Exam 2: Lecture 12: Fractures of the Pelvic Limb I Flashcards
What are femoral fractures usually caused by?
trauma
Femoral fractures may occur secondary to pre-existing bone pathologic conditions known as?
pathologic fracture
What is the most common cause of pathologic fractures
primary or metastatic bone tumors
How can we remeber the location of primary or metastatic bone tumors
away from the elbow, towards the knee
- check this to make sure its true but he said it in class (I also have this written down - B)
When pre-existing disease is present _____ _____ and new bone formation occurs in the area of the fracture
cortical lysis
What is the primary bone tumor in animals with primary or metastatic bone tumors?
lytic - proliferative lesions
What does the image show?
Primary or metastatic bone tumor
The most common cause of traumatic femoral fractures are?
high-velocity injuries
What are some examples of high-velocity injuries that are responsible for traumatic femoral fractures?
- most result from HBC
- gunshot injuries
- Blunt trauma
Thorough PE r/o concurrent injuries should be examined in which areas of the animal to rule out life threating problems (Because you need to treat them first)
- thoracic trauma
- coxofemoral luxations
- pelvic girdle injuries
What techniques help detect cardiac or airway abnormalities
thoracic auscultation and percussion
Abnormal heart rhythm and pusle deficiency suggest what issue in animals with trauma
traumatic myocarditis
- this is when the heart gets hit
Lack of normal air movement on auscultation may indicate which issues due to trauma
- pulmonary contusion
- pneumothorax
- diaphragmatic hernia
Thoracic radiographs and electrocardiograms can be done as part of anesthesic preoperative database for patients with high velocity injures. Which electrocardiogram is commonly used?
lead II electrocardiogram
CF luxations may occur with femoral fractures. Dx made when radiographs are taken. Which technique can no longer be used to test the formal head position due to swelling of the limb
palpation or thumb test to check for boney structures / movement / displacement
What needs to be considered when choosing an implant for femur fracture stabilization?
Concurrent fractures or luxations considered when implant chosen for femur fracture stabilization
Pelvic girdle symmetry and what other technique can help determine presence of pelvic fractures
- additional radiographs centered on pelvis if abnormalities found from these 2 techniques
gentle rectal palpation
- ALWAYS DO
If a fracture of the pevlis is found, what should be done next?
carefully assess the urinary tract integrity
Femoral diaphyseal fractures disrupt which function?
continuity of diaphyseal cortical bone
What is defined as fractures of the distal diaphysis
supracondylar fractures
What is the signalment of animals with femoral fractures?
- any age, breed or sex (dog or cat)
- young male dogs most likely for trauma - induced femoral fractures because they are more likely to roam and chase things
History of patients presenting with femoral fractures may include?
- trauma may (or may not) have been observed
- HBC causes most cases of femoral fractures
- gunshots
- falls
What is the most common cause of femoral fractures
HBC
Upon PE animals with femoral fractures would show?
- usually NWB
- varying degrees of limb swelling
- pain and crepitus often elicated with limb manipulation
- Propioceptoin may appear abnormal
Why could propioception appear abnormal upon PE in animals with femoral fractures
- animal may not lift paw when placed on dorsum
- animals reluctance to move limb could be caused by pain
What radiographic views should be taken in an animal with femoral fractures
craniocaudal + lateral
DI may be painful for animals with Femoral fractures. What can be done to ensure the safety/ comfortability of the animals and ensure the best images can be taken?
may require sedation or general anesthesia for proper positioing = quality radiographs
Radiographs can be taken under anesthesia just before surgery, but what does that cause
reduce the time available for planning surgical repair
Why are radiographs or the contralateral limb important for femoral fractrues (3 things)
- useful in assessing normal bone length + shape
- used to contour bone plate more precisely before surgery = reducing operating time
- As reference to select appropriately sized implants
Labatory findings in animals with Femoral fractures may show no consistent labatory abnormalities. But, animals sustaining fratures secondary to trauma need to do what?
need sufficient blood work done to determine appropriate anesthesic regimens + concurrent diseases
What differential diganosis for femoral fractures
- muscle contusion
- CF luxation
- fractures of pelvic girdle
- ligamentous injury to stifle
When can / should you give antibiotics to animals with fractures?
after the tissue / whatever else has been cultured
medical management of animals with femoral fractures include?
