Application of interspinous dynamic stabilization system for prolapsed or sequestered type of lumbar disc herniation

English Keywords:【Key words】 Lumbar disc herniation  Interspinous dynamic stabilization system  Outcome

English Abstract:

  【Abstract】 Objectives: To evaluate the long-term outcome of interspinous dynamic stabilization system(Coflex) for prolapsed or sequestered type of lumbar disc herniation, and to compare with discectomy retrospectively. Methods: 59 patients with prolapsed or sequestered type of lumbar disc herniation in our department during the period from May 2007 to April 2009 were studied retrospectively. The group of discectomy plus Coflex included 20 males and 11 females, with the age ranging from 28 to 52 years(mean 42.1±8.9 years). The control group undergoing only discectomy included 17 males and 11 females, with the age ranging from 30 to 54 years(mean 41.5±9.5 years). All the patients presented with the pain in hips and lower limbs or numbness with sign of positive straight leg raising test. All were diagnosed as prolapsed or sequestered type of lumbar disc herniation through MRI. Conservative treatment had no effects after more than 3 months. Before operation, 3 months, 1 year, 3 years and 5 years after operation, VAS of pain in low back and lower limbs, JOA score were recorded. Patients had regular lumbar X-ray, dynamic X-ray and MRI in the final follow-up. t test and variance analysis statistics and rank-sum test were used. Results: The patients were followed up. The mean follow-up time was 65±4 months(from 61 to 69 months). During the follow-up, the complications such as fracture of spinous process and implant displacement were not observed. At each time point after operation, low back and lower limb VAS, JOA scores of the two groups significantly improved compared with the preoperative indexs(t=6.35-24.2, Ｐ<0.05). VAS of low back pain in Coflex group at final follow-up was lower than that in control group, but the difference was not statistically significant(t=2.12, Ｐ>0.05). At 3 years after operation and final follow-up, posterior disc height(pDH) in Coflex group showed significant difference with that in the control group(t=5.36 and t=7.53, separately, Ｐ<0.05). Scale of disc degeneration in Coflex group was better than that in the control group at 5 years of follow-up(Z=2.85, Ｐ<0.05). Discectomy combined with Coflex group had no recurrence, while one case in the control group was noted recurrence. Conclusions: Disc height maintaining and delaying the degeneration of disc is noted with Coflex for prolapsed or sequestered type of LDH, which may decrease the recurrence rate of lumbar disc herniation. Long-term results remian good.