OITE - Trauma Flashcards
Single most important factor for increased risk of infection in open LE fx? Study?
Time to transfer to a definitive trauma centre (LEAP study)
Utility of obturator-oblique INLET view?
Supra-acetabular screw/pin placement relative to tables of the ilium
Utility of Iliac-oblique INLET view?
AP position of superior ramus screws
LISS? Where holes place SPN at risk?
1-Less invasive stabilization system (synthes)
2-Holes 11 to 13
Distance from tip of acromion to axillary nerve?
7cm
Axillary nerve innervates which 2 muscles?
Exits which space, with what structure?
1-Deltoid, Teres minor
2-Quadrangular space, with posterior humeral circumflex art.
3 possible mal-alignment complications of tibia fx IMN?
Valgus, procurvatum, anterior translation of proximal fragment.
One technique to maintain reduction while placing IMN for tibia fracture?
Anterior uni-cortical plating
Indication for buttress plating in a tib plateau fx?
Simple partial articular. Not for articular depressed fx.
Locked plating indicated for?
1-Intra-articular fx
2-osteoporotic bone
3-comminuted fx needing bridging
Most common complication of proximal humerus locking plate construct, for 2- part fx?
Screw penetration (or cut out)
Second most common complication of prox-humeral fx ORIF with locked plating?
Varus displacement
Two recommended views for AP orientation in sacral screw placement?
1-Lateral sacral view
2-Pelvic inlet view
Recommended views for Sup-Inferior orientation in sacral screw placement?
Pelvic outlet view
Proximal locking screws for femur IMN, above or below LT?
Safer above LT, danger if within 4-5 cm below LT.
Dangers: Profunda femoral artery, femoral nerve
The 5 simple acetabular fractures?
1-Posterior column
2-Posterior wall
3-Anterior column
4-Anterior wall 5-Transverse
The 5 associated acetabular fracture patterns?
1-T-type. 2-Transverse and posterior wall
3-Post column and posterior wall
4-Anterior and posterior hemi-transverse
5-Associated both column (ABC)
Surgical access for posterior wall and column fractures?
Kocher-Langenbeck
Surgical approach for both column fractures?
Extended ilio-femoral
Surgical approach for anterior wall, or anterior column fracture?
Ilio-inguinal approach
Surgical approach for Anterior column as well as the internal aspect of the iliac wing and quadrilateral plate?
Modified stoppa
Anterior cortex penetration of femur by IMN, due to lesser or greater radius of curvature?
Greater radius of curvature (ie. straighter nail)
Valgus IT osteotomy, converts what to what? (2 points)
1-vertical fracture non-union to horizontal
2-Shear force to compressive force
Denis Zone 3 sacral fx?
Medial to sacral foramina, highest rate of nerve injury (56%)
Denis Zone 2 sacral fx?
Through sacral foramina
DR fx + ulnar styloid fx, do you fix or not fix ulnar styloid fx too?
No difference on wrist stability or function, if not fixed
Which posterior wall fx are deemed unstable (ie percentage involved)? Stable?
Unstable: 40-50% involvement of posterior wall
Stable: less than 20%
Unknown: 20 to 40%
To prevent procurvatum in proximal tibial fx IMN, what intra-op technique?
Posterior blocking screws in proximal tibial segment
Advantage to ORIF of mid-shaft clavicle fx?
1-Faster time to union
2-Decreased rate of non-union
3-Decreased rate of symptomatic mal-union
TAD (tip to apex distance) measurement?
Summation of the distance between the end of the screw and the apex of the femoral head on AP and lateral radiographs
Ideal TAD?
Right or left sided IT fx at increased risk of proximal fragment mal reduction, due to SHS?
Left sided, as clockwise torque of SHS causes flexion deformity.
Proximal humerus GT fx, associated with what kind of dislocation?
Anterior dislocation
Proximal humerus LESSER Troch fx, associated with what kind of dislocation?
posterior dislocation
3 reasons to restore length, alignment, rotation of fibula fx?
1-reduction of talus
2-buttress to talar motion (if incompetent deltoid)
3-allow syndesmotic ligs to heal with appropriate tension
Stress fx appearance on MRI?
Decreased signal on T1
Increased signal on T2
Structure most at risk with antero-lateral acromial approach?
Axillary nerve
Distance of axillary nerve from GT prominence?
35 mm
Subcapital neck fx, optimal cannulated screw config?
