Clinical And Radiologic Study Of Dynesys For Lumbar Degenerative Disease

Objective:To study the indications and curative effect of Dynesys for Lumbar Degenerative Disease by following-up the patients with Lumbar Degenerative Disease who were treated by Dynesys and analysising its radiographic examination and clinical results..Methods: A total of 35 consecutive patients, who had undergone semirigid fixation of the lumbar spine with the Dynesys system between August 2008 and October 2009, took part in the study.24 cases were followed up for a minimum of 3 months with an average of 7.7 months.The mean age was 35～80 years with an average of 59 years.There were 15 women and 9 men. The primary indication for surgery was degenerative disease(disc/stenosis/spondylosis) resulting in some form of instability associated with neurogenic or radicular pain and/or chronic back pain. The main diagnosis was in 13 of 24 cases stenosis, in 10 of 24 Lumbar Disc Prolapse, in 1 of 24 Lumbar Spinal Stenosis with Degenerative Spondylolisthesis.For all of the patients, the Dynesys fixation was their first spinal operation. Preoperative evaluation included patient history, imaging, and clinical and neurologic evaluation by the treating surgeon. All of the patients underwent decompression surgery in addition to Dynesys instrumentation. Clinical evaluation included patient's self evaluation,Oswestry disability index (ODI) ,JOA and Visual Analog Scale (VAS) preoperative and postoperative.Results:Mean operating time was 190 minutes (range 155–290). Mean blood loss was 483 cc (range350–700). The mean follow-up duration was 7.7 months (range 3-16months).There were no implant failures, such as pedicle fracture,screw loosening or screw malposition, as of the last following-up.The ODI scores were 1.8～28.8 with an average of 11.4 at the final following up. The JOA scores were 13～29 with an average of 24.8 at the final following up. The VAS scores were 0～4 with an average of 2.1 at the final following up.The NASS Patient Satisfaction Index was used to asses treatment satisfaction: patients were asked"would you have the same treatment again for the same outcome?"and they could answer: definitely yes, probably yes, not sure, probably not, or definitely not. There were 20 patients who would definitely and 3 who would probably undergo the same operative procedure again.Conclusion:This study revealed that the dynamic stabilization system could preserve segmental motion with stability and clinical improvement. Thus, it is considered safe and effective to apply the dynamic stabilization system instead of conventional fusion after adequate decompression in selected patients. The Dynesys is a safe stabilization system in elderly patients with Lumbar Degenerative Disease. Because no bone grafting is necessary,using the Dynesys system eliminates donor site morbidity entirely. Further long-term and randomized studies are necessary to confirm our data.