Table 1.

Inclusion and exclusion criteria.

Inclusion Criteria:
Age greater than 20 years and less than 65 years
Back pain of greater than 6-month duration
Has telephone and willing to complete telephone interviews
Ability to communicate in English
Physician diagnosis of discogenic back pain
One or two level disc degeneration on MRI scan
Exclusion Criteria:
Leg pain greater than back pain
Pregnant
Instability on lumbar flexion-extension radiographs (if done)
Motor deficit on physical examination
Abnormal electrodiagnostic studies (if done)
Lumbar spinal stenosis requiring a laminectomy.
Prior lumbar fusion or multilevel laminectomy
Spondylolisthesis of more than 25% (>grade I)
Inflammatory spondyloarthropathy
Spinal malignancy or infection
Severe co-morbid illness that would contraindicate surgery or result in major functional decline
Developmental spine deformities or vertebral fractures
Disc protrusion or extrusion on imaging with either:
Nerve root compression or displacement, or pain radiating below the knee