MSK
A&P Review
Periosteum: connective tissue covering bone
Inner layer (cambium): vascular and nerves (pain sensitive)
Diaphysis: long shaft of bone
Metaphysis: between (in the middle of) epiphysis and diaphysis
Epiphysis: End of bone
Epiphyseal plate: growth plate
Medullary cavity: hollow chamber in bone
Endosteum: thin layer lining the medullary cavity
Red bone marrow: hematopoietic (makes blood cells)
Short/flat bones/long bone epiphyses
Yellow bone marrow: fat storage
Medullary cavities of long bones
Ligament: bone to bone
Sprain (joint-sprain): overstretch/tear ligament
Tendon: muscle to bone
sTrain: overstretch/tear of Tendon
Tendinopathy: inflammation of tendon
Epicondylopathy: inflammation of tendon at bone attachment
Valgus vs varus
Most proximal part of bone/joint is reference point
Varus: distal part is medial (deformation toward midline)
VaLgus: distal part is Lateral (deformation away from midline)
OsteoBlasts Build bone - Express RANKL (Ligand)
OsteoClasts Clear out bone - Express RANK
Osteoprotegerin (OPG)
⊣ RANK-RANKL ➔ ↓ osteoclast activity
PTH (from parathyroid glands)
Low levels of PTH ➔ osteoclast apoptosis
High levels of PTH (from hyperparathyroid or ↓ serum Ca)
Osteoclast activation ➔ ↑ serum Ca from bone
Stimulates renal synthesis of calcitriol
Calcitriol (active Vitamin D)
↑ GI absorption and ↓ renal excretion of Ca ➔ ↑ serum Ca
↓ vitamin D ➔ ↓ Ca absorption ➔ ↑ PTH
Calcitonin (from thyroid)
Opposes PTH ➔ ↓ osteoclast activity
↓ GI absorption and ↑ renal excretion of Ca ➔ ↓ serum Ca
Estrogen
⊣ apoptosis of osteoblasts and ↑ apoptosis of osteoclasts
Low levels of estrogen ➔ ↑ resorption ➔ osteoporosis
Fractures
Always check (and document) Pulse-Motor-Sensory above and below the injury site
Get imaging of the joint above and below the injury site, bilateral (compare injured to uninjured)
Generally, immobilize (splint) the joint above and below the injury site and get imaging before and after reduction/immobilization
Check out SplintER Series for common splints