Ankylosing spondylitis is a chronic inflammatory disease characterized by inflammation of the spine and sacroiliac joints that commonly affects the axial skeleton. It is strongly associated with the HLA-B27 gene and causes new bone formation that can result in fusion of the vertebrae and loss of spinal mobility. Physical therapy aims to maintain flexibility while NSAIDs and COX-2 inhibitors are first-line treatments for pain and stiffness. Surgical options may include spine stabilization for fractures or osteotomies to correct spinal deformities.

1. Ankylosing spondylitis
Dr. Sairamakrishnan S

2. • Bechterew's disease
• Bechterew syndrome
• Marie Strümpell disease

3. • An systemic chronic autoimmune seronegative
spondyloarthropathy characterized by
– HLA-B27 histocompatability complex positive
(90%)
– primarily affect axial spine.

4. • Pathoanatomy
– exact mechanism is unknown, but most likely due
to an autoimmune reaction to an environmental
pathogen in a genetically susceptible individual.
• Theories of relation to HLA-B27 include
– HLA-B27 aggregates with peptides in the joint and
leads to a degenerative cascade
– cytotoxic T-cell autoimmune reaction against HLA-
B27

5. • Human Leukocyte Antigen B*27 is a class I
surface antigen encoded by the B locus in the
major histocompatibility complex (MHC) on
chromosome 6
• Presents microbial antigens to T-cells.
• HLA-B27 is strongly associated with
“seronegative spondyloarthropathies.”

6. Enthesitis
• Enthesis is defined as the insertion of tendon,
ligaments, or muscle into bone
• Entheses inflammation leads to bony erosion,
surrounding soft-tissue ossification, and
eventually joint ankylosis
• preferentially targets sacroiliac joints, spinal
apophyseal joints, symphysis pubis

7. • disc space involvement
– inflammation of the annulus lead to bridging
osteophyte formation (syndesmophytes)

8. • Genetics
– there is a genetic predisposition, but mode of
inheritance is unknown
– HLA-B27 is located on sixth chromosome, B locus

9. • Epidemiology
– 4:1 male:female
– usually presents in 3rd decade of life
– fewer than 10% of HLA-B27 positive patients have
symptoms of AS

12. Systemic manifestations
• acute anterior uveitis & iritis
• heart disease (cardiac conduction abnormalities)
• pulmonary fibrosis
• renal amyloidosis
• ascending aortic conditions (aortitis, stenosis,
regurgitation)
• Klebsilella pneumoniae synovitis
– HLA-B27 individuals are more susceptible to Klebsilella
pneumoniae synovitis

13. Symptoms
• lumbosacral pain and stiffness
– present in most patients
– worse in morning
– Reduces with exercises and not with rest
– insidious onset in 3rd decade of life
• neck and upper thoracic pain
– occurs later in life
– acute neck pain should raise suspicion for fracture
• loss of horizontal gaze
• shortness of breath
– caused by costovertebral joint involvement, leading to
reduced chest expansion

14. Physical examination
• limitation of chest wall expansion
– < 2cm of expansion is more specific than HLA-B27
for making diagnosis
• decreased spine motion
– Schober test
• Sacroiliac provocative tests
• Hip examination

15. • kyphotic spine deformity
– chin-on-chest (flexion) deformity of the spine
– caused by multiple microfractures that occur over
time
– chin-brow-to-vertical angle (CBVA)
• measured from standing exam
• useful for preoperative planning
• correction of this angle correlates with improved
surgical outcomes

18. Radiographs
• spine
• negative in 50% of cases with spine fractures
• squaring of vertebrae with vertical or marginal
syndesmophytes
• late vertebral scalloping (bamboo spine)
• chin-brow to vertical angle
– used to measure chin-on-chest deformity
– useful for preoperative planning for osteotomy

19. Marginal syndesmophytes

20. Bamboo spine

21. • pelvis & lower extremity
• Ferguson pelvic tilt view
• bilateral symmetric sacroiliac erosion
– earliest radiographic sign is erosion of iliac side of sacroiliac
joint
• joint space narrowing
• ankylosis

23. • CT
– will show bony changes but not active inflammation
– CT is most sensitive test to diagnose cervical fractures
in patients with AS
• MRI
– will detect inflammation, making it the best modality
for early detection of AS in young patients
– obtained with cervical fractures to look for epidural
hemorrhage

24. Differential Dx - DISH

25. Treatment
• Physiotherapy
– Main stay of treatment to maintain flexibility
– Never should be done forcefully
• NSAIDS, COX-2 inhibitors
– first line of treatment for pain and stiffness
– oral steroids not recommended

26. • Spine fractures
– Treated with posterior stabilisation
– high rate of complications
• progressive deformity
• nonunion
• hardware failure
• infection

27. • Spine deformity
– Lumbar osteotomy
• Thoracolumbar kyphosis
• types
– closing wedge (pedicle subtracting) osteotomy
– vertebral body resection
– single-level opening wedge osteotomy
– multi-segment opening osteotomy
– C7-T1 cervicalthoracic osteotomy
• cervicothoracic kyphotic (chin-on-chest) deformity

28. • Total hip replacement
– Higher risk of dislocation