Ankylosing spondilitis

ankylosing spondylitis and its management

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 P resents microbial antigens to T-cells. HLA-B27 is strongly associated with “ seronegative spondyloarthropathies .”

6. E nthesitis Enthesis is defined as the insertion of tendon, ligaments, or muscle into bone E ntheses 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. Marginal syndesmophytes

16. Bamboo spine

17. 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

18. 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

19. Differential Dx - DISH

20. 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

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

22. 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

23. Total hip replacement Higher risk of dislocation