Dynamic stabilization for degenerative spondylolisthesis: evaluation of radiographic and clinical outcomes.
OBJECTIVE
To evaluate the dynamic stabilization system in degenerative lumbar spondylolisthesis.


METHODS
This retrospective study included 38 patients (mean age 63.7 years) with one- or two-level lumbar spinal stenosis who underwent laminectomy and Dynesys (Zimmer Spine, Minneapolis) stabilization. Pre-operatively, 24 had degenerative spondylolisthesis while the other 14 did not. Radiographic and clinical evaluations were analyzed with a mean follow-up of 41.4±6.9 (30-58) months.


RESULTS
The mean range of motion (ROM) at the index level was significantly reduced post-operation (10.0±3.3° to 2.7±1.5°, P<0.001). Screw loosening occurred in 13.3% of levels, 21.1% of patients, and 4.6% of screws. There were no differences between patients with and without spondylolisthesis in ROM and screw loosening. Overall, the mean Visual Analogue Scale (VAS) of back and leg pain improved significantly (6.0±3.2 to 1.9±2.6 and 7.4±2.6 to 2.5±2.9, both P<0.001, respectively), and the Oswestry Disability Index (ODI) also improved significantly (50.6±19.5 to 27.3±24.9, P<0.001) after the operation. Moreover, there were no differences between the groups of spondylolisthesis and non-spondylolisthesis, or among the patients with and without screw loosening.


CONCLUSIONS
There is significant clinical improvement after laminectomy and dynamic stabilization with Dynesys for lumbar spinal stenosis. While there was restriction (<3°) in segmental ROM, Dynesys provides similar radiographic stability and clinical effects regardless of pre-operative spondylolisthesis.
Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taiwan. leofay1978@gmail.com
Li-Yu
LY
Fay
Jau-Ching
JC
Wu
Tzu-Yun
TY
Tsai
Ching-Lan
CL
Wu
Wen-Cheng
WC
Huang
Henrich
H
Cheng
D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D015331:Cohort Studies; D004185:Disability Evaluation; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007796:Laminectomy; D017116:Low Back Pain / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D019637:Orthopedic Procedures / Q000379:methods*; D010147:Pain Measurement; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D013130:Spinal Stenosis / Q000000981:diagnostic imaging / Q000601:surgery; D013168:Spondylolisthesis / Q000000981:diagnostic imaging* / Q000601:surgery*; D016896:Treatment Outcome