Fracture Repair Flashcards
What repairing device is preferred for long oblique fractures and spiral fractures?
Cerclage wire
What repairing device is preferred for short oblique fractures?
Skewer Pin
What repairing device is used for simple fractures of flat, non-weight bearing bones that interdigitate well? Ex: mandibular or maxillary fractures
Interfragmentary wire
What is the preferred method of repair for Salter Harris 1 and/or 2 fracture: simple, transverse fractures close to joints?
cross pinning
How do you repair a Salter Harris type 1 fracture of the femoral at the physis in an 8 month old labrador?
diverging pin technique
What is the best technique to use for repairing avulsion fractures and some osteotomies?
Tension band wire
What technique do you use to repair comminuted fractures in the diaphysis?
Interlocking Nails
What device do you use to repair fractures at articular surfaces?
Lag Screws
What technique do you use for metaphyseal fractures that prevent collapse of adjacent articular surfaces?
Buttress Plate + Lag Screws
What technique is used to repair complicated fractures of tibia and radius, distraction osteogenesis (bone lengthening procedures), and correction of angular limb deformities?
circular fixation devices
T/F: A Spica Splint is used in a patient with medial shoulder luxation?
FALSE! Velpeau Sling is used
What is the characteristic posture and clinical sign of medial compartment disease?
“Toed Out” posture. Pain on flexion and extension
What type of cast is used for lateral, cranial and caudal shoulder luxations?
Spica Splint
A dog is hit by a car and has a traumatic lateral elbow luxation. What type of cast is used?
Spica Splint- holds limb in extension
Name the 3 diseases included in Medial Compartment Disease?
Fractured coronoid process, OCD (medial ridge of talus) and joint incongruity
T/F The treatment for hyperextension injuries is NSAIDS and cage rest, followed by surgery if no improvement is seen within 2 weeks.
FALSE. NSAIDS and cage rest will not help. Surgery is always indicated. Partial carpal arthrodesis or pancarpal arthrodesis
Fractured Coronoid Process is caused by what?
Microtrauma due to incongruity of joint bc of a short radius
Ununited Anconeal Process is caused by what?
Radioulnar incongruity due to a short ulna-> displaces the humeral condyle
Long tarsal collaterals are taut when limb is in extension, flexion or both?
When limb is extended! Think Long collateral Ligaments when limb is Long.
What is the most common joint site for luxations in dogs?
Coxofemoral
T/F: In caudoventral coxofemoral luxation, the affected limb is longer than the unaffected limb and the treatment is Hobbles for 10-14 days following the reduction.
Absolutely.
In craniodorsal luxation of the coxofemoral joint, the affected limb is shorter than the unaffected limb. The treatment is what?
Ehmers sling for 4-14 days
T/F Caudoventral luxation is more common than craniodorsal luxation of coxofemoral joint?
FALSE. Craniodorsal is most common.
Name the characteristic posture of a dog with craniodorsal coxofemoral luxation?
Limb adducted in relaxed extension, stifle externally rotated and foot is drawn under body
T/F: Scapular fractures are most common in young, small breed dogs.
False! common in young, large breed doggies
T/F: Humeral condylar fractures are the more common on the lateral side than on medial side
True! And seen in spaniel breeds
What is a Monteggia Fracture? What type is most common?
Fracture of ulna with displacement of radial head. Type 1 is most common.
T/F: Distal Diaphyseal Fractures of radius/ ulna are most commonly seen in young, large breed dogs?
False, young, small breed dogs. Surgery is indicated! Just putting on a cast will not help.
What pelvic fractures are considered to be the highest priority for surgery?
Acetabulum, Ileal and sacroiliac luxations
A dachshund comes in with spinal fractures. How shocking! What are the 2 most common sites in the spine to look for the fractures?
T3-L3 or L4-L7
For the poor little weiner dog with the spinal fracture, what types of imaging is the most sensitive for evaluating the vertebral column?
MRI or CT
List the 4 common joints and site within the joints affected by OCD:
Shoulder: cranial and lateral humeral head
Elbow: medial humeral condyle
Hock: medial or lateral talar ridge
Stifle: Medial or Lateral femoral condyle
A dog has just come into your emergency clinic. It has a spiral fracture of the left humerus. You go to surgery to fix this. What do you use and how do you use it to correct the fracture?
Cerclage wires (at least 2)
Place them .5 cm from fracture ends perpendicular to the bone. They should be spaced .5-1x the diameter of the bone apart from one another.
Cut wire using 2-3 twists ir 5010mm arm
Do not bend the twist over bc it will loosen the wire
T/F: A dog has a short oblique fracture of the femur. You should use a skewer pin + cerclage wire to repair.
That would be a hard NO. Cannot use skewer pin on femur
Cross Pinning is used for which Salter Harris type fractures?
