Fractures - Answers

Arlo Guthrie — Tue, 21 Apr 2009 10:06:09 GMT

Current Revision posted to Revision Guide For Student Nurses - Part 2 by Arlo Guthrie on 4/21/2009 10:06:09 AM

ANSWERS

What is the term that describes a fracture resulting from the normal use of a bone weakened by a disease process?
A pathological fracture.
List 8 signs or symptoms that may be displayed by an animal suffering a fractured limb bone.
- Inflammation/swelling.
- Heat.
- Pain (and associated signs such as vocalisation, depression and/or aggression).
- Contusions.
- Lameness/abnormal mobility/guarding of the affected limb.
- Loss of function.
- Visible or palpable deformity of the affected limb.
- Crepitus.
Briefly describe the principles of fracture first aid.
- Ensure adequate restraint.
- Prioritise treatment remember the first aid A-B-C.
- Treat shock - administer fluid therapy and ensure that the animal is kept warm.
- Cover any open wounds with clean, sterile dressings.
- Immobilise the fracture before attempting to move the animal.
- Control haemorrhage.
- Perform a full clinical examination.
- Administer drugs in accordance with the directions of the veterinary surgeon.
State the 3 main indications for fracture fixation.
- Pain relief.
- Prevention of displacement of the bone fragments in order to provide accurate anatomical reduction.
- Prevention of movement that may delay healing or cause non-union.
What is the name of the large support dressing often used to immobilise a fractured limb in a first aid situation?
Robert Jones dressing.
What should always be performed in cases of a suspected fracture?
Radiography; in order to confirm the diagnosis.
What is the name given to a fracture affecting the mid-shaft of a bone?
Diaphyseal fracture.
What is a physeal fracture?
A fracture through the growth plate of an immature animal.
By what name is a physeal fracture also known?
Salter Harris fracture.
What part of the body is most likely to be affected by a depressed fracture?
The skull.
What is a greenstick fracture?
An incomplete fracture where the bone is fissured, but the fragments are not completely separated by the fracture line. This type of fracture is most common in immature animals.
What is the difference between a compound and a complicated fracture?
A compound fracture is one in which there is a wound communicating between the skin or mucous membranes and the fracture site, whilst a complicated fracture is one in which important structures or organs around the fracture site are damaged.
What is the name given to a complex fracture creating 3 or more bone fragments?
A comminuted fracture?
Give 3 examples of terms used to describe the direction of a fracture line relative to the bone.
- Oblique.
- Spiral.
- Transverse.
List the 4 main processes involved in fracture healing.
- Haematoma formation (within 6-8 hrs).
- Granulation (invasion of stem cells).
- Callous formation (of fibrous tissue).
- Remodelling (replacement of the callous with new bone).
How long does it take for a fracture to heal in a normal adult animal?
12-16 Weeks (although remodelling may persist for years).
List 6 factors that may cause delayed healing of a fracture.
- The animal is geriatric.
- The animal was debilitated and in poor general health prior to the accident.
- The fracture is of cortical rather than cancellous bone.
- The fractured bone has a poor blood supply.
- The fracture is transverse rather than oblique.
- The fracture has been poorly reduced or repaired (mal-union).
What is the term that describes a fracture that is healing more slowly than originally anticipated?
Delayed union.
What complication is associated with poor aseptic technique and/or where the local blood supply to a fracture site is damaged?
Osteomyelitis.
List 5 factors that may influence the reason for choosing a particular method of fracture repair.
- Type of fracture.
- Cost.
- Species/breed.
- Skill of the veterinary surgeon.
- Availability of equipment.
What are the 2 main types of external coaption?
- Casting.
- Splinting.
Why can splints only be used to immobilise joints below the elbow and stifle?
The large muscle masses that surround the joints above these mean that immobilisation is impossible.
List 6 types of splint.
- Use of the body itself (eg. the binding of the scapula to the rib cage).
- Wood.
- Metal with foam padding (eg. Zimmer splint).
- Plastic (eg. gutter splint).
- Wood.
- Plaster slabs or resin.
Give an example of a type of extension splint.
Schroeder-Thomas traction device.
When might the use of an extension splint be indicated?
