Bone/Joint Disorders - textbook Flashcards
osteoporosis
common & often silent disorder causing significant morbidity and mortality and reduced quality of lif
osteoporosis: characterized by
low bone density
loss of bone strength resulting in an inc risk & rate of bone fx
risk of developing osteoporosis
-age (inc after 50)
-sex (African Americans have the highest BMD, while Asian Americans have the lowest)
-race/ethnicity (white, old women have the highest %)
-common sites of fx: spine (kyphosis), hip, wrist but all can be affected
moat common skeletasl disorder
osteoporosis
osteoporosis classified as
primary (no known cause) - most often: postmenopausal women & aging men
secondary (caused by drugs or other diseases)
why do postmenopausal women have accelerated bone loss?
loss of estrogen
secondary causes of osteoporosis
such as hypogonadism, are found more commonly in men with low trauma fractures
osteoporosis is known for
an imbalance in bone remodeling (accelerated w/ decreased estrogen in the first 5 years)
osteoclastic activity is enhanced, resulting in overall bone loss
BMD
low bone mineral density
diagnosis osteoporosis
-assessment of BMD
-vertebral imagining
-labs
-other factors for secondary causes
-biochemical markers for bone turnover
measuring BMD
dual-energy x-ray absorptiometry (DXA) (WHO recommended) to measure central (hip and/or spine) and peripheral (heel, forearm, or hand) sites: peripheral quantitative computed tomography, radiographic absorptiometry, single-energy x-ray absorptiometry
T-scores & Z-scores: indicating osteoporosis
T-score more than –2.5 standard deviations below the mean BMD in young adults
osteopenia
low bone mass, is defined as a T-score between –2.5 and –1.0
National Osteoporosis Foundation (NOF) and AACE recommend BMD measurements in the following groups
women age 65 and older, men age 70 and older, perimenopausal women and men age 50 to 69 with risk factors, anyone with a fracture after age 50, and adults with a secondary cause for osteoporosis
vertebral imagining is recommended in patients with a central T-score:
–1.0 or less and at least one other factor:
(a) women age 70 and older and men age 80 and older
(b) reported decrease in height of 4 or more centimeters
(c) reported or documented prior vertebral fracture
(d) glucocorticoid therapy of at least 5 mg daily of prednisone (or equivalent) for at least 3 months
screening labs:
-complete blood count cell
-serum chemistries (electrolytes w/ calcium, phosphorus, liver enzymes)
- vit D
-urinalysis
monitoring bone turnover markets (BTMs)
c-terminal telopeptide (CTX) for bone resorption
serum carboxy-terminal propeptide of type I collagen (PINP) for bone formation
nonmodifiable risk factors
-family hx
-age
-ethnicity
-sex
-concomitant disease states
-smoking
-low calcium intake
-poor nutrition
-inactivity
-heavy alcohol use
-vit D deficiency
prevention should start at an early age
calcium supplement doses should be limited to
500-600mg per dose
calcium carbonate
take w/ food to maximize absorption
-pts taking PPI/h2RAs difficulty absorbing due to reduced stomach acidity
calcium citrate
do not need an acid environment for absorption
-taken w/ or w/o food
calcium supplements a/e
-constipation
-bloating
-cramps
-flatulence (esp calcium carbonate)
calcium salts reduce absorption of
iron and some antibiotics, such as tetracycline and fluoroquinolones
**admin calcium supplements 2 hrs prior or 4 hrs after **
NOF recommends a daily vitamin D intake of
800 - 1000 IU for all adults age 50+
max for chronic use is 4000 IU/day
bisphoshonates
1st-line option for M & F in preventing osteporotic fractures
-decrease resorption by quickly binding to the bone matrix and inhibiting osteoclastic activity
highest affinity to bone from bisphosphonates class are:
alendronate and zoledronic acid (IV)
“broad spectrum” due to efficacy in decreasing hip, vertebral and nonvertebral fractures
alendronate, risedronate, and zoledronic acid
which bisphosphonate is for postmenopausal osteoporosis
ibandronate
a/e of bisphosphonate
-bone, muscle, joint pain (stop when dicon’t)
-upper GI (N/V/D), dyspepsia, abd pain, GERD
-esophageal ulceration, erosion w/ bleeding, perforation, stricture, esophagitis (inc w/ age, previous upper GI tract disease, use of NSAID) …risk decreased w/ once-week admin
zoledronic acid
monitor creatinine, alkaline phosphatase, phosphate, magnesium, and calcium prior to each dose
-flu-like symptoms last for days (give Tylenol)
long-term use of bisphosphonate
-osteonecrosis of the jaw (ONJ)
-atypical femoral fractures (AFF)
discontinue after 10 years of oral therapy or 6 years of IV therapy
oral bishosphonates absorption
is poor especially when taken with food or calcium supplementation
Contraindications to bisphosphonates
hypersensitivity, hypocalcemia, pregnancy, and renal impairment (creatinine clearance less than 30–35 mL/min [0.50–0.58 mL/s]), or failure
-esophageal abnormalities delaying swallowing (eg, achalasia, stricture), GI malabsorption (eg, celiac disease, Crohn disease, or gastric bypass), or who cannot remain upright for 30 minutes should avoid oral bisphosphonates; consider IV bisphosphonates for these patients
