Ortho Flashcards
Osteoporosis
Low bone mass and microarchitectural deterioration of bone tissue. Leads to enhanced bone fragility and an increased fracture risk
Most common types of osteoporosis related fractures
1/2 vertebral, 1/4 are hip, 1/4 are wrist
Fracture rate increases after age…
75
After what age are women 3x more likely to have a fragility fx
50
Risk factors for osteoporosis
Caucasian, female, late menarche, nulliparity, early menopause, excessive exercise, age > 75, family hx, small body frame
Idiopathic secondary osteoporosis
Subset of women with no apparent etiology or secondary cause
Nutritional osteoporosis
Milk intolerance, vegetarianism, low calcium diet, excessive alcohol intake
Lifestyle osteoporosis
Caused by smoking, inactivity
Medical osteoporosis
Type 1 diabetes, cushings, chronic renal disease, IBD, cystic fibrosis, hyperparathyroidism, hyperthyroidism, anorexia nervosa, celiac disease, idiopathic hypercalciuria, premature ovarian failure
Medications causing osteoporosis
glucocorticoids, long term lithium therapy, chemotherapy, antivonculsants like phenytoin, phenobarbital, valproate, and carbamazepine… long term phosphate binding antacid, thyroid replacement drugs, methotrexate
Prevent bone loss in asymptomatic females
change nutrition, change lifestyle
decreased bone strength is related to many factors other than bone mineral density
effected by rates of bone formation, rates of bone resorption (turnover), bone geometry (size and shape), microachitecture
Age related loss of trabecular bone
breakdown of the trabecular network where it thins with separation of vertical structures or horizontal structures – pictures c and d are defined as osteoporosis
bmd screening for postmenopausal women and men
no universally adapted approach for screening
premenopausal women bmd screening
not routinely recommended. healthy, premenopausal women with concerns about bone health may request one, but it is not recommended
international society of clinical densitometry guidelines allow screening for premenopausal women with 2 select circumstances
- history of fragility fracture, known secondary causes of osteoporosis, needing pharmacological therapy for osteoporosis, need to monitor drug therapy for osteoporosis, women in menopausal transition with a specific risk factor like low body weight, low trauma fx or high risk med
T Score
diagnostic threshold for low bone mass and osteoporosis based upon BMD measurements compared with a young adult reference population
The majority of postmenopausal women with osteoporosis have bone loss related
estrogen deficiency and/or age
WHO defines osteoporosis as bone mineral density score of
2.5 standard deviations less than the mean value for a young person of the same gender
vertebral fx are assoc with
loss of stature caused by a progressive increase in the degree of kyphosis and lordotic curve flattening – causing shrinking leading to vertebral collapse
premenopausal considerations
bmd alone cannot define osteoporosis. like fragility fx, bmd is an indicator for further evaluation. fx and low bone mass are less common in premenopausal women.
low bone mass may be related to
either inadequate peak bone mass acquisition and or ongoing bone loss
postmenopausal considerations
no manifestations until fx, if no s/s they assume they do not have osteoporosis, vertebral fx is the most common fx, 2/3 of fxs are asymptomatics dx as incidental findings on xray, hip fx common in 15 percent of women and 5 percent of men by age 80
making the dx of osteoporosis
may be made with a fragility fx particularly spine, hip, wrist, humerus, rib, pelvis without a measurement of BMD
Fragility fx
occur from a fall from a standing height or less, without major trauma like a MVA
Bones not a/w fragility fx
skull, cervical spine, hands, feet, ankles
stress fx
associated with repetitive injury and are not fragility fx
BMD useful for
dx osteoporosis, predict fracture risk, monitor response to therapy. Low BMD a/w increased risk of fx, regardless of the technique of measurement
serology evaluation of osteoporosis
CMP, CBC, TSH. Normal ca, tsh and cr rule our hyperparathyroid, hyperthyroid and renal disease. normal blood count, serum protein and normal ca rule out multiple myeloma. for elderly, order 25-hydroxyvitamin D and PTH
radiography imaging osteoporosis
plain radiography are unremarkable until bone loss has reached 30%. signs of overall bone loss density (osteopenia) can be caused by moderate osteoporosis of the thoracic and lumbar spine. widening of the medullary canal with thinning of the cortices can be seen with long bones. fx may not be seen on initial radiographs, and may require bone scintigraphy, CT, MRI or repeat plain radiographs
BMD Zscores - age matched comparison will
identify individuals requiring futher evaluation for secondary causes of osteoporosis
clinical risk factors for fracture
advancing age, previous fx, glucocorticoid therapy, partental hx of hip fx, low body weight, current cigarette smoking, excessive alcohol consumption, RA, secondary osteoporosis
standard test to dx osteoporosis
dual-energy xray absorptiometry (DEXA)
DEXA
measures bone density at the femoral neck, spine and distal radius. Results are related to T scores: the number of standard deviations the bone mineral density measurement is above or below the young normal mean BMD. Only method for dx osteoporosis in the absence of a fragility fx
Bone strength =
bone mineral density
Bone quality =
other properties of bone other than BMD/bone strength
Non-BMD determinents of bone strength
bone turnover, architecture (size, shape and bone geometry), microarchitecture (trabecular thickness, trabec connectivity, trab perforation, cortical thickness, cortical porosity), damage accumulation, matrix properties (crystal size and orientation)
T Score
classification of BMD by DXA according the SD difference between a patients BMD and that of a young adult reference population.