1-Inverted triangle
2-Inferior screw posterior to midline and adjacent to calcar
Which structure most important to pelvic ring stability, anterior or posterior SI ligaments?
Posterior
Difference between APC 2 and APC 3 injuries?
Posterior SI-ligaments spared in APC 2, injured in APC 3
Best predictor of improved patient outcome post acetab fx orif?
Post-op hip strength, regardless of surgical approach
BTT (brake travel time) after LE fx, increases or decreases?
Increases up to 6 weeks after initiation of weight bearing (both long bone and articular fx) of Right LE.
BTT returns to normal when post long-bone or articular LE fx?
By 9 weeks after initiation of weight bearing.
3 principles needed for tension band construct?
1-Eccentrically loaded bone
2-Construct applied to tensile side
3-Opposite cortex must withstand compressive forces
Deforming forces on proximal fragment in subtroch hip fx?
1-Flexion (iliopsoas)
2-Abducted (TFL, glut med)
3-ER (piriformis)
Reduction maneuver for proximal fragment displacement in sub-troch hip fx?
Extension, ADDuction, internal rotation
Which tendon can be used to adequate assess humeral height in shoulder arthroplasty?
1-Pec Major tendon
Distance between top of humeral head, and superior edge of pec major tendon?
5.6 cm
Classification for femoral head fx?
Pipkin classification
What is a Pipkin II femoral head fx?
Supra-foveal
Needs surgical fixation
Crescent fx of iliac wing, what type of pelvic injury?
LC type 2 (Young-Burgess classification)
Most common position of talar neck mal-union?
Varus, leading to diminished subtalar and forefoot motion
Exam under anaesthesia for post-wall fx instability, what is the best xray view?
Obturator oblique view
Tibial IMN insertion technique to ensure perfect alignment?
Critical that nail is parallel to lateral and anterior cortex
Where do blocking (Poller) screws go in tibial IMN?
- Concave side of deformity
- i.e. where you don’t want the nail to go
Flexion procurvatum deformity is typically a result of what?
Extensor mechanism of the knee
What is the semi-extended nailing technique?
-Patella subluxed, allowing access to insertion site at 15 deg knee oflexion
What leg position exerts lease intraneural pressure (stretch) on sciatic nerve in Kocker-Langenback approach?
Extend the hip
Flex the knee
Ileopectineal disrupted?
Anterior column
Ilioischial line disrupted?
Posterior column
IOWA mnemonic?
Iliac oblique wall anteior
What correlates most closely with good outcome post ORIF of posterior wall fx?
Quality of reduction
and degree of displacement on post op Pelvic CT scan
Pelvic spur sign is pathognomonic for what injury?
Both column fx
=dissociation of articular surface from innominate bone / axial skeleton
What is the actual spur, in the spur sign?
Intact portion of the ilium , still attached to axial skeleton
(seen postero-superior to displaced acetabulum)
What is the Lauge-Hanser classification short form?
PA/PER/SA/SER
Pro/adduction
Pro/external rotation
Vertical shear component of medial mal ankle fx, is pathognomonic for which L-H class?
Supination adduction (SA) injury
Comminuted fibula fx more likely in which L-H ankle fx?
Pronation abduction (PA) ankle injury
1 mm shift of talus lateral decreaess tibio-talar contact area by how much?
42%
Syndesmosis instability is greatest in which plane?
A to P plane (rather than M-L)
Antegrade femoral IMN nail with fx table rather than manual traction leads to what?
- Higher percentage of internal rotation deformities
- longer OR time
- more fluoro time
What is the most common femoral shaft deformity with IMN via piriformis fossa, patient SUPINE?
Internal rotation deformity
What is the most common femoral shaft deformity with IMN via piriformis fossa, patient LATERAL?
External rotation deformity
What 2 factors tend to increase rotational mal-alignmnent in femoral shaft IMN?
- night time surgery
- increased fx communition
What are 2 iatrogenic fx etiologies in fem shaft IMN?
- Failure to overream canal by atleast 0.5mm
- Antegrade starting point that is >6mm anterior to the intramedullary axis
Incidence of concomitant proximal femur neck fx, with ipsilateral femur shaft fx?
Ipsilateral femoral neck-shaft combo in upto 9%
Incidence of osteonecrosis with femoral neck fx? Increased risk with?
