Total Disc Arthroplasty

When spinal fusion is performed at one or more levels (discs) of the spine, the adjacent segments above and below the fused area may be subjected to increased mechanical stress. This can lead to accelerated degeneration and the development of symptoms. It is estimated that up to 25% of patients will develop adjacent segment disease within 10 years, which may eventually require surgery.

The development of artificial spinal discs aims to achieve the same clinical outcomes as the traditional anterior cervical discectomy and fusion (ACDF), but without its long-term disadvantages. For example, while the affected disc is still removed and nerve compression is relieved, the use of an artificial disc offers a greater chance of reducing adjacent level degeneration.

The technology behind artificial disc replacement is designed to fully replicate the function of the natural intervertebral disc. The artificial disc is implanted between the vertebral bodies after decompression of the spinal cord and nerves. Ideally, an artificial disc should mimic the biomechanical properties of a healthy disc—maintaining segmental motion and absorbing axial loads.

Today, there are many artificial disc models commercially available, and long-term follow-up studies are available for some of them.

The indications for artificial disc replacement are similar to those for anterior cervical discectomy. The patient must be symptomatic, primarily experiencing arm pain, with or without weakness or numbness. These symptoms should result from a degenerated disc and/or osteophytes. In most cases, candidates are younger patients, typically under the age of 40, and the affected level should exhibit only disc pathology, without significant posterior joint osteophytes.

Additionally, it is currently considered safer to use an artificial disc in cases with nerve root compression rather than spinal cord compression, although studies show that outcomes in patients with cervical myelopathy are also generally satisfactory.