General Flashcards
What are some of the most predictive factors of death within orthopaedic surgery?
Chronic renal failure, CHF, COPD, hip fractures, and age greater than 70 yrs. Karaeminogullari et al found that hip fracture in patients on chronic hemodialysis had a 2 year mortality rate of 45%.
Causative pathogen of Lyme Disease?
spirochete Borrelia burgdorferi.
Treatment for acute lyme disease?
doxycycline.
What are the three stages of lime disease and how long do they last?
Stage 1: rash 1-30 days after bite.
Stage 2: Neurologic and cardiac. Weeks and months after bite. 15-20% of untreated patients. Lyme cartitis is rare.
Stage 3: Arthritis, usually the knee. Months to years. 60% of untreated patients.
What is different between Bell’s Palsy and CN VII palsy from Lyme disease?
Bilateral 50% in Lyme disease.
What study(s) is used to confirm Lyme disease?
ELISA positive and Western blot Positive.
Vaccination will not have a Western blot.
What is the mechanism of doxycycline?
Inhibits the 30s ribosomal subunit.
Inheritance pattern for Neurofibromatosis type 1?
Mutation?
Autosomal dominant.
NF1 gene.
What percentage of ulcers that probe to bone are associated with osteomyelitis?
Are bone biopsies indicated?
2/3.
Yes, despite us never doing them.
what is the inheritance pattern of achondroplasia?
What is the mutation?
autosomal dominant
FGFR3
What is sequestrum?
The necrotic bone that becomes walled off from its blood supply.
Becomes a nidus for chronic osteomyelitis.
What is involucrum?
A layer of new bone growth outside existing bone.
Seen in osteomyelitis.
What inflammatory marker is most sensitive to monitor therapeutic response to treatment of an infection?
CRP
elevated within 6 hours. ESR rises much more quickly.
Should decline after 48-72 hours of treatment.
Is procalcitonin low or high in the following situations?
Bacterial infection?
Viral infection?
Inflammatory conditions?
High
Low
Low
When is pharmacologic treatmetn of osteoporosis indicated?
DEXA T-score between -1.0 and -2.5 at the femoral neck/spine AND 10 year risk of hip fracture >= 3% OR 10 year risk factore of major osteoporosis-related fracture of >= 20% as calculated by FRAX
DEXA T-score -2.5 or less
Prior hip or vertebral fracture
PATIENTS MUST BE POST-MENOPAUSAL WOMEN OR MEN > 50 YRS
Describe the gait cycle.
What is the difference between CRPS 1 and CRPS 2?
CRPS Type I is symptoms in the entire extremity.
CRPS Type 2 is symptoms in a single nerve distribution.
True or Flase gender is not a risk factor for Elder abuse?
True
Bruises from elder abuse are?
commonly over 5cm in size.
located on the face, neck, or back.
What percen of women experience some form of domestic violence?
males?
Children in homes where domestic violence occurs?
25%
15%
50%
Does a physician have a duty to report domestic abuse?
ethically yes but reporting requirements are not standardized among states.
A physician does not have authority to provide protection to abused spouses in most states.
Where are two common locations for osteomyeltis in dialysis patients?
Spine and ribs.
Most common site of osteomyelitis that occurred by hematogenous spread in adults?
Vertebrae
What is the recurrence rate of despite surgical debridement and long-term antibiotics of osteomyelitis in adults?
30%
What organism is most likely in an IV dug abuser with AC or SC joint infections?
Still Staphylococcus aureus
Pseudomonas.
How much bone loss must there be in acute osteomyelitis before it is evident on plain films?
50%
What is a penumbra sign?
Dark central abscess with bright internal wall and dark external sclerotic rim on T1 sequence of an MRI.
Found in patients with osteomyelitis.
What is the gold standard culture for guiding abx therapy in osteomyelitis?
Bone culture.
What are the benefits of vacuum-assisted wound closure?
Remove insteritital fluids that contain inhibitory factors on healing.
Removal of the excess fluid pulls out excess proteins and electrolytes to help maintain an osmotic and oncotic gradient.
