New Techniques in Lumbar Spinal Instrumentation: What the Radiologist Needs to Know

Abstract

Lumbar spinal fusion is a commonly performed procedure, and, despite changes in cage types and fixation hardware, radiologists have, over the years, become familiar with the imaging features of typical spinal fusion and many of the complications seen in patients after surgery, including pseudoarthrosis, hardware loosening, and recurrent or residual disk herniation. Recently, however, novel approaches and devices have been developed, including advances in minimally invasive surgery, the increasing use of osteoinductive materials, and a wide variety of motion-preserving devices. These new approaches and devices manifest with characteristic imaging features and the potential for unusual and unexpected complications. Several of these devices and approaches are experimental, but many, including those devices used in lateral approaches to fusion, as well as the use of bone morphogenic protein, disk arthroplasty, and interspinous spacers, are seen with increasing frequency in daily clinical practice. Given the recent advances in spinal fusion surgery, it is important that radiologists have a basic understanding of the rationale behind these procedures, the common imaging features of the devices, and the complications associated with their use.

Metal artifact reduction using virtual monochromatic images for patients with pedicle screws implants on CT

“…However, the insertion of pedicle screw is very difficult to control during operation, even causing the perforation of pedicle wall, injury to neural, vascular and visceral structures, leading to an incidence rate of 20-40 % [1][2][3][4]. Therefore, an accurate evaluation on both screw position and the relationship between screw and adjacent tissues made by radiologists at imaging reexamination are usually required by the clinicians [2][3][4][5]. Multi-slice computed tomography (MSCT) has been used to observe whether the screw perforated pedicle cortex and to evaluate complications [6].…”

Quantitative dual-energy CT for phantomless evaluation of cancellous bone mineral density of the vertebral pedicle: correlation with pedicle screw pull-out strength

“…Transpedicular screw fixation is a routinely performed surgical procedure for treatment of unstable spinal fractures, existing spinal instability, degenerative scoliosis and spinal fusion in anterior strut grafting [1,2]. Stability of transpedicular screw fixation in healthy and osteoporotic bone has been assessed in cadaver studies with pedicle screw pullout strength [3].…”

Metallic artefact reduction with monoenergetic dual-energy CT: systematic ex vivo evaluation of posterior spinal fusion implants from various vendors and different spine levels

“…Complications of spinal fusion surgery comprise implant fracture, loosening, faulty placement and infections which may all be associated with substantial morbidity [6]. Thus, early detection of complications is desirable and poses a frequent radiological question in daily routine practice [7].…”