Nucleus prosthesis: a new concept.

In a large number of low-back pain patients, the pain is related to disc herniation or prolapse of the nucleus pulposus. Although the pathogenesis is still the topic of debate, the nucleus seems to play an important role not only in the progression of low-back pain, but also in its treatment. Numerous surgical treatment solutions have been patented or described in the literature; however, only a few seem promising and are in use today. After the development of numerous ideas, for instance metallic implants, the concept of a compressible material encased by a strong, inelastic outer layer emerged as the logical conclusion. Specific requirements during operation and during the entire life of the implant have to be taken into consideration in developing new solutions. In this paper, the development of the nucleus prosthesis will be discussed and a new concept presented.