- To immobilise a fracture distal to the middle of the femur in the hindlimb.
- To immobilise a fracture distal to the middle of the humerus in the forelimb.
- To immobilise a joint at or below the level of the stifle in the hindlimb.
- To immobilise a joint at or below the level of the elbow in the forelimb.
State 2 advantages of a split cast.
- Enables frequent inspection of the limb with minimal hassle.
- Has a little "give" and is therefore useful in growing animals.
The use of casts to immobilise fractures is much reduced as a result of improved techniques in internal fixation. It can however play a useful role in certain types of fracture. What types of fractures are suitable for casting?
Easily reducible, stable fractures that are distal to the elbow and stifle.
Greenstick fractures.
List 5 disadvantages of Plaster of Paris.
- Takes a long time to dry and achieve maximum strength.
- Heavy.
- Affected by water and wear and tear.
- Relatively radiodense.
- Messy to apply, and quite difficult to remove.
Give 2 examples of casting materials that are generally considered to be preferable to plaster of Paris.
- Thermomoldable plastics (eg. Hexcelite).
- Cold water setting fibre glass materials (eg. Vetcast).
State 8 advantages of cold water setting fibre glass materials.
- Light.
- Conforming.
- Rapid drying.
- Water-proof.
- Reasonably radiolucent.
- Stands up well to wear and tear.
- Non-invasive.
- Easy to apply.
State the basic principles that must be adhered to when casting to ensure maximum success with this technique.
- General anaesthesia should be used to aid reduction.
- The joint above and below the fracture must be immobilised.
- Cast padding should be snug enough to prevent chafing, but not excessive since this may cause the cast to loosen and rub.
- If it is decided that the toes are to be left exposed when casting a limb, ensure that not too much of the foot is exposed otherwise swelling is almost inevitable.
- The cast should be changed at 2 weeks following reduction since soft tissue swelling will have subsided with the subsequent loosening of the cast.
- Growing animals require more frequent cast changes than adults.
- Ensure that the owner is given full instructions regarding cast care.
List 10 factors regarding cast care that an owner should be made aware of.
- The cast should be checked daily.
- Exercise must be restricted (lead exercise only for dogs; cage rest only for cats).
- Any problems should be reported immediately.
- Patient interference must be prevented.
- The cast must be kept clean and dry.
- Be watchful for swelling or coldness of the toes in a limb cast where the digits are left exposed.
- Report any incidence of odour emanating from the cast.
- Report any incidence of damage to the cast.
- Ensure that the cast is not rubbing.
- The cast should be inspected by a veterinary surgeon at least once a week.
What is external skeletal fixation?
A means of stabilising long bone fractures using percutaneously placed fixation pins that are connected externally to form a rigid frame.
How can pin tract infections be reduced during external skeletal fixation.
- Good aseptic technique.
- Avoidance of pin insertion through large muscle masses.
- Insertion of the pins via small stab incisions rather than through intact skin or open wounds.
Why should the use of high pressure, high speed power equipment be avoided when inserting fixation pins?
The heat generated by such equipment may cause heat necrosis, which will cause premature pin loosening.
During external skeletal fixation, why is it important that the fixation pins are placed at 35-40° angles to one another?
- To lessen the chance of accidental dislodgement of the device.
- To minimise side-to-side sliding of the device as it loosens with time.
State the name of an external skeletal fixation device commonly used in small animal practice.
Kirschner splint.
List 6 indications for the use of external skeletal fixation.
- Comminuted fractures - can stabilise fractures relatively quickly with little risk to damaging the blood supply to small bone fragments.
- Open or infected fractures - pins can be placed well away from an infected area; especially useful for gun shot wounds.
- Fractures of the skull and jaw.
- Fractures of long bones in immature animals - pins can be placed to avoid passing through growth plates.
- Immobilisation of joints - can maintain a joint in the correct anatomical position until complete fusion has occurred.
- Combinations of internal and external fixation - may be combined with an intramedullary pin in order to prevent rotation at a fracture site.