G. Osteoporosis/Osteoarthritis/RA Flashcards
What is Osteoporosis?
Low bone mass & microarchitecture deterioration –> fragile bones
What is the prevelence of osteoporosis in post-menopausal women?
30%
What are the outcomes for hip fracture?
20% die
20% return to normal
20% instituitionalized
20% need a lot of assistance
What % of bone mass & bone remodeling does trabecular & cortical bone account for?
Trabecular = 20% mass & 80% turnover
Cortical is the opposite
What age has peak bone density?
28
Patients with severe osteoporosis tend to present with what posture?
Keyphosis
Rib cage dropped down to pelvis
Stomach pushed out
Overall height decreased
How is the trend of bone density different in men & women?
Both peak at 28, but peak is higher in men
Both decrease after 28, but men decrease linearly & women have a big decrease around menopause
Risk factors for Osteoporosis?
Female White Low body weight Low calcium intake Sedentary lifestyle Steroid deficiency Alcohol & smoking
Lab tests for osteoporosis work up?
Ca P Alkaline phosphatase 24 hour urinary Ca Testosterone if makle Creatine Albumin CBC TSH Estradiol, prolactin, FSH & LH Serum protein electrophloresis PTH Vit D 24 hour urinary Free cortisol Carotene
How are bone densities reported?
T = difference between patient & idealized 28 yo
Z = difference between patient & idealized age matched patient
-1 to -2.5 standard deviations from idealized 28 yo = Osteopenia
> -2.5 = osteoporosis
> -2.5 + fractures = severe osteoporosis
How do the lifetime risk of fractures in males & females compare?
Women about 40% & men about 10%
How is osteoporosis prevented?
Primary Prevention =
- Good nutrition (Ca)
- Stop smoking
- Exercise
- Hormone Replacement Therapy
Secondary Prevention = preventing fractures by preventing falls
What drug interferes with Ca absorption?
H2 blockers
What causes osteoporosis pain?
Acute fractures & muscle spasms associated with spinal deformity
Osteoporosis drug therapy?
Ca Vit D Estrogen Calcitonin Anabolic steroids Bisphosphonates
Why do elderly need more Ca?
Ca absorption is decreased?
Why do elderly need more Vit D?
They create less via sun exposure
What frequently coexists with osteoporosis?
Osteomalacia (Vit D)
What is the standard of care treatment for osteoporosis? When to use? Efficacy?
Estrogen
10% increased bone mass & 50% fewer fractures
Debate over increased risk of malignancy
Decreased Ca absorption can be overcome with supplementation of what?
Vit D in high doses
What forms of Vit D are available for supplementation?
Vit D
1,25 dihydroxy Vit D3 (If dont think kidney & liver can convert precursor)
Need pharmacologic doses
What form of Ca has the highest levels of elemental Ca? Which type is better for people with achlorhydria (H2 blocker or PPI)?
Ca Carbonate
Ca Citrate
What supplement reduces bone resorption? Outcome?
Bisphosphonates
Increase bone mass 10% & reduce fractures 50%
When to take bisphosphonate supplement?
30 minutes before eat when first wake up
How to Glucocorticoids lead to osteoporosis?
Increase Ca excretion by kidneys Decrease Ca absorption by intestine Increase bone breakdown Decrease bone synthesis Decrease LH
How are Glucocorticoids used correctly?
Give minimal necessary dose Encourage weight bearing exercise Eliminate smoking & alcohol Supplement Ca & Vit D Measure 24 hour urinary Ca
What are the different definitions for osteoarthritis listed in order of prevalence?
Cartilage changes at autopsy (almost 100% at 50)
Osteoarthritis at autopsy
Osteoarthritis by X ray (50% by 50)
Symptomatic Osteoarthritis
Chronic disabling Osteoarthritis (10% by 70)
Clinical definition for osteoarthritis?
Enlarged tender joints No joint warmth Crepitus (grating sound with movement) Morning stiffness Age >50
Radiographic findings for Osteoarthritis?
Osteophytes
Joint space narrowing
Subchondral cysts & sclerosis
Malalignment
What are the 2 major classifications for Osteoarthritis?
Idiopathic = localized, general or Ca crystal associated
Secondary = Trauma, congenital/developmental or other diseases
Swelling of the DIP & PIP due to osteoarthritis are called what?
DIP = Haverdens Node PIP = Bouchard's Node
Osteoarthritis of what finger(s) tend to be painful?
most fingers aren’t painful, but osteoarthritis of the thumb can be very painful
What is the pathosphysiology of osteoarthritis?
Aging or immobilization –> chondrocyte malnutrition –> chondrocyte injury –> matrix degeneration
How is weight bering physical activity related to chondrocyte nutrition?
The chondrocytes are avascular, they only get nutrients when they are compressed –> forces fluid out –> “sucks” in new nutrient rich fluid
Intrinsic risk factors for osteoarthritis?
Age Sex Bone density Joint Mechanics Heredity Metabolic
How is weight correlated with Osteoarthritis?
Only men with weight in the highest quintile have increased risk
Risk is more dispersed gradually over the quantiles for women
Women will benefit from small weight reduction. Men only benefit if they are obese & lose a lot of weight
Which joints are disproportionately represented in each sex?
Men = hip Female = knee
What are the 3 most important determining factors for osteoarthritis?
Age
Weight
Genetics
In 2 words, what is the basis of osteoarthritis?
Chondrocyte dysfunction
What is the prevalence of RA? Effect on lifespan?
1%
Shortens lifespan by 3-18 years
What age groups & sex get RA most often?
Young (30-50)
Women
What HLA Gene Complexes are associated with RA?
DRB1
DR3
Clinical criteria for RA?
Morning stiffness
3 or more joints
Symmetric
Hands involved
What cytokines are related to the pathophysiology of RA?
TNF alpha
IL-1
Imbalance of these cytokines & anti-inflammatory cytokines (Soluble TNF receptor, IL1 receptor agonist & IL-10)
What is the predominant microscopic appearance of the synovium in RA?
Inflammatory infiltrate
What joints are usually effected in RA?
Spine & DIP not effected
Other than those small distal joints are traditionally effected more than proximal (hand & feet more so than knees & elbow)
What finger positions are associated with RA? Cause?
Swan Neck = flexed DIP
Boutenneires = Flexed PIP
Tendon destruction
What are the 2 main organs outside of the joints that can effected by RA?
Eyes
Lungs
What is Rhuematoid Factor?
Autoantibody directed against Fc portion of IgG
How accurate is the RF test for RA?
Not very
Only 80% of RA patietns test + (low specificity)
Can get false + from infection (TB, hep, endocarditis, viral & parasitic), neoplasms, healthy elderly & a lot of other stuff
What two tests should be performed if RA is suspected? What is the combined specificity? When do these markers present as +?
RF & anti-CCP
99.5%
CCP is early & RF is later (once symptomatic)
Ways to differentiate RA from OA?
RA is younger patients
RA pain gets better through day
RA affects small joints
RA has elevated ESR, RF/CCP, anemia, luekocytosis
How accurate is anti-CCP test for RA?
Very specific
