16- Musculoskeletal Emergencies Flashcards
What are common injury complexes?
certain mechanisms of injury cause injuries/diseases in multiple parts of the body.
Why must you be thorough in your physical exam if you recognize a common injury complex mechanism?
because the patient might only present with foot pain (from a fall), but you have to look into all the body systems because there might be additional injuries that are not causing symptoms
What are the 3 most common causes of spinal cord injuries?
motor vehicle accidents, falls from heights, or gunshot wounds.
Which vertebrae are injured most? Least?
Cervical –> lumbar –> thoracic
What are some Sy/Sx that might show a high risk for spinal cord injury?
pain anywhere along the spine, loss of sensory or motor function or incontinence
Why can cancer increase the risk for compression fractures of the spine?
metastisis can cause spinal bone destruction
How can IV drug use increase the risk for compression fractures of the spine?
it can cause epidural abscesses
How can prior spine surgery increase the risk for compression fractures of the spine?
it makes the spine stiff and weak
What are 3 other things that can increase the risk for compression fractures of the spine?
rheumatic diseases, chronic steroid use and osteoporosis
What is the initial management of spinal cord injury?
IMMOBILIZATION. You need to do this to complete a full neuro exam
What are the 3 X-ray views you need for the cervicals?
AP, lateral and odontoid views
When do you need a CT of the spine following an injury?
patients with identified fractures, neurological deficits without identifiable fractures, pain out of proportion to the injury, or equivocal finding on plain X-rays.
What is a crush injury?
prolonged, continuous pressure on an extremity, usually following collapse of a structure.
How can a crush injury lead to hyperkalemia?
since there is a lot of potassium inside cells (relative to the outside), when cells pop from ischemia a lot of potassium pours out into the interstitum. This leads to hyperkalemia
Which molecules rush into cells when ischemia happens from crush injuries?
there is a large influx of sodium, chloride, calcium and water into the cells.
What molecules enter the blood from muscle cells after a crush injury?
release of muscle cell components can cause hyperkalemia, myoglobinemia, hypocalcemia, hyperhosphatemia, metabolic acidosis and hyperuricemia.
Which molecules increase the risk of renal failure after a crush injury?
K, PO4, and myoglobin from the blood
Acute renal failur with severe crush injuries leads to what % of mortality?
20-40% mortality
What causes the pt to die in acute renal failure from crush injuries?
Cardiac arrhythmias occur because of hyperkalemia and hypocalcemia, and hypoperfusion and hypovolemia also depresses cardiac function.
What are 2 neurological complications with crush injuries?
flaccid paralysis with patchy loss of sensation that mimics a spinal cord injury.
How can you differentiate neurological problems from a peripheral crush injury from that of a spinal cord injury?
spinal cord injuries lead to incontinence.
What is the anatomical makeup extremities that can lead to compartment syndrome?
muscle groups are separated from one another via fascial sheaths. Increased pressure within these closed myofascial spaces causes decreased perfusion and oxygen deprivation. This hurts muscle cells, nerves, blood vessels and the supporting tissue matrix.
What is compartment syndrome?
damage to a tissue from an increase in tissue pressure.
What are the external factors that can cause compartment syndrome?
o Those that reduce the size of the muscle compartment
o Tight casts and splints, various occlusive dressings and eschar of burns
What are the internal factors that can cause compartment syndrome?
o Those that increase the compartment volume.
o Bleeding, tissue swelling, iatrogenic fluid infusion infusion.
What are the 2 signs that a patient might be suffering from compartment syndrome?
pain out of proportion to the injury and pain when passively stretching the muscle.
What is compartment syndrome confirmed?
the measurement of an elevated compartment pressure via a handheld device
What pressure (mmHg) is considered dangerous in a compartment and thus defined as compartment syndrome?
> 40mmHg above normal
What is the treatment of comparment syndrome?
surgical decompression of the compartment.
What is the time limit before permanent myoneural damage occurs in compartment syndrome?
8 hours
What is an open/compound fracture?
any fracture with a puncture wound or laceration to the soft tissue or frank exposure of the bone
How severe is a grade I open Fx?
<1 cm long wound size
Minimal contamination
Low-energy MOI
What are the antibiotic regimens for a grade I open Fx?
1st/2nd cephalosporin 3 days
How severe is a grade II open Fx?
1-10 cm long wound size
Moderate contamination
Moderate MOI
What are the antibiotic regimens for a grade II open Fx?
1st/2nd cephalosporin + aminoglycosides for 3 days
How severe is a grade III open Fx?
>10 cm long wound size High-energy MOI Comminuted Fx Extensive tissue damage Extensive contamination
What are the antibiotic regimens for a grade III open Fx?
1st/2nd cephalosporin + aminoglycosides for 5 days
What % of open fractures have multiple system injuries?
30%
What are the initial treatments for open fractures?
o Removal of obvious debris by irrigation
**o Cover the wound
o Tetanus prophylaxis
**o Antibiotics that cover gram + and gram - bacteria
o Temporarily stabilizing the limb
What are the epidemiologies of pelvic Fx’s?
motor vehicle accidents (MVA’s), motor cycles (murder cycles), and pedestrian collisions.
