MSK & Rheumatology Flashcards
What is bone structure made up of?
1) Cortical bone outside (arranged in osteon functional units) 2) Trabecular bone inside
Structure of osteons?
Made up of concentric lemellae (like a tree trunk) and central Haversian canal - Haversian canal supplies a single longitudinal osteon - horizontal communication between osteons = volkmann canals
Component of bone? (Inorganic and organic)
Inorganic component = hydroxyapatite (Ca2(PO4)3) - stiffness Origanum component = collagen T1 - elasticity
Purpose of trabecular bone?
Bone marrow structural meshwork Low in mass but high in strength
Three types of joints?
1) Fibrous (synarthrosis, unmovable) - skull sutures 2) Cartilaginous (amphiarthrosis, partially moveable) - IV disc, pubic symphysis 4) Synovial (diarthrosis, freely moveable) - most joints of body (knee, hip, shoulder etc)
Synovial joint components?
- articular cartilage - joint capsule (inner lining = synovial membrane) - synovial cavity filled with little synovial fluid
Attachment from bone to bone?
Ligaments
Attachment from muscle to bone?
Tendons
Most common type of arthritis?
Osteoarthritis
What is osteoarthritis?
- Traditionally a “non-inflammatory” age-related “degenerative” joint disorder characterised by joint pain and functional limitation. - No longer thought to be the case as it is shown to be inflammatory too. - Metabolically active and dynamic process that is mediated by cytokines. - Often symmetrical and bilateral
What joints does osteoarthritis typically affect?
Knees Hips Hands Spine (cervical and lumbar) Base of thumb pain pain almost ALWAYS osteoarthritis
Non modifiable risk factors for osteoarthritis?
- Age (50+) - uncommon in those under 45 - Females (hip OA is twice as common in women than men) - Genetics (COL2A1= predisposition) - more common when it presents bilaterally - High bone density - but actually protective against osteoporosis - abnormal biomechanics - joint hypermobility or congenital hip dysplasia
Modifiable risk factors for osteoarthritis?
- obesity (3x increased risk) as it is a low grade inflammatory state with release of cytokines - joint injury and damage (history of inflammation can increase risk) - Exercise stresses (occupation with lots of standing or professional athletes) footballers more likely to have osteoarthritis of knees and those with lots of manual labour more likely to have osteoarthritis in the hands
Aetiology of osteoarthritis?
Imbalance between extracellular matrix synthesis vs degradation regulated by chondrocytes within the cartilage => loss of cartilage, remodelling of adjacent bone and subsequent inflammation
Pathophysiology of osteoarthritis?
Increased metalloproteinase secretion by chrondocytes which degrades T2 collagen and causes cysts - bone attempts to overcome this with T1 collagen leading to abnormal bony growths (osteophytes) + remodelling
Symptoms of osteoarthritis?
- Transient morning pain (<30min) - joint pain exacerbated by movement and gets worse as the day goes on - swelling - joint locking (particularly common at the knee) - functional impairment such as walking or activities of daily living
Signs of osteoarthritis in the hands?
Haberden’s nodes: asymmetrical bony swelling at the distal interphalangeal joint -Bouchard’s nodes: asymmetrical bony swelling at proximal interpharangeal joint (also seen in RA) -Thenar wasting -First carpometacarpal joint: most typically affected as most stressed
Sign of osteoarthritis in the knee?
Crepitus: crackeling or grating sensation when moving a joint
Signs of osteoarthritis in the hips?
Antalgic gait: patients may walk with a limp Restricted internal rotation: when hip flexed
Investigations to diagnose osteoarthritis?
joint x-rays: LOSS LOSS of joint space osteophytes Subchondral cysts Subchondral sclerosis -bloods will be normal with no inflammatory markers
Treatment of osteoarthritis?
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Complications of Osteoarthritis?
Biopsychosocial: NSAID complications Low mood Chronic pain Fictional decline in activities of daily living
What is rheumatoid arthritis?
Chronic, systemic inflammatory disease => deforming, symmetrical inflammatory arthritis of the small joints and progresses to involve larger joints and other organs
Genetic risk factors for rheumatoid arthritis?
HLA-DR1 and DR4 are crucial in activating t-cells -PTPN22 also implicated
Environmental triggers for rheumatoid arthritis
Smoking
Epidemiology of rheumatoid arthritis?
Age- peak onset = 30-50 years of age Females (2-4x more common) Prevalence is 1% in the UK
Pathophysiology of rheumatoid arthritis?
- arginine -> citrulune mutation in T2 collagen causes anti - CCP (cyclic citrulinated peptide) formation - IFN -a catses further pro inflammatory recruitment to synovium - synovial lining expands and tumour like mass “pannus” grows past joint margins - pannus destroys Subchondral bone and articulatar cartilage
Symptoms of rheumatoid arthritis?
Often worse in the morning (~30mins) eases as day goes on - often struggle to make a tight fist
Signs of rheumatoid arthritis?
1) Boutonnière deformity (PIP flexion and DIP hyperextension) 3) swan-kneck deformity (PIP hypertension and DIP flexion) 4) z-thumb deformity (hypertensions of the thumb IP joint with flexion of MCP joint) 5) ulnar deviation of fingers - usually symmetrical and DIPs are spared
How to differentiate psoriatic arthritis from rheumatoid arthritis?
DIP joints often spared in rheumatoid arthritis but affected in psoriatic arthritis
What is felty syndrome?
Triad of: 1) rheumatoid arthritis 2) granulocytopejia 4) splenomegaly = life threatening risk of infection
Extra-articular complications for rheumatoid arthritis?
Lungs - Pericardial effusion, pulmonary fibrosis - Heart - Increased IHD risk - Eyes - episcleritis, keratoconjuctivitis sicca (dry Eyes) - spinal cord compression - kidney (CKD) - rheumatoid skin nodules (often at elbows) - peripheral sensory neuropathy
Investigations to diagnose rheumatoid arthritis?
BLOODS: Increased ESR/CRP (used to monitor disease progression), normocytic normochromic anaemia (mc) SEROLOGY: +ve anti CCP (80% specific), +ve RF (70% non specific) X-RAY: LESS - Loss of joint space - Eroded bone - Soft tissue swelling - Soft bones (osteopenia)
Treatment for rheumatoid arthritis?
1) DMARD- methotrexate (CI in pregnancy as it is a folate inhibitor) => DNA synthesis affected - gold standard and often give with biologic 2) BIOLOGICS (v good but expensive) -1st line (given with methotrexate) = TNF-d inhibitor INFLIXIMAB or ETANERCEPT -2nd line = b cell inhibitor (CD20 target) - RITUXIMAB Referral to physio, OT, podiatry as indicated
What is gout caused by?
Hyperuricemia which results in sodium urate crystal deposition along joints + intrarticularly (inside entry to joint)
Most common inflammatory arthritis in the uk?
Gout
What is an arthroplasty?
surgical reconstruction or replacement of joint
What are crystalline arthropathies?
Group of joint disorders caused by deposits of crystals in joints and the soft tissues around them
How does gout typically present?
Middle aged overweight men who drink a lot of BEER
Risk factors for Gout?
Purine rich foods i.e meat, seafood, beer - CKD - Diuretics
Food group that can be anti-gout?
Dairy
Pathophysiology of gout?
Underlying hyperuricaemia Uricase not found in humans so uric acid is insoluble Hence USIC acid deposits in joints causing symptoms
Symptoms of Gout?
Monoarthritis; -Typically BIG TOE (metatarsophalangeal joint) PODAGRA -Sudden onset -Severe swollen red toe -Can’t put weight on it -Low grade fever Onset is typically at night
Differential diagnosis for gout?
Septic arthritis but this typically affects the knee rather than big toe Trauma Rheumatoid arthritis
Does hyperuricemia guarantee gout?
No it increases gout risk
Investigations to diagnose gout?
- measure serum urate level to see if there’s hyperuricemia - if not high but still suspected, repeat in 2-4 weeks Gold standard: (if still unsure) - Joint aspiration and light microscopy of synovial fluid
Treatment for acute gout?
-Change diet: decrease purines and increase dairy intake -NSAIDs -> colchine -> prednisolone Don’t use nsaids if they have renal failure, peptic ulcer disease or some pts with asthma and reduce colchine dose for patients with renal failure
Prophylactic/long term treatment for gout?
PREVENTION: (after several attacks) Allopurinol as part of Urate Lowering Therapy (ULT) = xanthine oxidase inhibitor - decreases uric acid production - target uric acid <360 mmol/l If that doesn’t work due to intolerance or inefficacy can use febuxostat Plus colchicine 500 micrograms OD for up to 6 months for gout prophylaxis
What is Pseudogout?
Calcium pyrophosphate (not sodium urate) crystals deposit along joint capsule
Typical presentation of pseudogout?
Elderly female, 70+
Risk factors for pseudogout?
Diabetes -Metabolic diseases -Osteoarthritis
Symptoms of pseudogout?
Often polyarticular with knee commonly involved = Swollen, hot, red joint
Differential diagnosis of pseudogout?
Sceptic arthritis as both effect the knee
Investigations to diagnose Pseudogout?
Aspirate joint and analyse sample with polarised light microscopy = gold standard - chrondocalcinosis on x ray
Light microscopy results with pseudogout?
Positively birefringent, rhomboid shaped crystals
Light microscopy results of gout?
Negatively birefringent needle shaped crystals
Treatment for pseudogout?
Only acute management: NSAIDS –> colchicine–>steroid injections
What is osteoporosis?
Decreased bone density by 2.5+ SDs below young adult mean value (T<2.5) Systemic skeletal disease characterised by low bone mass and micro architectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture.
What is a decrease in bone mineralisation known as?
Osteomalacia
Typical patient presentation of osteoporosis?
50+ postmenopausal Caucasian women
Risk factors for osteoporosis
SHATTERED -Steroids -Hyperthyroid/Hyperparathyroid -Alcohol+smoking -Thin (decreased BMI) -Testerone (decreased) -Early menopause (decreased oestrogen) -Renal / liver failure -Erosive + inflammatory disease -DMT1 or malabsorption
What is T-Score?
Standard deviations from gender-matched young adult mean > -1 Normal -1 to -2.5 Osteopenia (precursor) < -2.5 Osteoporosis < -2.5 plus fracture is severe osteoporosis
Symptoms of Osteoporosis?
Only Fractures: 1) Proximal femur (falls) 2) Collles’ (forked wrist - fall on outstretched wrist) 3) Compression vertebral crush (may cause kyphosis “widows stoop”)
Investigations to diagnose osteoporosis?
Dexa scan (gold standard) = Dual energy XR absorptiometry; yields T score by comparing patient BMD to reference Also use FRAX score (fracture risk assessment tool in osteoporotic patients)
Treatment for osteoporosis?
1) FIRST LINE: = bisphosphonates (osteoclast inhibitors) eg. aldrenoate, risedronate which inhibits RANK-L signalling =CHEAP + EFFECTIVE 2) SECOND LINE: -mAB denosumab (inhibits RANK L) -HRT (testosterone, oestrogen) -Recombinant PTH - Teriparatide -Oestrogen receptor modulator - raloxifene
What is systemic lupus erythmatosus? (SLE)
Hypersensitivity T3 reaction (A-A complex depositon) = autoimmune systemic inflammation
Who does SLE typically effect?
-Females -Afro Caribbean -20-40 (premenopausal)
Risk factors for SLE?
-Female (12x more than males) (90% are women) -HLAB8/DR2/DR3 + low C4 (null allele) -drugs (isoniazid)
Pathophysiology of SLE?
Impaired apoptotic debris presented to TH cells -> B cell activation -> antigen-antibody complexes
Symptoms of SLE?
-butterfly rash -photosensitivity -glomerulonephritis -seizures + psychosis -mouth ulcers -anamia -joint pain -raynauds -pyrexia -serositis (pleural/pericardial inflammation of lungs) -pericarditis
Investigations to diagnose SLE?
-Bloods -> anaemia -Increase ESR + normal CRP -Urine dipstick -> haematuria++++ proteinuria++ (NephrItic syndrome) -Serology: -ANA Abs (99% of cases) -Anti ds DNA Ab’s (to monitor progression) -Decreased C3+C4
Which combination of v. specific and v. sensitive tests are used as essentially diagnostic for SLE?
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Treatment of SLE?
-Lifestyle changes (less sunlight or UV protection + stop the triggering drugs) - Drugs: 1) Corticosteroids (main) 2) + hydroxychloroquinine 3) + NSAIDS (+ azathioprine, mycophenolate if severe (cytotoxic)) - even biologically like rituximab if they don’t work - if patient exhausts all treatment options they can be considered for stem cell transplant
Treatment for SLE once stable?
Aim to taper off other drugs leaving only hydroxychloroquine
What is antiphospholipid syndrome characterised by?
Thrombosis -Recurrent miscarriage -aPL Abs
Presentation of antiphospholipid syndrome?
Can be primary (idiopathic) or secondary (to other diseases, especially SLE) -Higher risk in Females
Symptoms of antiphospholipid syndrome?
CLOTS Coagulopathy Livedo reticularis (purple discolouration of skin, lace-like) Obstetric issues - miscarriages Thrombocytopenia + Higher risk of arterial (stroke, MI) + venous thrombosis (DVT)
Investigations to diagnose antiphospholipid syndrome?
1) lupus anticoagulant 2) Anti cardiolipin antibodies (IgG/M) +ve 3) Anti beta-2 glycoprotein-1 antibodies
Treatment for antiphospholipid syndrome?
1st line = warfarin long term if have had a thrombosis * if pregnant give aspirin + heparin
Prophylactic treatment for antiphospholipid syndrome?
If not had a thrombosis = ASPIRIN
What is sjogrens syndrome?
An autoimmune exocrine dysfunction DRY!!!
Typical presentation and risk factors of Sjogren syndrome?
-Can be primary or secondary to other autoimmune diseases - Females (40-50) - fHx - HLAB8/DR3
Symptoms of Sjogren syndrome?
1) Dry eyes (keatoconjuctivitis sicca) 2) Dry mouth (xerostoma) 3) Dry vagina
Complication/association of Sjogrens?
Directly confers an increase risk of lymphomas
Investigations to diagnose Sjogren syndrome?
Serology = anti-RO + anti LA Ab’s (ANA often +ve) Schrimer test = induce tears + place filter paper under eyes-tears travel <10mm (should be 20mm+)
Treatment of Sjogren’s?
Artificial tears, saliva + lubricant for sexual activity *Sometimes hydroxychloroquine given for fatigue, myalgia and rashes (up to dr)
What is scleroderma?
Systemic condition also known as systemic sclerosis, is a group of rare diseases that involve the hardening and tightening of the skin.
Most common type of scleroderma?
CREST- limited cutaneous scleroderma
Conditions CREST is made up of?
Calcinosis Raynauds Esophageal dysmotility/strictures Sclerodactyly Telenagiectaria
What is Calcinosis and what does it lead to?
Ca deposits in SC tissue -> renal failure Look like bright white deposits on x-ray
What is Raynaud’s?
Digit ischemia due to sudden vasospasm, often precipitated by the cold and relieved with heat Classic patient has white fingers
what is Sclerodactyly and what dose it lead to?
Local skin thickening or tightening on fingers/toes -> movement restriction
What is Telangiectasia and what does it lead too?
Spider veins -> risk of pulmonary htn
Investigations to diagnose scleroderma (CREST)?
Anti centromere antibodies (ACAs) - 70% ANA often +ve
Treatment for scleroderma (CREST)?
No Cure Treat Sx (e.g raynauds = handwarmers, GI Sx = PPI etc) Annual echo’s and pulmonary function tests Prevent renal crisis using ACEi
What is polymyositis/dermatomyositis?
Inflammation + necrosis of skeletal muscle Where skin is involved it is called dermatomyositis
Risk factors for polymyositis/dermatomyositis?
Females -HLA B8/DR3 genetic link
Symptoms of polymyositis/dermatomyositis?
Symmetrical wasting of muscles of shoulders + pelvic girdle - Hard to stand from sitting, to squat - Hard to put hands on top of head Dermatomyositis = + skin changes - Gottron papules- scales on knuckles - Heliotrope - purple eyelid
Investigations to diagnose polymyositis/dermatomyositis?
Muscle enzymes (CK)Muscle fibre biopsy, necrosis = diagnostic LDH + CK raised Anti Jo1 + Anti Mi2 Ab’s –> dermatomyositis only
Treatment for polymyositis/dermatomyositis?
Bed rest + prednisolone (1 month then taper dose down) => Steroids and then immunosuppressive drugs
What is fibromyalgia?
MSK equivalent of IBS = chronic widespread pain (MSK) for 3months+ with all other causes ruled out *Affects non nociceptive pain pathway
What is nociceptive pain compared to non-nociceptive pain?
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Typical patient presentation of fibromyalgia?
-Females -Depression + stress -Poor -60+
Symptoms of Fibromyalgia?
-Stressed depressed female 60+ -Fatigue -Sleep disturbance + morning stiffness (esp back, neck stiff) -Pain
Investigations to diagnose Fibromyalgia?
-No serological markers -No increased ESR/CRP -Pain in 11+ / 18 regions palpated on body => DIAGNOSIS CLINICALLY MADE
Treatment of fibromyalgia?
- Educate what it is to patient - Physiotherapy - Antidepressants for severe neuropathic pain (eg. TCAs, -Amitriptyline) - CBT
Differential diagnosis for fibromyalgia?
Polymyalgia Rheumatica (PMR)
What is PMR?
Large cell vasculitis presenting as chronic pain syndrome - affects muscles and joints (similar to fibromyalgia)
Who does PMR effect?
Females always 50+
Investigations to diagnose PMR?
Increase ESR + CRP = diagnostic - Temporal artery biopsy may show GCA, and may have anaemia of normocytic/chronic disease
Treatment of PMR
Oral prednisolone
What is Vasculitis and where can it occur?
Inflammation of vessels -> large/medium/small vessels
What conditions occur in large vessels?
GCA (giant cell arteritis) -Takayatsu (asian women, affects aortic arch, otherwise same as GCA)
What conditions occur in medium vessels?
- Polyarteritis nodosa - Buerger’s disease (male smokers 20-40, peripheral skin necrosis) - Kawasaki disease (children, causes coronary artery aneurysms)