Rheum Flashcards
(134 cards)
What is Paget’s Disease of the Bone?
excessive bone turnover (reabsorption and formation) due to increased osteoclast and osteoblast activity.
Turnover is not coordinated, so get patchy (high density) sclerosis and (low density) lysis
Paget’s effect on bones
- Enlarged and misshapen bones
- Structural problems
- Increased risk of pathological fractures
- Particularly affects the axial skeleton (the bones of the head and spine).
Presentation of Paget’s
asymptomatic (incidental on xray) or:
- Bone pain
- Bone deformity
- Fractures
- Hearing loss
Paget’s Ix
X-ray findings include:
- Bone enlargement and deformity
- Osteoporosis circumscripta
- Cotton wool appearance of the skull
- V-shaped osteolytic defects in the long bones
Blood tests include:
- Raised ALP (needs monitoring)
- Normal calcium
- Normal phosphate
Paget’s Mx
Bisphosphonates
- calcitonin if can’t have bisphosphonates
- NSAIDs for bone pain
- calcium and vit D
Paget’s complications
- Hearing loss (if it affects the bones of the ear)
- Heart failure (due to hypervascularity of the abnormal bone)
- Osteosarcoma (rare but poor prognosis)
- Spinal stenosis and spinal cord compression
Define osteomalacia
soft bones due to insufficient vit D
low Vit D = low calcium and phosphate
low calcium = high PTH which increases calcium resorption from bones
RF- dark skin, low sunlight exposure, colder climate
Osteomalacia presentation
May be asymptomatic
Fatigue
Bone pain
Muscle weakness
Muscle aches
Pathological or abnormal fractures
Looser zones (fragility fractures partially through bone)
Osteomalacia Ix
- serum 25 hydroxyvitamin D (<25= deficiency, 25-50= insufficiency)
- low serum calcium
- low serum phosphate
- high ALP
- high PTH
- Xray: osteopenia (radiolucent bones)
- DEXA: low bone mineral density
Osteomalacia Mx
colecalciferol (vit D)
loading dose 50,000 IU once a week for 6 weeks or 4000 IU daily for 10 weeks.
then maintenance dose of 800-2000
Define Osteoporosis
reduction in bone density
DEXA <-2.5
-1 to -2.5 = osteopenia
DEXA on femoral neck most important to check
Osteporosis RFs
- older age
- post-menopausal
- reduced mobility
- low BMI
- low calcium or vit D intake
- alcohol and smoking
- long term steroid use (7.5mg and above)
- fracture hx
- CKD, hyperthyroidism, RA
- SSRI, PPI, anti-epileptic, anti-oestrogen
Osteoporosis Ix
QFracture tool
FRAX tool
measures 10 year risk of fracture
above 10%= do DEXA
Osteoporosis Mx
- stop smoking and alcohol
- exercise
- calcium
- Vitamin D
- Bisphosphonates (take on empty stomach to reduce reflux)
- denosumab
- HRT
Side effects of bisphosphonates
- reflux and oesophageal erosions
- atypical fractures
- osteonecrosis of the jaw
- osteonecrosis of external auditory canal
Define Gout
crystal arthropathy
high uric acid
raised serum urate level
joint aspiration: monosodium urate crystals, needle shaped, negative bifringent
Xray- maintained joint space, lytic lesions in bone, punched out eosions
Gout presentation
- hot swollen and tender joint
- gouty tophi in hands elbows and ears (subcut uric acid deposit)
- base of big toe (MTP joint)
- base of thumb (CMC joint)
wrist - larger joint (knee/ankle)
Gout RF
male
FH
alcohol
obesity
high purine diet (meat/seafood)
diuretic
CVD
Kidney disease
Difference between gout and pseudogout
Monosodium urate crystals of gout are needle-shaped and negatively birefringent of polarised light.
The calcium pyrophosphate crystals of pseudogout are rhomboid-shaped and positively birefringent.
Gout Mx
acute:
naproxen
colchicine
prednisolone
Chronic
allopurinol
febuxostat
use NSAID alongside allopurinol at beginning as it can trigger gout flare
- lose weight and hydrate
- no alcohol and purines
Define pseudogout
calcium pyrophosphate crystals
Pseudogout presentation
Many asymptomatic
chronic pain and stiffness in joints
>65 y/o
hot swollen stiff and painful knee
or shoulders, hips, wrists
Diagnosing pseudogout
Need joint aspirate to exclude septic arthritis: rhomboid positive birefringent
Xray: chrondrocalcinosis - calcium deposits in joint cartilage.
Similar xray changes to OA
L: LOJS
O: osteophytes
S: subarticular sclerosis (increased bone density on joint line)
S: subchondral cysts (fluid filled holes in bone)
Pseudogout Mx
resolve spontaneously
symptomatic mx:
NSAID
colchicine
joint steroid injection
oral steroids