10-45%
High risk with - non-anatomic reduction, increased time to reduction, increased initial displacement
What has a higher dislocation rate THA or hemiarthroplasty for femoral neck fx?
7x higher than with THA (10%)
What kind of malreduction most closely correlates with failure of fixation after reduction and cannulated screw fixation, of fem neck fx?
Varus mal-reduction
Non-union rate 5-30%
Indications for THA for femoral neck fx?
-Older ACTIVE pt with pre-existing hip OA
more predictable pain relief and better function
Outlet view allows viewing?
- Avoid S1 exiting foramina
- Vertical displacement, SI joint widening
Inlet view
- Avoid L5 nerve root
- AP displacement
Lateral sacral view allows?
- Most important intra-op view for SI screw
- Avoid alar slope
- Transverse sacral fx
Benefit of outlet obturator oblique (O-O-O) image?
Supra-acetabular pin placement
-starting point is the confluence running from ASIS to AIIS
Markers of adequate fluid resuscitation?
Most important :
-Base deficit 60, UOP 0.5-1 ml/kg/hr, HR
What does compensated shock mean?
Underresuscitated patient (beware) Increased IL-6 levels
What percentage of normal circulating blood loss is needed for a patient to become tachycardic with a narrowed pulse pressure?
Class 2 to Class 3 hemorrhagic shock is when you being having HD instability, needs (15-30% blood loss)
What triad in a polytrauma patient is bad?
- Head injury
- Femur fx
- Hypotension
Two key technical points in shoulder hemi-arthroplasty (for prox hum fx)?
-restore head height & retroversion
reference sup border of pec major, 5.6cm
What are 2 possible technical problems with shoulder hemi-arthroplasty?
-Tuberosity mal-position (KEY concept) restricts motion/rotation
10mm below articular surface
If too high, decreased abduction & elevation
-Tuberosity non-union (restricts overhead motion)
Acceptable parameters for humeral shaft fx, for non-op mgt?
20 deg a-p angulation
30 deg V/V
What would you consider if >6cm non-union in humeral shaft fx?
Plate & graft with vascularized free fibula
Recovery of radial nerve palsy/neuropraxia in hum shaft fx?
70% recover within 3 mos, 95% within 4 months
What kind of radial nerve injury:
a) Transverse humeral shaft fx ?
b) Distal 1/3 spiral
a) neuropraxia
b) laceration / entrapment (Holstein-Lewis fragment)
How do you interpret EMG/NCV at 6 weeks for radial nerve palsy?
Fasciculations –> continued observation
Denervation (fibrillations) –> exploration
Non-op mgt of ulna fx?
Distal 2/3rd fx,
When is grafting indicating in ORIF for BBFA?
Grafting if only failure of bone contact/gap. Not comminution
Tension band construct for olecranon fx, indications?
Stable and not comminuted.
If comminuted –> excision upto 50% and reattach triceps
If olecranon fx that is comminuted or unstable, with extension into the coronoid, mgt?
ORIF + plate (not tension band)
In a medial compartment fasciotomy, what must you ensure to do with soleus?
Medially, must take down soleus insertion to access deep compartment
Risk with proximal peri-fibular approach in fasciotomy, SPN or CPN?
CPN
SPN is at risk more distally (and lateral)
Is early mobilization a risk for non-union for ORIF clavicle?
NO, no effect.
What type Schatzker classification has the highest rate of meniscal and vascular injury?
- Type 4
- acts like knee dislocation
What type Schatzker are ACL injuries most common?
Type 5 and 6
What variable is most important preidctor of long term outcomes with Tib plateau ORIF?
Restoration of joint stability (limb mechanical axis)
In talar neck fx, varus malunion, how is the subtalar ROM altered?
- residual decreased subtalar eversion
- Stands on the lateral border of the foot
What can lead to varus malunion in talar neck fx? Tx?
Medial comminution, or over-compressing the medial side
Tx with triple arthrodesis
Dorsal impingment post tx of talar neck fx, what kind of malunion?
Dorsal malunion
Caphut fragment in tibial plafond fx?
Anterior-inferior tib-fib ligament
Volkmann’s fragment?
Posterior-inferior tib-fib ligament
Sliding hip compression screw is contra-indicated in what type of IT hip fx?
Reverse obliquity fracture
What is the most frequent intra-op complication with ante-grade nailing of subtroch fem fx?
Varus and procurvatum (or flexion) malreduction
