Ankylosing spondylitis complications

The ankylosed spine is prone to fracture even after trivial trauma 1). A high index of suspicion and an appreciation of the extreme instability of a fracture in ankylosing spondylitis must be present 2) Patients with ankylosed spines, particularly those with ankylosing spondylitis, should be educated in simple measures to prevent fracture of their spines 3)

see Management of Thoracic Spine Fracture with Neurological Impairment in an Elderly Patient with Ankylosing Spondylitis


Spinal Fusion: One of the most common complications is the gradual fusion of the spine. This happens due to inflammation in the joints, particularly in the sacroiliac joints (where the spine meets the pelvis), leading to reduced mobility and posture changes, such as a forward stoop.

Osteoporosis: Inflammation associated with AS can weaken bones, increasing the risk of osteoporosis and fractures, particularly in the spine.

Peripheral Joint Involvement: While AS primarily affects the spine, it can also cause inflammation in peripheral joints, such as the hips, shoulders, and knees. This can lead to joint damage and reduced function over time.

Uveitis (Eye Inflammation): AS can lead to uveitis, which is inflammation of the middle layer of the eye. This can cause pain, redness, blurred vision, and light sensitivity, and if left untreated, may lead to vision loss.

Cardiovascular Issues: People with AS are at higher risk of heart problems, including aortic valve insufficiency (where the valve doesn't close properly) and other heart-related conditions due to the inflammation that can affect the heart and blood vessels.

Respiratory Issues: The inflammation in the chest and spine can restrict lung expansion, leading to reduced lung function and difficulty breathing, especially during physical exertion.

Bowel Involvement: AS is often associated with inflammatory bowel diseases such as Crohn's disease or ulcerative colitis, which can lead to digestive symptoms, including diarrhea and abdominal pain.

Fatigue: Chronic inflammation often leads to fatigue, which can significantly impact the quality of life.

Cervical Spine Involvement: Severe AS can affect the cervical spine (neck), potentially leading to serious complications, such as difficulty moving the head, nerve compression, or in extreme cases, spinal cord compression.

Kidney Issues: There may be an increased risk of kidney disease, particularly due to the use of certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), or the development of amyloidosis (a buildup of abnormal proteins in the organs).

Early diagnosis and treatment are crucial to managing these complications and preventing long-term disability. Medications, physical therapy, and lifestyle modifications play a key role in controlling inflammation and maintaining mobility.


A nationwide longitudinal study suggests an increased risk of ischemic stroke in AS patients 4).

AS is a type of seronegative spondyloarthropathy, meaning that tests show no presence of rheumatoid factor (RF) antibodies.

It is also within a broader category known as axial spondyloarthritis.

Fractures in lumbar spine with ankylosis are difficult to reduce and it is like attempting to reduce the ends of a long bone fracture of an extremity. Simple compression from the posterior results in the anterior column opening in lumbar spine because of the inherent lordosis present there, which usually requires combined approach, if the gap is extensive 5).

1)
Hunter T, Forster B, Dvorak M. Ankylosed spines are prone to fracture. Can Fam Physician. 1995 Jul;41:1213-6. PMID: 7647627; PMCID: PMC2146165.
2)
Finkelstein JA, Chapman JR, Mirza S. Occult vertebral fractures in ankylosing spondylitis. Spinal Cord. 1999 Jun;37(6):444-7. doi: 10.1038/sj.sc.3100837. PMID: 10432265.
3)
Young JS, Cheshire JE, Pierce JA, Vivian JM. Cervical ankylosis with acute spinal cord injury. Paraplegia. 1977 Aug;15(2):133-46. doi: 10.1038/sc.1977.19. PMID: 909718.
4)
Lee DH, Choi YJ, Han IB, Hong JB, Do Han K, Choi JM, Sohn S. Association of ischemic stroke with ankylosing spondylitis: a nationwide longitudinal cohort study. Acta Neurochir (Wien). 2018 May;160(5):949-955. doi: 10.1007/s00701-018-3499-7. Epub 2018 Feb 22. Erratum in: Acta Neurochir (Wien). 2018 Mar 24;:. PubMed PMID: 29470721.
5)
Mahajan R, Srivastava A, Patel N, Nanda A, Kanagaraju V, Tandon V, Chhabra HS. A novel technique for reduction of unreducible lumbar fractures in ankylosing spondylitis. Eur Spine J. 2014 May 18. [Epub ahead of print] PubMed PMID: 24838507.