The occurrence of adjacent-level ossification following anterior cervical fusion

Purpose of review: Anterior cervical decompression and fusion, with and without plate fixation, has been widely used for the treatment of degenerative and traumatic cervical pathology. Although such procedures are generally associated with satisfactory clinical results, a number of studies have demonstrated that adjacent-level degeneration occurs commonly following cervical fusions. Recent findings: Recent reports have suggested that one form of adjacent-level degeneration, termed adjacent-level ossification development, may be related to improper plate placement. The proximity of an anterior cervical plate to the adjacent disc space significantly increased the prevalence and severity of adjacent-level ossification development. It is therefore recommended that the shortest possible plate be used, keeping it a minimum of 5 mm away from the adjacent disc space. As far as the timing, if there is no adjacent-level ossification development at 12 months or only mild adjacent-level development at 24 months postoperatively, it is very unlikely to progress to advanced ossification. Summary: While some degree of adjacent-level degeneration may be an unavoidable consequence of anterior cervical decompression and fusion, careful attention to surgical techniques may help to reduce unintended adjacent-level ossification.