Musculoskeletal Flashcards
What is amyloidosis?
A (heterogenous) group of diseases characterised by extracellular deposition of amyloid fibrils
What are the two main subtypes of amyloidosis?
Type AA: serum Amyloid A protein
-non-familial secondary amyloidosis: inflammatory polyarthropathies account for 60% of cases
Type AL: immunoglobulin light chain amyloidosis (primary amyloidosis)
Which are the main 2 organs affected by amyloidosis?
Kidneys
Heart
What is the epidemiology of amyloidosis?
In the UK, the age-adjusted incidence is between 5.1 and 12.8 per 1 million per year, with around 60 new cases annually- RARE
What are the presenting symptoms of amyloidosis?
PMH of inflammatory conditions (RF) Chronic infections (RF) Positive FH (RF) Fatigue Weight loss Dyspnoea on exertion
What are the signs of amyloidosis on physical examination?
Jugular venous distension- high right-sided filling pressure
Lower extremity oedema (nephrotic syndrome)
Macroglossia- most specific finding for AL
Diffuse muscular weakness
Shoulder pad sign- psudeohypertrophy of amyloid
What are the appropriate investigations for amyloidosis?
1st line:
Serum/ urine immunofixation- presence of monoclonal protein
Immunoglobulin free light chain assay- diagnosing AL
Bone marrow biopsy- clonal plasma cells
Others:
Tissue biopsy, ECG (for conduction abnormalities)
What is ankylosing spondylitis?
A chronic progressive inflammatory arthropathy (arthritis which affects multiple joints) affecting preferentially the axial skeleton and large proximal joints
What is the aetiology of ankylosing spondylitis?
A strong genetic component in the risk of developing AS with a link to HLA-B27.
Inflammation starts at the entheses (sites of attachment of ligaments to vertebral bodies)
Persistent inflammation is followed by reactive new bone formation resulting in the calcification of ligaments
Changes start in lumbar and progress to thoracic and cervical regions
What is the epidemiology of ankylosing spondylitis?
Common: Affects 0.25–1% of UK population.
Earlier presentation in males (M:F is 6:1 at 16 years and 2:1 at 30 years)
What are the presenting symptoms of ankylosing spondylitis?
Inflammatory back pain (Low back and sacroiliac) pain
Disturbances in sleep (worse in morning, improves on activity, returning with rest).
Progressive loss of spinal movement.
Symptoms of asymmetrical peripheral arthritis.
Non-specific symptoms: malaise, fatigue.
Lower limb pain (enthesitis)
What are the signs of ankylosing spondylitis on physical examination?
Reduced range of spinal movements (particularly hip rotation).
Reduced lateral spinal flexion
Schobers test: reduced flexion
There may be tenderness over SI joints
Signs of extra-articular disease:
-Anterior uveitis (red eye)
-Apical lung fibrosis
-Reduced chest expansion (fusion of costovertebral joints)
-Aortic regurgitation (cardiac diastolic murmur)
What is Schobers test?
A mark is made on the skin of the back in the middle of a line drawn between the posterior iliac spines.
A mark 10 cm above this is made. The patient is asked to bend forward and the distance between the two marks should increase by >5 cm on forward flexion.
*This is reduced in ankylosing spondylitis
What are the appropriate investigations for ankylosing spondylitis?
Bloods: ESR/CRP
Pelvic X-ray: sacroiliitis
Radiographs: “bamboo spine” vertebral body fusion
HLA-B27
What is gout?
A disorder of uric acid metabolism causing recurrent bouts of acute arthritis caused by deposition of monosodium urate crystals in joints, and also soft tissues and kidneys
What is the aetiology of gout?
Underlying metabolic disturbance is hyperuricaemia which may be caused by:
- Increased urate intake or production: dietary, lymphoma, leukaemia
- Decreased renal excretion: idiopathic, drugs, renal dysfunction
What drugs can cause decreased renal excretion?
CANT LEAP: Ciclosporin Alcohol Nicotinic acid Thiazides Loop diuretics Ethambutol (AB for TB) Aspirin Pyrizinamide (AB for TB)
What is the epidemiology of gout?
Prevalence 0.2 %. M:F is 10:1.
Very rare in pre-puberty and in pre- menopausal women. More common in higher social classes
What are the presenting symptoms of gout?
