[Postoperative findings in the spinal column].

Postoperative imaging after spinal surgery is usually performed to document the correct positioning of implants or to rule out complications if patients still suffer from pain after surgery. Depending on the question various imaging modalities can be used all of which have benefits and limitations. Conventional X-ray is used for the documentation of the correct positioning of spinal implants, stability (olisthesis) and during follow-up to rule out fractures or instability of the implants, whereas soft tissue changes cannot be completely assessed. Besides these indications, imaging is usually performed because of ongoing symptoms (pain for the most part) of the patients. Soft tissue changes including persistent or recurrent herniated disc tissue, hematoma or infection can best be depicted using magnetic resonance imaging (MRI) which should be performed within the immediate postoperative period to be able to distinguish physiological development of scar tissue from inflammatory changes in the area of the surgical approach. Often imaging alone cannot differentiate between these and imaging can therefore only be considered as an adjunct. Computed tomography is the modality of choice for the evaluation of bony structures and an adjunct of new therapies such as image-guided application of cement for kyphoplasty or vertebroplasty.