- analgesics for post-traumatic pain
- antibiotics to treat open fractures
What is said about casts/splints for femoral fractures
contraindicated for femoral fractures
- adequate stabilization of femur difficult with these methods
Can you splint a femur fracture?
HECK NOOOOOOOO
- he ask this on exams every year
- you can splint a radius fracture though
Surgical treatment of femoral diaphysis fractures include?
- IM pins
- interlocking nails
- IM pins plus ESF
- ESF alone
- bone plates used for femoral diaphysaeal fractures
Implant system for femoral fractures should be based on?
FAS
All affected animals should be examined for concurrent injury and _______ if necessary before surgery
stabilized
Why aren’t femoral fractures usually immobilized preoperatively?
difficulty in applying coaptation splints
In some rare cases when would spica splints be applied for femoral fractures?
preoperative only
Which muscle group helps immobilize bone fragments in animals with femoral fractures
contraction of thoigh muscles
Where should patients be kept while waiting for femoral fracture surgery
patients confined to small area until surgery to decrease movement
- analgesics provided to posttraumatic animals
What dictates the pin sized used in the femur
shape of the femur
How is the feline (cat) femur compared to the canine
- cat femur is straighter
- little to no cranial-to-caudal bend
During surgery normal anatomy of the femuar and surrounding tissues may be less apparent with fractures. What else may make fractured bones difficult to identify
hematomas and serum
Implant applications techniques specific to the femur include?
- IM pins
- interlocking nails
- external skeletal fixation (ESF)
- bone plates and screws
stabilize all forces
What type of placement is defined as:
- cutting pin at level of trochanter
normograde placement
What should we be concerned about with cutting pin at the level of the trochanter (normograde placement)
pin end may injure sciatic nerve
What type of placement is defined as:
- hold femur adducted + help in extension driving IM pins through trochanteric fossa
Retrograde placement
What should we be concerned about when we hold the femur adducted and hip in extension while driving the IM pin through trochanteric fossa?
may injure sciatic nerve
What technique does this show?
interlocking nails
What are the 3 types of principles of orthopedic surgery I and II used for interlocking nails?
Bending
Rotational
Axial
What does this image show
external skeletal fixation
- IM pin combined with type Ia with pin “tied” to fixator
Why is the ESF application to the femur challenging?
surrounding muscle, abdomen and motion of the stifle
An IM pin with type Ia fixator with pin “tied” to fixator is used to?
supply bending, axial and rotational support
Number and type of fixation pins varies based on?
rigidity of fixation needed and length of time fixator stays in place
Which technique is ideal for complex or stable fractures of the femur when prolonged healing is anticipated?
- or when optimal postoperative limb function is needed
Bone plates
Bone plate size depends on?
patient size and plate function
Bone plate and screws may serve as:
- briding plate
- compression plate
- __________________ plate
neutralization plate
What is A
Compression plate
What is B
Neutralization plate
What is C
Bridging plate
+/- IM Pins
What is A
dynamic compression plate
What is B
Limited Contact dynamic compression plate
What is C
Locking compression plate
Does the following image show Compression or Neutralization?
Compression
How does the plate shift using compression
plate shifts towards the left
How does the bone shift using a compression plate
Bone shift right
- towards the fracture
Can the compression plate occur in only one direction or both?
only one direction
With the compression plate where do you place the screw in the mechanism
towards the outerside of the hole - seen in this image
Using the Neutralization plate where do you place the screw
in the center - see the image
How is the screw placed in this image
screw placed in compression mode
How is the screw placed in this image
screw placed in neutral mode
Complications of femur when treatment does not work includes?
