Trauma Flashcards
What is the most commonly injured nerve root in Sacral fractures
S1/2
Denis 3 most common (60%)
28% of neurology overall with any sacral fracture
What is the strongest construct for SI joint fixation
Triangular osteosynthesis > plates > Perc Screws
- involves L5 pedical Screw, screw in ilium and sacrum with bar connection between.
Rate of AVN with hip dislocation
2-17% - increases with time to reduction (>12hr)
Hip Dislocation Clang associations
Posterior
Anterior
Obturator
Posterior - sciatic nerve injury (10-20%)
Anterior - vascular injury
Obturator - obturator nerve palsy
Rate of OA post-traumatic hip dislocation
15-20%
Up to 88% with femoral head or acetabular fracture (JAAOS)
What is the best radiographic view for a posterior hip dislocation
Obturator oblique - can visualize posterior wall for #
Are anterior or posterior femoral head dislocations more commonly associated with head #s
Anterior (68%)
Posterior (7%)
Which approach to the hip has the highest rate of HO
Anterior approach (6-64%)
What are the joint reactive forces across the hip in:
A) Double leg stance
B) single leg stance
A) 0.5x body weight
B) 4x body weight
A cane in the opposite hand can reduce single leg stance forces across the hip by 40%
Anatomic landmarks to ID piriformis muscle in kocher langenback approach
1) fat overlying short ER
2) 135 degree angle to femoral shaft
3) 2cm of tendon
4) small bursa deep to short ER
Indications for tibia plateau ORIF
1) articular depression 2mm-1cm
2) condylar widening >3mm
3) varus/valgus instability (not ligamentous) > 10 degrees
4) bicondylar plateau fractures
Acceptable alignment for non-op adult tibia diaphyseal #s
<5 deg varus
<10 deg A/P angulation
>50% cortical apposition
<1cm shortening
<10 deg rotational alignment
Radiographic Indications of an unstable scaphoid fracture
Displacement >1mm
DISI
RL > 15 deg, SL > 60 deg,
intrascaphoid > 35 deg
Sangeorzan classification
Navicular fractures
1) axial plane fracture
2) dorsolateral to plantermedial fracture
3) comminution o body in Sagittal plane, forefoot laterally displaced
Contraindications to electrical stimulation in non-union
Synovial paeudoarthrosis
Mobile non-unions
Fracture gap > 1cm
Limb deformity order of correction
Angulation
Translation
Length
Rotation
Critical bone defect
> 50% circumferential loss
2cm length lost
Management of post traumatic segmental bone defects
Length(cm)
0.1-1. Shortening
0.5-3. Cancellous bone grafting
2-10. Bone transport
5-12. Free vascularized bone graft
10-30. Amputation
Normal compartment resting pressure
0-4mmHg, 8-10mmHg with exertion
Exertional compartment syndrome diagnostic criteria
Resting pressure >15mmHg
Immediate post exercise is >30mmHg
>15mmHg at 15min post exercise.
Most common compartment syndrome
Proximal 1/3 tibia, transverse, fibula intact - 20% incidence.
Second most common is proximal 1/3 forearm #
