Table 2.

Criteria for patients with Pro-Disc C and RSA study

Inclusion criterIa	Exclusion criteria
Mono-segmental cervical disc disease between C3 and C7	Marked cervical instability on resting or flexion/extension radiographs
	Greater than 11 of angulations
	Translation greater than 3 mm
Unresponsive to conservative treatment or presence of signs of nerve root compression with paresis	More than one level pathology
Soft disc herniation	Myelopathy
Age between 20 and 60 years	Radiographic confirmation of severe facet joint degeneration
Signed informed consent	Hard disc disease
	Osteoporosis, infection, rheumatoid arthritis
	Spondylodiscitis and active infection
	Malignant disease
	System disease, e.g. Hepatitis, HIV, AIDS
	Known allergy to cobalt, chromium, molybdenum, titanium, or polyethlene
	Traumatic injury of spine
	Pregnant or possible pregnancy in the next 3 years