- delayed union
- nonunion
- malunion
- osteomyelitis
- Pin tract infection
- Fixation failure
- Sciatic nerve injury with improperly placed IM pins
What is the main complication we have to look out for when placing an IM pin in the femur
sciatic nerve injury
premature loosening + migration of IM pins, ESF pins and cerclage wire are all issues that come from what issue?
poor implant choice relative to fracture assessment
If inappropiate implants or techniques are chosen the implant + bony connection subjected to excessive stress which promotes what?
micromotion at implant-bone interface
If stress is moderate over time then how would the implant expect to remain
stable
Breakage of implants occurs through?
fatigue
With bone plates, complications occur when reduction and stabilization of zone of comminution with cerclage wire or lag screws is _______
unsuccessful
With bone plates reduction and stabilization of zone comminution with cerclage wire or lag screws is unsuccessful. It causes _______ bone fragments = leads to small fracture gaps
devascularized
Small gaps unfavorable for healing
- ________ _______ over small section of bone plate
concentrates stress
Failure to provide adequate rotational stability leads to which issues, even in young animals
delayed union + nonunion
______ IM pins used to stabilize a femoral diaphysis fracture
- results in fracture instability + implant migration
Single IM pin used
Attempting to reconstruct nonreducible fractures destroyes _____ ______ and delayes healing
- contributes to implant failure
biological environment
Where do femoral neck fractures occur
base of the neck where it joints metaphysis of proximal femur
Articular fractures involve _____ surface
joint
What type of fractures occur in trabecular bone at proximal or distal end of the femur
epiphyseal fractures
metaphyseal fractures
Femoral neck-femoral shaft junction in frontal plane is known as?
angle of inclination
What is the normal angle for angle of inclination
135 degrees
- should be approximated when surgical reduction performed
What does this show?
Angle of inclination
_______ is external rotation of proximal femur relative to distal femur
anteversion
What is the normal angle of anteversion degrees?
15 to 20 degrees
What should be taken into consideration when screws or pins inserted into femoral neck
angle
What does this image show
Angle of anteversion
Which approach to the hip is most often used and for capital physeal fractures
craniolateral approach to the hip
If anglement of fracture is difficult for femoral head and neck fractures what procedure should be performed to improve accessability
trochanteric osteotomy
Femoral head + neck fractures are best stabilized with what technique
lag screws
If biological assessment is favorable for femoral head and neck fractures which technique can be used?
K-wire
What is the overall problem in this picture
femoral neck fracture
What does A show?
Lag screws centered between 2 K-wires
What does B show?
Triangulated K-wires
(Divergent K-wire)
What is the overall problem in the picture
femoral condylar fractures
What does A show?
stabilization of femoral unicondylar fracture done with lag screws
What does B show?
repairing bicondylar fracture
- stabilizes condyles with lag screws
- condyles then attached to shaft of femur with steinmann pins (dynamic cross pinning) or bone plate
In this image (B) how would you repair bicondylar fracture
- stabilize condyles with lag screws
- condyles then attached to shaft of femur with steinmann pins (dynamic cross pinning) or bone plate
After surgery, what should be done during post-op care and assessment to evaluate fracture reduction and implant location
postoperative radiographs
- post-operative pain management
- activity restricted to leash walking + physcial rehabilitation until fractured healed
Physical rehabilitation of fractures in the pelvic limb is controlled limb use.
- ________ limb function after fracture healing
- especially important after fractures affecting stifle
- develop customized protocols for each patient
optimizes limb function
Developed customized protocols for each patient depends on what criteria for physical rehabilitation
- fracture location
- stability
- type of fracture fixation
- potential for healing
- abilities + attitudes of patients
- Willingness or ability of client to provide for animals care
Radiographs should be repeated at _____ week intervals until the fracture is healed
6 weeks
Femoral metaphyseal + articular fractures may take how long to heal depending on biological FAS
6 to 12 weeks
When are implants generally removed
never, unless they cause a problem
The most common problem reported with femoral neck fractures are?
inapproprite reduction + poor implant choice
Significant bending + shear stress across fracture plance may place extreme bending loads on ______
implants
What is the most common implant error in animals with fractures of the pelvic limb?
Use K-wires or small pins when fracture assessment indicated prolonged healing
_________ at pin interface from high stress
- may cause pins to loosen early
- avoided by lag screws + antirotational pin
(except when biological assessment indicates rapid healing )
micromotion
How are Femoral neck fractures that fail to heal treated?
