Unit 3 - Chapter 45 Alterations of musculoskeletal fx Flashcards
Direction of fracture line
1) linear - break parallel to long side of bone
2) oblique - break has curved or sloped pattern
3) spiral - one part of bone has been twisted at break point
4) transverse - broken piece of bone is at right angle to long bone’s axis (right across - separating
Incomplete fractures that occur in children
1) greenstick - incomplete fracture (side) d/t bone is bent; occurs most often in children
2) torus - common with falling, as wrist absorbs most of impact and compresses the bony cortex on one side and remains intact on other side (bulging effect around incomplete fracture)
3) bowing (incomplete fracture of tubular longs bones in forearm [radius and ulna] // heal with remodeling
fatigue fracture
- occurs in normal bone
- d/t abnormal stress
normal weightbearing
can cause insufficiency fracture in abnormal bone
Dislocation
- loss of contact between the surfaces of two bones
- subluxation is partial loss of contact between two bones
-
as bone separates from joint it may cause:
1) damage adjacent nerves
2) damaged blood vessels, ligaments, tendons, and muscle
Strains and sprains
- tendon tears (strains) - muscle to bone
- ligament tears (sprains) - bone to bone
- avulsion – complete separation of tendon or ligament from its attachment
Epicondylopathy
- degeneration of tendon where it attaches to bone
Bursitis
- inflammation of bursae (small sac line with synovial membrane and filled with synovial fluid); can be inflammatory, septic, or hemorrhagic
Muscle strain
- mild - severe
- can lose muscle fx
Rhabdomyolysis
- life-threatening complication of severe muscle trauma l/t leakage of muscle cell content into circulation (CK, myoglobin, and various electrolytes)
- may l/t myoglobinuria, presence of myoglobin in urine and associated with acute renal failure / end organ complications
- most common etiologies
1) mechanical trauma or muscle ischemia (crush injury, electric shock, seizure, compartment syndrome)
2) drugs and toxins (statins, antibiotics, anxiolytics, antipsychotics, cocaine, amphetamines, alcohol)
3) infection (influenza a/b, coxasackievirus, staphylococcus aureus) - sx:
1) muscle weakness
2) myalgias (muscle ache and pain - include ligaments, tendons, and fascia (soft tissues that connect muscles, bones, and organs)
3) reddish-brown urine
diagnosis: hx + lab CK (creatine kinase of typically 5 times the upper limit
tx: IV fluids + other
compartment syndrome
1) tissue edema that occurs after injury
2) if edema develops within a closed fascial compartment, typically in anterior or posterior compartment of legs [there is little expansion] => interstitial (compartment) pressure increases
3) if comparment pressure exceeds normal capillary pressure approximately 8 mm Hg, cellular perfusion slows and may stop (can disappear even if pulse is present)
4) tissue ischemia worsens edema in cycle
5) muscles necrose => can l/t rhabdomyolysis, infections, and hyperkalemia
6) loss of limb + death
note – hypotension or arterial insufficiency can compromise tissue perfusion with even mildly elevated compartment pressures can cause or worsen compartment syndrome
* contractures may develop after necrotic tissue heals
causes
* fractures, crush injuries (contusion), perfusion injury after vascualr injury or repair
* others: snakebites, burns, exertion, casts, tight bandages
* prolonged pressure on muscle during coma => rhabdomyolysis
sx
* worsening pain followed by:
* paresthesias, paralysis, pallor, pulselessness
* may feel tense when palpated for compartment and passive stretching can change pain severity
* pain more than expected of severity of apparent injury (consider compartment syndrome)
diagnosis
* >30 mm Hg or within 30 mm Hg of diastolic pressure w/ pressure monitor
tx
* fasciotomy (cutting open inflexible tissue to relieve the pressure) // debride any unviable tissue
* monitor potassium levels
* treat rhabdomyolysis
* cut off constricting structure (cast)
* correct hypotension, analgesia (inability to feel pain), supplemental o2
* amputation may be indicated
Osteoporosis
- bone tissue normal mineralization
- density or mass of bone reduced d/t bone remodeling cycle being disrupted
- progresses silently for decades until fractures occur
- alteration in OPG/RANKL/RANK system
1) PTH stimulate osteoblast to express RANKL ligand on its surfrace which then stimluate osteoclast precursor to become active [has RANK receptors] // PTH inhibits OPG expression from osteoblast
2) OPG is competitor of RANKL and thus blocks it from activating osteoclast
Postmenopausal osteoporosis
- middle aged / OA women
- increased osteoclast activity d/t
1) changes in osteoprotegerin (regulate osteoclasts)
2) degreased IGF levels (insulin-like growth hormone)
3) inadequate dietary calcium intake and lack of vitamin D
4) decreased Mg+ (low mg l/t release of PTH and low mg means bone density is low [60% of bone is mg])
5) lack of exercise
6) lower estrogen (promotes osteoblasts - formation of new bone)
7) family hx
Glucocorticoids
*
increase RANKL expression and inhibit OPG production by osteoblasts => lower bone density
Osteomalacia
- metabolic bone disease
- inadequate bone mineralization