What is the assocation between the MOI’s and injury complexes to cause pelvic Fx’s?
o Often takes a large MOI to cause pelvic Fx’s so there is usually other injuries present as well.
What are the compliations to pelvic Fx’s?
pelvic compartment syndrome with blood (lots of vessels down there), death from hemorrhagic shock, and damage to the reproductive organs and GI.
Where should the physical exam focus for pelvic Fx’s?
should focus on ecchymosis (bruising), hematomas in perineal or scrotal area, pelvic instability, gross blood at the urethral opening, high-riding or nonpalpable prostate on rectal exam, and vaginal bleeding.
When should you do an angiography for a pelvic Fx pt?
considered for hemodynamically unstable patients believed to have massive bleeding in the pelvis. It can see which vessels are injured so that immediate embolization can be performed.
What are the 2 main causes of long bone fractures?
- Blunt trauma (MVA or fall)
* Penetrating trauma (gunshot wounds)
What are the 3 early complications to long bone Fx’s?
o Blood loss, rarely leading to shock
o Fat embolism syndrome
o Infection
What is fat embolism syndrome?
the release of fat globules into the circulation.
What are the complications with fat embolism syndrome?
progressive respiratory decline, fever, change in mental status and thrombocytopenia.
What are the 3 steps for the initial management of long bone Fx’s?
- Splint, preferably in anatomical alignment to decrease the bleeding and pain.
- Pain medication
- Surgical consultation
How much blood is lost in femur Fx’s?
1.0-1.5 L
How much blood is lost in humerus Fx’s?
0.2-0.5 L
How much blood is lost in tibia/fibula Fx’s?
0.4-0.8 L
How many pt’s visit the hospital every year for bite wounds?
3 million
What type of animals bite the most, from most –> least?
dogs –> cats –> humans/rodents/wild animals
What is a special consideration in human bites?
closed-fist injuries.
What happens in closed-fist injuries?
a closed fist hits another’s mouth and inoculates the wound with oral secretions (spit).
What types of injuries are caused by human and dog bites?
Crush injuries
What types of injuries are caused by cat bites?
Puncture wounds and abrasions
What types of infections could occur following a bite wound?
cellulitis, nectrotizing faciitis, tenosynovitis, septic arthritis, and osteomyelitis.
Which bacteria are mostly at fault for infections post bite?
S. aureus and streptococci in all bite wounds.
Which bacteria is common in cat bites?
Pasturella multocida
Unprovoked animal bites should raise suspicion of what type of infection?
Rabies
Where should the physical exam focus on bite wounds?
o Should focus on the skin, tendons, joints, bones and neurovascular status.
o Signs of flatulence, drainage and erythema indicate infection.
o Closed-fist injuries should be examined for joint involvement and extensor tendon injury
When should radiographs be performed for bite wounds?
to rule out foreign bodies (teeth), presence of air or gas (gangrene) and involvement of the underlying bone.
How should you treat bite wounds?
**• All bite wounds should be irrigated.
**• Necrotic tissue should be débrided (scraped off)
• Bites to extremities might benefit from elevation and immobilization
• If rabies is suspected (cave dogs), active and passive rabies vaccinations should be administered.
• Tetanus prophylaxis should be updated as well.
What is an effusion?
abnormal fluid accumulation in the joint.
Which 2 types of effusions signify an acute condition?
Blood or pus in the joint
Which joints are most commonly effected with joint effusions?
knee, hip, shoulder, wrist, ankle and elbow are most commonly affected.
Which diseases does multiple joint effsions suggest in a pt?
suggests a systemic condition such as gout, pseudo-gout, rheumatoid arthritis, septic arthritis or osteoarthritis.
What is an arthrocentesis?
needle aspiration of joint fluid to determine the cause of the joint swelling and/or relieve symptoms by decompressing the joint.
What should synovial fluid be analyzed for in the lab?
cell count, gram stain, presence of crystals, and culture.
Fat droplets in an effusion signifies what type of etiology?
Joint fracture
What count of WBC’s in joint fluid signifies an infection?
50,000 cells/mm3
What is a dislocation?
when the 2 articular surfaces of a joint are no longer in contact.
What is a subluxation?
occurs when there is only partial contact between articular surfaces, resulting in the disruption of normal joint alignment.
What would happen if you miss a Dx of a dislocation?
if they are missed they can lead to ischemic bone death, permanent neurologic injury and rarely can it lead to amputation.
What happens to the surrounding structures in a dislocation?
around the joint can become impinged, stretched, or lacerated when the bones are suddenly moved out of alignment.
What might occur to the vascular structures in a dislocation?
injury may cause bone ischemia, resulting in osteonecrosis.
What might occur to the neural structures in a dislocation?
injury from impingement can cause neurapraxia (temporary loss of neural function) and paresthesias (tingling, burning or prickly sensations).
How can you avoid the complicaitons of neurological injury and osteonecrosis?
Immediate reduction
What is the most commonly dislocated joint?
Shoulder
Which direction does the shoulder dislocate in >95% of the cases?