FHO
Do intra-articular or extra-articular fractures result in postoperative degenerative joint disease
- minimized w/ careful reduction rigid fixation
intra-articular
What type of fracture involves the joint surface
articular surface
What type of fractures involve growth plates in immature animals
physeal fractures
Which system is used for classification of physeal fractures
salter-harris classification
(BE SURE TO REVIEW)
Femoral physeal fractures mostly affect what age animals
those less than 10 months of age
Are young male or female dogs more likely for trauma resulting in femoral physeal fractures
- because of tendency to roam
young male dogs
What type of cats are at risk for femoral physeal fractures
young heavy male cats neutered before 6 months of age
What does this image show?
VD radiograph of young cat with bilateral capital physeal fractures
Capital physeal injuries may occur without significant trauma. Femoral physeal fractures occur through the ?
cartilage of the growth plate
Capital physeal injuries may occur without significant trauma. This is true in what type of cats?
young heavy male cats neutered before 6 months of age
Delayed physeal closure and cartlage abnormalities may increase susceptibility to what type of fractures?
physeal fractures
Capital physis provides femoral neck length until around _____ months of age
8 months of age
Which area of the physis provides most of the femoral length
distal physis
In most fractures which area is damaged either from traumatic incident, in post-traumatic period or during surgery
growth cartilage damaged
Physeal fractures heal _______. Most often physis does not continue to function
rapidly
The younger or older the animal the more dramatic effect of premature closure of physis
younger the animal
Surgical treatment of femoral physeal fractures is required to prevent?
severe DJD + Lameness
Which surgical treatment of physeal fractures will NOT interfere with any remaining physeal function
anatomic reduction + stabilization with K-wires or small pins (smooth!!)
How do fractures heal with surgical treatment of femoral physeal fractures
these fractures heal rapidly
- smooth implants generally sufficient
What type of implants are generally sufficient to help fractures heal rapidly
smooth
If close to maturity what type of implants are used to increase stability of fixation during surgical treatment of femoral physeal fractures
threaded implants
Anatomic reduction critical for optimal outcome with capital physeal fractures to overall decrease the progression of which disease
DJD
Prevention of movement in which two areas of femoral physeal fractures can be assisted by shape of fractured physeal surfaces
capital physeal + distal physeal fractures
With greater trochanter seperation the physis must be anatomically reduced and stabilized with what technique? This counteracts distractive forces of gluteal muscles
reduced and stabilized with tension band
With greater trochanter seperation the physis must be anatomically reduced and stabilized with tension bands. This counteracts distractive forces of which muscles?
gluteal muscles
What does A show?
3 wires thru femoral neck to fracture surface
What does B show?
reduce fracture and advance wires into epiphysis
Stabilize femoral capital physeal fracture with cortex bone screw (used as a lag screw)
- Place which technique in femoral neck perpendicular to fracture surface
(one proximal and one distal)
Place 2 K-wires
Where do you drill glide holes to help stabilize femoral capital physeal fracture with cortex bone screw
between the K-wires
Reduce fracture and advance K-wires into the ______ ______
- drill thread hole in epiphysis
- measure screw length and tap thread in epiphysis
femoral epiphysis
- then insert lag screws
Are smooth or ridgid K-wires good for growing animals
smooth
What does A show?
Stabilize femoral capital physeal fracture with cortex bone screw (used as a lag screw)
- Place 2 K-wires in the femoral neck perpendicular to fracture surface
(one proximal and one distal)
What does B show?
Reduce fracture and advance K-wires into the femoral epiphysis
- drill thread hole in epiphysis
- measure screw length and tap thread in epiphysis
What does C show?
Insert lag screws
What does this image show
apple coring (thinning of the neck)
- a frequent postop observation
- rarley clinical significance
How is the proximal femoral physeal fracture fixed in this image?
stabilized by K-wire
(6 weeks after surgery)
If proximal physeal fracture is not appropriately reduced or if implants penetrate articular cartilage which developmental diseasemay develop needing additional surgical treatment
significant osteoarthritis
What does A show?
multiple pins placed
- dynamic cross pinning
- little bit of movement
What does B show?
Single IM pin
- the exception
What does C show?
static crossed pins
Why are single intramedually (IM)pins the exception with stabilization of the distal femoral physeal fracture?
beacuse they heal in around 3 weeks