Types 1 and 2- simple, transverse fractures close to joint
Pins should be ABOVE fracture line
Diverging Pin Technique is used for what salter harris type fractures?
Type 1: proximal humerus or femoral head
T/F: When placing Intramedullary pins, the end point should be at the physis.
FALSE. The end point should be at the metaphysis
How much of the canal should be filled with the IM pin when used with cerclage wire? with plate?
cerclage wire- IM pin should fill 70% of canal diameter
plate- IM pin should fill 35-40% of canal diameter
IM Pins resist what force(s)?
Bending only
T/F: IM Pins cannot be used in the radius?
True. IM Pins are contraindicated for use in radius.
Name the requirements when placing Transfixation Pins:
Pin diameter< 25% of bone diameter
Place pins .5x bone diameter from fracture and from one another.
At least 2 pins per segment required (3 is ideal)
Clamps connect pins and rods at least 1cm from skin
What is the term used to describe the planned decrease of stability for external skeletal fixators? When is this typically started?
Dynamination
6 weeks post op
What type of External Skeletal Fixators is used on the humerus and femur?
1B- unilateral, biplanar. Pins 60-90 degrees from one another and do not go all the way through the bone
External Skeletal Fixators allow bones to heal via primary or secondary bone healing?
Secondary
When using plates, what side of the bone should they be placed on?
The tension side of the bone
What type of plate is used for cases of MIPO and soft, porous bones?
locking plates
Plates overcome which force(s)?
bending and torsion
When using screws, the diameter should be less than ____ % of the diaphyseal bone diameter?
<40%
Which type of screw is best for dense, cortical bone?
Best for ends of bone at metaphyseal and epiphyseal?
Cortical screws best for dense cortical bone. Have decreased outer diameter and increased inner diameter
Cancellour screws best for metaphyseal and epiphyseal bone. Increased outer diameter and decreased inner diameter.
T/F: Dynamic Compression Plates you tighten the screws and it moves the fracture ends closer together
TRUE
Self-tapping screws have the largest core diameter and are thus most resistant to bending force
FALSE. Locking screws have the largest diameter and are most resistant to bending force
LC-DCP have flat surfaces while DCPs have contoured surfaces.
FALSE. LC-DCP have contoured undersides while DCP has flat surfaces.
What type of screw is used for a fragmented humeral head?
Position screws- no comoression across fracture ends is achieved. Allows growth plate to keep growing
What two devices are contraindicated for use in radius?
IM Pins and Interlocking nails
How many screws are required for conventional vs locking plates above and below the fracture?
Conventional: 6 above and 6 below
Locking: 4 cortices above and 4 below
T/F: compression mode may promote primary bone healing?
True
What device and mode is used for MIPO and bioosteosynthesis? What type of healing does this mode promote?
Locking Plate in Bridging mode. Promotes secondary bone healing.
In what mode does the plate bear the entire weightload?
bridging mode
What qualifications must be met to use external coaptation (casts)?
non- articular fractures
greenstick fractures (expected to heal quickly)
fractures below knee or elbow: minimally displaced fractures or those amenable to reduction (transverse, simple, closed)
Name the types of implants that are primary implants:
bone plates, interlocking nails, and External Skeletal Fixators
Name the secondary implants:
K-wires, cerclage wire, interfragmnetary screws
Name the term that describes the measurable (in length) effect of stress.
Strain
T/F: Plastic change is reversible
FALSE. Plastic change is permanent. Elastic is reversible.
What is the term given for the point between elastic and plastic change, when material begins to deform plastically?
Yield point
What is a long oblique fracture?
The length of the fracture is > 2x the diameter of diaphysis
What is the most common bacterial infection of fractures? What antibiotic do you use to treat?
Staph Pseudintermedius
Cephazolin
What two types of Salter Harris fractures may go unnoticed on rads?
I (straight across physeal line) and V (crush/ compression of growth plate)
may interfere with normal growth of long bone
For a CCL tear, how can you tell if it is a craniomedial or caudolateral tear?
Craniomedial: taut in flexion and extension
Caudolateral: taut in extension only
A 8 month old yorkie comes into the clinic with lameness. Her rads show “apple core focal lysis.” What dz is it? How do you treat it?
Legg-Perthes.
FHO is treatment of choice
What type of dogs often get CCL dz?
Large breed F>M Neutered> Intact Parapatellar divot 50% bilateral
Medial Meniscus attaches to?
Tibia
Lateral meniscus attaches cranially to_____ and caudally to _____?
cranially: tibia
caudally: femur
T/F: “Bucket Handle” longitudinal tear is the most common type of meniscal tear
True
What is the most common congenital joint deformity?
Patellar Luxation
Is medial or lateral patellar luxation most common?