Acute attacks: sudden excruciating monoarticular pain, the symptoms peak at 24 h and resolve in 7–10 days
Foot joint distribution: most commonly involved are joints in the feet, especially the first metatarsophalangeal
Joint stiffness: morning stiffness is prominent
*Attacks are often recurrent, but the patient is symptom free between attacks.
What is the asymptomatic period between acute attacks known as?
Intercritical gout
What can precipitate an acute attack of gout?
Trauma Infection Alcohol Starvation Introduction or withdrawal of hypouricaemic agents
What is the main symptom of ankylosing spondylitis?
Lower back and sacral pain that is worse in the morning and better with exercise
What are the two main x-ray findings in ankylosing spondylitis?
Bamboo spine
Sacroiliac joint fusion
What are the signs of gout on physical examination?
Foot joint distribution Swelling and joint effusion Tenderness Erythema and warm Painful tophi (urate deposits)- best seen on tendons and the pinna of the ear
What are the appropriate investigations for gout?
Arthocenteisis (aspirate) with synovial fluid analysis: presence of monosodium urate crystals which are strongly negative birefringent needle-shaped
X-ray of affected joint: periarticular (around joint) erosions
Blood: FBC ( raised WCC), U&E, raised urate (but may be normal in acute gout), raised ESR
AXR/KUB film: Uric acid renal stones are often radiolucent
What is pseudogout?
Arthritis associated with deposition of calcium pyrophosphate dihydrate (CPPD) crystals in joint cartilage
What is the aetiology of pseudogout?
CPPD crystal formation is initiated in cartilage located near the surface of chondrocytes.
The disorder is associated with CPPD crystal formation/deposition.
Shedding of crystals into the joint cavity precipitates acute arthritis.
Most causes of joint damage predispose to pseudogout (e.g. osteoarthritis, trauma)
What is the epidemiology of pseudogout?
More common in the elderly (>60)
What are the presenting symptoms of pseudogout?
Acute arthritis: Painful, swollen joint (e.g. knee, ankle, shoulder, elbow, wrist)
Chronic arthropathy: Pain, stiffness, functional impairment.
What are the risk factors for pseuodgout?
Advanced age
Family history
Previous injury or surgery to the joints
Other metabolic disorders e.g. hyperparathyroidism
What are the signs of pseudogout on physical examination?
Acute arthritis: Red, hot, tender, restricted range of movement, fever. Chronic arthropathy (similar to osteoarthritis): Bony swelling, crepitus, deformity, e.g. varus (displacement) in knees, restriction of movement
What are the appropriate investigations for pseudogout?
Blood: FBC (raised WCC in acute attack), ESR (may be raised), blood culture (excludes infective arthritis) Joint aspiration (arthrocentesis): Microscopy shows short rhomboid brick-shaped crystals, with weak positive birefringence under polarized light. Plain radiograph of the joint: Chondrocalcinosis (linear calcification of cartilage), or signs of osteoarthritis: loss of joint space, osteophytes, subchondral cysts, sclerosis
What is fibromyalgia?
A chronic pain syndrome diagnosed by the presence of widespread body pain for at least 3 months in addition to tenderness of at least 11 out of 18 designated tender point sites (American College of Rheumatology 1990)
What is the aetiology of fibromyalgia?
One of many pain disorders that co-aggregate strongly in individuals and families, including irritable bowel syndrome and tension headaches
Patients and family members are likely to have several of these conditions
What are the risk factors for fibromyalgia?
Family History
Rheumatological conditions e.g. rheumatoid arthritis
Age between 20 and 60 years
Female sex
What is the epidemiology for fibromyalgia?
A common condition worldwide in all ethnic and socio-economic groups.
More common in women and it has strong genetic factors
What are the presenting symptoms of fibromyalgia?
Chronic widespread pain Fatigue unrelieved by rest Sleep disturbance Mood disturbance Headaches Stiffness Numbness and tingling sensations
What are the signs of fibromyalgia on physical examination?
Diffuse tenderness to palpation
Sensitivity to sensory stimuli
What are the signs of fibromyalgia on physical examination?
Diffuse tenderness to palpation
Sensitivity to sensory stimuli e.g. bright lights, odours, noises
What are the appropriate investigations for fibromyalgia?