Decreases capillary afterload which promotes better blood inflow.
Micromechanical forces exerted on individual cells causes a release in local growth factors such as VEFG.
What is a common organism in patients with HIV other than staph aureus?
Baronella Henselae
What pathogen is suspected in cases of human bites?
Eikenella corrodens
What WBC count is consistent with a native spetic arthritis?
WBC > 50,000
Gram stains only identify infective organism 1/3 of time
What percent should the glucose level of a joint aspirate be of serum glucose level?
Less than 60%
How much saline for the knee is needed to determine an arthrotomy with 95% sensitivity?
99% sensitivity?
155ml
175ml
How long before Biofilm production usually occurs?
4 weeks.
What is the mortality rate of necrotizing fascitis?
32%
Correlates with time to surgical intervention
What is the most common adult brachial plexus injury?
Complete with involvement of all roots.
75-80% of traumatic brachial plexus injuries.
Do uppper or lower plexus injuries have an improved prognosis?
Upper, becuase they have preservation of hand function.
Recovery of reconstructed plexus can take up to 3 years.
What lesions suggest a preganglionic plexus injury?
Horner syndrome- due to disruption of sympathetic chain.
Winged scapula medially(inferior border goes medially)-loss of serratus anterior(long thoracic) and rhomboids(dorsal scapular nerve)
flail arm but sensory intact
Elevated hemidiaphragm(phrenic nerve)
Lattissimus dorsi, supraspinatus, or infraspinatus injury.
Normal histamine test (C8-T1 sympathetic ganglion)-intact triple response (redness, wheal, flare)
What is normal cervical paraspinal muscle activity on EMG characteristic of?
Post-ganglionic injury.
What does fractures of the first or second rib suggest?
Possible damage to overlying brachial plexus.
What is gold standard for defining a nerve root injury as oppossed to a plexus injury?
CT myelogram. Scan should be done 3-4 weeks after injury. This gives time for blood clot to resorb and characteristic meningocele to form.
MRI for plexus injuries.
What findings on MRI are consistent with brachial plexus injury?
pseudomeningocele. T2 will show increased water content in a pseudomeningocele.
Empty nerve root sleeves. T1 images demostrate the fat in the empy nerve root sleeves
Cord shift away from midline.
What is significant about fibrillation potentials on EMG?
show up when there is denervation.
In plexopathies as early as 10-14 days for proximal muscles and as late as 3-6 weeks in distal muscles.
What are the signigicance of SNAPs in a brachial plexus injury?
What test is needed along with the EMG?
SNAPs = sensory nerve action potentials
Obtained from nerve conduction velocity.
SNAPs are preserved in lesions proximal to dorsal root ganglia. So it helps distinguish preganglionic from postganglionic lesions.
For example if a patient is insensate in the ulnar nerve distribution but has a normal SNAP this is consistent with a preganglionic injury to C8 and T1.
What are nerve action potentials(NAP) used for.
Test the nerve accross a lesion.
Often intraoperative
Can detect reinnervation months before EMG
NAP postivie across a lesion signifies preserved axons or signficant regneration.
What physical exam finding is the best clinical sign of effective nerve regneration in a plexopathy?
Advancin Tinels sign.
What is neurotization?
Nerve transfer
When is immediate surgical exploration indicated for brachial pexus injury?
Sharp penetrating trauma. This doesn’t include gun shots.
Iatrogenic injuries.
Open injuries
Progressive neurologic deficits
Expanding hematoma or vascular injury.
When is delayed surgical intervention indicated for adult brachial plexus injuires(3-6 months)?
Partial upper plexus involvement and low energy mechanism.
Plateau in neurolgic recovery
Do not wait beyond 6 months.
At this point usually invovles tendon/muscle transfers to restore function.
What are the priorities of repair or reconstruction for muscle and tendon transfers in brachial plexus injuries?
Elbow Flexion
Shoulder stability
Brachial thoracic pinch
C6-C7 sensory (lateral cord)
Wrist extension/finger flexion (lateral and posterior cords)
Wrist flexion/finger extension
Intrinsic function
What should be done prior to any surgery on a patient with Marfan Syndrome
Cardiology consultation.
