Case 2: Osteoporosis Flashcards
Define osteoporosis
- Reduction in bone mass
- Disruption of skeletal micro-architecture
- Fragility of skeleton
What is a person with osteoporosis at increased risk for?
Fracture 2/2 decreased bone strength
What happens to the trabecular bone with increasing age?
Continuous trabecular network begins to breakdown there is thinning of horizontal trabecula, eventually the vertical trabecula is unsupported.
RF:
- Women>men
- White or Asian
- Low body wt <127lbs or BMI <20
- Fhx or personal hx of fragility fx
- Long-term glucocorticoids
- Estrogen deficiency- postmenopausal
- Testosterone deficiency
- Increasing age
- *lifetime osteoporotic fx risk for a women who reaches 50 is 50%.
Causes of secondary osteoporosis
- Meds- steroids, anti epileptics
- Vit D deficiency
- Low Ca intake
- Alcohol >2-3 drinks/day
- Sedentary lifestyle
- Current tobacco use
What does FRAX calculate?
- Fracture risk assessment tool
- Calculates pt’s 10y fx probability
Who can you calculate FRAX score on?
- Postmenopausal women and men age 40-90
- *only validated for untreated pts, DXA scan input needed.
What is the gold standard for bone density testing?
DXA of lumbar spine and hip
Who gets a DXA scan?
- Women ≥65 years old
- ?men ≥70 years old- no consensus
- Younger but at risk for osteoporosis or osteomalacia
- Pathologic fractures
- Radiographic evidence for diminished bone density
What determines the interval between scans?
Based on T score
What is the interval between DXA scans for: T score -1.0 to -1.5 T score -1.5 to -2.0 T score < -2.0
T score -1.0 to -1.5: every 5 years
T score -1.5 to -2.0: every 3-5 years
T score < -2.0: every 1-2 years
T score range for normal, osteopenia, osteoporosis, severe/established osteoprorosis?
- Normal: w/in 1 SD, T score > -1
- Osteopenia: b/w 1 and 2.5 SD below NL, -1 to -2.5
- Osteoporosis: 2.5 SD or more below, T score < -2.5
- Severe/Established: 2.5 SD or more below with 1 or more fragility fractures
What is a z score?
bone density as standard deviation from age-matched, race-matched, and sex-matched.
Who is Z score used in?
Premenopausal women, younger men, and kids
what is the first sign/symptom of osteoporosis?
asxs/silent until fx occurs
Clinical manifestations of a vertebral fx:
- Height loss or kyphosis
- Acute episodes may be associated with pain
- Often no preceding trauma or minor trauma (ie: speed bump, standing up)
- Acute back pain with sudden lifting, coughing, bending
- Usually pain localized to midline spine, variable quality - May refer into flank, anterior abdomen, posterior superior iliac spine, radiation into legs rare
- May have pain on palpation/percussion of affected vertebrae
Xray findings:
- Radiolucency
- Cortical thinning
- Occult fx
Bone loss has to be greater than __% to be detected?
30%
Life style modification for osteoporosis
- Smoking cessation
- Limit alcohol intake
- Regular weight bearing and muscle-strengthening exercise- At least 30 mins, 3x/week
- Consume at least 1200 mg of calcium/day
- Adequate calorie intake
- Take measures in the home to avoid falls
- Wearing a brace
When should a pt be started on pharmacological tx?
- Hx of hip fx or vertebral fx
- T-score < -2.5 (DXA) at femoral neck or spine, after evaluation to exclude 2/2 cause
- T-score b/w -1 and -2.5 at femoral neck or spine, 10 yr probability hip fx > 3%, or other fx > 20%
What should total Ca and vit D daily intake be?
- Ca 1200mg/day
- Vit D 800 units
Calcium SE:
Supplements ↑ risk nephrolithiasis, may ↑ CV disease (controversial- data points away), dyspepsia, constipation. Interfere with iron & thyroid hormone absorption (take at different times)
Vit D SE:
- Excessive amounts- hypercalcemia, hypercalciuria, nephrolithiasis
- Chronically high levels of Vit D linked to ↑cancer, mortality, and falls
- Measure vitamin D levels with 25(OH)D
1st line tx for osteoporosis
Bisphosphonates
Bisphosphonate examples and action?
- Alendronate (Fosamax)
- Risendronate (Actonel)
- Work on inhibiting osteoclast activity
- Shown to improve BMD- bone mineral density and decrease fractures
Pretreatment evaluation before starting bisphosphonates?
- Calcium
- 25(OH)D
- Creatine
- Correct hypocalcemia and vit D def before starting tx
Bisphosphonate contraindications:
- Esophageal disorders
- After bariatric surgery
- Unable to follow dosing requirements
Bisphosphate directions:
- Must be taken 1st thing in the morning on empty stomach for maximal absorption
- Take with at least 8 oz water
- Do not eat, drink or take any other medications for at least ½ hour afterwards
- Remain upright (sit or stand) for 30 minutes after administration
- IV regimens available for those who can’t tolerate oral bisphosphonates
When to stop taking bisphosphonates?
- If taking alendronate or risendronate (Actonel) for 5 years or zoledronic acid (Reclast) yearly x 3 years + have a stable BMD + no previous vertebral fractures + low risk for fracture in near future -> discontinue drug
- If highest risk for fracture, continue PO therapy for up to 10 years, IV therapy for up to 6 years.
- There is some residual benefit after discontinuation.
Risks of bisphosphonates?
- Upper GI irritation (reflux, esophagitis, esophageal ulcers- eats into it if it gets stuck)
- IV bisphosphonates can cause acute-phase reaction (fever, myalgia, arthralgia),
- Osteonecrosis of the jaw
- Renal: Not recommended in patients with CrCl <30
Calcitonin action?
- Increases spine bone density and may decrease vertebral fracture risk
- Inhibits osteoclast activity- works on PTH
When is calcitonin beneficial?
Beneficial for short-term pain relief in those with acute pain related to vertebral fractures
Calcitonin adverse rxns?
- Rhinitis
- Increased malignancy risk
Oral analgesics used in osteoporosis?
- Acetaminophen
- NSAIDs (controversy of impaired bone healing)
- Narcotics.
Kyphoplasty/ vertebroplasty what is it?
- Vertebroplast: Injection of bone cement under image guidance into fractured vertebra
- Kyphoplasty uses a balloon to expand first
Candidates for Kyphoplasty/ vertebroplasty?
- Those unable to achieve pain control
- Significant benefit to pain control in trials
Kyphoplasty/ vertebroplasty adverse events:
- Extravasation of cement
- Cement PE
- Infection
