Lecture 12: Fractures of the Pelvic Limb I (Exam 2) Flashcards
What commonly causes femoral fractures
Trauma
Describe a pathologic fracture
Fracture that may occur secondary to preexisting bone pathologic condition
What is the most common cause of pathologic fractures
Primary or metastatic bone tumors
What can be seen in the radiographs of a pathologic fracture (primary or metastatic)
- Show cortical lysis & new bone formation in the area of fracture
- lytic proliferative lesion (primary bone tumor)
What type of trauma is the most common cause of femoral fractures
- High velocity injuries
- Mostly HBC
What does thoracic auscultation & percussion help detect
Cardiac or airway abnorms
What does abnorm heart rhythm & pulse deficits suggest
Traumatic myocarditis
What can a lack of norm air movement on auscultation indicate
- Pulmonary contusions
- Pneumothorax
- Diaphragmatic hernia
T/F: Proprioception may appear abnorm when the px has a femoral fracture
True
How are contralateral limb radiographs useful
- Assessing norm bone length & shape
- Contour bone plate more precisely before surgery
- A reference to select appropriately sized implants
What are the medical tx used to for femoral fractures
- Analgesics for posttraumatic pain
- Antibiotics to treat open fractures
Are casts & splints used for femoral fractures
- Cantaindicated for femoral fractures
- Adeq stabilization of the femur difficult w/ these methods
What surgical tx is used for femoral diaphyseal fractures
Bone plates
What is normograde placement
- Cutting pin @ the level of the trochanter
- Pin end may injure sciatic nerve
What is retrograde placement
- Hold femur adducted & hip in extension driving IM pin thru the trochanteric fossa
- May injure the sciatic n
What forces are found @ the fracture site that are countered by the use of an interlocking nail
- Bending
- Rotational
- Axial
Why is ESF application to the femur challenging
B/c of the surrounding muscle mass & abdomen and the motion of stifle
What is the IM pin combined w/
Type Ia fixator w/ the pin tied to the fixator
What are bone plates ideal for
For complex or stable fractures of the femur when prolonged healing is anticipated
What may bone plates serve as
- Compression plate
- Neutralization plate
- Bridging plate
Label these plates
Describe compression
What is this showing
What are the common complications that can occur
- Delayed union
- Nonunion
- Malunion
- Osteomyelitis
- Pin tract infection
- Fixation failure
- Sciatic nerve injury w/ improperly placed IM pins
What can cause premature loosening & migration of IM pins, ESF pins, & cerclage wire
Poor implant choice relative to fracture assessment
What can occur if inappropriate implants or tech are chose
- Implant & bony connection subjected to excessive stress (promotes micromotion @ implant bone interface)
- If the stress is moderate over time the implant is expected to remain stable
What can cause breakage of implants
- Occurs through fatigue
- When reduction & stabilization w/ cerclage wire or lag screws is unsuccessful
What can occur if implants break
Devascularized bone fragment
What are common errors that occur
- Failure to provide adeq rotational stability (leads to delayed union & nonunion)
- Single IM pin used (leads to fracture instability & implant migration)
- Attempting to reconstruct nonreducible fractures
What are femoral neck fractures
Occur @ the base of the neck where it joins metaphysis of the proximal femur
What does an articular fracture involve
The joint surface
Where do epiphyseal fractures & metaphyseal fractures occur
In the trabecular bone @ the proximal or distal end of femur
What is the angle of inclination
Femoral neck & femoral shaft junction in the frontal plane
What is anteversion
External rotation of proximal femur relative to distal femur
What is the norm angle of anteversion
15 to 20 degrees
Describe how femoral head & neck fractures are dealt w/
- Craniolateral approach to the hip
- Trochanteric osteotomy performed
- Femoral head & neck fractures best stabilized w/ lag screws
- If biological assessment is favorable K-wires can be used
What is this pic showing
What is this pic showing
Describe controlled limb use for physical rehab
- Optimizes limb function after healing
- Esp important after fractures affecting the stifle
What should be done post op & assessment
- Radiographs repeated @ 6 weeks intervals until the fracture is healed
- Implants are generally not removed unless they cause a prob
What is a common complication w/ femoral head fractures
- caused by inappropriate reduction & poor implant choice which cause extreme bending loads on the implants
What is the most common implant error seen w/ femoral head fractures
Use of k wires or small pins
What can happen if micromotion @ pin bone interface from high stress
- May cause pins to loosen early
- Avoided by lag screws
How are femoral fractures that fail to heal treated
W/ an FHO
How is post intra articular fracture degenerative joint disease minimized
W/ careful reduction rigid fixation
Who is most commonly affected by femoral physeal fractures
- < 10 M
- Young male dogs are more likely for trauma resulting in femoral physeal fracture
- Young heavy male cats neutered before 6 M of age
What is this showing
T/F: Capital physeal injuries only occur w/ significant trauma
False they can occur w/o significant trauma
When does the capital physis stop providing femoral neck length
~ 8 months of age
What provides most of the femoral length
Distal physis
What is true about physeal fractures
They heal rapidly but most often the physis does not continue to function
The younger the animal = ?
The more dramatic effects of the premature closure of the physis
Describe surgical tx of femoral physeal fractures
- Sx is req to prevent severe DJD & lameness
- Anatomic reduction & stabilization will not interfere w/ any remaining physeal function
- Smooth implants are generally sufficient b/c these fractures heal rapidly
What should be done w/ physeal fractures w/ greater trochanter separation
- Physis must be anatomically reduced & stabilized w/ the tension band
- Counteract distractive forces of the gluteal muscles
What is this pic showing
Describe stabilization of proximal femoral physeal fractures w/ lag screws
- Place 2 K wires in the femoral neck perpendicular to fracture surface
- Drill a glide hole btw/ K wires
- Reduce the fracture & advance K wires into the femoral epiphysis
- Insert lag screws
What is a common post op observation seen w/ proximal femoral physeal fracture
- “apple coring”
- Loss of bone density circumferentially on femoral neck
- Rarely has clinical significance
What can happen if the proximal physeal fracture is not appropriately reduced or if implants penetrate articular cartilage
Significant OA may dev needing additional surgical tx
