Efficacy of Coflex in the treatment of lumbar spondylolisthesis

Objective To study the clinical results of Coflex and lumbar posterior decompression and fusion in the treatment of lumbar degenerative spondylolisthesis at L4-5. Methods Thirty-eight patients with Grade Ⅰ degenerative spondylolisthesis, from January 2008 to December 2011 in Beijing Chaoyang Hospital, Capital Medical University were reviewed, and patients were divided into two groups by randomness. Group A was treated with Coflex and group B with pedicle instrumentation and interbody fusion. Fifteen patients were included in group A, and 23 patients were included in group B. In group A, the average age was (56.3±9.1) years. In group B, the average age was (58.2±11.2) years. The clinical results were evaluated by visual analogue scale (VAS) and Oswestry disability index (ODI). Slip distance (SD) was measured before and after surgery, and the changes of intervertebral angle at index level and adjacent level were also recorded. Results The follow-up period was 36 to 68 months, with the average of (39±14) months in the both groups. The operation time and bleeding volume of patients in group A were significantly less than that of group B (P<0.05). In both groups, the difference of ODI and VAS before operation and postoperative follow-up were statistically significant (P<0.05). There was no significant difference between lumbar intervertebral angle and the sliding distance in group A at all time points. In the group B, there was a significant increase in the intervertebral angle and the sliding distance at L3-4 and L5-S1 level after surgery, the difference at upper and below adjacent segment before and after surgery were statistically significant. Conclusions Coflex interspinous dynamic stabilization system has same excellent clinical results as pedicle screw instrumentation and fusion surgery for the treatment of L4-5 degenerative spondylolisthesis; no significant progression of spondylolisthesis been observed during more than 3 years follow-up, and no obvious adjacent segment degeneration has been found. Key words: Spondylolysis; Lumbar vertebrae; Internal fixators; Fusion