Clinical application of Dynesys system for treatment of lumbar degenerative disc disease

Objective To explore the clinical efficacy of Dynesys system for treatment of lumbar degenerative disc disease.Methods The clinical data(from July 2008 to May 2012) of 120 patients with lumbar degenerative disc disease,who were treated with Dynesys system,were retrospectively reviewed.A total of 108 cases were followed;and 52 cases were followed-up for more than 2 years,including 24 males and 28 females.There were 40 cases having lumbar canal stenosis and 12 having lumbar disc herniation.The mean preoperative visual analogue scales(VAS) score was 5.5(3-9) for the low back pain and 5.36(2.6-9.0) for the leg pain,with the Oswestry disability index(ODI) being 61.4%.The height and range of motion(ROM) of fixed disc were measured preoperatively and postoperatively.The ROM of proximal adjacent segment was measured at the same time.Results The mean follow-up period was 29 months in the 52 cases.The operation time was 95 min±16 min,with blood loss of 183 mL±32 mL.There were no death patient,no aggravation of symptom,or deterioration of neurological function.One case developed cerebrospinal fluid leakage and was cured with changing position and local dressing;one case with wound fat liquefaction was cured with debridement and dressing.The postoperative VAS score of the low back pain was significantly reduced(P0.05) compared with the preoperative one.The same reduction was also noticed in leg pain VAS score and ODI(P0.05).The intervertebral height was decreased after operation,but without significant difference(P0.05).The ROM of fixed segment was significantly reduced(P0.05).The ROM of the proximal adjacent segment was increased,but without significant difference(P0.05).Conclusion Dynamic fixation system Dynesys is simple and easy to master,and it can avoid fusion surgery-related complications.The clinical result is satisfactory.Certain ROM does exist in fixed segment.The ROM of proximal adjacent segment increase slightly.However,its long-term clinical efficacy and the ability to reduce the postoperative adjacent segment degeneration should be verified with long time,multicenter clinical observation.