Midterm clinical effects of decompression and Dynesys dynamic stabilization in treating multi-segmental lumbar spinal stenosis

English Keywords:Lumbar spinal stenosis  Multiple segments  Dynamic stabilization  Efficacy  Complications

English Abstract:

  【Abstract】 Objectives: To assess the midterm clinical outcomes after decompression and dynamic stabilization(Dynesys system) in multi-segmental lumbar spinal stenosis. Methods: The clinical data of 59 patients with lumbar spinal stenosis treated with decompression and 3 or more segments dynamic stabilization in our hospital from March 2010 to June 2015 were retrospectively reviewed. There were 28 males and 31 females, with an average age of 67.6±8.9 years(49-80 years). The operative time, blood loss and complications of the patients were collected. Before operation, at 3 months after surgery and final follow-up, visual analog scale(VAS) was used to assess the pain status of low back and leg, and Oswestry disability index(ODI) was adopted for functional evaluation, and also lumbar lordosis, range of motions(ROMs) of fixed segments and the first upper adjacent segment were evaluated with X-ray examination in the mean time, and the retention of ROM of the fixed segments was also calculated. Results: 3 segmental Dynesys dynamic stabilizations were performed in 44 patients, 4 segmental dynamic stabilizations were in 13 patients, 5 segmental stabilizations were in 2 patients. The operative time was 259±58min, and the average blood loss was 593±296mL. The mean follow-up period was 7.2±1.3 years(range 5-9 years). The VAS scores and ODI at 3 months after operation improved significantly compared with those preoperatively(P<0.05). At final follow-up, loosening was observed in 6 screws in 4 patients, who were asymptomatic; Wound infection developed in 1 patient at 34 months after surgery, which was cured by puncture pumping pus, irrigation and antibiotics for 4 weeks; None of the patients underwent revision surgery. At final follow-up, the ROM of the fixed segments was 13.1°±4.7°, which on average retained 43.8% of the preoperative ROM(28.9°±8.1°), and the ROM of the adjacent upper segement, and lumbar lordosis were preserved compared with before operation with no statistical difference(P>0.05). Conclusions: Decompression and dynamic stabilization with Dynesys system was a safe and effective treatment in patients with multi-segmental lumbar spinal stenosis, which preserves lumbar activities with minor injury.