A pilot study of intervertebral disc replacement

The aim of this study was to establish whether disc replacement can restore function reduced by back pain.Forty-six patients deemed suitable for disc replacement were assessed using the Oswestry Disability Scoring system pre-operatively and post-operatively to assess function. The surgery was carried out between 1990 and 1995 using the Link (R) Charite 111 prosthesis. The post-operative assessment was carried out by postal questionnaire.The diagnosis was recorded as degenerative disc disease in 41 patients, contained disc prolapse in one, sequestrated disc in three, foraminal stenosis in one and recurrent disc in two patients. Two or more diagnoses were recorded in six patients. Five patients who had intervertebral disc replacement had undergone previous surgery.The mean duration of follow-up was 3 years (range 11-72 months). Of the 46 patients (17 male and 29 female) two were converted to fusion, one was lost to follow-up and three were excluded because of incomplete data sets. The mean Oswestry Disability score improved from 52.2 pre-operatively to 33.4 at follow-up. This is statistically significant (p = 0.001).This small but carefully studied group suggests that disc replacement can improve function in patients disabled by back pain. The present technology does not fail immediately nor does it simply sink into the vertebral bodies. Interbody fusion does not occur.