Diagnostic imaging: Small animal orthopedics Flashcards
What particular feature of the ends of a bone varies among animals?
There is variation in the physeal closure time among animals.
For the appendicular skeleton, how are fractures defined?
Fractures are defined by the following:
(i) Limb and bone involved
(ii) Fracture type
(iii) Direction of displacement
(iv) Articular involvement
(v) Soft tissue changes
What is the name of the special classification in animals with open physis?
Salter-Harris classifications are special classifications in animals with open physis?
In the case of fracture healing, how can we evaluate the initial postoperative radiographs?
In the case of fracture healing, we can evaluate the initial postoperative radiographs using the 4A’s :
(i) Apposition
(ii) Alignment
(iii) Appliance
(iv) Articular surface
By which process does healing usually occur and what can be seen on radiographs over 8 weeks?
Healing is usually through secondary bone formation that is seen on radiographs as the following:
(i) First week: Increase in the width of the fracture gap
(ii) At 10 to 14 days, variable amount of callus begin to appear.
(iii) At 4 to 8 weeks, fracture is less distinct with larger amounts of relatively smooth callus.
List 7 complications of fracture.
(i) Nonunion: Lack of progression of healing after 16 weeks
(ii) Malunion: Fracture healed in abnormal alignment
(iii) Osteomyelitis:Variable osteoproductive and lytic
(iv) Implant fracture: Broken or migration of implants
(v) Angular limb deformity:Common in premature closure of the distal ulnar physis
(vi) Sequestrum formation: Portion of bone lacking vascular supply is not incorporated in healing process
(vii) Fracture associated sarcomas: Rare, approximately 5 years after fracture
How is aggressive bone disease defined?(3)
Defined by:
(i) type of periosteal reaction
(ii) type of bone lysis, and
(iii) zone of transition between normal and abnormal bone
What are the different types of periosteal reaction from least to most aggressive?(5)
Types of periosteal reaction from least to most aggressive: smooth, lamellar, irregular, sunburst, amorphous
What are the different types of bone lysis from least to most aggressive?
Types of bone lysis from least to most aggressive: geographic, moth eaten, permeative
What is the relationship between the length of the zone of transition and the aggressiveness of the disease?
The longer the zone of transition, the more aggressive the disease
What is the most common type of primary bone neoplasia?
Osteosarcoma is the most common type of primary bone neoplasia(away from the elbow and toward the knee plus distal tibia). Usually does not cross joints.
NOTE: Neoplasia is characterised by a variable degree of osteolysis and production.
Give examples of infectious disease which will have a variable degree of osteolysis and osteoproduction.
Infectious disease will have a variable degree of osteolysis and osteoproduction:
a. Granulomatous or fungal disease
b. Osteomyelitis
What can help with providing a definitive diagnosis?
A bone biopsy is often required to get a definitive diagnosis.
Relating to congenital disorders, define the following:
(i) Polydactyly
(ii) Syndactyly
1.Polydactyly: one ormore extra digits
2.Syndactyly:Bony fusion of one or more digits
Many types of dwarfisms and skeletal dysplasia occur but are uncommon. These usually result in abnormal ossification and shape/length of the skeleton.
Give two examples of developmental disorder that is a disease of young, large to giant breed dogs.
Panosteitis and hypertrophic osteodystrophy ares disease of young, large to giant breed dogs.
Most common in the German Shepherd(can be seen in older shepherds) and basset hiund.
What can be seen on radiographs for each type of developmental disorder?
In which dog breeds is panosteitis more common?
Panosteitis(check folder for radiographs picture-5)
Radiographs: Increased intramedullary opacity of long ones.
Most common in the German shepherd(can be seen in older shepherds) and basset hound
Hypertrophic osteodystrophy(check picture 6)
Radiographs: abnormal lucent lines(double physeal line) in the metaphysis(most commonly the distal antebrachium).
Which condition in dogs would usually predipose them to hypertrophic osteopathy?
Hypertrophic osteopathy generally affects older dogs secondary to a thoracic (and less commonly abdominal) mass.
What can be seen on radiographs with hypertrophic osteopathy?
Radiographs: Palisading periosteal reaction and soft tissue swelling of multiple long bones; bilaterally symmetrical.
Describe the progression of the periosteal reaction in hypertrophic osteopathy.
Hypertrophic osteopathy: the periosteal reaction starts distally and eventually progresses up the limb.
What type of radiograph is usually recommended in the case of hypertrophic osteopathy and why?
Hypertrophic osteopathy: always take a thoracic radiograph to check for a mass.
Give examples of disorders that can affect the axial skeleton: spine.(7)
1/Atlantoaxia subluxation 2/Cervical spondylopathy 3/Lumbosacral instability 4/Intervertebral disk disease 5/Spondylosis deformans 6/Neoplasia 7/Diskospondylitis
Define atlantoaxial subluxation. Which breeds are usually affected?
What should one be careful when taking radiographs in this case?
Congenital malformation or hypoplasia of the dens
Young small and toy breeds.
Be careful to avoid excessive flexion of the neck in these patients during radiography.
Describe radiographic findings with atlantoaxial subluxation.
- Widening of the space between the atlas and spinous processes if the axis
- Abnormal or absent dens
What other terms can be used to describe cervical spondylopathy?
In which dog breeds is cervical spondylopathy more common?
