Imaging Assessment of the Postoperative Spine: An Updated Pictorial Review of Selected Complications

Abstract

Imaging of the postoperative spine requires the identification of several critical points by the radiologist to be written in the medical report: condition of the underlying cortical and cancellous bone, intervertebral disc, and musculoskeletal tissues; location and integrity of surgical implants; evaluation of the success of decompression procedures; delineation of fusion status; and identification of complications. This article presents a pictorial narrative review of the most common findings observed in noninstrumented and instrumented postoperative spines. Complications in the noninstrumented spine were grouped in early (hematomas, pseudomeningocele, and postoperative spine infection) and late findings (arachnoiditis, radiculitis, recurrent disc herniation, spinal stenosis, and textiloma). Complications in the instrumented spine were also sorted in early (hardware fractures) and late findings (adjacent segment disease, hardware loosening, and implant migration). This review also includes a short description of the most used diagnostic techniques in postoperative spine imaging: plain radiography, ultrasound (US), computed tomography (CT), magnetic resonance (MR), and nuclear medicine. Imaging of the postoperative spine remained a challenging task in the early identification of complications and abnormal healing process. It is crucial to consider the advantages and disadvantages of the imaging modalities to choose those that provide more accurate spinal status information during the follow-up. Our review is directed to all health professionals dealing with the assessment and care of the postoperative spine.

The Right Imaging Protocol for the Right Patient

“…Plain radiography can be helpful and sufficient in initial imaging of the postoperative spine to evaluate the position of prosthetics and hardware. 14 With ionizing studies, one should always follow the principle of "as low as reasonably achievable": refer the patient for studies that use ionizing radiation only if absolutely necessary, and make "every reasonable effort to maintain exposures to ionizing radiation as far below the dose limits as practical." 15 This is especially true in pediatric cases.…”

Postoperative Bildgebung der Wirbelsäule

“…Cave. Der exzellente Weichteilkontrast, die Möglichkeit zur multiparametrischen Darstellung und die fehlende Strahlenbelastung machen die MRT zum Goldstandard der Wirbelsäulenbildgebung [4].…”

“…Neben Untersuchungstechniken, die speziellen Fragestellungen vorbehalten sind, wie Ultraschall, Single-Photon-Emissions-Computertomographie (SPECT-CT) und Positronen-Emissions-Tomographie (PET), stehen den Radiologinnen und Radiologen hauptsächlich vier Modalitäten zur Verfügung: konventionelle Röntgenuntersuchung, CT, CT-Myelographie und Magnetresonanztomographie (MRT) [ 4 ]. Die Wahl der richtigen Untersuchungstechnik hängt von der initialen Pathologie und der präoperativen Symptomatik ab, sowie vom operativen Zugangsweg und Operationsverfahren, dem Intervall zwischen Eingriff und eventuellem postoperativem Symptombeginn, sowie der Art der aktuell vorliegenden Symptomatik.…”

“…Mit dieser Technik können neben Myelon, Nervenwurzeln und paravertebralem Weichteilgewebe auch knöcherne Strukturen durch den Nachweis von Knochenmarködem beurteilt werden [ 4 ]. So lassen sich einige Pathologien (z.…”

“…Akute Komplikationen können in den ersten sechs bis acht Wochen postoperativ auftreten, chronische Komplikationen auch noch Jahre nach der Operation. (Angelehnt an[4])…”