Artificial disc: preliminary results of a prospective study in the United States.

Artificial discs have been used in Europe for many years with good results. This technology has recently been available in the United States on a limited, investigational basis. The purpose of this study is to review the preliminary results of one center's experience using the SB Charité III disc replacement. The study group consisted of the series of our first consecutive 56 patients who received the Link SB Charité III artificial disc. There were 25 men and 31 women, with a mean age of 39.9 years. All patients had single-level symptomatic disc disruption at L4-5 or L5-S1. The discs were implanted using the same approach as used for mini-open anterior lumbar interbody fusion procedures. The primary data recorded included visual analog scales (VAS) assessing pain and the Oswestry Disability Questionnaire. Data were collected pre-operatively and at 6 weeks, 3 months, 6 months, and 12 months post-operatively. Peri-operative data as well as complications were recorded. At the time of this preliminary study, 22 patients have reached the 12-month post-operative follow-up period. There was a significant improvement in the VAS and Oswestry scores at the 6-week follow-up period. These improvements were maintained throughout the 12-month follow-up period. The preliminary results of this prospective study indicate that the artificial disc yields significant improvement that is maintained during a 12-month follow-up. Data from more patients and with longer follow-up are needed to determine whether these results can be maintained in the long term.