Artificial nucleus pulposus replacement in lumbar disc(Primary report of 20 cases)

Objectives:To observe the effect of artifical nucleus polposus replacement in lumbar disc.Methods Results:20 cases of nucleus pulposus prosthesis replacement were performed following extirpation of the herniated lumbar intervertebral disces in last 7 years.19 cases of prostheses were keep in the center of the disces and maintain the intervertebral space as high as preoperation.But 1 prosthesis was escaped to the posterior aspect of the lumbar canal.The cause of escape and its preventive method were described.The prothesis was made by silicon and injected into the intervertebral space with a special injector,through the ordinary dorsal approach after extirpation of the herniated lumbar disc.Conclusions:Long term follow up study of the implantation cases,the lumbar intervertebral space was maintained as high as preoperative and preserved the function of this disc anatomically or biomechanically.The technique of replacement was as usually as the extirpation of the herniated lumbar disc and easily accepted by the patients and surgeons.