The postsurgical lumbosacral spine. Magnetic resonance imaging evaluation following intervertebral disk surgery, surgical decompression, intervertebral bony fusion, and spinal instrumentation.

It should be clear to those who perform and interpret medical images of the spine following one or more forms of surgical therapy that the images are often difficult to interpret in part because of the superimposition of the original disease process, alteration engendered by the surgery, or a complication of the surgical procedure. Although long-term experience in this area is helpful in regard to improving interpretive skills, certain sequela can be predicted regardless of the interpreter's background. Once the normal or expected postsurgical findings are understood, the subtle and gross changes that depart from these observations can be analyzed better. The importance of a high level of competence in the domain of post-therapeutic neurodiagnostic imaging is in the knowledge that the patient returning for restudy may be acutely in distress or even in medical danger (e.g., postoperative spondylitis). In fact, the clinical presentation posttherapeutically may well be more severe or dire than was observed pretherapeutically. An indepth appreciation of the broad range of clinicoradiologic possibilities as presented [figure: see text] here should place the medical imaging physician in an excellent position to provide an experienced diagnostic evaluation in the patient presenting with recurrent or new signs and symptoms following any one of the spectrum of possible spinal surgical procedures.