Disc Prosthesis Versus Multidisciplinary Rehabilitation

Inclusion Criteria: * Low back pain as the main symptom for at least one year. * Structured physiotherapy or chiropractic treatment for at least 6 months without (significant) effect. * Oswestry Disability Index score of 30% points or more * Degenerative changes in the intervertebral disc in one or both of the two lowest levels of the lumbar spine (L4/L5 and/or L5/S1). (Degenerative changes are classified based on MR findings according to the following criteria: At least 40% reduction of disc height, Modic changes type I and/or II, "High intensity zone" in the disc, Morphological changes classified as changes in signal intensity in the disc. To classify the disc as degenerative the first criteria alone or at least two of the other criteria must be present. The MR series are evaluated by two independent observers.) Exclusion Criteria: * Generalized chronic pain syndrome (widespread myofascial pain) * Degeneration established in more than two levels. To be classified as a normal disc, the disc height must not be reduced more than 40% and all other criteria of degenerative disc disease aforementioned must be absent. The classification of a normal disc is performed by two independent observers. If disagreement, the pictures will be classified by a third observer and the outcome decided by simple majority. * Symptoms of spinal stenosis * Disc protrusion or recess stenosis with nerve root affection * Spondylolysis * Isthmic spondylolisthesis * Arthritis * Former fracture of L1 -…