral pedicle screw fixation with lumbar interbody fusion for lumber degenerative diseases. Methods From October 2008 to December 2010, unilateral pedicle screw fixation with lumbar interbody fusion was performed for a consecutive cohort of 42 patients. There were 18 males and 24 females with an average age of 52 (38-69) years. The operation level at L3-4 (n=2), L4-5 (n=19), L5-S1 (n=21) and multilevel (n=0). Their clinical outcomes were assessed by Oswestry (ODI) scores and Japanese Orthopedics Association (JOA) questionnaires before and after operation. Operative duration, intraoperative blood loss, incision status and complications were recorded. Radiological examination was performed to assess the height of intervertebral space, the postoperative intervertebrai fusion conditions and the degeneration of adjacent segments. Results The mean operative duration was 90 minutes and mean blood loss 150 ml. All incisions healed primarily. The mean follow-up period was 40 (36-58) months. The ODI scores decreased significantly from 59.1±9.6 preoperatively to 8.5±2.7 postoperatively (P<0.05). The JOA scores improved markedly from 8.3±2.7 preoperatively to 23.3±2.1 postoperatively (P<0.05). And the proportion of optimal outcomes was 88.1%. The ventral and dorsal heights of intervertebal disc were significantly higher than those before operation. The fusion rate was 95.2% and the incidence of adjacent segment degeneration 9.5%. There was no occurrence of such complications as secondary scoliosis, screw loosening, internal fixation failure and cage slippage. Conclusion Unilateral pedicle screw fixation with lumbar interbody fusion is efficacious for lumber degenerative diseases with little surgical trauma. Key words: Spinal fusion; Lumbar vertebrae; Degenerative diseases