Cervical Intervertebral Disc Arthroplasty: Update

ABSTRACT

Since 1966 the first metal ball shape implant was inserted into the cervical and lumbar areas by Dr. Fernstrom, numerous attempts and prostheses have been tried to maintain physiologic range of motion and prevent adjacent segment degeneration (ASD) after surgery. However fusion itself is not a single causative factor of ASD and other biologic factors including natural progression of degenerative process and mechanical factors also contribute in the development of ASD. Several well designed prospective randomized control studies for Bryan disc and Prodisc C have been recently documented preservation of spinal motion, superior or, at least, equivalent clinical outcome in comparing with anterior cervical arthrodesis, and less adverse postoperative events both in frequency and severity. Still remained or undetermined problems in cervical arthroplasty are heterotopic ossifications, segmental kyphosis of implanted levels, MR imaging compatibility, vertebral body fracture by keeled prostheses and long term wear properties. In spite of these unsolved problems and incompleteness of prosthetic design, cervical arthroplasty is now considered as one of standard methods in surgical management of one or two level cervical disc diseases and its indication may be broader in near future.