OBJECTIVETo compare the clinical effects between interspinous dynamic internal fixation with Coflex system and posterior lumbar interbody fusion in treating lumbar degenerative disease.

METHODSFrom Jan. 2007 to Jan. 2010, 42 patients with lumbar degenerative disease were treated with interspinous dynamic internal fixation with Coflex system (non-fusion group, 21 cases) and posterior lumbar interbody fusion (fusion group, 21 cases), including 19 males and 23 females with an average age of (46.5 +/- 8.5) years (range, 33 to 62 years). The range of course of disease was from 6 to 84 months with an average of 36 months. All pathological changes were single segment in L4.5 by X-ray films or CT scanning, among them, single lumbar disc herniation was in 14 cases,combined with lumbar spinal stenosis in 28 cases. The clinical effects of all patients were evaluated according to Japanese orthopaedic association (JOA, 29 points) and Oswestry disability index (ODI); range of motion (ROM) of lumbar segments were measured by X-ray films; operative time, intraoperative blood loss,hospital stay were compared between two groups.

RESULTSAll patients were followed up for 10 months at least. In non-fusion group, JOA increased from 13.8 +/- 3.7 preoperatively to 24.6 +/- 4.6 at final follow-up (P < 0.01); ODI decreased from 65.8 +/- 7.5 to 25.6 +/- 5.1 (P < 0.01), ROM improved from 4.2 +/- 0.7 to 5.3 +/- 0.6 at L4,5 (P < 0.01 ). In fusion group,JOA increased from 13.2 +/- 3.2 preoperatively to 24.5 +/-4.3 at final follow-up (P < 0.01); ODI decreased from 65.5 +/- 8.2 to 26.5 +/- 6.1 (P < 0.01); all ROM at L.4,5 had lose (decreased from 4.2 +/- 3.2 to 0). There were significant differences in the operative time, intraoperative blood loss, hospital stay between two groups (P < 0.01), in non-fusion group was respectively (71.2 +/- 12.8) min, (56.6 +/- 25.5) ml, (4.4 +/- 1.3) d and in fusion group was respectively (121.0 +/- 23.2) min, (135.8 +/- 19.8) ml, (12.6 +/- 2.4) d. No complications were found with the Coflex system.

CONCLUSIONInterspinous dynamic internal fixation with Coflex system in treating lumbar degenerative disease is better than that of posterior lumbar interbody fusion in some aspects. Coflex system have high safety, less trauma, and can reserve lumbar mobility, which is effective in preventing adjacent intervertebral disc degeneration.