Anteriorly
Fractures of what part of the humerus can lead to a posterior dislocation?
lesser tuberosity of the humerus leads to posterior dislocations.
Why can a shoulder chronically dislocate?
large humeral head is in contact with a shallow socket, the ligamentous capsule and rotator cuff muscles play a major role in shoulder stability –> restraints are often torn during a dislocation –> chronic instability
What is the MOI of hip dislocations?
Though the hip is pretty stable, dislocations can occur from high-energy injuries like MVA’s.
Why do hip dislocations usually occur in the posterior direction?
The hip is reinforced anteriorly by the iliofemoral ligament and posteriorly by the ischiofemoral ligament. The ligaments are stronger anteriorly, so most hip dislocations are posterior (85%)
What anatomical position causes a posteriorly dislocated hip?
when the hip and knee are flexed and the extremity experiences an anterior blow to the knee (like when a car passenger’s knee hits the dashboard during a sudden stop or collision)
How can a hip dislocation lead to osteonecrosis of the femoral head?
- Hip dislocations may result in damage to the arterial network supplying the femoral head.
- If there is a long delay in reduction to the hip, there is an increase risk of osteonecrosis to the femoral head.
Which joint usually dislocates at the knee?
patellofemoral joint.
Why doesnt the joint between the femur and the knee occur often?
There are strong ligaments that support it, but when it does happen, there is lots of damage.
What are the complications to a knee dislocation?
The popliteal artery lies behind the knee and is highly susceptible to traction injuries if the knee dislocates.
What is an intimal tear?
reducing a knee dislocation may not resolve an arterial injury because there may be damage to the inner lining of the vessel
What are the physical findings of a shoulder dislocation?
- Squared appearance
- Loss of acromial fullness
- Possible axillary nerve damage
What are the initial management of a shoulder dislocation?
- Closed reduction
- Sling immobilization
What are the physical findings of a hip dislocation?
-Posterior dislocation
(shortened, adducted, flexed, internally rotated)
-Anterior dislocation
(abducted, externally rotated)
What are the initial management of a hip dislocation?
- Immediate closed reduction
- Open reduction if Fx fragments are in the joint
What are the physical findings of a knee dislocation?
- Gross instability
- Possible popliteal artery injury
- Possible compartment syndrome findings.
What are the initial management of a knee dislocation?
- Closed reduction
- Serial vascular examinations
- Surgery for vascular compromise
- Fasciotomy for compartment syndrome.
How can a DVT lead to death?
the development of a pulmonary embolism (PE) and thus result in sudden death.
What 3 things can cause DVT’s (Virchow’s triad)?
at least one of the following 3 factors: venous stasis, endothelial injury, and hyperocagulability.
How can surgery increase the risk for a DVT?
patients are supine, which decreases venous return to the heart, resulting in stasis.
What are the risk factors for DVT’s in surgical pts?
o Casts and splints contribute to venous stasis o Endothelial injury in surgery o Prior DVT’s o CHF o Malignancy o Pregnancy o Oral contraceptives o Certain genetic traits o History of long-term immobilization
What is the process of getting a thrombus to death from a PE?
thrombus forms in the lower extremities –> embolization –> lodge in the pulmonary arteries –> saddle embolus formation –> cardiac failure –> death.
What are the findings on the physical exam for a pt with a DVT?
pain and asymmetric swelling and erythema of the involved extremity.
Does the degree of pain, swelling and redness correlate with the size of the thrombus?
No
What is the initial test to Dx a DVT?
Doppler ultrasound
What is the gold standard to Dx a DVT?
Contrast venography, but it’s invasive and might cause allergic reactions to the contrast.
What are the Sy/Sx of PE’s?
o Dyspnea o Tachypnea o Hypoxia o Pleuritic chest pain o Hemoptysis
What is the intial test to Dx a PE?
Ventilation-perfusion scan is the first-line scan because it compares the pulmonary distribution of the gas to an IV contrast.
What is the gold standard to Dx a PE?
pulmonary angiography, but it’s invasive and uses contrast.
What type of medications are given for the prophyaxis and treatment of DVT’s?
Anticoagulants
What are the meds you can give for the Tx of DVT’s?
unfractionated heparin, LMW heparin, thrombin inhibitors and warfarin.
What is an occult Fx?
A fracture that does not occur on plain X-rays. Delayed diagnosis may be harmful.
Why is a scaphoid Fx unique?
o The scaphoid fracture is unique because its blood supply is derived from the distal aspect of the palmar arterial arch, which enters from the distal aspect of the bone and proceeds proximally.
o An injury to the distal portion of the bone may disrupt the blood supply.
What are the Sx of a scaphoid Fx?
pain and swelling of the hand, wrist or forearm. Snuffbox tenderness, tenderness of the scaphoid tubercle and pain on axial loading of the thumb are indicative of a scaphoid Fx.
How can you Dx a scaphoid Fx?
up to 20% of them do not appear on radiographs, so you need a bone scan and CT in conjunction with a good history.
What is the Tx of a scaphoid Fx?
immobilization
