To evaluate the long-term efficacy of Coflex interspinous process dynamic stabilization device in the treatment of lumbar spinal stenosis.
The clinical and imaging data of 73 patients undergoing Coflex interspinous process dynamic stabilization surgery from July 2008 to June 2012 were retrospectively analyzed. Clinical data include: visual analogue scale of pain (VAS), Owestry disability index(ODI) and Japanese Orthopedic Association Scores(JOA) of preoperation, 6 months after surgery, and last follow-up; complications; reoperation rates and incidence of adjacent segment degeneration(ASD). Imaging data including: lumbar range of motion(ROM), intervertebral space height(ISH) and intervertebral foramen height (IFH) of operative and adjacent segment at preoperative, 6 months after operation and the last follow-up.
56 patients were followed up. The follow-up time was 107.6 ± 13.3 months, the operation time was 10.0 ± 3.1 minutes, the intraoperative blood loss was 153.9 ± 80.6 ml, and the hospitalization time was 10.2 ± 3.2 days. The VAS, ODI and JOA scores improved significantly after surgery. At 6 months after surgery and the last follow-up, ROM was significantly lower than that before surgery with statistical significance (P < 0.001). ROM was slightly increased at the last follow-up compared with that 6 months after operation, but the difference was not statistically significant (P > 0.05). The ROM of adjacent segments increased at 6 months and at the last follow-up compared with that before surgery, but the difference was not statistically significant (P > 0.05). At 6 months after surgery, ISH and IFH of implanted segment was significantly higher than that before surgery, and the difference was statistically significant (P < 0.05). At the last follow-up, there was a decrease in ISH and IFH, with no statistical difference compared with that before the operation. During the follow-up period, a total of 11 patients (19.6%) experienced complications and 6 patients (10.7%) underwent secondary surgery.
Coflex interspinous process dynamic stabilization is effective in the treatment of lumbar spinal stenosis in the long term. The surgical segment retains a small range of motion. The incidence of complications and reoperation is low. However, the ISH and IFH of implanted segment can only be maintained for a short period of time.