Echocardiogram.
What medication can decrease the risk of aortic dilation in a patient with Marfan Syndrome?
Beta Blockers.
Can intracranial pressure (ICP) be elevated because of pain?
Yes
Are peripheral nerve injuries more common in open or closed fractures?
More common in closed fractures.
How far from the knee joint can a gastrocnemius flap provide coverage?
15cm
Lateral gastroc is generally smaller and has less excursion.
What bacteria do you expect most from a human bite?
Eikenella
What are the cardiac effects of hypothermia?
Initially tachycardia then ->
Decreased BMR, HR. and Cardiac output
Myocardial irritability
Will have an abnormal EKG
What are the neurological effects of hypothermia?
Disorientation, coma
Anaerobic shivering until core temp drops below 30-32
Below this temp shivering stops and muscle rigidity ensues.
Resembles death they have absent respirations, dilated pupils, and rigor mortis
Must rewarmed before pronounced dead.
what is the classification for frostbite?
What treatment is recommended for frostbite?
What is an adjunctive treatment that can be used for severe frostbite with no blood flow on bone scan but has severile contraindications?
Resuscitation with warm I fluids, tetanus prophylaxis, NSAIDs, silver sulfadiazine ointment, topical antibiotics to open wounds, and rapid rewarming with 40-42C water bath with mild antibacterial agent for 30 minutes. Do this until skin becomes pliable and red-purple.
Debride clear blisters.
Drain/aspirate hemorrhagic blisters.
Late debridement/amputation after demarcation occurs at 1-3 months.
intravenous tPA within 24 hours can reduce rates of digital amputations.
What complications are seen from frostbite in adults?
What else can be seen in pediatric patients?
Persistent pain 50%
Cold intolerance
Vasospastic disease that can present late. Can be treated with calcium channel blockers, vasodilators, beta blockers, and surgical sympathectomy.
Joint contractures
Premature growth plate closure that can occur 1-2 years after exposure. Can lead to joint laxity, angular deformities, short digits, excess skin, and degenerative joint changes.
What is classified as a thin, intermediate, and thick ski graft?
Thin- .005-.012 inch
Intermediate- .012-.018
Thick- .018-.030
Should subcutaneous fat be included for full-thickness skin grafts?
No, because it decreases vascular ingrowth and survival.
Takes 2 to 3 days to revascularize.
Describe the regeneration process after nerve transection?
Distal segment undergoes Wallerian degeneration (axoplasm and myelin are degraded distally by phagocytes)
Existing Schwann cells proliferate and line up on basement membrane.
Proximal budding occurs after 1 month delay.
Leads to sprouting axons that migrate at 1mm/day to connect to the distal tube
What factors affect the success of recovery following repair of a peripheral nerve?
#1 Age- Single most important factor
Level of injury- the more distal the better
Sharp transection vs crush
Repair delay- time limit for repair is 18 months.
Free tissue transfer after a severe upper extremity trauma in the upper extremity should occur after how many hours to minimize complications?
72 hours
What is an axial pattern local flap?
Single arteriovenous pedicle (a named vessel)
length-width ratio needed > 2:1
What is a random pattern flap?
Supported by numerous microcirculation with no single arteriovenous pedicle.
Length-width ratio needed < 2:1
What is a venous flap with regards to soft tissue coverage of defects?
uses veins as inflow and outlfow of arterial blood.
Describe following leg muscle flaps in the image reagarding their use, blood supply, and any structures at risk?
Describe the following bone flaps in the image regarding their use and blood supply.
When do most VTE events after major hip or knee surgery occur?
2-6 weeks after surgery.
After hosptial discharge.
What is the optimal timing for stage 2 of the Masquelet technique?
4-6 weeks following stage 1
Highest amount of BMPs, VEGF, and IL-6 expressed from the membrane at that time.
Big advantage of the membrane is that it prevents resorption of the bone graft
What is a complication after a person recovers from heat stroke?
How long can it last?
