MSK Flashcards
What is Paget’s disease of the bone
Osteitis deformans
- increased bone turnover
- disorganise remodelling, deformity, weakness
cause of Pagets disease of the bone
- genes- SQSTM1, RANK
- viral- RSV,
sx of pagets disease of the bone
- asx in most
- deep, boring pain
- deformity- pelvis, L spine, femur, tibia, frontal bossing of the skill
- headaches
- pathological #
- OA
- nerve compression
- malignancy, HF, kidney stones
ix ?paget’s
- skeletal XR survery
- bloods - ALP raised, Ca PO4 normal
- **- boneturnover markers in urine
- **- bone scans
tx paget’s
- analgesia
- bisphos- alendronic acid
- calcitonin 3m
- surgery- osteotomy, arthroplasty, # alignment
What is osteomalacia
normal amount of bone, low minerl acontent
causes of otseomalacia
- Vit D deficiency
- CKD- 1,25,dihroxy cholecalciferol deficiency
- liver disease- reduced hydroxylation of Vit D and malabs
- tumour induced- hyperphosphaturia
describe the way in which UV, vitamin D is processed in the body and used
- UV on skin causes 7-dehydrocholesterol to be converted to pre- vit D3
- pre- vit D3 is converted into cholecaliferol (vit D3)
- vit D3 and D2 are eaten via supplements, fish and meat
- Vit D3 is converted in 25-hydoxyvitD3 in LIVER
- KIDNEYS release 1alpha hydroxylase, whihc converts hydroxy vit D3 into 1,25-dihydroxyvitmain D ie calcitriol
what does calcitriol do
ie 1,25-dihydroxycholecalciferol
INCREASES SERUM CA
- increases Ca absorption in gut
- increases reabs of Ca in kidneys
- increases bone breakdown (osteoclasts)
presentaiton of osteomalacia
- rickets
- hypocalcaemia- confusion, numbness, spasms, seizure, MI
- bone pain
- pathological #
- proximal myopathy- waddling
ix osteomalacia
bloods- hypoCa, hypophosphataemia, increased ALP and PTH, decreased vit D
XR- loss of cortical bone, #
bone biopsy- poor mineralisation
management of osetomalacia
- vit D
- Ca
- calcitriol
- phsophate
What is oeseoporosis
- low bone mass and microarchitectural deterioration-
- thinned, disconnected trabeculae
causes of OP
- inflammation- cytokines increase bone resorp
- endocrine- hyperthyroid, Cushing’s, steroids,
- oestrogen/testosterone
- poor skeletal loading (immobility, low body wt)
ix OP
- FRAX score- 10 yr prob of hip/bone #
- dual energy XR- t-score
what are the cut offs and definitions of a T-score
> -1 = normal
-1 to -2.5= Osteopenia
< -2.5 = OP
< -2.5 + # = severe OP
Management of OP
Cause
- HRT in early menopause/hysterectomy
- control thyroid
- control inflammatory conditions
Bisphosphonates
- alendronate PO, Zoledronate IV
- Denosumab- monoclonal antibody to RANKL- blocks bone resorption
- Teriparatide-
- synthetic PTH analogue, daily injection
- increases osteoblast activity and bone formation (dont think too hard about it)
what instructions do you give some taking oral alendronic acid
- dont lie down for 30min after
- have with water
- get dental appt before taking- linked with osteonecrosis of the jaw
what is osteogenesis imperfecta
- disorder of type 1 collagen
- brittle , fragile bones
- bone heals with deformity
types of osteogenesis imperfecta
Type 1- least severe
Type 3- severe, pogressively deforming
presentation of oesteogenesis imperfecta
- #
- bowing of long bones
- blue sclera
- hearing loss
- short stature, scoliosis
- ***- ligamentous laxity– hyperextensible joints
ix ?osteogenesis imperfecta
- foetal USS_ only picks up severe, type 3
- bloods- ALP raised
- genetic testing
- skin biopsy- assess collagen
- bone biopsy
- XR
Management of osteogenesis imperfecta
- Ca
- bisphosphonates
- synthetic calcitonin (opposes PTH, usually produced by thyroid)
- intramedullary rods to prevent bowing
What is Scheuermann’s disease
- slow growth of anterior spine
- leads to kyphosis, deformity