MSK and Rheumatology Flashcards
what is the structure of bone
cortical bone on the outside - osteon functional units
trabecular bone on the inside - BM structural mesh
what is the structure of osteon
it is concentric lamellae and a central haversian canal which supplies a single longitudinal osteon
what are volkmann canals
these are canals that allow communication between osteons
what is the inorganic component of osteon made from
hydroxyapatite (ca2(Po4)3) = stiff
what is the function of hydroxyapatite in the bone
to provide stiffness
what is the organic component of the osteon
collagen T1
what is the function of collagen T1 in the bone
to provide elasticity
what are the different types of joints
fibrous
cartilaginous
synovial
where do you find fibrous joints
in the skull sutures - immovable
where do you find cartilaginous joints
IV disc, pubis symphysis - partially movable
where do you find synovial joints
most joints of the body - freely movable
what are the different kinds of synovial joint
articular cartilage
joint capsule (inner lining of synovial membrane)
synovial cavity filles with synovial fluid
what connects bone to bone
ligaments
what connects bone to muscle
tendons
what is osteoarthritis
it is the most common form of arthritis, characterised by non inflammatory degenerative mechanical shearing
what are the risk factors of osteoarthritis
age - over 50
obesity
occupation/sports
genetic
what genetic factor predisposes you to osteoarthritis
COL2A1
what is the pathophysiology of osteoarthritis
there is imbalanced cartilage breakdown compared to repair due to increased chondrocyte metalloproteinase secretion. this causes degradation of collagen and cyst formation. The bone attempts to overcome this with type 1 collagen leading to abnormal bony growths (osteophytes) and remodeling
what are the symptoms of osteoarthritis
transient morning pain - worse as day goes on
Bouchard + Heberden nodes on fingers
inflamed joints
what are features of Bouchard and Heberden nodes
asymmetrical hard inflamed joints
typically found on the most stressed joints of the body
how do you diagnose osteoarthritis from an X ray
LOSS
loss of joint space
osteophytes
subchondral sclerosis
subchondral cysts
Normal bloods
how do you treat osteoarthritis
lifestyle changes - weight bearing and physio
NSAID and cortisol injections
last resort = arthroplasty - replacements
what is rheumatoid arthritis
an inflammatory autoimmune polyarthritis
is rheumatoid arthritis symmetrical or asymmetrical
symmetrical