Problems related to cervical fusion: malalignment and nonunion.

Two common complications associated with cervical surgery are malalignment, particularly after multilevel laminectomies, and nonunion. In both situations, prevention and early recognition are critical in clinical management. In postlaminectomy kyphosis, the prevailing cause is an alteration in the normal spinal biomechanics. The exact incidence is unknown; however, this malalignment can cause significant morbidity. Surgical treatment is used once a patient becomes symptomatic. Anterior cervical procedures are frequently used to correct the deformity. Like postlaminectomy kyphosis, most nonunions can be prevented. The reported incidence of pseudarthrosis has ranged from 0% to 50%. With advances in instrumentation and attention to surgical detail, the frequency of this complication has decreased. Fortunately, not all nonunions are symptomatic or require treatment. For symptomatic nonunions, surgical options include anterior, posterior, and combined cervical procedures depending on the pathology. As the frequency of cervical procedures continues to increase, it is paramount for spine surgeons to be aware of these complications and the various methods to treat them.