Clinical efficacy of dynamic interspinous assisted motion system in treatment of degenerative lumbar disease

Abstract

Objective To investigate clinical efficacy of dynamic interspinous assisted motion(D1-AM)system in treatment of degenerative lumbar disease.Methods Eight cases with lumbar vertebral insta-bility were treated with the DIAM system at Peking Union Medical College Hospital from June 2006 to Jan-uary 2008.There were 6 female and 2 male cases,with a mean age of 46.9 years ranging from 40 to 52years.Radiographs and scores on outcome measures including the visual analogue scale(VAS)for pain and Oswestry Disability Index(ODI)were recorded before surgery and at 3-month,6-month,1-year intervals and final follow-up after surgery.Results The follow-up time ranged from 12 to 31 months,with the mean of20.6 months.The ODI scores before surgery and at 3-month,6-month,1-year intervals and final follow-up af-ter surgery were 67.75±12.12,22.25±15.76,19.75±17.12,20.00±18.48 and 23.00±19.09,while VAS seores were 8.44±1.35,2.88±3.41,2.63±3.51,2.50±3.78 and 3.50±4.15,respectively.There were significant differ-ence between preoperative ODI and VAS scores and postoperative ones(P＜0.05); however no difference was found at the different postoperative follow-up time(P＞0.05).The L4,5 segment activity were 10.38°±5.13°,4.25°±2.19°,2.63°±0.92°,2.00°±0.86°and 2.13°±1.55°,respectively.There were significant difference be-tween preoperative L4,5 segment activity and postoperative ones(P＜0.05); however no difference was found at the different postoperative follow-up time(P＞0.05).The ODI and VAS score improvements were directly cor-related with segment activity(r＞0.7,P＜0.05).Conclusion The DIAM system appears to be a useful and ef-fective alternative in the surgical management of degenerative lumbar disease if the patients are correctly selected.However long-term follow-up is needed to evaluate clinical outcomes of the device. Key words: Lumbar vertebrae; Low back pain; Prostheses and implants; Treatment outcome