MSK and Rheumatology Flashcards
What is osteoarthritis?
- Osteoarthritis (OA) is an age-related, dynamic reaction pattern of a joint in response to insult or injury.
- All tissues of the joint are involved, but primarily the articular cartilage.
What is the clinical presentation of osteoarthritis?
- Joint pain exacerbated by exercise
- Joint stiffness after rest (Including short-lived pain in the morning <30 mins)
- Bony swellings (on the distal interphalangeal are called Herberden’s nodes, on the proximal interphalangeal are called Bouchard’s nodes - both are more common in osteoarthritis).
- Deformity of joint/ surrounding structure.
- Crepitus (Describes popping, clicking and crackling sounds within the joint).
- Asymmetrical
What is the pathophysiology of osteoarthritis?
- Chondrocytes and inflammatory cells in the surrounding tissues release enzymes.
- These enzymes result in the breakdown of collagen and proteoglycans, subsequently the breakdown of articular cartilage.
- This exposes the subchondral bone which then becomes sclerosed.
- Bone is remodelled, resulting in the formation of osteophytes and subchondral cysts.
- Joint space is lost/narrowed over time.
What are the risk factors of osteoarthritis?
- 40 to 60 years old
- Female
- Family history
What are the diagnostic tests for osteoarthritis?
- DIAGNOSIS IS USUALLY CLINICAL.
- X-ray will show: Osteophytes, subchondral cysts, reduced joint space, subarticular sclerosis.
How is osteoarthritis treated?
1st line:
- Exercise/physio (increases joint lubrication, therefore decreasing pain).
- Topical analgesics, (NSAID’s such as diclofenac)
- Paracetamol.
2nd line:
- Corticosteroid injections (if NSAIDS/paracetamol are not sufficient or contraindicated).
If pain persists despite multiple treatment modalities, or patient has severe disability:
- Surgery (joint replacement).
What is rheumatoid arthritis?
- Chronic inflammatory disease.
- Affects the small joints of the hands and feet
What is the clinical presentation of rheumatoid arthritis?
- Tender and swollen joints.
- Active symmetrical arthritis lasting >6 weeks.
- Joint pain on touch.
- > 1 hour of morning stiffness.
- Characteristic deformities: Swan neck, Boutonnière deformity, ulnar deviation, rheumatoid nodules.
What is the pathophysiology of rheumatoid arthritis?
- Inflammation of the synovium.
- Angiogenesis, cellular hyperplasia, influx of inflammatory cells (both innate and specific ones), cytokine secretion (TNF-a, IL1 and IL6).
- Locally invasive synovial tissue forms (called a “pannus”).
- Pannus causes the the bony erosions typically seen in RA.
What are the risk factors associated with rheumatoid arthritis?
- HLA DR4 and HLA DR1 make a person susceptible to rheumatoid arthritis.
- Family history.
- Smoking.
What are the tests used to diagnose rheumatoid arthritis?
1st line: RF. If this comes back negative but RA still suspected, use anti-CCP (more accurate).
X-ray: If bony erosions seen, prognosis is significantly worse.
How is rheumatoid arthritis treated?
1st line:
- Methotrexate or hydroxychloroquine if methotrexate not tolerated (unless pregnant or planning pregnancy).
- Often low dose oral prednisolone to help help symptoms before the DMARD kicks in.
2nd line:
- Add a biological agent such as infliximab (TNF-a inhibitor).
For acute flares: Corticosteroid injections such as methylprednisolone acetate, or NSAIDS such as ibuprofen.
What are the complications of rheumatoid arthritis?
- Work disability.
- Increased mortality
- CVD risk increased
What are the differential diagnoses for RA? How are they different?
- PA (usually has psoriasis too)
- SLE (arthritis seen in SLE doesn’t normally cause deformations).
- OA (Gets WORSE with movement, and is usually asymmetrical).
What is osteoporosis?
- Progressive skeletal disease with reduced bone mass and micro-deterioration of the bones.
- Results in increased susceptibility to fracture and increased bone fragility.
OSTEOMALACIA IS REDUCED MINERALISATION OF BONES DUE TO VIT D DEFICIENCY.
OSTEOPOROSIS IS REDUCED OVERALL BONE MINERAL DENSITY.
What is the clinical presentation of osteoporosis?
- Often the first sign is fracture, typically of the neck of the femur.
- Micro-fractures in the thoracic vertebrae over time may lead to kyphosis of the spine, and back pain.
- Symptoms all relate to the increased bone fragility.
What are all the different pathophysiologies of osteoporosis?
Varied and depends on the root cause. For example:
- Coeliac (impaired calcium absorption in gut).
- RA (disrupts bone remodelling)
- Hyperparathyroidism (increases bone resorption).
There are many other causes too…
What are the risk factors of osteoporosis?
- Female
- Old
- Low BMI
- Low calcium and/or vitamin D
- Post menopause
- Smoking
- Alcohol
- Corticosteroid use.
What are the causes of osteoporosis?
SHATTERED:
- Steroid use
- Hyperthyroidism/parathyroidism
- Alcohol and tobacco
- Thin
- Testosterone LOW
- Early meopause
- Renal or liver failure
- Erosive/inflammatory bone disease
- Dietary calcium decrease/ DM type 1.
What are the tests used to diagnose osteoporosis?
- Bone mass density assessment (DEXA scan)
- T score < or = -2.5 indicates osteoporosis
- -1 > T score > -2.5 indicates osteopenia
- If there are ALSO micro-fractures present, indicates severe osteoporosis.
What treatment is given for osteoporosis?
1st line:
- Calcium and calciferol (vitamin D) supplementation.
