This side-by-side comparison chart consists of two lateral X-ray radiographs of the lumbar spine, demonstrating different patterns of syndesmophyte formation in axial spondyloarthritis. Image A shows Psoriatic Arthritis with axial involvement, characterized by coarse, 'chunky', and asymmetric syndesmophytes. These bony outgrowths appear irregular and do not uniformly bridge the vertebral segments. Image B demonstrates a classic 'bamboo spine' appearance typical of advanced Ankylosing Spondylitis. This is characterized by thin, symmetric, and marginal syndesmophytes that create a continuous vertical bridge of ossification between the vertebral bodies, leading to complete spinal fusion and a rigid, straightened alignment. The educational focus is on the diagnostic differentiation between the irregular, non-marginal ossification of psoriatic spondylitis and the uniform, marginal ossification of axial spondyloarthritis. These visual signs are critical for clinicians in rheumatology and radiology for identifying specific seronegative spondyloarthropathies.

This diagnostic image consists of two radiographic views of the human spine, labeled A and B, demonstrating classic features of ankylosing spondylitis. View A is a lateral X-ray of the lumbar spine showing 'squaring' of the vertebral bodies, where the normal anterior concavity is lost, leading to a rectangular morphology. The intervertebral disc spaces are preserved but show early signs of marginal ossification. View B is an anteroposterior (AP) X-ray illustrating the 'bamboo spine' appearance. White arrows point to syndesmophytes, which are thin, vertical bony bridges formed by the ossification of the outer fibers of the annulus fibrosus. These syndesmophytes connect adjacent vertebral bodies across the intervertebral disc spaces. The fusion of the vertebral column results in a rigid, undulating lateral contour characteristic of advanced axial spondyloarthritis. The image serves as a definitive educational example of progressive spinal fusion and ligamentous calcification in seronegative spondyloarthropathies.

Multimodal imaging of the cervical spine demonstrating severe cervical kyphotic deformity. Panels A, B, and C show lateral x-ray radiography in hyperflexion, neutral, and hyperextension positions, respectively. These views reveal a fixed or progressive kyphosis with a Cobb angle exceeding 70 degrees in the neutral position, with minimal correction on extension. Panel D presents a sagittal CT scan highlighting the bony anatomy; the vertebral bodies maintain relatively normal rectangular morphology and bone density without significant osteophyte formation or syndesmophytes, suggesting a non-degenerative etiology like Ankylosing Spondylitis. Panel E consists of sagittal T2-weighted MRI slices, which show the severe sagittal malalignment but indicate no evidence of significant spinal cord compression or myelomalacia at the apex of the deformity. This imaging series is characteristic for evaluating Ankylosing Spondylitis-induced cervical kyphosis (AICK) and planning surgical correction such as anterior cervical discectomy and fusion (ACDF) or osteotomy.

A lateral view X-ray of the lumbosacral spine demonstrating advanced radiographic features of Ankylosing Spondylitis. The image shows the classic 'bamboo spine' appearance, characterized by the formation of thin, vertical marginal syndesmophytes that bridge the intervertebral spaces. There is significant bony ankylosis (fusion) of the vertebral bodies, with blurring and near-complete loss of distinct intervertebral disc spaces. The vertebral endplates appear indistinct and merged. Additional findings include 'squaring' of the lumbar vertebrae and ossification of the spinal ligaments, specifically the interspinous and supraspinous ligaments (indicated by a white arrow pointing to the fused posterior elements). There is a notable loss of the normal lumbar lordosis, suggesting severe spinal stiffness and reduced mobility. The image serves as a definitive educational example of end-stage axial spondyloarthritis involving the lumbar region and sacrum.

This diagnostic imaging shows anteroposterior (AP) and lateral X-ray views of the lumbar spine and pelvis, demonstrating classic radiographic hallmarks of advanced ankylosing spondylitis. The lumbar spine exhibits 'bamboo spine' morphology, characterized by the ossification of the annulus fibrosus and the formation of syndesmophytes. These vertical bony bridges connect adjacent vertebral bodies (highlighted by blue arrows), resulting in a continuous, straightened, and fused vertebral column with significant loss of normal intervertebral disc space. In the pelvic region, the sacroiliac (SI) joints show evidence of bilateral ankylosis (indicated by red arrows), with complete obliteration of the joint spaces, subchondral sclerosis, and bony fusion. These findings are clinically significant as they represent the end-stage structural damage typical of axial spondyloarthritis, leading to spinal rigidity and decreased mobility. The image serves as a definitive educational example of progressive inflammatory arthritis affecting the axial skeleton.

This composite diagnostic image consists of two X-ray radiographs illustrating radiographic manifestations of Ankylosing Spondylitis (AS). Panel A is a lateral view of the spine showing a significant thoracic kyphosis. Key findings include 'squaring' of the vertebral bodies, sclerosis along the vertebral margins, and calcification of the anterior longitudinal ligament (syndesmophytes). The facet joints appear blurred with narrowing or disappearance of the joint spaces. Panel B is an anteroposterior (AP) pelvis radiograph showing bilateral sacroiliitis, characterized by blurred articular surfaces of the sacroiliac joints. The image demonstrates the skeletal progression of a spondyloarthropathy, emphasizing the structural changes in the axial skeleton and pelvic girdle including vertebral fusion and joint erosion. These features are clinically significant for diagnosing advanced autoimmune inflammatory arthritis in the rheumatology domain.