What is a bamboo spine differential diagnosis?

Answered by Douglas Hiatt

Differential diagnosis for bamboo spine includes conditions that can cause spinal fusion or similar radiographic findings. These conditions may present with similar symptoms or radiographic features, making it important for clinicians to consider and differentiate between them.

1. Ankylosing Spondylitis (AS): AS is the most common cause of bamboo spine. It is a chronic inflammatory disease that primarily affects the spine, leading to fusion of vertebral bodies and posterior elements. Other characteristic features of AS include sacroiliitis, uveitis, enthesitis, and peripheral arthritis.

2. Diffuse Idiopathic Skeletal Hyperostosis (DISH): DISH is a condition characterized by calcification and ossification of ligaments and entheses, particularly on the anterior aspect of the spine. It can result in vertebral fusion similar to bamboo spine. However, DISH typically affects older individuals and is not associated with inflammation or involvement of sacroiliac joints.

3. Ossification of the Posterior Longitudinal Ligament (OPLL): OPLL is a condition in which there is abnormal calcification and ossification of the posterior longitudinal ligament of the spine. This can lead to spinal stenosis and fusion of vertebral bodies. OPLL typically affects the cervical spine, but in some cases, it can involve the thoracic and lumbar spine as well.

4. Rheumatoid Arthritis (RA): RA is a chronic autoimmune disease that primarily affects the joints, including the spine. In advanced cases, RA can lead to vertebral fusion, resembling bamboo spine. However, the pattern of fusion in RA is typically different from AS, with involvement of the atlantoaxial joint and subaxial spine.

5. Psoriatic Arthritis (PsA): PsA is a form of inflammatory arthritis that occurs in some individuals with psoriasis. It can affect the spine and lead to fusion of vertebral bodies, similar to bamboo spine. However, PsA often presents with distinctive features such as dactylitis (swelling of an entire digit) and nail changes.

6. Reactive Arthritis: Reactive arthritis is an inflammatory arthritis that occurs following an infection in another part of the body, typically the genitourinary or gastrointestinal tract. It can cause spinal inflammation and fusion, resembling bamboo spine. However, reactive arthritis often presents with other features such as urethritis, conjunctivitis, and asymmetric arthritis.

7. Seronegative Spondyloarthropathies: This group of conditions includes conditions like enteropathic arthritis, undifferentiated spondyloarthritis, and reactive arthritis. These conditions can cause spinal inflammation and fusion similar to bamboo spine. They are characterized by the absence of rheumatoid factor and anti-cyclic citrullinated peptide antibodies.

It is important to note that a thorough clinical evaluation, including assessment of symptoms, physical examination, laboratory tests, and imaging studies, is necessary to make an accurate diagnosis and differentiate between these conditions. The presence of specific clinical features, such as sacroiliitis in AS or psoriasis in PsA, can help guide the diagnosis.