Long bones, joints

Question 1

Describe Radiography of long bones.

Answer 1

Sedation/anesthesia should be used for best quality. Diagnostic quality is very important!

Minimum 2 views
- Mediolateral + craniocaudal or
caudocranial.

Take images of both limbs for comparative purposes.

Remember Mach lines!

Question 2

Define Mach lines.

Answer 2

The apparent line of contrasting density bordering a soft tissue shadow on a radiograph; it is an optical illusion constructed by the observers retina.

Question 3

Describe bone loss / lysis on radiography.

Answer 3

Bone loss (lysis) is radiographically observable after ca 7-10 days.
- when 30-60% of mineral content loss

Picture of osteosarcoma.

You can also have mixed reactions that consist of both lysis and new bone production (sclerosis).

Question 4

New bone production is also called

Answer 4

Sclerosis: increased bone capacity →
increased density, hardening of tissue.

Sorta like a bone scar, looks whiter/more dense on xray.

You can also have mixed reactions that consist of both lysis and new bone production (sclerosis).

Question 5

Describe pediatric patient radiography.

Answer 5

Growth plates are open, time of closure varies between joints. Cartilage is NOT visible on xrays.

Factors that affect closure time:
- Breed, nutrition, anatomical location etc.
- Hormonal effect
- Growth hormone, thyroid hormone, sex hormones, insulin.
- Individual variation

Question 6

Describe mature patient radiography.

Answer 6

Epiphysis and diaphysis fused, physis closed.
- Different age in different bones

Dogs: usually all physes closed by age of 18 months.

Young castrated cats: physes open until age of 18 months, very often open until age of 2-3 years.

Physeal “scar” – thin horizontal radiopaque line in place of closed physis.

Nutrient foramina and vessel channels can be mistaken as fracture lines.

Pictured white line is a sort of “scar” from where the growth plate closed.

Question 7

Describe Premature closure of growth plate.

Answer 7

e.g. distal ulna such as in image

results in growth discrepancy and may disrupt the function of the joint

Question 8

What does this depict?

Answer 8

Premature closure of growth plate distal radius.

Question 9

What is the Cut-back zone?

Answer 9

The area of irregular and hazy bone margins where the metaphysis remodels to the narrower diaphysis during bone growth seen specifically in young animals. Due to
Osteoclastic activity.

If its seen in adult animals, its suspicious!

Question 10

What are Retained endochondral cartilage cores?

Answer 10

Disturbed ossification phenomenon seen in
Young large or giant dogs.

Most commonly distal metaphysis of ulna.

Cause unknown for certain. Overnutrition, food additives theorized.

Bilateral symmetrical changes

Shortening of general length, mimics traumatic premature closure of growth plate.

In the image: the flame shaped radiolucent area with sclerotic rim.

Question 11

What are nutrient foramens?

Answer 11

Foramens superimposed on medullary cavity.

Fractures aren’t symmetrical so if the exact same mark is in the same spot in both limbs, consider nutrient foramens.

In the image: the thin dark lines. There is also a Mach line to the left of the nutrient foramen.

Question 12

Describe the canine humerus on xrays.

Answer 12

Normal findings include:
- Tricipital line
- Area of teres minor attachment
- Deltoid tuberosity

+ Supratrochlear foramen (but not all dogs)

Question 13

Describe the feline humerus on xrays.

Answer 13

Large supracondylar foramen that looks like a black hole on xray.

Question 14

Canine vs feline radius-ulna on xray.

Answer 14

Dog: olecranon pointed and angular.

Cat: olecranon more square.

Question 15

whats this

Answer 15

Chondrodystrophic breed changes. Not pathological, just a certain breed thing.

The long bones are affected but the joints themselves are not affected.

Question 16

Describe the canine and feline femurs on radiography.

Answer 16

Dogs: Fabellas may be on different levels.

Cat: Fabellas can be different size, sometimes only one present.

(fabella (Latin for little bean) (or flabella) is a small sesamoid bone found in some mammals embedded in the tendon of the lateral head of the gastrocnemius muscle behind the lateral condyle of the femur.)

Question 17

Describe the canine tibia-fibula on radiography.

Answer 17

Dog: often a small rounded
radiolucent area may be seen in
proximocranial area of tibia and is considered normal.
- Cartilage retention? Its not certain why its there.

Is an Incidental finding and is only abnormal if its not in exactly that area of the tibia.

Question 18

Describe radiography of fractures.

Answer 18

Anamnesis is super important!

Fracture line is mostly radiolucent
But If superimposition of impacted or compressed bone fragments, you may see radiopaque lines.

NB! Do not confuse the following with fractures:
- Physes
- Nutrient foramen
- Mach lines
- Soft tissue shadows (skin fold)

At LEAST 2 views needed!