Osteoporosis T score
2.5 SD or more below the young adult mean BMD provided that other causes of low BMD are ruled out like osteomalacia
Osteopenia
t score 1-2.5 SD below the young adult mean
Normal bone density
within 1 SD of the mean value in the young adult reference population
Osteoporosis screening uses these two tests
BMD and fracture risk assessment
severe established osteoporosis
more than 2.5 SD below the adult young female reference in the presence of one or more fragility fx
Z Score
comparison of the patients BMD to an age matched population. 2.0 or lower is below the expected range. lower than 2 need to screen for glucocorticoid therapy, malabsorption, hyperparathyroidism, alcoholism
The FRAX tool
eval fracture risk in patients. Based on individual patient models that integrate the risks associated w clinical risk factors as well as BMD of the femoral neck. Gives a 10 yr probability of fracture. 10 year probability of a hip fx and of a major osteoporotic fx like clinical spine, forearm, hip or shoulder
Pathological findings osteoporosis
excessive bone loss results from abnormalities in the bone Remodeling cycle. This involved resorption of old bone by osteoclasts, recruitment of osteoblasts to deposit the new matrix and mineralization of the newly deposited matrix. in osteoporosis a loss of a small amount of bone occurs with EACH CYCLE. Hyperparathyroidism increases the rate of activation of bone remodeling.
DDx in Osteoporosis
osteomalacia, neoplasm (leukemia, myeloma), pagets disease, OI osteogenesis imperfecta inherited connective tissue disorder with many phenotypic presentations – brittle bone disease
Activity on bone
activity increases BMD modestly
First line therapy medications in osteoporosis
calcium supplements 1,200mg per day. Vitamin D 800 IU per day. Diphosphonates causes decreased osteoclast activity, decreases fractures of hip, spine, and wrist by 50%. ca and vit d for most benefit. weekly Alendronate or Risedronate, monthly Ibandronate is available
second line therapy for osteoporosis
selective estrogen receptor modulators reduce the vertebral fx by 50 percent by have no effect on hip fx. Raloxifene only fda approved selective estrogen receptor modulator for tx osteoporosis
estrogen therapy benefit and risk
reduce risk of fx but increases risk of cardiovascular and thromboembolic events
calcitonin
Inhibits bone resorption by acting on osteoclasts
recombinant parathyroid hormone
results in stimulation of new bone formation, expensive. prescribed by specialists.
Back Pain
most comon musculoskeletal condition, 80% will have back pain at some point. primarily in middle aged adults. Pathologic back pain: originate in the spine or outside the spine. Classified as Traumatic and Atraumatic
Traumatic back pain
fractures, microfractures (causes severe and immediate back pain), dislocations, herniated discs, ligament tears
Atraumatic back pain
degen disc disease, degenerative spinal stenosis, inflammatory arthritis, osteoporosis, spondylolysis and spondyylolistehsis, neoplasms, primary or metastatic tumor, infection
mechanical low back pain
structural, spine is not aligned, need a chiropractor. lumbar strain, degenerative disease, discs spondylosis, herniated disc, spinal stenosis, osteoporosis, fractures, congenital disease, kyphosis, scoliosis
nonmechanical spine disease
spine aligned – outside of the bone. neoplasm, MM, metastatic carcinoma, lymphoma and leukemia, spinal cord tumors, infection, osteomylitis, septic discitis, paraspinous abscess, bacterial endocarditis, paget disease
visceral disease
pelvic organs, prostatotis, endometriosis, PID, renal disease, pyelonephritis, aortic aneurism, gi disease, pancreatitis, cholecystitis, penetrating ulcer
risk factors linked to low back pain
smoking, obesity, age, female, strenuous work, low education, workers comp insurance, job dissatisfaction, psych factors including somatization disorder, anxiety, depression
s/s low back pain
low back discomfort, stiffness, numbness. paravertebral muscle spasm, motor weakness, loss of DTR, loss of sensation, clonus, positive babinski sign
hx back pain
dx and radiographs are ineffective, need a thorough hx. objective history taking approach to eliminate the subjective of the patients pain experience. have the patient map out the area of pain instead of merely describing its location
physical exam of spine
begin with inspection of the spine, not any asymmetry of the ribs, flank, pelvis and inspect the natural sagittal curvatures of the patient. Assess ROM and determine local tenderness. Note flexion, extension, lateral bending, and rotation of the lumbosacral spine. elicit paravertebral muscle spasms and percussion tenderness
neuro exam
motor testing, strength testing, DTR, sensation, gait
L1
pain inguinal region. sensory loss in inguinal region. weakness - rarely hip. stretch loss - none.
