8.6 Types and Causes of Acute and Chronic Back Pain Flashcards
What are the four “buckets” of lower back pain red flags? What symptoms might make us suspicious of each of them?
- Cancer (fever, weight loss, night sweats, anorexia, smoking, prev Hx )
- Infection (steroids, fever, IV drug use, immunosuppression)
- Fracture (trauma, corticosteroids/osteoporosis)
- Cauda equina syndrome (saddle anaesthesia, bladder/bowel changes)
Alternatively: TUNA FISH
What are Wadell’s five signs of non-organic back pain?
- Superficial tenderness
- Pain with axial compression or rotation
- Distractability
- Non-dermatomal loss of sensation
- Overreaction
What are the leading causes of chronic lower back pain?
- Loss of flexibility
- Loss of strength
- Stressful living
- Decline in fitness
What are some causes of acute lower back pain?
- Infection
- Compression fracture
- Herniated disc
- Kidney stones
- Trauma
What gene may be the cause of spondyloarthritis?
HLA-B27. Mechanism not entirely clear, but this is thought to be it.
What does HLA-B27 encode? How might this explain the pathophysiology of spondyloarthritis?
- Encodes MHC Class 1
- Incorrect antigen presentation may lead to autoimmune mechanism of disease
What are the two classifications of spondyloarthritis?
- Axial
- Predominantly peripheral
What is the difference between non-radiographic and radiographic spondyloarthritis?
Non-radiographic is earlier in the disease progression (hence why findings are not seen radiographically)
How do inflammatory cells protect entheses? (This is cool)
- Live in enthesis, and detect stress
- If too much stress, generate inflammation
- This causes us to move the joint less, protecting it
Where are the highest concentrations of entheses throughout the body? Why is this useful to remember clinical features of spondyloarthritis?
- Spine
- Heel
- Sacroiliac joints
- Eye (ciliary body)
Inflammation occurs here during SpA
Where is the main site of inflammation in rheuamtoid arthritis vs spondyloarthritis?
Rheum: synovial capsule
SpA: enthesis
Symptoms of inflammatory vs mechanical back pain
- Inflam has early morning stiffness, mechanical doesn’t
- Inflam improves with exercise, worsen with rest (inflam is opposite)
What are some peripheral clinical features of spondyloarthritis?
- Enthesitis
- Dactylitis
- Synovitis (usually asymmetrical, lower limb)
Recall the DES mnemonic for MSK and extraskeletal manifestiations of ankylosing spondylitis?
MSK: dactylitis, enthesitis, synovitis
Extraskeletal: digestive tract (IBD), Eyes (uveitis), Skin (Psoriasis)
What investigations might we perform if we suspect spondyloarthritis?
- MRI (check for oedema = inflammation)
- X ray (inflammation of sacroiliac joint)
- HLA-B27 testing
Need to consider clinical features and Hx too
Outline the principles of spondyloarthritis management following diagnosis
- Test first line NSAID response
- If good, continue and monitor
- If bad, consider targeted therapy
Outline non-pharmacologic management of spondyloarhritis
- Physical activity
- Smoking cessation
Describe the macroscopic appearance of a synovial joint
- Articular cartilage
- Articular capsule
- Synovial membrane (where fluid is produced, acts like blood/aqueous humour)
- Ligaments
Describe the microscopic appearance of the hyaline cartilage of a synovial joint (in terms of cell layers)
- Basal layer of mesenchymal stem cells to replenish
- As we head superficially, cells become less spherical
What are the effects of inflammation on bone?
- Decreased production
- Increased resorption
What are the effects of inflammation on cartilage?
- ECM degradation
- Oxidative stress inc.
- Synovial fibrosis
- Decreases autophagy
- Chondrocyte hypertrophy
What are the effects of inflammation on synovium?
- Hyperplasia
- Fibroblast proliferation
- Angiogenesis
What causes axial vs radicular back pain?
Axial: joint damage/muscular strain
Radicular: Compression of spinal nerve roots
What are some back pain mimics?
- Prostatitis
- Kidney stones
- Abdo aortic aneurysm
- Gastro disease
