What is bamboo spine, also known as Ankylosing Spondylitis (AS)?

From the Guidelines

Bamboo spine, a condition characterized by the radiographic appearance of the spine in advanced ankylosing spondylitis, should be treated with a combination of nonsteroidal anti-inflammatory drugs (NSAIDs) and tumor necrosis factor inhibitors (TNFi) to reduce symptoms, maintain spinal flexibility, and decrease disease complications, as recommended by the American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 recommendations 1.

Treatment Approach

The primary goals of treatment are to reduce symptoms, maintain spinal flexibility and normal posture, reduce functional limitations, maintain work ability, and decrease disease complications.

• Nonsteroidal anti-inflammatory drugs (NSAIDs) are the mainstay of treatment for pain and inflammation.
• Tumor necrosis factor inhibitors (TNFi) such as adalimumab, etanercept, or infliximab are often prescribed for more severe cases.
• Physical therapy is crucial to maintain posture and spinal mobility, with daily exercises focusing on extension and deep breathing.

Disease Management

The condition results from an autoimmune process where the body's immune system attacks its own tissues, particularly at the attachment points of ligaments and tendons to bone, leading to inflammation, calcification, and eventual fusion of the vertebral joints.

• Early diagnosis and treatment are essential to prevent progression to complete spinal fusion.
• The Assessment of SpondyloArthritis international Society (ASAS) proposed classification criteria can help identify patients in the early stage of the disease 1.
• Treatment recommendations should be based on the evidence from the literature on benefits and harms associated with specific treatment decisions, the quality of that evidence, and patients’ values and preferences, as outlined in the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method 1.

From the FDA Drug Label

The safety and efficacy of Enbrel were assessed in a randomized, double-blind, placebo-controlled study in 277 patients with active AS. Patients were between 18 and 70 years of age and had AS as defined by the modified New York Criteria for Ankylosing Spondylitis Patients with complete ankylosis of the spine were excluded from study participation.

The term "bamboo spine" refers to a condition where the spine becomes fused, resembling a bamboo rod. Ankylosing Spondylitis (AS) is a type of arthritis that can cause this condition.

• The study excluded patients with complete ankylosis of the spine, which is a characteristic of "bamboo spine".
• The study did assess the efficacy of Enbrel in patients with active AS, but it did not directly address the question of "bamboo spine" 2.

From the Research

Definition and Prevalence of Bamboo Spine

• Bamboo spine is a condition characterized by the fusion of the spine due to chronic inflammation, commonly seen in patients with ankylosing spondylitis (AS) 3.
• The prevalence of bamboo spine in patients with axial spondyloarthritis is approximately 8.9% 3.

Clinical and Laboratory Factors Associated with Bamboo Spine

• Male sex is more common among patients with bamboo spine 3.
• Higher body mass index (BMI) is associated with bamboo spine, with a median BMI of 27.7 in patients with bamboo spine compared to 25.9 in those without 3.
• Hip arthritis is more common in patients with bamboo spine, with 53.7% of patients having hip arthritis compared to 34% in those without 3.
• Enthesitis is also more prevalent in patients with bamboo spine, with 29.1% of patients having enthesitis compared to 15.9% in those without 3.
• Smoking is more prevalent in patients with bamboo spine 3.

Treatment and Management of Ankylosing Spondylitis

• Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat ankylosing spondylitis, but their long-term efficacy and potential influence on disease progression are unknown 4.
• Tumor necrosis factor-alpha (TNF-alpha) inhibitors, such as adalimumab, etanercept, and infliximab, have been shown to be effective in treating ankylosing spondylitis, with improvements in clinical symptoms and reduction in spinal inflammation 5, 6, 7.
• The use of TNF-alpha inhibitors has been associated with an increased risk of adverse events, including serious infections and malignancies 7.