Lumbar disc prosthesis. Surgical technique, indications and clinical results in 22 patients with a minimum of 12 months follow-up.

Twenty-two patients with 29 lumbar disc prosthesis have been reviewed clinically and radiologically with a minimum of 12 months follow-up. The first operation in France with the SB Charity model was carried out in January 1989 with the help of the German authors Schellnäck and Büttner. The surgical technique consists of an anterior extraperitoneal approach with the patient in a supine and hyperlordotic position and must be very precise. The indications are very rare. At the moment, we only consider the prosthesis as an alternative to an arthrodesis in young patients with good-quality bone. We limit the indication to cases where fusion in situ is to be avoided: degenerative disease with collapsed disc, failed backs and instability at a maximum of one or two levels. The immediate results are encouraging, and no loosening of the prosthesis or osteolysis at the bone-prosthesis interface has been noticed in patients with 2 or more years follow-up. The segmental mobility still remains in bending and flexion/extension and is demonstrated by dynamic X-rays. Because we do not know the long-term results of implantation of the prosthesis, it must continue to be a rare procedure and the patient must be informed that in case of failure, fusion by a posterior or anterior approach may be necessary and is always possible.