Dynesys dynamic stabilization system for the lumbar degenerative disease: a preliminary report from China

Dynesys dynamic stabilization system was first implanted in patients in 1994, and introduced to China in 2007. Therefore, it was a new technique for Chinese orthopedics and hence necessary to collect clinical data about Dynesys in China. The objective of this study was to report the preliminary results of Dynesys for the lumbar degenerative disease in China.

Twenty-seven patients were treated with the Dynesys between July 2007 and January 2009. The diagnosis included degenerative spondylolisthesis (12 cases), degenerative spinal stenosis (nine cases), and lumbar intervertebral disc herniation (six cases). Back pain and leg pain were evaluated using 100-mm visual analog scales (VAS). The Oswestry Disability Index (ODI) was used to evaluate the patients' function. The intervertebral disc height and range of motion at the operative level were taken on radiographs.

All the patients were followed-up, with an average of (22.40 ± 4.23) months (range 15-32 months). VAS of back pain and leg pain were improved significantly (P < 0.05) at follow-up. The ODI scores were reduced from (62.58 ± 12.01)% preoperatively to (15.01 ± 5.71)% at follow-up (P < 0.05). The preoperative mean height of the intervertebral disc was (11.21 ± 1.58) mm (range 8.5-13.8 mm) and mean was (10.10 ± 1.78) mm (range 7.0-13.4 mm) at follow-up (P < 0.05). The mean range of motion of the implanted segment was (6.00 ± 1.79)° (range 2.5-9.3°) preoperatively and (5.47 ± 1.27)° (range 2.9-7.8°) at follow-up (P = 0.11).

The preliminary results of Dynesys for the lumbar degenerative disease in China are similar to the published results of other countries. It can significantly improve the clinic symptoms and preserved motion at the level of implantation. However, the long-term follow-up data need to be collected.