Trauma Conf./Education Flashcards
What is impairment?
Loss of use or derangement of any body part, system or function. Impairments are determined on the basis of a physical exam by a physician.
What is disability?
The loss of an individuals capacity to meet personal, social or occupational demands because of impairment. It is the gap between what a person can do and what they need or wan to do.
What is osteoprotegrin?
Osteoprotegerin is a decoy receptor for RANKL. Binding to RANKL causes decreased production of osteoclasts by inhibiting the differentiation of osteoclast precursors.
What is osteocalcin?
“Osteocalcin is the most prevalent noncollagenous protein in bone” (from Miller’s Review). It is expressed by mature osteoblasts and is a marker of osteoblast differentiation. Osteocalcin is the most specific marker of the osteoblast phenotype and is expressed only in mature osteoblasts. During osteoporosis treatment, serum levels correlate with increases in bone mineral density. Osteonectin, not osteocalcin, is a glycoprotein that binds calcium.
Cervical facet dislocations are caused by what mechanism?
flexion/distraction injury
Describe the ASIA (American Spinal Injury Association) classification
The ASIA system describes the exam below the level of the injury. ASIA A: Complete. No motor or sensory ASIA B: Incomplete. No motor function but some remaining sensory ASIA C: Incomplete. 50% or more of muscles below injury are less than Grade 3. ASIA D: Incomplete. 50% or more of muscles below injury are equal to or greater than Grade 3. ASIA E: Normal
What do synovial type B cells produce?
Synovial fluid
What is key to understanding the meaning of an intact bulbocavernosus reflex?
If the bulbocavernosus reflex is intact then the patient is no longer in spinal shock and we can determine a final classification of their spinal cord injury pattern. If the bulbocavernosus reflex is absent, then it is possible the patient is in a state of spinal shock, and therefore we can not classify his final spinal cord injury pattern
Describe the mechanism by which osteoprotegerin (OPG) plays a role in RANKL-mediated osteoclast bone resorption?
Osteoprotegerin (OPG) acts as a decoy receptor by binding to RANKL and blocking the interaction between RANKL and the RANK-receptor and consequently inhibiting osteoclast formation and activation
How is an inlet view of the AP pelvis taken?
Pt supine, tube directed 60 deg caudal, perpendicular to pelvic brim
What is the usefulness of the inlet view?
Determining ant or post displacement of SI joint, sacrum or iliac wing. Also helps to determine internal and external rotation and sacral impaction injuries
How do you know when you have an adequate inlet view?
When S1 body overlaps S2 body
What is this?
Inlet view pelvis
What is this?
Outlet view pelvis
How do you know when you have an adequate outlet view of pelvis?
When the pubic symphysis overlies S2 body
How is an outlet view of pelvis taken?
Pt supine with tube directed 45 deg cephalad.
What is the usefulness of an outlet view of a pelvis?
Shows vertical displacement of hemipelvis. Allow for further visualization of subtle sigs of pelvic disruption like wide SI joint, sacral fx, or disruption of the sacral foramina
What are some radiographic signs of pelvic ring instability?
- SI displacement of 5mm in any direction
- Post fracture gap (rather than impaction)
- Avulsion of 5th lumbar TP (iliolumbar lig), lateral border of sacrum (sacrotuberous ligament), ischial spine avulsion fx (sacrospinout lig)
What is a lateral comprssion pelvic ring injury?
Implosion injury of the pelvis secondary to laterally applied force that shortens the ant SI, sacrospinous, and sacrotuberous lig. May see oblique or transverse fx of ipsilateral OR contralateral rami.
What is a type LC I injury?
Sacral impaction on side of impact with or without transverse fx of pubic rami
What is the treatment of an LC I injury?
NON op. Protected weight bearing
What is an LC 2 fracture?
Lateral force with rami fx and ipsilateral post iliac wing (crescent fracture) on side of impact. It is vertically stable.
Treatment for LC II?
ORIF of iliac wing fx
What is an LC III fracture?
Ipsilateral lateral compression and contralateral APC (windswept pelvis).
Common mechanism is rollover vehicle accident or pedestrian vs auto.
Treatment for LC III?
Posterior stabilization with plate or SI screws as needed. Percutaneous or open based on injury pattern and surgeon preference
Define APC I injury
less than 2.5 cm symphyseal diastasis. Vertical fx of one or both rami occur w/intact post ligaments
Define APC II injury
Symphysis widening > 2.5 cm. Anterior SI joint diastasis . Posterior SI ligaments intact. Disruption of sacrospinous and sacrotuberous ligaments and ant SI ligs.
Treatment for APC I
Non op. Protected weight bearing
Treatment for APC II
Anterior symphyseal plate or external fixator +/- posterior fixation
Define APC III
Disruption of anterior and posterior SI ligaments (SI dislocation). Disruption of sacrospinous and sacrotuberous ligaments.
APCIII associated with vascular injury
Treatment for APC III
Anterior symphyseal multi-hole plate or external fixator and posterior stabilization with SI screws or plate/screws
What are the main goals in ORIF of a pilon fracture?
Anatomic joint reduction, restore length, reconstruct metaphyseal shell, bone graft, reattatch metaphysis to diaphysis
What are the steps of ORIF of a pilon fracture?