Wobbler syndrome, cervical vertebral instability
Young Great Danes and older Doberman pinschers
What are the radiographic findings with cervical spondylopathy?(6)
- Malformation of the vertebral bodies(C5-C7)
- Malalignment of the vertebral bodies
- Invertebral disk space narrowing
- Spondylosis deformans
- Sclerosis of the vertebral end plates
- Degenerative changes of the articular facets
What are the radiographic findings for lumbosacral instability?(4)
Radiographic findings:
NOTE: These same findings are found in dogs with degenerative disease that do not have signs of neurologic disease)
-Narrowing of invrtebral disk space at L7-S1
-Spondylosis deformans at L7-S1
-Sclerosis of the end ploates at L7-S1
-Malalignment of the sacrum and L7
What other diagnostic tool is usually used to confirm lumbosacral instability?
Often need computed tomography(CT) or magnetic resonance imaging(MRI) to confirm.
Which dog breeds are predisposed to intervertebral disk disease?
Most common in chondrodystrophic breeds(dachshund).
What are some radiographic findings in intervertebral disk disease?
- Narrowing or wedging of the intervertebral disk space
- Narrowing of the intervertebral foramina
- Increased opacity in the spinal canal
- Narrowing of the joint space at the articular facets
Intervertebral disk disease
What procedure can be used to confirm a lesion prior to surgery?
Myelography is performed to confirm a lesion prior to surgery.
What is spondylosis deformans?
Spondylosis deformans is degenerative change of the spine.
What are some radiographic findings with spondylosis deformans?
Smooth new bone formation that may be bridging at the ventral(and sometimes lateral) vertebral endplates.
In the case of neoplasia, how many vertebrae are usually affected by primary bone tumors?
Primary bone tumors generally affect one vertebra.
Can spincal cord tumors be usually detected without myelography?
Spinal cord tumors usually cannot be detected without myleography.
What changes can result from extension of neoplastic disease from the caudal abdomen and perineal tissues ?
Eextension of neoplastic disease from the caudal abdomen and perineal tissues can result in osteolytic and osteoproductive changes at L5 through the sacrum and caudal vertebrae.
What is diskospondylitis?
Diskospondylitis is infection of the invertebral disk space and adjacent vertebral endplates.
What are some radiographic findings with diskospondylitis?
Radiographic findings:
- Osteolysis of the vertebral endplates
- Multiple sites may be affected.
- Widening or collapse of the interverterbral disk space.
Give examples of two types of trauma that can happen at the axial skeleton(spine).
Trauma
(i) Compression fractures
(ii) Subluxation and luxation
Give examples of conditions that can affect the axial skeleton(skull).
- Ear disease
- Nasal disease
- Dental disease
- Others(Cranial mandibular osteopaythy, neoplasia)
What can be seen on radiographs with:
(i) Otitis externa
(ii) otitis media
(iii) Nasopharyngeal polyps
Ear disease
- Otitis externa: Thickening and mineralisation of the external ear canals, with partial to complete occlusion of the normally air filled canals
- Otitis media: Soft tissue or fluid opacity of the tympanic bulla with occasional changes in the bulla wall in severe cases
- Nasopharyngeal polyps: May see increased soft tissue opacity of tympanic bulla and nasopharynx
What are the two different types of nasal disease?
Destructive and non-destructive rhinitis.
What are 4 different causes of destructive rhinitis?
Destructive rhinitis Causes: (1)Neoplasia:Adenocarcinomas most common (2)Fungal rhinitis (3)Chronic foreign bodies (4)Chronic inflammatory disease
What are some radiographic findings with destructive rhinitis?(3)
- Increased soft tissue opacity in the nasal passages and frontal sinuses
- Destruction of the nasal turbinates
- Destruction of the bones surrounding nasal passages, usually most severe with neoplasia
What are three causes of non-destructive rhinitis?
- Inflammatory disease
- Bacterial rhinitis
- Foreign bodies
What is the most common type of dental disease?
Peridontal disease is the most common type of dental disease.
What are some radiographic findings of periodontal disease?
Radiographic findings include:
(i) Widening of the periodontal space
(ii) Loss of the radiopaque lamina dura
(iii) Root resorption
(iv) Tooth loss
Which breeds are usually affected by cranial mandibular osteopathy?(CMO)
Cranial mandibular osteopathy affects terrier breeds.
What are some radiographic findings of cranial mandibular osteopathy?
(1) Irregular new bone involving the mandibles and occasionally parietal, frontal and maxillary bones.
(2) Can result in temporomandibular joint(TMJ) ankylosis.
What is the most common type of neoplasia in the skull and what processes usually characterise such conditions?
Neoplasia: Can occur anywhere on the skull. Osteosarcoma is most common, with a variable degree of osteolysis and osteoproduction.
What are the different categories of joint disease?(5)
Remember VITAMIND
- Traumatic
- Degenerative
- Neoplastic
- Inflammatory
- Developmental
Give examples of trauma that can occur to the joints. What type of radiograph may be helpful in demonstrating instability?
- Luxations and fractures
- Stress radiographs may be helpful to demonstrate instability.
Give examples of degenerative causes of joint instability.
Commonly stifle secondary to cranial cruciate rupture, coxofemoral joints secondary to hip dysplasia and elbow and shoulder joints.
What are some radiographic findings with joint disease?(7)
- Increased synovial mass/intraarticular swelling
- Decreased joint space width
- Periarticular osteophyte formation
- Enthesopathy:New bone at soft tissue attachment sites
- Subchondral bone sclerosis
- Subchondral cystic changes in severe cases
- Mineralisation of soft tissues: Intra articular or peri articular
