Mandibular and Maxillary Fractures

1
Mandibular and Maxillary Fractures
2
List 3 considerations in repair of mandibular
fractures caused by the presence of teeth.

• Avoid iatrogenic trauma to teeth and associated
  neurovascular structures
• Remove diseased teeth in fracture line
• Restore correct dental occlusion
• Small malalignments at fx may cause large
  malocclusion

3
How does the blood supply of the mandible
restrict fracture repair, especially of rostral
mandibular fractures?

• Mandibular alveolar artery is sole supply to
  alveolar bone, periodontal ligament and teeth
• Soft tissue attachments in rostral mandible must
  be preserved for revasularization of bone

4
What is the salvage procedure that may be used?

• Rostral mandibulectomy

5
Describe the direction of the fracture line in
stable and unstable fractures of the body of the
mandible.

• Stable
• Unstable

6
When would external coaptation be indicated for a
mandibular fracture?

• Fx of body mandible
• Bilateral or multiple fractures

7
How is this done?

• ???
• Methylmethacrylate external bar is preferred-
  lightweight and versatile
• External coaptation tape tape around muzzle,
  then another piece of tape around back of head to
  muzzle, wrap it around muzzle then tape to back
  of head.????

8
What fracture is most common in the mandible of
the cat?

• Fx of mandibular symphysis

9
How is it repaired?

• Repair with cerclage wire passed through skin
  ventral to jaw, into oral cavity, around
  mandubular symphysis, and out through skin
• Wire is passed through hypodermic needles

10
When would an external fixator be used on the
mandible?

• For bilateral or multiple fractures

11
What are the requirements for owner care?

• Owener must clean pin tracts several times each
  day

12
What is the triad of injuries seen with high-rise
syndrome?

• Thoracic trauma
• Facial trauma
• Fx of extremities

13
Describe postoperative management of the patient
with fractures of the jaw.

• Antibiotics if fx is open
• Feed soft or liquid food for 4-7 days
• NG tube or gastrostomy tube may be indicated,
  esp in cats
• With intraoral wounds or appliances, mouth must
  be rinsed daily

14
Surgical Conditions of the Coxofemoral Joint
15
Speculate on the reason that gt90 of coxofemoral
luxations in dogs and cats occur in a
cranio-dorsal direction.

• joint capsule is more lax in that direction pull
  of gluteals.

16
Can you think of a reason that this joint is
traumatically luxated more often that the
shoulder, although is more stable?

• survive more often if hit that hard, also b/c see
  more bad hips in dogs

17
You see a 6-month-old standard poodle with a
coxofemoral luxation of 3 days duration. No
fractures are present. How should you treat
this dog?

• Perform a closed reduction of the hip
• Externally rotate limb to bring head of femur
  below acetabular rim while applying distal
  traction
• When head clears acetabulum, internally rotate
  limb
• Apply medial pressure while joint is put through
  full range of motion, to clear debris from joint
• Test for stability by lifting femur laterally
• If stable, place in Ehmer sling fro 10-14 days

18
What is the prognosis with your treatment plan?

• Good if less than 24 hours since injury
• Failure of closed reduction is common if greater
  than 24 hours since injury

19
What other treatment options exist?

• Open reduction
• Leave alone

20
What are 2 contraindications to closed
reduction?

• If injury occurred more than 24 hours ago
• In presence of fx or DJD

21
Do these same conditions preclude open
reduction and stabilization?

• No
• But if patient is walking well on limb, do not do
  sx

22
What salvage procedures may be used?

• FHO
• Total hip replacement

23
Why has elimination of hip dysplasia by selective
breeding been unsuccessful in purebred dogs?

• Bc it is a polygenic inheritance its not a gene
  you can select for and breed against it
• Bc if select just for healthy hips will most
  likely loose specific characteristics of the
  specific breed. Specific breed characteristics
  are linked to bad hips

24
What could be done to make such a program more
successful?

• Nothing unless the owner is willing to give up
  the particular breed traits

25
Why is this disease of concern to you as a small
animal practitioner?

• Bc your hands are tied.
• All you can do is help to keep these animals
  comfortable

26
Describe one preventative procedure that is often
done.

• Triple pelvic osteotomy
• Also Pelvic symphodesis (not commonly done)
• Also can be prevented if keep puppy caged
• Early detection with Penn-Hip must be certified
  to do

27
What is the goal of this procedure?

• Triple pelvic osteotomy improves dorsal coverage
  of head of femur by axial rotation and acetabular
  lateralization
• Done on 5-8 month old dogs without radiographic
  evidence of DJD

28
What salvage procedures may be used?
29
What is Legg-Clave-Perthes disease?

• Aseptic necrosis of femoral head
• Hereditary predisposition, conformation,
  infarction of femoral head

30
What is the usual signalment and history
associated with this condition?

• Toy and small breed dogs
• Hx
• Chronic weight bearing lameness
• Acute non weight bearing lameness
• Irritability
• Inappetance
• Chewing at skin over hip
• Usually always unilateral

31
What is its etiology?

• Unknown
• Hereditary predisposition, conformation,
  infarction of femoral head
• Blood supply to femoral head is occluded
• Aseptic necrosis followed by revascularization
  occurs
• Bone becomes weaker and collapses

32
What is the recommended treatment?

• Femoral head and neck excision
• Prognosis very good