*Clinical diagnosis: presence of chronic (>3 months), widespread body pain in the muscles and joints, plus at least 11 of 18 tender points Other tests: -ESR/CRP -Vitamin D levels -Rheumatoid factor/ anti-CCP antibody
What is giant cell arteritis?
Granulomatous inflammation of large arteries (vasculitis), particularly branches of the external carotid artery, most commonly the temporal artery
What is the aetiology of giant cell arteritis?
Exact cause is unknown but the condition is probably triggered by an environmental cause in a genetically predisposed person
Associated with HLA-DR4 and HLA-DRB1
What are the risk factors for giant cell arteritis?
Age > 50 years
Female sex
Smoking and atherosclerosis (weak)
(genetic and ethnic background, and infection may have causative role)
What is the epidemiology of giant cell arteritis?
The condition typically occurs in people over 50.
Its incidence rises steadily after age 50 and is highest between 70 and 80 years
Women are affected 2 to 4 times as often as men
What are the presenting symptoms of giant cell arteritis?
Headache
Visual disturbances
Systemic: malaise, lethargy, weight loss low grade fever
Polymyalgia rheumatica symptoms
What are the headache symptoms of giant cell arteritis?
Scalp and temporal tenderness (pain on combing hair)
Jaw and tongue claudication
What are the visual disturbances of giant cell arteritis?
Blurred vision, sudden blindness in one eye
What are Polymyalgia rheumatica symptoms?
Early morning pain and stiffness of the muscles
of the shoulder and pelvic girdle
Pain and swelling of the distal joints may occur
What are the signs of giant cell arteritis on physical examination?
Swelling and erythema overlying the temporal artery
Scalp and temporal tenderness
Thickened non-pulsatile temporal artery
Reduced visual acuity
What are the appropriate investigations for giant cell arteritis?
ESR levels
Bloods: FBC, CRP, LFTs (transaminases and alkaline phosphatase are often mildly elevated)
Temporal artery biopsy: granulomatous inflammation
Temporal artery ultrasound: thickened wall of temporal artery
What is the management for giant cell arteritis?
Corticosteroids:
-Start on high dose oral prednisolone (40–60mg/day) immediately to prevent visual loss.
-After 4 weeks of treatment, the daily prednisolone dose should be gradually tapered by about 10% every 2 weeks (over 6 to 12 months if possible- average disease course is close to 3 years)
-If GCA is complicated by visual loss: IV pulse methylprednisolone (1 g for 3 days) followed by oral prednisolone
Low dose aspirin:
-prevention of platelet aggregation in preventing ischaemic complications of GCA
CXR monitoring:
-identify thoracic aortic aneurysms
What is the risk of not starting prompt treatment in giant cell arteritis?
Vision loss due to ischaemic optic neuropathy (ION) from GCA is regarded as irreversible
What are the complications of giant cell arteritis?
Carotid artery or aortic aneurysms
Vision loss (thrombosis or embolism to the ophthalmic artery): visual disturbances, amaurosis fugax or sudden monocular blindness
Large vessel stenoses
What is the prognosis for patients with giant cell arteritis?
- The majority of patients respond rapidly to initial treatment with glucocorticoids, and vision loss in treated patients is rare
- In most cases the condition lasts for 2 years before complete remission
What sort of inflammation causes giant cell arteritis?
Granulomatous
What are the main symptoms of giant cell arteritis?
Headache on one side of head at temple
Swelling and tenderness over temporal artery
Jaw claudication
Sudden blindness
Recall the medical management of temporal arteritis
Analgesia
High dose prednisolone
Aspirin
Inflammation in which branch of the external carotid causes jaw claudication in giant cell arteritis?
Maxillary
What are idiopathic inflammatory myopathies?
A group of acute, sub-acute and chronic diseases with moderate-to-severe proximal muscle weakness and inflammation of skeletal muscle and skin (dermatomyositis)
What is the aetiology of idiopathic inflammatory myopathies?
Unknown.
What are the factors thought to contribute to idiopathic inflammatory myopathies?
Infection e.g. influenza, EBV
Genetic: HLA subtypes
Environmental: UV radiation
Immunological: autoantibodies
What are the risk factors for idiopathic inflammatory myopathies?