denosumab
a broad-spectrum, twice-yearly injectable human monoclonal antibody that prevents nuclear factor-kappa B ligand (RANKL) from binding to its receptor, thereby decreasing osteoclast maturity, function, and survival
use up to 10 years
injected once q6months
denosumab: proven for
benefit in reducing hip, vertebral, and nonvertebral fractures through its antiresorptive effects
-its reversible; decreases in BMD may be seen within months of discontinuation of therapy
-drug holidays not recommended bc ^^^
patient cant tolerate bisphosphonate, rx
denosumab
denosumab a/e
back pain, arthralgias, fatigue, headache, dermatologic reactions, D/N
serious a/e: hypophosphatemia, hypocalcemia, dyspnea, and skin and other infections
parathyroid hormone analogs
-teriparatide (recombinant human PTH [1-34]
-abalopratatide (synthetic analog of PTH-related protein [PTHrP] for postmenopausal only
activation of receptor promotes osteoblastic activity and bone formation but also enhances bone resorption
(not for hip fracture reduction)
1st line therapy for prior fractures or those deemed very high risk
-daily subq self-injection prefilled pens
parathyroid hormone analogs: a/e
- N
- headache
- leg cramps
-dizziness
-orthostatic hypotension - hypercalciuria
- hypercalcemia
abaloparatide=palpitations
parathyroid hormone analogs: contraindicated in
hypercalcemia, hyperparathyroidism, patients at risk of osteosarcoma (Paget’s disease, hx of skeletal radiation)
** Black box warning: observation of osteosarcoma in animal studies, not confirmed in humans **
therapy for 2 years & s/n discon’t
Romosozumab
monoclonal antibody that promotes bone formation and reduces resorption by binding to and inhibiting sclerostin, thereby increasing production of mature osteoblasts
higher reduction in vertebral fx than alendronate and denosumab
indicated for treatment of osteoporosis in postmenopausal women at high risk of fracture (history of fracture or multiple risk factors for fracture) who have failed or are intolerant to other treatment options
administration of romosozumab
210 mg is administered as 2 subq injections once monthly by a healthcare provider
-treatment recommended for 12 months
-start on bisophosphonate or denosumab to prevent the loss of benefit, including gains in BMD and reduction in fracture risk
black box warning for romosozumab
risk of myocardial infarction, stroke, or cardiovascular death.38 Patients should not take the drug if they have had a stroke or myocardial infarction in the past yea
raloxifine
estrogen-like activity on bones and cholesterol metabolism and estrogen antagonist activity in breast and endometrium
-reduces bone resorption and decreases overall bone turnover
-not effective in reduction hip or nonvertebral fractures
-decreases breast cancer risk in pts at risk for osteoporosis
raloxifine: a/e
hot flushes, leg cramps, and increased risk of venous thromboembolism
* previous hx of VTE is a contraindication for this therapy*
calcitonin
naturally occurring mammalian hormone that plays a major role in regulating calcium levels
-inhibits bone resorption by binding to osteoclast receptors
calcitonin: a/e
-rhinitis
-nasal irritation
-dryness
-safety & effectiveness of calcitonin has been studied for up to 5 years. Once discontinued, benefits of drug therapy are lost within 1 to 2 years
estrogen
either alone or in combination with a progestin as hormone replacement therapy (HRT), has a long history as an effective treatment for osteoporosis
-may be considered in women with past hysterectomy intolerant to other therapies who are less than 10 years postmenopause and experiencing vasomotor symptoms
estrogen
either alone or in combination with a progestin as hormone replacement therapy (HRT), has a long history as an effective treatment for osteoporosis
-may be considered in women with past hysterectomy intolerant to other therapies who are less than 10 years postmenopause and experiencing vasomotor symptoms
combination therapy
The AACE states that addition of a bisphosphonate or denosumab to prevent hip fracture may be reasonable in patients using raloxifene to reduce breast cancer risk
Glucocorticoids
eg, prednisone, hydrocortisone, methylprednisolone, and dexamethasone) play a significant role in bone remodeling, including increasing bone resorption, inhibiting bone formation, and changing bone quality
he American College of Rheumatology (ACR) recommends oral bisphosphonate therapy for all patients …
age 40 or over at moderate to high risk of fracture (as determined by FRAX) receiving glucocorticoids (prednisone 2.5 mg or more daily or equivalent) for 3 months or longer
for patients unable to take oral bisphosphonates
lternative therapy recommendations include IV bisphosphonates, teriparatide, denosumab, and raloxifene in that order.46 Frequent clinical fracture risk assessment with BMD testing every 1 to 3 years is recommended while receiving glucocorticoids
