Lumbar Spine Fusion and Stabilization: Hardware, Techniques, and Imaging Appearances

Abstract

Stabilization and fusion of the lumbar spine may be performed by using various anterior and posterior surgical techniques and a wide range of devices, including screws, spinal wires, artificial ligaments, vertebral cages, and artificial disks. Because spinal procedures are increasingly common, such devices are seen more and more often in everyday radiologic practice. For evaluation of the postoperative spine, radiography is the modality most commonly used. Computed tomography and magnetic resonance (MR) imaging may be useful alternatives, but MR imaging of the postoperative spine is vulnerable to metal-induced artifacts. For an accurate postoperative assessment of spinal instrumentation and of any complications, it is important that radiologists be familiar with the normal imaging appearances of the lumbar spine after stabilization, fusion, and disk replacement with various techniques and devices.

Comparison of Lumbar Lordosis in Lateral Radiographs in Standing Position with supine MR Imaging in consideration of the Sacral Slope

“…In clinical practice, healthy patients could undergo an MRI in supine position to avoid unnecessary exposure to radiation [27,28], if only the level of global lumbar lordosis needs to be assessed as a first planning of conservative treatment of low back pain. If further information should be required, particularly single level angles, for instance when planning a surgical procedure such as spinal fusion [29,30], the two scanning technologies should be used simultaneously because of their increasing differences between upper and lower spinal levels.…”

Spinal fusion-hardware construct: Basic concepts and imaging review

“…It is more common in dorsal and lumbar regions (e.g., posterior inter-lumbar body fusion or PILF) as it is easier and adequately visualizes neural elements. It avoids the high-risk of the anterior approach in these regions, while it is mostly avoided in the cervical region for cord manipulation risks at that level [3,4] . Posterior fusion uses autografts placed along decorticated facets, laminae and/or transverse processes [7] .…”

“…In PLIF, bilateral partial laminectomies are performed and are followed by diskectomy (Figure 1). Bone graft material is packed into the anterior disk space before the insertion of one or two interbody spacers; placed side by side; and packed with graft material [4,7,8,18] . When there is a severe loss of disk space height and when the insertion of a posterior interbody spacer might cause neurologic compromise, Trans-laminar inter-body fusion with cortical screws is used as a simple method of posterior fixation.…”

“…When there is a severe loss of disk space height and when the insertion of a posterior interbody spacer might cause neurologic compromise, Trans-laminar inter-body fusion with cortical screws is used as a simple method of posterior fixation. The bone graft material is placed laterally (between transverse processes) rather than anteriorly (between vertebral bodies), for posterolateral spinal fusion [4,7,8,18] . Rods are commonly used for long segment spinal fixations e.g., in scoliosis, as they can be individually cut and molded as required to facilitate maintenance of sagittal alignment, while plates are favored for short segment fixations e.g., in traumatic and degenerative etiologies [4,6,7,18] .…”

“…Early surgeries relied upon extended bracing for solid fusion to occur with considerably long convalescence periods [3] . Currently, a vast array of implants and surgical approaches are available for spinal surgeries to aid graft incorporation with early mobility and shorten postoperative recovery period [3][4][5][6][7][8][9] the loads acting on the spine, usually until solid biological fusion occurs [5][6][7][8][9] . Subsequent instrument failure occurs if solid bony fusion is not achieved [5][6][7][8][9] .…”