ISASS Policy Statement – Lumbar Artificial Disc

Degenerative Disc Disease (DDD) in one vertebral level between L3 and S1. Diagnosis of DDD requires back and/or leg (radicular pain); and radiographic confirmation of any 1 of the following by CT, MRI, discography, plain film, myelography and/or flexion/extension films:

• Instability (≥3mm translation or ≥5° angulation;

• Decreased disc height >2mm;

• Scarring/thickening of annulus fibrosis;

• Herniated nucleus pulposus; or

• Vacuum phenomenon

Age between 18 and 60 years

Failed at least 6 months of conservative treatment

Oswestry Low Back Pain Disability Questionnaire score of at least 20/50 (40%) (Interpreted as moderate/severe disability)

Psychosocially, mentally and physically able to fully comply with this protocol including adhering to follow-up schedule and

Signed inform consent

No more than 1 vertebral level may have DDD, and all diseased levels must be treated

Patients with involved vertebral endplates dimensionally smaller than 34.5 mm in the medial-lateral and/or 27 mm in the anterior-posterior directions

Known allergy to titanium, polyethylene, cobalt, chromium or molybdenum

Prior fusion surgery at any vertebral level

Clinically compromised vertebral bodies at the affected level due to current or past trauma

Radiographic confirmation of facet joint disease or degeneration

Lytic spondylolisthesis or spinal stenosis

Degenerative spondylolisthesis of grade > 1

Back or leg pain of unknown etiology

Osteopenia or osteoporosis: A screening questionnaire for osteoporosis, SCORE (Simple Calculated Osteoporosis Risk Estimation), will be used to screen patients to determine if a DEXA scan is required. If DEXA is required, exclusion will be defined as a DEXA bone density measured T score < -2.5.

Paget's disease, osteomalacia or anything other metabolic bone disease (excluding osteoporosis which is addressed above)

Morbid obesity defined as a body mass index > 40 or a weight more than 100 lbs. over ideal body weight

Pregnant or interested in becoming pregnant in the next 3 years

Active infection – systemic or local

Taking medication or any drug known to potentially interfere with bone/soft tissue healing (e.g., steroids)

Rheumatoid arthritis or other autoimmune disease

Systemic disease including AIDS, HIV, Hepatitis

Active malignancy: A patient with a history of any invasive malignancy (except non-melanoma skin cancer) unless he/she has been treated with curative intent and there has been no clinical signs or symptoms of the malignancy for at least 5 years