ABSTRACT
Nonunion, or pseudarthrosis, should always be included in the differential for any patient with progressive pain following an attempted prior fusion procedure. Likewise, a patient may also present with leg symptoms in the setting of a lumbar nonunion. Along with determining if the patient is symptomatic from a potential nonunion, further imaging should be used to verify the presence of a nonunion. Given the biological hurdles for bony fusion during revision nonunion surgery, iliac crest autograft or bone morphogenetic protein is strongly encouraged due to the osteoinductive potential. Larger-diameter and longer screws are used based on the torque required for the removal of prior instrumentation, as well as preoperative image templating. If neural decompression or a contralateral transforaminal lumbar interbody fusion approach is required, the medial edge of the remaining pars is identified and a plane is created between the epidural fibrous tissue using Cobb, curette, and Kerrison rongeurs.
