MSK Flashcards
What investigations are suggestive of a diagnosis of gout?
- Serum urate level >360 micromol/L (can be normal)
- Joint aspiration → needle-shaped monosodium urate crystals with negative birefringence confirms diagnosis
- X-ray of affected joint → if uncertain diagnosis
- Maintained joint space, lytic lesions in the bone, punched out erosions which can have sclerotic borders with overhanging edges.
How is an acute flare of gout managed?
- 1st line → NSAIDs (co-prescribed with PPI cover). Naproxen 500mg BD
- 2nd line → colchicine 500mg BD
- Useful if NSAIDs contraindicated
- Abdominal symptoms & diarrhoea are common side effects
- 3rd line → oral steroids. Prednisolone 30mg OD 7 days
What medications can be started for gout prophylaxis? When should they be started, what is the target urate levels & what happens when there is an acute flare?
- 1st line → allopurinol, aiming for urate level <300
- 2nd line → febuxostat
Start >2 weeks after an acute flare. Continue allopurinol during any future gout flares.
How does polymyalgia rheumatica present?
- Symptom onset days-weeks → must be present for 2 weeks before a diagnosis is considered.
- Pain & stiffness of:
- Shoulders → can radiate to the upper arm & elbow
- Pelvic girdle → around hips & radiating to thighs
- Neck
- Symptoms are worse in the morning & take >45mins to improve, after rest/inactivity, and interfere with sleep.
- Associated features:
- Systemic symptoms → weight loss, fatigue, low-grade fever
- Muscle tenderness
- Carpal tunnel syndrome
- Peripheral oedema
How is polymyalgia rheumatica managed?
- Low-dose corticosteroids
- 15mg prednisolone & follow-up in 1 week. Patients notice a dramatic improvement in symptoms within 1 week → if not, then consider an alternative diagnosis.
- Typically on steroids for 1-2 years, with the steroids being gradually reduced.
- Vitamin D & calcium supplementation, consider bisphosphonates → due to steroid-related osteoporosis risk.
- Consider PPIs for gastro-protection
What is fibromyalgia & how does it present?
= a chronic widespread pain disorder of unknown origin.
- Widespread pain → constant, dull ache
- Low back pain with/without radiation to the bum & legs
- Neck pain & across the shoulders
- Fatigue, unrefreshing sleep
- Sleep disturbance
- Morning stiffness
- Mood disorders → depression & anxiety
- Cognitive problems → focus, memory, word-finding difficulties
- Headaches
What is ankylosing spondylitis, and how does it present?
= a seronegative, chronic inflammatory arthritis affecting the axial skeleton (spine & sacroiliac joints).
- Typically a male in their 20’s, with symptoms developing gradually over 3 months.
- Inflammatory back pain
- Pain & stiffness in lower back, worse in the morning & at night, improves with activity.
- Sacroiliac pain
- Large joint arthritis
- Extra-articular involvement:
- Anterior uveitis
- Aortic regurgitation
- IgA nephropathy
- Upper lobe fibrosis
- Inflamed costosternal & costovertebral joints → chest pain & SOB due to restricted movement.
- imited ROM of back in all directions
- Abnormal Schober’s Test
- Reduced chest expansion
What gene is present in 90% of people with ankylosing spondylitis?
90% of patients with AS will have the HLA-B27 gene, so this can be tested for in secondary care to support a diagnosis.
How does ankylosing spondylitis look on an x-ray?
- Sacroiliitis, or fusion of the joint in more advanced disease
- Squared vertebral bodies
- In late disease → bamboo spine, due to complete fusion of the vertebral spine
How is ankylosing spondylitis managed?
- PA & physiotherapy → to improve & maintain posture, flexibility & mobility.
- Pharmacological:
- 1st line → NSAIDs (with PPI). Trial of at least 2 for 2-4 weeks before moving to 2nd line.
- 2nd line → Biologics, anti-TNF such as infliximab
- If peripheral joint disease → DMARDs, such as sulfasalazine & methotrexate, but these are not effective for axial disease
What are the common joints in the hand which are affected in rheumatoid arthritis?
MCP, PIP, wrist
How is rheumatoid arthritis managed initially or during an acute flare?
- Short-term steroids → oral or IM, for shortest possible period, at lowest possible dose.
- NSAIDs (with PPI) → for analgesic benefit
What are the side-effects of methotrexate?
- Mouth ulcers & mucositis
- Liver toxicity
- Bone marrow suppression & leukopenia
- Teratogenic
What are the 2 common triggers of reactive arthritis?
- Gastroenteritis
- STIs → chlamydia. Gonorrhoea will typically cause septic arthritis rather than RA.
How does compartment syndrome present?
- Pain → Disproportionate pain, severe, medications do very little. Worsened by passive stretching of muscles. Increasing with time
- Paraesthesia
- Tense on palpation, difficult to mobilise.
- Will still have a pulse, differentiating this from acute limb ischaemia