Heat sensitivity
1 year
What is the definition of heat stroke?
hyperthermia with body temperature above 40.5 degrees celsius
Anhidrosis
Central nervous system dysfunction
Tachypnea
Tachycardia
Heat exhaustion is a core temperature less than 39 celsius with absence of central nervous system dysfunction.
Define the various types of muscle movements and give an example.
For Anaerobic, Glycolytic, and Aerobic define the following:
Energy source
Muscle type
Exercise Duration
What muscle fibers increase over time with endurance training?
Increase in the percentage of more highly oxygenated Type IIA fibers.
With regards to exercise science what is periodization?
Planned variation in intensity and duration of a specific workout over a predefined duration of time.
What is exercise induced laryngeal obstruction (EILO)?
obstruction due to supraglotic(arytenoids and supporting structures) or glottic (vocal cords) level of the larynx.
Diagnosed by a negative bronchodilator reversibility test (with beta2-agonist) and a negative bronchoprovocation test. Both of which would be positive in exercise induced bronchoconstriction.
Muscle strains most commonly occur at what area of the muscle?
What type of contraction does it most commonly occur with?
Myotendinous junction.
Eccentric contraction.
What is the recommended treatment for a partial muscle laceration?
3-5 days of immobilization followed by an exercise and ROM program.
More prolonged immobilization will lead to fatty atrophy and disordered healing.
True or False atrophy is more prominent if immoblization occurs without tension?
Ture.
Quadriceps atrophy greater than hamstrings with knee immobilization in extension.
What is hyphema?
Treatment?
Blood in anterior chamber
May represent vitreous or retinal injury
Place eye patch and refer to ER or Optho.
What are symptoms of retinal detachment?
Bright flashes, stabbing pain, and visual field cut.
Diagnosis and treatment for a corneal abrasion?
Diagnoses with fluorescent stain and UV light.
Treat with topicla antibiotics, topical NSAIDs, eye patch, and nonurgent referral to opthalmologist.
What is traumatic mydriasis?
Treatment?
A transient phenomenon during which the iris fails to contrict properly, resulting in a dilated pupil.
Caused by a contusion to iris sphincter.
Treated with bedrest.
What is commotio cordis?
Disrupted cardiac conduction as a result of a blow to the chest.
More common in young children such as a little league batter hit in the chest with a pitch.
Fatal unless immediate cardiac defibrillation is performed.
What murmur warrants further work-up on pre-participation physical?
Any diastolic murmur warrants further work-up
Grade II or greater systolic murmur.
Which of the following are normal EKG findings in endurance athletes?
Ventricular hypertrophy
Primary AV block
Nonspecific STT- wave changes in the lateral leads on EKG.
Resting sinus bradycardia at 40 beats per minute
True of false hypertrophic cardiomyopathy is an absolute contraindication to vigorous exercise and sports?
True
What murmur is concerning for hypertrophic cardiomyopathy?
A murmur that increaes with standing or valsalva maneuver
Will be a systolic murmur
What is long QT syndrome?
Symptoms
An abnormality of ventricular repolarization that can lead to ventricular tachycardia, torsades de pointes, and sudden cardiac death if not recognized and treated
Symptoms are syncope or near-syncope with exercise.
Diagnosed by ECG.
Return to play on a case by case basis.
Which viscera are more likely to undergo deceleration injuries?
Spleen, liver, and kidnery.
What may cause acute abdominal pain with nausea, vomiting, and pain with active trunk flexion or rotation?
Rectus sheath hematoma.
Symptoms mimic surgical abdomen.
Diagnosis can be made with a CT which can rule out other injuries as well.
Caused by injury to epigastric or intramuscular vessels.
Treat with ice and rest unless symptoms are perisstent.
Will a hematocoele transilluminate?
Hematocoele is a rupture of tunica albuginea (outer covering)
Causes a painful firm scrotal mass
does not transilluminate
Diagnosis with ultrasound.
Treatment observation.
What is initial treatment for small MRSA lesions in athletes?
Mupirocin
Larger lesion Bactrim and rifampin with I&D.