Question 19

NB! Do not confuse with fracture: (4)

Answer 19

• Physes
• Nutrient foramen
• Mach lines
• Soft tissue shadows (skin fold)

Question 20

Fractures can be either..

Answer 20

primary or secondary.

Also, complete or incomplete. (periosteum can be intact with fracture line otherwise).

Left image: gunshot caused fracture.

Right image: osteosarcoma caused fracture.

Question 21

identify

Answer 21

incomplete fractures

Question 22

identify left to right

Answer 22

left to right:
Transverse fracture
Oblique fracture
Spiral fracture

Question 23

Describe osteomyelitis.

Answer 23

Bone infection or inflammation that results in:

Formation of new bone thats radiographically visible, takes 2-3 weeks.

Can have Osteolysis in the same area as well. So both darker areas and lighter areas.

Question 24

Bone neoplasia on radiography.

Answer 24

Seen on radiographs as lysis and/or new bone formation (usually combined).
- with Periosteal reaction

Usually cancerous and aggressive.

Differential diagnoses: osteomyelitis, very rarely cysts in bone.

Can be primary neoplasms in bone or metastases.

Question 25

What is the periosteal reaction?

Answer 25

A bone change seen radiographically with neoplasias that can also be characterized into a type (4). - solid - onion peel or lamellated - spiculated - codman's

Question 26

Benign neoplasms in bone are

Answer 26

rare (but can happen). Not spiculated and not typically with lysis.

Question 27

identify

Answer 27

classic osteosarcoma CCLR secondary to neoplasia metastasis to lungs first (other intestinal organs also poss.) osteosarc. can have both new bone formation as well as lysis.

Question 28

Describe Metastatic bone tumors.

Answer 28

Epiphysis affected most commonly. Often Nutrient foramen, vessel canal area. Humerus, femur commonly. “Moth eaten” appearance ddx osteomyelitis can look very similar

Question 29

Describe Incidental findings – “kissing lesions”.

Answer 29

Cortical modelling in the area of the interosseous ligament between the radius and ulna is occasionally seen at the level of the nutrient foramen. At the junction of the proximal and middle thirds of the caudal radial diaphysis. Less commonly in the cranial ulnar diaphyses. Mild periosteal reaction to discrete osteolysis with unknown exact etiology. - Interosseous ligament strain or Enthesopathy? (refers to inflammation around your joints)

Question 30

What is Panosteitis? exam q!

Answer 30

Panosteitis is a painful inflammation of the outer surface or shaft of one or more long bones of the legs. It is sometimes called growing pains. Usually young dogs. Found in animals up to 7 yo. Very painful! Radiographically seen Patchy areas of increased opacity (“clouds”). Or Periosteal reaction/ Endosteal thickening. Is self limiting. Treat with analgesia, NSAIDs (opioids if very severe pain).

Question 31

identify

Answer 31

Growth arrest lines. - White lines horizontally - Not clinically significant also known as Harris lines, are lines of increased bone density that represent the position of the growth plate at the time of insult to the organism and formed on long bones due to growth arrest.

Question 32

identify

Answer 32

osteopetrosis, systemic disease. very painful. calcification of the medulla is group of a rare disorders that cause bones to grow abnormally and become overly dense. When bones become overly dense, they are brittle and can fracture (break) easily. image: cat

Question 33

Describe osteopenia. (2)

Answer 33

Radiographically visible when 30-60% of mineral content is lost. 2 forms: osteomalacia and osteoporosis. Osteomalacia - Decreased mineralization - Normal bone matrix - Vitamin D deficiency Osteoporosis - Decreased mineralization - Decreased bone matrix (image, shrunken bone with fracture)

Question 34

Difference between osteomalacia and osteoporosis?

Answer 34

Osteomalacia: characterized by the softening of bones due to a defect in the bone mineralization process. It occurs when there is insufficient calcium, phosphate, or vitamin D to harden the bone tissue properly. Osteoporosis: involves a reduction in bone density and mass, leading to fragile, porous bones that are more susceptible to fractures. The bone structure remains normal, but the amount of bone tissue decreases.

Question 35

identify

Answer 35

Bone cyst Usually Puppies, young adults. Diaphysis or metaphysis of radius or ulna most commonly Other locations also possible though ddx bone tumor, osteomyelitis

Question 36

Joints on radiography.

Answer 36

Subchondral bone seen as relatively homogenous radiopaque bone that forms apparent margin of joint surface. Joint cartilage not visible. Sesamoid bones may be visible, but often are not. Joint problems that can be seen on xray - Soft tissue swelling - Increased/decreased width of joint space - Irregular subchondral bone margin - