Musculoskeletal and rheumatological conditions Flashcards
Osteoarthritis: epidemiology
Worldwide, uncommon in black population, twice as common in women, occurs in over 50s.
Osteoarthritis: age
Mostly over 60s.
Osteoarthritis: sex
Women over 55 more likely to have it than men of a similar age.
Osteoarthritis: clinical symptoms.
Joint pain - pain exacerbated by movement, relieved by rest. Gelling on rest.
functional limitation
Osteoarthritis: clinical signs
Crepitus
Restricted movement
Bony enlargement
Joint effusion and variable levels of inflammation.
Osteoarthritis: investigations.
Blood tests, X-rays, MRIs, aspiration of synovial fluid.
Osteoarthritis investigations: blood tests.
ESR normal, sometimes high-sensitivity CRP elevated. Rheumatoid factor and anti-nuclear antibodies are negative.
Osteoarthritis investigations: X-rays.
Abnormal only when advanced. Used pre-operatively.
Theoretically will show LOSS - loss of joint space, osteophytes, subarticular sclerosis, and subchondral cysts.
Osteoarthritis investigations: MRI
Used to look for for meniscal tears, early cartilage injury and subchondral bone marrow changes.
Osteoarthritis investigations: aspiration
Shows viscous fluid with few leukocytes.
Osteoarthritis treatments.
All aimed at relieving symptoms. Physical measures, paracetamol, NSAIDs, intra-articular steroids or surgery.
Hyaluronic acid injections, topical capsaicin.
Osteoarthritis pathology
Multifactorial process, mostly mechanical factors. Significant inflammation and also alteration of cartilage structure.
Red flag symptoms for back pain (divisions to help memory)
Divide into age, type of pain, associated symptoms, cancer, neuro and infectious to remember
Red flag symptoms for back pain (actual)
Age: under 20 or over 55.
Type of pain: If the pain is constant/progressive, nocturnal/worse when in a supine position, or if it is thoracic.
Associated symptoms: fever/night sweats/weight loss, morning stiffness or claudication in the leg.
Cancer: history of malignancy, abdo mass (also AAA).
Neuro: neurological disturbance (inc sciatica), leg pain (bilateral or alternating unilateral), sphincter disturbance.
Infection: current infection or immunosuppression.
Normal distribution of psoriasis
Forearm extensor surfaces.
Complications of chronic kidney failure
Hyperkalaemia, high levels of erythropoietin, hypocalcaemia.
Rheumatological conditions causing diffuse pain with no early morning stiffness
Chronic pain syndromes
Fibromyalgia
Malignancy
Rheumatological conditions causing diffuse pain with early morning stiffness
Polymyalgia rheumatica
Inflammatory myositis
Rheumatological conditions causing localised pain, with no early morning stiffness and no joint swelling
Osteoarthritis/arthropathy
Tendinopathy
Bursitis
Rheumatological conditions causing localised joint pain with early morning stiffness, in a single joint.
SEPTIC ARTHRITIS
Crystals (gout)
Reactive
Spondyloarthritis.
Rheumatological conditions causing localised joint swelling and pain with early morning stiffness, in multiple joints
Rheumatoid Viral (if less than 6 weeks) SLE Sponyloarthritis Crystals
Joints commonly affected by osteoarthritis
Distal interphalangeal joints, first CMC joint in hand, MTP joint of foot, and weight-bearing joints.
Heberden’s nodes
Bony swellings at DIPJ
Bouchard’s nodes
Bony swellings at PIPJ
Rheumatoid arthritis definition
A chronic symmetrical bony arthritis caused by a systemic autoimmune disorder with extra-articular involvement
Rheumatoid arthritis - epidemiology
Peak prevalence 30-50 years, pre-menopausal women affected more than men, familial association.
Rheumatoid arthritis - pathology
Activation of synovial T cells by unknown antigen leads to synovitis, synovial infiltration, angiogenesis and formation of a pannus. This leads to destruction of articular cartilage and subchondral bone. Rheumatoid nodules also form in the skin, pleura, pericardium and lung.
Rheumatoid arthritis - clinical features
Pain, early morning stiffness, and swelling of small joints. Joint effusions and wasting of surrounding muscles.
Periarticular features. Rheumatoid nodules at pressure points.
Progressive disease: joint instability, subluxation and deformity
Rheumatoid arthritis - investigations
Bloods: anaemia, raised inflammatory markers
Serum autoantibodies:RhF, antinuclear factor and anti-citrulline-contaiining peptide antibodies.
X-ray.
Aspiration: synovial fluid stirle with high neutrophil count.
Rheumatoid arthritis - treatment
Smoking cessation, NSAIDs, disease-modifying drugs (DMARDs). Anticytokine agents, coricosteroids, surgery.
Rheumatoid arthritis - joints affected
PIPJ, MCPs and wrist. Can involve elbows, shoulders, spine, knees, ankles and feet.
Ankylosing spondylitis - definition
An inflammatory disorder of the back
Ankylosing spondylitis - epidemiology
Typically young men
Ankylosing spondylitis - clinical features
Increasing pain and morning stiffness in lower back, alleviated by exercise not rest. Progressive loss of spinal movement.
Increased loss of lumbar lordosis and increased kyphosis. Limitation of lumbar mobility and chest expansion.
Ankylosing spondylitis - investigations
Bloods: raised inflammatory markers
X-ray may be normal or show erosion.
MR shows early changes suggestive of osteitis and oedema.
Ankylosing spondylitis - treatment
Exercises.
Slow release NSAIDs taken at night.
In severe AS if NSAIDs fail, use TNFa blockers such as adalimumab and golimumab.
What is a greenstick fracture?
A fracture in a child that involves partial cortical disruption.
Pars interarticularis position
A fracture of the area on a vertebra between the superior and inferior facet
Pars interarticularis result.
The fracture may lead to the vertebral body slipping anteriorly and leading to vertebral canal compression. Common in athletes at LIV and LV levels.
Which nerve weakness leads to inablility to raise the arm above the head and weakness in attempting to raise the shoulder?
CN XI
Which nerve damage leads to inability to do a pull up?
Thoracodorsal nerve
When do you see polyarticular gout?
Occasionally, but in chronic renal failure particularly
Which crystals cause gout?
Monosodium urate monophosphate
Which crystals cause pseudogout?
Calcium pyrophosphate dihydrate
Pattern of gout
Usually feet, esp first metatarsalphalangeal joint in men, and knee in women, but can affect any foot joint. Generally in men, affecting 1% of population.
Timescale of gout
Acute onset of swelling, pain and redness for a few days, before returning to normal. These intermittent attacks occur more frequently without treatment leading to chronic problems, as severity of flares decreases.
Examination findings in gout
Low grade pyrexia, redness, swelling and tenderness of joint. If chronic, tophi over pinna of ear, elbow and lateral hand.
DD is septic arthritis, gout and pseudogout.
Risk factors of gout.
What increases serum uric acid level?
Diet: animal purines, alcohol, seafood
Synthesis
Decreased renal excretion
Metabolic pathway key to pathogenesis of gout
Nucleic acids –> purines –> hypoxanthine –> xanthine –> URIC ACID (which we can’t metabolise and is not v water soluble, so is supersaturation level of serum)
Lesch-Nyhan syndrome
Paediatric condition due to mutation in uric acid pathway, leading to hyperuracemia in children.
What interferes with renal excretion of uric acid?
mutation in URAT1 channel in Mauris; drugs inc loop and thiazide diuretics, cyclosporin and low dose aspirin; lead toxicity; INSULIN RESISTANCE and high levels of insulin which interfere with excretion
What alters uric acid synthesis in the body?
Increased cellular turnover - lymphoproliferative disorders and malignancy;
Increased uric acid synthesis - fructose high diets.
How do uric acid crystals cause gout?
They are unstable, and can be released into the joint leading to recognition by innate immune system activating the inflammasome leading to neutrophil activation and symptoms of gout
What triggers gout attacks?
Intercurrent infection, acute increase or decrease in serum uric acid (commencing treatment, alcohol or dietary changes), possibly trauma.
Investigations when faced with suspected gout?
SYNOVIAL FLUID ANALYSIS (exclude septic arthritis)
Renal function (increased creatinine is a risk for gout)
Serum uric acid - a NEGATIVE marker as drops in an acute attack, so likely to be normal but can still be high.
Blood cultures
Synovial fluid appearance in septic arthritis and crystal synovitis
Runny, greenish, opaque. (crystal synovitis can be more yellowish)
Synovial fluid appearance in inflammatory arthritis and crystal synovitis
Cloudy, straw-coloured, low viscosity. (crystal synovitis can be more greenish).
Normal synovial fluid looks like…
Olive oil
What investigation is used to diagnose gout definitively?
Polarised light microscopy. Needle shaped crystals visible.
Treatment of gout - matches causing fire in joint. Fire extinguisher, dampen matches, reduce number of matches.
A fire extinguisher: NSAIDs very effective - carry with them, and take at start immediately. Steroidal anti-inflammatories also work if NSAIDs contraindicated.
Dampen matches: colchicine interferes with neutrophil microtubules. OD, BD or TD.
Reduce the number of matches: reduce uric acid levels in body. Decrease insulin - weight reduction. Check drugs. This risks flares.
Allopurinol inhibits xanthine oxidase.
What is pseudogout?
A crystal arthropathy that can be thought of as an aggressive form of nodal osteoarthritis.
What is likely to be a background history for patients with pseudogout?
Nodal osteoarthritis.
What is a ‘flare’ of osteoarthritis likely to be?
Pseudogout
Presentation of pseudogout
Episodes of pain, early morning stiffness, swelling and redness of affected joint, lasting weeks (not days).
Triggers for pseudogout
Intercurrent infection, dehydration, local trauma.
NOT diet.
Investigations for suspected pseudogout
Joint aspiration - look for crystals, but can be difficult to see. Exclude septic arthritis CRP/ESR raised Blood cultures negative Uric acid normal X-ray as crystals are radioopaque