- Alendronic acid (biphosphonates).
2nd line:
- Denosumab. This is a RANK ligand inhibitor.
- Oestrogen can be given to young post-menopausal women with low oestrogen levels.
What are the main complications of osteoporosis?
- Recurrent fractures (especially hip/rib).
- Chronic pain.
What is osteomalacia?
What is rickets?
- Metabolic bone disease.
- Incomplete mineralisation of the underlying bone matrix FOLLOWING GROWTH PLATE CLOSURE.
- Rickets is the same pathophysiology, but occurs prior to growth plate closure.
What is the clinical presentation of osteomalacia?
- Fractures (especially long bones such as the femur).
- Bone pain at the typical fracture sites.
- Signs of vit. D or calcium deficiency.
What is the pathophysiology of osteomalacia/rickets?
- Depends on the causative mechanism.
- Low vit. D and/or calcium causes growth plate disorganisation (rickets) or deficient mineralisation of the bone (osteomalacia).
- CKD causes increased FGF-23 release. This stimulates increased calcium excretion, increased phosphate retention, decreased vit. D production.
- KEY DIFFERENCE: OSTEOPOROSIS WILL SEE OVERALL LOSS OF BONY MATRIX, OSTEOMALACIA IS JUST DEMINERALISATION RATHER THAN LOSS OF BONE MATRIX ITSELF.
What are the risk factors of osteomalacia?
- Calcium/vit D deficiency.
- Malabsorption disorder (e.g. coeliac).
- Malnutrition.
- CKD.
- Hyperparathyroidism.
- Low sunlight.
What diagnostic tests are used for osteomalacia?
- Serum calcium. Low or normal.
- 25-hydroxyvitamin-D. Less than 25 nanomol/L indicates high risk of osteomalacia.
- PTH - High in Ca 2+ or Vit D deficiency.
- Raised ALP.
GOLD STANDARD: Bone X-ray to assess for defective mineralisation.
What is the treatment for osteomalacia?
1st line:
- Ergocalciferol (source of vitamin D)
AND
- Calcium carbonate/calcium citrate (source of calcium).
2nd line: Swap ergocalciferol (vit. D) for calcitriol (activated form of vitamin D).
What is Systemic Lupus Erythematosus (SLE)?
- A heterogenous and inflammatory muti-system autoimmune disease.
- It is characterised by the presence of antinuclear antibodies in the patient’s serum.
What is the clinical presentation of SLE?
There are a vast number of symptoms due to the systemic nature of the disease:
- General symptoms (fatigue, fever, weight loss)
- Arthralgia
- Malar (butterfly) rash.
- Photosensitive rash.
- Alopecia.
- Renal (GLOMERULONEPHRITIS) due to autoimmune attack.
What is the pathophysiology of SLE?
- Autoimmune disorder. ANA (anti-nuclear antibodies) produced.
- Cell necrosis increased, and clearance of apoptosed material is decreased.
- Further stimulates autoimmune processes and production of ANAs.
- Type III hypersensitivity disorder.
What are the risk factors of SLE?
- Female
- 30-70 YO
- FH
- SLE can be drug induced (e.g. sulfasalazine).
What are the potential complications of SLE?
- Thrombocytopenia
- Leukopenia
- Anaemia
- Corticosteroid-induced disorders (such as osteoporosis, due to reduced calcium absorption and increased bone resorption).
What are the investigations carried out on a patient with suspected SLE?
- ANA testing. Positive suggests SLE
- If positive, then an anti dsDNA test is done. If elevated, suggests SLE.
- ESR/CRP (ESR is raised, CRP normal as SLE is an autoimmune disease).
- Urea/creatinine. Raised if there are renal manifestations of SLE.
- aPPT elongated in certain forms of SLE.
What is the treatment for a patient with SLE?
1st line:
- Avoid sunlight and smoking.
- Give hydroxychloroquine (DMARD)
- Naproxen (NSAID) for arthralgia, or celecoxib (COX-2 inhibitor) if high risk of GI ulceration.
2nd line:
- Prednisolone (oral or IV) if the DMARD + NSAID are not adequate. LOWEST POSSIBLE DOSE FOR SHORTEST PERIOD OF TIME.
What is the disease pattern of SLE?
- 70% of patients have a relapsing-remitting form of the disease.
What is SLE short for?
- Systemic Lupus Erythematosus.
What are the two types of crystal arthropathy?
- Gout
- Pseudogout
What is gout?
Hyperuricaemia resulting in the deposition of urate crystals in the joints.
What is the clinical presentation of gout?
- A joint becomes swollen, extremely tender and erythematous.
- Usually affects 4 or less joints.
- Presence of tophi (uric acid crystal depositions in the skin/joint surfaces).
- Usually seen in the metatarsalphalangeal joint of the big toe.
- “One of the most painful acute conditions human beings can experience”.
What is the pathophysiology of gout?
- Purine broken down into urate via xanthine oxidase enzymes.
- Uric acid is excreted renally. However, if too much is in the blood (hyperuricaemia), it precipitates in the joints causing gout.
What are the potential complications of gout?
- Nephropathy (CKD risk increased)
- Nephrolithiasis.
What are the risk factors associated with gout?
- Male
- Meat/seafood consumption
- Alcohol
- Diuretics, ciclosporins, pyrazinamide.
- Genetic predisposition.
What are the investigations used for gout?
- Arthrocentesis (joint aspiration) + synovial fluid analysis.
- Will show NEGATIVELY BIFRINGENT NEEDLE CRYSTALS.
- “N+N”
- Gout can usually be diagnosed by examination.