Medial. Caused by medial malalignment of quadraceps
Name the 3 common signs of medial patellar luxation:
Medial displacement of tibial tuberosity
Abnormal/ shallow trochlear groove
Hypoplasia of medial condylar ridge
An incomplete fracture is termed a ________ fracture.
Greenstick
T/F: Biological Osteosynthesis promotes primary bone healing.
False. Biological Osteosynthesis promotes secondary bone healing. (Open anatomic reduction/ reconstruction promotes primary bone healing.)
T/F: MIPO could be a good option to use with a complicated fracture of the tibia.
True. She used this as an example.
T/F: DCPs can be used to achieve compression of fracture lengths or to just achieve neutral positioning based on how you place the screws
True.
Which type of plate incurs less disruption of the periosteal vascularity?
LC-DCPs bc they have a contoured underside that distributes stress more evenly across the plate and have less contact with bone
T/F: With locking plates, it is necessary to contour to achieve plate-bone contact for stabile repair
False! Locking plates don’t need to be contoured and fit to bone to ensure stability,
Locking plates are better than non-locking plates for what types of situations?
Locking plates are better for osteoporotic bone, soft bone and comminuted fractures. Most common type of plate to used with MIPO
Lag Screws are placed _______ to the fracture line in ______ or ________ fractures to promote compression of the fracture ends.
Perpendicular: Sagittal or oblique
What “mode” when using plates and screws to heal a fracture is most commonly used for biological osteosynthesis?
Bridging mode. All weight is taken on by the plate at the level of the fracture. Ex. Used with IM pin for a fracture in femur.
What “mode” with plates and screws is used for transverse and short oblique fractures?
Compression mode. May promote primary bone healing.
Buttress Mode is used for fractures in the _______ region of the bone.
Metaphyseal
T/F: Interlocking nails are used to treat diaphyseal comminuted fractures
True
Do interlocking nails achieve primary or secondary bone healing/ biological osteosynthesis?
Secondary healing/ biological osteosynthesis (see calluses- stage of secondary healing). There is no compression along fracture surfaces.
What type of secondary implant is ONLY used on long obliques and spiral fractures?
Cerclage wire!!!
With ESF, the pin diameter should be no more than ____% of the bone diameter. There should be a minimum of ___ pins per bone segment. Normally ____ pins per bone segment is ideal.
With ESF, the pin diameter should be no more than 25% of the bone diameter. There should be a minimum of 2 pins per bone segment. Normally 3 pins per bone segment is ideal.
With ESF, Pins should be placed ____% of the bone diameter away from and fracture and from eachother.
With ESF, Pins should be placed 50% of the bone diameter away from and fracture and from eachother.
T/F: Using acrylic frames with ESF can connect pins in various planes and eliminate the need for fixation clamps.
True! Lightweight and good for use in birds and exotics
Fractures of the humeral condyle are normally on the medial/ lateral aspect of the condyle, and the primary means of fixation are with ________ & ________.
Fractures of the humeral condyle are normally on the LATERAL aspect of the condyle, and the primary means of fixation are with lag screws & anti-rotational wire. (except for Y and T fractures involving the articular surface!!)
Diaphyseal Fractures of the Distal Radius/ Ulna are most common in: young small breed dogs OR young large breed dogs?
Small breed dogs!!!! Seen all the time, and always recommend surgery to be repaired.
When is surgical stabilization of the metacarpals indicated?
When all 4 metacarpals are fractured.
When more than one of the metacarpals are fractured and there is severe displacement.
When metacarpals 3 AND 4 are fractured (weight bearing digits)
Which pelvic fracture doesn’t require surgical stabilization?
a. cranial portion of acetabulum
b. wing of ilium
c. luxation of sacroiliac joint
d. pubis
Fracture of pubis!
Acetabular/ iliac fractures and sacroilial luxations are all involved in weight bearing.
T/F: With the complication of Delayed Union, the fracture line will remain evident on radiographs with “feathery or wooly ends” and no evidence of sclerosis.
TRUE. Also, a callus is visible on radiographs, but may not be as advanced as expected.
What is the difference between viable and non-viable non-union fracture complications?
Viable Non-Union: a biologically active fracture with cartilage and fibrous tissue between fracture ends. Can be difficult to distinguish between viable non- union and delayed union.
Non-Viable Non-Union: fracture ends ate sclerotic with rounded bone edges and visible fracture gap
Quadriceps contracture is a complication with ESF. All of the following is associated with this condition except for:
a) Distal femoral fractures
b) Skeletally mature patients (>8 months)
c) Prolonged immobilization
d) Excessive muscle/ soft tissue trauma
e) Often irreversible
f) Fibrotic tissue replaces muscle and adhesions form between muscle and bone
B) it is seen in young dogs! <6 months
For Femoral fractures, external coaptation/ casting is not a viable option. Need to use internal or external fixation and get the dog into rehab as quickly as possible. Use of NSAIDS can help, but success is rare.

