Flashcards in Musculoskeletal disorders? Deck (28):
What is antalgic gait?
a limp with weight bearing on the unaffected side, decreased swing phase of unaffected limb
Radiographic features of arthritis?
Joint space narrowing
Clinical features of osteoarthritis?
Who does OA affect commonly?
Management of OA?
Line 1: Education advice, weight loss support, strengthening exercises
Line 2: Paracetamol, topical NSAIDS
Line 3: Oral NSAIDs, opioids, capsaicin, injections, arthroplasty, supports/assisting devices
What is a T score?
Measurement of bone mineral density
T score in osteoporosis and osteopaenia?
T score of -1.0 to -2.5 - osteopaenia
T score of less than -2.5 - osteoporosis
What is osteopenia?
Slightly reduced bone mineral density
In what situations should you give a DEXA scan?
• Low trauma (osteoporotic) #
• Height loss/kyphotic
• Vertebral deformity on X ray
• FHx of #
• Steroid use
• Early menopause
• Low BMI
• Heavy smoker/excess alcohol/ malabsorption
Treatment choices for osteoporosis? Examples?
SERMs (Selective Estrogen Receptor Modulator) e.g. raloxifene
Bisphosphonates e.g. alendronate
Teriparatide is a synthetic parathyroid hormone
Mode of action of SERMs and Bisphosphonates?
SERMs - inhibit bone resorption by stimulating oestrogen receptor in bone
Bisphosphonates - bind to hydroxyapetite and inhibit osteoclast bone resorption
Risks associated with bisphosphonates?
Risks associated with SERMs?
Risk of VTE
Worsen peri-menopausal vasomotor symptoms
When would you use a SERM?
Healthy post menopausal women worried about breast cancer, with vertebral osteoporosis (not effective in hip)
Teriparatide mode of action?
synthetic parathyroid hormone - increases formation more than it increases bone resorption.
Denosumab mode of action?
Inhibits formation of osteoclasts.
When would you use Teriparatide?
Steroid induced osteoporosis
Basic process of bone formation?
Bones initially appear as flat layers of CT
Mesenchymal stem cells in the CT differentiate to form osteoblasts
Bone matrix builds up to form trabeculae
Trapped osteoblasts become osteocytes
Basic process of cartilage formation?
Development of primary ossification centre at diaphysis
Marrow cavity formed by death of chondrocytes within bony collar
Longitudinal bone growth formed by chondrocyte hypertrophy at growth plate
Why does bone remodelling occur?
Adaptation to mechanical loading
Enabling fracture healing
Prevents “bone fatigue” by continually renewing matrix
Patho-physiology of arthritis?
Focal destruction of articular cartilage
Remodelling of adjacent bone = hypertrophic reaction at joint margins (osteophytes)
Remodelling and repair process (efficient but slow)
R/F for osteoarthritis?
Family history (genetics)
Fracture through joint
Joint steroid injection
What is an autologous bone graft, and a allogenic bone graft?
Specific bone graft with the patients human stem cells - autologous
Off the shelf made from an animals stem cells - allogenic
Advantages and disadvantages to an autologous bone transplant graft over allogenic?
No infectious disease risk
Patient specific therapy
High mfg. cost
Main differences in bone and cartilage?
Inorganic matrix in bone is heavy mineralised, in cartilage it is only mineralised in the growth plate
Bone is 90% collagen 4% proteoglycans, cartilage is 50% collagen and 50% proteoglycans
Cartilage is avascular and bone is vascular
Bone undergoes appositional growth and cartilage interstitial
Two types of bone formation?
Intramembranous - on top of a membrane
Endochondral - on top of cartilage