Musculoskeletal Flashcards
Which cancers are most likely to metastasise to bone?
- prostate
- breast
- lung
- kidney
- thyroid
- myeloma
What are some side effects of bisphosphonates?
- fever / flu-like symptoms
- hypocalcaemia
- bone & joint pain
- constipation / diarrhoea
- oesophagitis / oesophageal irritation
- osteonecrosis of the jaw
Examples of bisphosphonates?
- alendronic acid
- zoledronic acid
(-dronic acid / -dronate)
Bisphosphonates mechanism of action?
- pyrophosphate analogues
- bind to hydroxyapatite crystals
- promote osteoclast apoptosis and disrupt cholesterol synthesis pathway (to decrease osteoclast function)
- decreased bone resorption
X ray features of osteoarthritis?
- joint space narrowing
- osteophyte formation
- subchondral cysts
- subchondral sclerosis
Investigation to diagnose Sjögren’s syndrome?
Schirmer’s test - strip of paper in eye to measure tear production.
Tear production is decreased in Sjögren’s syndrome.
What does a pencil-in-cup X ray deformity signify?
- arthritis mutilans
- may indicate psoriatic arthritis
What does a bamboo spine deformity signify?
Advanced ankylosing spondylitis
First-line management of ankylosing spondylitis?
Ibuprofen
Preventative gout medication?
Allopurinol
Allopurinol mechanism of action?
Reduces production of uric acid by inhibiting xanthine oxidase.
T score for osteoporosis?
< -2.5
T score for osteopenia?
-1 to -2.5
What autoantibodies are found in granulomatosis with polyangiitis?
cANCA (antis neutrophil cytoplasmic antibodies)
What was granulomatosis with polyangiitis formerly known as?
Wegener’s granulomatosis
What are some clinical manifestations of granulomatosis with polyangiitis?
- sinusitis
- nose bleeds
- saddle shaped nose (perforated septum)
- cough, wheeze, haemoptysis
- glomerulonephritis
Investigations for Sjögren’s syndrome?
Blood tests - ANA, anti-Ro, anti-La, rheumatoid factor
Schirmer test
What type of arthritis does Sjögren’s syndrome cause?
- chronic (there may be acute flares)
- systemic
- inflammatory
- symmetric
- autoimmune
- non-erosive
Management of Sjögren’s syndrome?
- artificial saliva / tears
- vaginal lubricants
- pilocarpine (muscarinic agonist)
- corticosteroids
- methotrexate / azathioprine / cyclophosphamide
What is Sjögren’s syndrome?
Lymphocyte-mediated autoimmune disease characterised by destruction of the minor salivary glands, lacrimal glands and joints.
Clinical triad found in Sjögren’s syndrome?
- xerostomia (dry mouth)
- xerophthalmia (dry eyes)
- inflammatory arthritis
What diseases might Sjögren’s syndrome occur secondary to?
- rheumatoid arthritis
- SLE
- other autoimmune conditions
What autoantibodies are found in patients with SLE?
- ANA
- anti-dsDNA
What gene is associated with ankylosing spondylitis?
HLA B27
X ray findings in ankylosing spondylitis?
- bamboo spine
- vertebral body squaring
- subchondral sclerosis and erosions
- syndesmophytes
- ossification of ligaments, discs and joints
- fusion of costovertebral & sacroiliac joints
Anti-TNF drug examples?
- infliximab
- adalimumab
- etanercept
Pathophysiology of osteoarthritis?
Imbalance between cartilage being worn down and chondrocytes repairing it.
What is Paget’s disease of bone?
Excessive uncoordinated bone turnover, with increased activity of both osteoblasts and osteoclasts.
Particularly affects the axial skeleton.
How does the skull appear in Paget’s disease of bone?
Cotton wool appearance due to patches of increased and decreased density.
Which antibody is most specific for rheumatoid arthritis?
anti-cyclic citrullinated peptide antibody
Management of rheumatoid arthritis?
- DMARD monotherapy (methotrexate / leflunomide / sulfasalazine)
- DMARDs x 2
- methotrexate + anti-TNF
- methotrexate + rituximab
What is Felty’s syndrome?