What is the pathogenesis of disuse osteoporosis?
Decrease in stress to the bone results in increased osteoCLAST activity. Seen with excessively strong ESF / implants and external coaptation.
T/F: Ligamentous Laxity as a result of disuse or immobilization is often a non-reversible change.
FALSE. It looks bad, but normally corrects on its own with time.
Name the 4 primary bone neoplasias. What is most common digital neoplasia in dogs? In cats?
- Osteosarcoma
- Chondrosarcoma
- Fibrosarcoma
- Hemangiosarcoma
Digital neoplasia:
Dogs: SCC and Melanoma
Cats: SCC, Fibrosarcoma, Adenosarcoma, Osteosarcoma, Hemangiosracoma
85% of canine skeletal tumors are:______
Where do they occur and who do they occur in?
Osteosarcoma. Large breed dogs are over represented, and there is a bimodal age distribution (18-14 months or >7 years). OSA has a predilection for appendicular skeleton and specifically the metaphyseal region of bones. (away from elbows, towards the knees). Tends to NOT cross joints.
Describe the radiographic changes associated with OSA:
- Corticol lysis
- Periosteal Rxn
- Possible mineralization of surrounding soft tissue
- loss of definition between normal and abnormal bone
- loss of trabecular pattern
What is the gold standard for diagnosing OSA?
Biopsy!!!!! get piece from the CENTER of the lesion, unlike most other types of biopsies in which the edges are impt.
(then repeat rads after biopsy to make sure you didn’t cause a fracture!)
* an increase in ALKP is associated with poorer prognosis
T/F: micrometastasis is common in most patients upon diagnosis of OSA, and the 3 most common sites are Lungs, Liver and other bones.
FALSE: Micrometastasis IS common in most patients upon diagnosis of OSA, but the 3 most common sites are Lungs, Lymph Nodes and other bones.
What is the difference between staging and grading neoplasia?
Staging: Looking at the patient as a whole and seeing how advanced the cancer is in that specific patient
Grading: Looking at the tumor itself- histological examination and seeing what type and degree the tissue is abnormal compared to normal tissue
T/F: Amputation alone increases median survival time in patients with OSA?
False. Amputation alone DOESN’T increase the survival time. (3-4 months). It can control pain though.
BUT! Chemo + Amputation CAN INCREASE median survival time to 9-12 months.
What is the first priority when dealing with an open, traumatic fracture?
Systemic stabilization of patient
Which Salter Harris fracture types put the patient at higher risk of developing osteoarthritis?
Types III & IV bc they involve the articular surface
What are the three characteristic types of strain?
Tensile, shear and compressive
Bending force is a combination of what two types of strain?
compression and tension
What is the term used to describe the point at which at material cannot withstand anymore force and fails.
Ultimate failure point
External coaptation is indicated for use in fractures with all of the following characteristics except:
a) simple, transverse fractures
b) closed fractures
c) fractures expected to heal quickly (greenstick fractures)
d) fractures involving articular surfaces
e) fractures below the knee or elbow
c) Casting is only useful for fractures NOT involving joints
T/F: Articular fractures can be set via closed anatomic reconstruction.
FALSE! Must always use OPEN anatomic reconstruction!
Name the type of procedure described below:
- goal is to return normal alignment and length to limb without disruption of the fracture
- uses fluoroscopy
- requires expertise- involves a steep learning curve
- involves placing implants through incisions distal to fracture
- performed w/o touching the fracture and through closed reduction
MIPO Minimally invasive plate osteosynthesis
Photo of ulna with a fractured anconeal process. How do you treat?
Pin and tension band
There is a fracture of the tibial tuberosity of the femoral head. Primary or Secondary bone healing indicated in this situation?
Primary bc it is at a joint surface.
A dog has been hit by a car and has a traumatic open fracture of his forelimb. There is significant debridement of soft tissue and not enough tissue remains to completely cover the wound. How do you repair this?
External Skeletal Fixation is always required in situation in open traumatic fractures of limbs in which so much soft tissue has been lost that the wound cannot be covered.
A closed femoral fracture- simple, transverse, through the diaphysis would be treated with what:
a. a plate
b. IM pins and cerclage wire
c. ESF
d. external coaptation
e: skewer pin
a. a plate.
skewer pins are the same as IM Pins + cerclage wire. Cannot be used in the femur and also this isn’t an oblique fracture.
Casts are only used for fractures below the knee or elbow.
ESF is not used on the femur?
A type ____ ESF is unilateral and biplanar- pins are inserted 60-90 degrees from one another and do not penetrate all the way through the bone.
Type 1B
A type 1B ESF can only be used in what two bones?
Femur and Humerus