Children
Age > 40 years
Exposure to high intensity UV radiation
Genetic predisposition
What is the epidemiology of idiopathic inflammatory myopathies?
Rare
Affects women more than men
Peaks at childhood (5–15 years) and adult (40–60 years)
What are the general presenting symptoms of idiopathic inflammatory myopathies?
Muscle weakness
Fatigue and general malaise
Dyspnoea
What are the presenting symptoms of polymyositis and dermatomyositis?
Gradual onset (3–6 months) Progressive painless proximal muscle weakness (difficulty raising objects above head, rising from chair, climbing stairs)
What are the presenting symptoms of inclusion body myositis?
Insidious onset (over months to years)
Affects rising from chair, climbing stairs and dexterity of hands.
There may be dysphagia and neck droop
What groups are commonly affected by idiopathic inflammatory myopathies?
Polymyositis and dermatomyositis: female predominance, black ethnicity
Inclusion body myositis: affects men more than women, more common in white patients
What signs can be seen of idiopathic inflammatory myopathies on physical examination?
Polymyositis and dermatomyositis: proximal muscle weakness and atrophy affecting both upper and lower limbs
Inclusion body myositis: proximal AND distal muscle weakness and atrophy (wrists, quadriceps)
Skin lesions in dermatomyositis:
Macular lilac heliotrope rash on upper eyelids
Periorbital oedema
Rash on chest wall, neck, elbows or knees
Gottrens papules (scaly erythematous raised plaques on finger joints)
What are the appropriate investigations for idiopathic inflammatory myopathies?
Bloods: FBC (reduced Hb of chronic disease), raised ESR, **CK (raised in 95% of cases), auto-antibody titres
EMG: increased spontaneous fibrillations; abnormal low-amplitude short-duration polyphasic motor potentials
Muscle biopsy: polymyositis, inflammatory infiltrates, muscle necrosis, atrophy, regeneration
LDH, alanine transaminases- elevated
*myoglobin: ensitive index of the integrity of muscle fibres
What is osteoarthritis?
Age-related degenerative synovial joint disease when cartilage destruction exceeds repair, causing pain and disability
What is the aetiology of osteoarthritis?
No single cause.
Primary: Aetiology unknown- likely to be multifactorial; wear and tear concept
Secondary: other diseases can cause altered joint architecture and stability e.g. inflammatory (RA, gout), metabolic (acromegaly)
What are the risk factors for osteoarthritis?
Age > 50 years Women are affected more than men Obesity Genetic factors Strong association with manual workers
What is the epidemiology for osteoarthritis?
Common, with 25% of those > 60 years symptomatic
More common in females, Caucasians and Asians
What are the presenting symptoms of osteoarthritis?
Joint pain or discomfort, usually use-related, stiffness or gelling after inactivity.
Difficulty with certain movements or feelings of instability.
Restriction walking, climbing stairs, manual tasks.
*Systemic features are typically absent.
What are the signs of osteoarthritis on physical examination?
Local joint tenderness
Bony swellings along joint margins, e.g. Heberdens nodes (at distal interphalangeal joints), Bouchards nodes (at proximal interphalangeal joints).
Crepitus and pain during joint movement, joint effusion
Restriction of range of joint movement
What is a relieving factor in osteoarthritis?
Rest - pain is worse on activity (although joints can grow stiffer on rest)
What types of bone deformities appear in osteoarthritis?
Bouchard’s (proximal interphalangeal joint)
Heberden’s (distal interphalangeal joint)
What are the appropriate investigations for osteoarthritis?
Joint x-ray of involved joints typically show four classic features:
1. Narrowing of joint spaces (resulting from cartilage loss)
2. Subchondral cysts
3. Subchondral sclerosis
4. Osteophytes
Others: inflammatory markers (ESR and CRP) to exclude differentials, RF/ anti-CCP antibodies, MRI of affected joints (cartilage loss, bone marrow lesions, and meniscal tears)
What is osteomyelitis?
An inflammatory condition of bone caused by an infecting organism, most commonly Staphylococcus aureus.
What is the aetiology of osteomyelitis?
May be caused from haematogenous spread, direct inoculation of micro-organisms into bone, or from a contiguous (touching) focus of infection.
What is the most common pathogen implicated in osteomyelitis?
Staphylococcus aureus