Restore fibula length to reestablsih lateral column, reduce articular surface (compare to conralateral side to see normal joint), attatch articular surface/metaphysis to shaft
What are the names of the major fragments in a comminuted distal Tibia (pilon) fracture?
Anterolateral piece is chaput fragment attached to ant/inf tib/fib ligament. Posterolateral piece is called Volkmann’s
What 4 ligaments make up the syndesmotic ligament?
Ant. Inferior tib/fib ligament, post. Inferior tib/fib ligament (thicker and stronger than ant), transverse tibiofibular ligament, interosseous ligament
What is Silverskiold test?
A test used to differentiate between tight gastroc and achilles tendon contracture
In which Condyle is a Hoffa Fragment more frequently seen?
Lateral.
http://www.orthobullets.com/testview?qid=181&ans=4
What are absolute indications for ORIF of humeral shaft fx?
Open fx with severe soft tissue injury, Vascular injury requiring repair, ipsilateral brachial plexus injury. The reason brachial plexus inj is absolute is because they often go on to nonunio w/out ORIF bc of lack of muscular support for fx
What is the algorithm for treatment of knee dislocations?
Rihn et al. outlined the treatment algorithm for acutely dislocated knees. If pulses return after reduction, radiographs and evaluation of ABI are indicated. If ABI<0.9, CT angiography or formal angiography is indicated. If ABI >0.9, a period of in-hospital observation is indicated. If pulses remain absent and the limb remains ischemic following reduction, emergent surgical exploration and revascularization in the operating room is necessary. The spanning external fixator supplies enough rigidity to maintain reduction and allows access for serial neurovascular examinations.
Who commonly gets central cord syndrome and what is mostly affected?
Seen in elderly pts with pre-existing cervical spondylosis. Usually from hyperextension injury. Usually motor affected more than sensory and upper ext more than lower.
What is Chi squared test for?
The Chi-square test is most appropriately used for comparing proportions of categorical or ordinal data. Fisher test is preferred when <5 data points
Definitions of delayed union and non-union?
Delayed is lack of union 20-26 wks post injury. Non union is lack of healing >9 mo post injuy or lack of progressive signs of healing on radiographs for 3 consecutive months. Order ESR and CRP t r/o infection
What cell produces RANKL?
Osteoblast. OPG binds to it so RANKL can’t bind to the receptor on the osteoclast and prevents activation
What is the function of calcitonin?
Binds to osteoclast to inhibit absorption. Also increases release of OPG to prevent osteoclast activation
Which immunoglobulin does rheumatoid factor bind to?
Rheumatoid factor is an IgM that attaches to IgG to form immune complexes
Classic radiographic image associated with psoriatic arthritis?
Pencil in Cup. This is a seronegative spondyloarthropathy. HLAB27. Sausage digit (dactylitis), They should get an optho referal for uveitis.
Function of homeobox gene products?
regulate somatization of the axial skeleton
Function of cathepsin K?
an enzyme produced and released by osteoclast at ruffled border to resorb bone.
Which bone graft substitute has fastest resporption?
Calcium sulfate>tricalcium phosphate>hydroxyapatite
This is why you may seen draining issues with the calcium sulfate
SHII fracture is most likely to occur in which cartilage zone?
Zone of provisional calcification
SCFE, RIckets, SED, MED all occur in the hypertrophic zone.
Peak bone mass in men and women is most influenced by what hormone/sex steroid?
Estrogen. It prevents bone loss by inhibiting bone resorption.
Differences in primary and secondary bone healing
Primary bone healing: no callus, absolute stability constrct, cutting cones
Secondary: with callus, relative stability (IMN), healing through endochondral healing
Pts with chronic renal disease have what changes in PTH?
Increased release. Dec calcium and hyperphosphatemia
Hypophosphatasia leads to what changes in alk phos?
Dec serum alk phos levels.
Tumor antigens: for colon, pancreatic, ovarian, breast and hepatocellular
CEA: colon ca
CA19-9: pancreatic
CA-125 ovarian
CA 15-3 : breast
AFP: hepatocellular
Who is best candidate for myoelectric prostheses?
Transradial amputation
Types of corrosion:
Crevice: oxygen tension
Fretting: load and force. contact site between 2 elements under load
Pitting:
Galvanic: difference in electric potential of 2 different metals that contact each other
Lead toxicity affects growth by inhibiting what factor?
May see basophilic stippling and peripheral n palsies (radial n)
It inhibits PTHr-P and TGF-beta
Which anticoagulant affects clotting cascade by inhibiting factors through gamma decarboxylation?
Warfarin.
Heparin inhibit Xa through ATIII and Thrombin
Pathognomonic sign of fat embolism syndrome
Petechial rash to upper aspect of body…fat floats.
Also goes to brain causing nerulogic symptoms, can cause ARDS
Pts may have immediate symptoms and then a period of no symptoms. (asymptomatic interval for 24-72 hrs)
Where are bisphosphanates excreted?
Kidneys (Bisphosph…Beans)
The distance between threads on a screw is known as what?
Pitch
The distance advanced by one revolution of a screw is what?
Lead
Fractures that are reduced with relative stability constructs heal with what type of bone healing?
Endochondral