Complication of rheumatoid arthritis.
- rheumatoid arthritis
- neutropenia
- splenomegaly
What is polymyalgia rheumatica?
Immune-mediated inflammatory disorder causing pain, stiffness and inflammation in the shoulders, neck, and hip muscles.
What is dermatomyositis?
Chronic inflammation of the skin and muscles.
What is polymyositis?
Chronic inflammation of the muscles.
What are some blood markers for dermato- / polymyositis?
- raised creatinine kinase
- anti-Jo-1
- anti-Mi-2 (dermatomyositis only)
- ANA (dermatomyositis only)
What are the muscle symptoms of dermato- / polymyositis?
- muscle pain, fatigue, and weakness
- bilateral
- typically proximal muscles affected
- shoulder and pelvic girdle
- develops over weeks
What are the skin symptoms of dermatomyositis?
- Gottron lesions (erythematous plaques)
- photosensitive erythematous rash on back, shoulders, and neck
- purple rash on face & eyelids
- periorbital oedema
- subcutaneous calcinosis
What is the function of 1-alpha-hydroxylase?
Hormone secreted by the proximal convoluted tubule, activates vitamin D to form calcitriol.
What condition causes brittle bones in adults due to a lack of vitamin D?
osteomalacia
What condition occurs in children due to a lack of vitamin D?
Ricketts
Why does Ricketts not occur in adulthood?
Ricketts occurs due to impaired bone mineralisation PRIOR to epiphyseal closure.
How is giant cell arteritis diagnosed?
Multinucleated giant cells seen on temporal artery biopsy.
Management of giant cell arteritis?
Steroids
Gout microscopy appearance?
- negatively birefringent on polarised light microscopy
- needle-shaped monosodium urate crystals
Pseudogout microscopy appearance?
- positively birefringent on polarised light microscopy
- rhomboid crystals of calcium pyrophosphate
Classic X ray change in pseudogout?
chondrocalcinosis - thin white line in joint space due to calcium deposition
Most common joint affected in pseudogout?
knee
What is fibromyalgia?
Disorder characterised by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues.
What are some risk factors for developing fibromyalgia?
- depression, anxiety, stress
- dissatisfaction at work
- middle age
- low income
- divorced
- low educational status
What empirical antibiotics are first line for septic arthritis?
Flucloxacillin + rifampicin for the first two weeks.
OA vs RA pattern of joint involvement?
OA - asymmetrical
RA - symmetrical
OA vs RA most common joints affected?
OA - DIPJs, knees, hips
RA - PIPJs (rarely DIPJs), wrists, feet
OA vs RA joint stiffness?
OA - less than 30 minutes morning stiffness
RA - more than 30 minutes morning stiffness
OA vs RA effect of movement?
OA - pain worsens with movement
RA - pain improves with movement
Osteoarthritis hand signs?
Bouchard’s nodes (PIPJ)
Heberden’s nodes (DIPJ)
B comes before H
Genetic associations of RA?
HLA DR4 / HLA DR2
RA X ray signs?
LESS
- loss of joint space
- erosions
- soft tissue swelling
- soft bones
RA hand signs?
- Boutonniere deformity
- swan neck deformity
- ulnar deviation
- Z shaped thumb deformity
Side effects of methotrexate?
- pulmonary fibrosis
- teratogenic
What is taken with methotrexate?
Folic acid (on a DIFFERENT day)
What is Caplan’s syndrome?
Rheumatoid pneumoconiosis - occurs in people with RA who have inhaled coal dust / silica.
Pulmonary fibrosis with pulmonary nodules.
What is osteoporosis?
Skeletal disease characterised by low bone density and micro-architectural defects in bone tissue, resulting in increased bone fragility and susceptibility to fracture.
Risk factors for osteoporosis?
- steroid use
- hyperthyroidism / hyperparathyroidism
- low BMI
- early menopause
- malabsorption
Protective factor for oestoporosis?
Oestrogen
Investigations for osteoporosis?
- x-ray shows fragility fractures
- DEXA scan
- FRAX score
What is the FRAX score?
Risk of a fragility fracture over the next 10 years.