The postsurgical spine

Failed back surgery syndrome is the persistence or reappearance of pain after surgery on the spine. This term encompasses both mechanical and nonmechanical causes. Imaging techniques are essential in postoperative follow-up and in the evaluation of potential complications responsible for failed back surgery syndrome. This review aims to familiarize radiologists with normal postoperative changes and to help them identify the pathological imaging findings that reflect failed back surgery syndrome. To interpret the imaging findings, it is necessary to know the type of surgery performed in each case and the time elapsed since the intervention. In techniques used to fuse the vertebrae, it is essential to evaluate the degree of bone fusion, the material used (both its position and its integrity), the bone over which it lies, the interface between the implant and bone, and the vertebral segments that are adjacent to metal implants. In decompressive techniques it is important to know what changes can be expected after the intervention and to be able to distinguish them from peridural fibrosis and the recurrence of a hernia. It is also crucial to know the imaging findings for postoperative infections. Other complications are also reviewed, including arachnoiditis, postoperative fluid collections, and changes in the soft tissues adjacent to the surgical site.