L2-L3-L4
pain in the back radiating to anterior thigh. sensory loss in anterior thigh. weakness is hip flexion, hip adduction, knee extension. stretch reflex loss is patellar tendon.
L5
pain is back radiating to butt, lateral thigh, lateral calf, dorsum foot, great toe. sensory loss is the lateral calf, dorsum foot, webspace between first and second toe. weakness in the hip abduction, knee flexion, foot dorsiflexion, toe extension and flexion, foot eversion and inversion. internal hamstring stretch reflex loss
S1
pain in back, radiating to butt, lateral or posterior thigh, posterior calf, lateral or plantar foot. sensory loss - posterior calf, lateral or plantar aspect of foot. weakness - hip extension, knee flexion, plantar flexion of foot. stretch loss - achilles tendon
S2-S3-S4
pain: sacral or butt pain radiating into the posterior aspect of the leg or perineum. sensory loss - buttock, perineal and perianal regions. weakness: may be minimal with urinary and fecal incontinence as well as sexual dysfunction. reflex loss - anal wink, bulbocavernosus
labs with back pain
no specific lab tests. if suspect infection, complete blood count and ESR should be ordered.
back pain imaging
use bone scans and radiographs, CT scans only to rule out a specific dx. not necessary for first time back pain esp if caused by a specific minor trauma. if structural abnormality like AS with substantive criteria can get imaging. can detect and localize abnormalities precisely with CT and MRI. CT will show fx or osteoid osteomas. MRI will show marrow abnormalities or soft tissue like mets bone disease. technetium bone scan will show early bone infections and localizing metastatic bone lesions.
tx back pain
can use NSAIDS, supin position and PT. Only 1-2 percent are candidates for surgery. prolonged bed rest not beneficial can do 2-3 days. if plain radiograph normal, can do PT and aerobic conditioning
PT
aimed at increasing endurance and strength, lowers recurrence rate and shortens the history of back pain. work hardening programs. passive modalities of therapy, such as massage, acupuncture, and electrical stimulation can provide immediate relief but they do not help in long term treatment
Medication back pain
NSAIDs are the meds of choice for decreasing inflammation. 4-6 weeks. if resolves, the medication is discontinued. muscle relaxants do not have major role but are helpful with spasm and anxiety. they are the best for short term pain relief. if infection, abx and rest.
radiography for back pain
exact point of pain is the most important facet of the information in fx. soft tissue mass is easily palpated on physical exam may not be seen on plain radiographs, need MRI
for suspected fx, dislocations, bone abnormalities
low kilovoltage to contrast bone and soft tissue. femur, tibia and fibula, radius and ulna require 2 radiographs at 90 degrees to one another (orthogonal projections). joints are imaged in 3 projections (frontal, lateral and oblique)
suspected bone tumor
orthogonal plain radiographs. MRI for detailed information on extent of the lesion and involvement of neighboring structures. CT to show calcified tumor matrix
soft tissue tumor
orthogonal radiograph will show calcification within the lesion if present and the effects on neighobring bony structures. large lesions can be seen on orthogonal radiographs but MRI is better for lesion characterization
osteomyelitis
orthogonal radiograph show definite bone destruction, sequestrum formation or periosteal reaction without other explanation in the appropriate clinical setting are relatively specific for OM, MRI and nuclear bone scan is more sensitive
arthritis imaging
need 3 views plain radiograph to show cartilage narrowing, erosions, ostephytes, soft tissue calcifications and pattern of joint involvement
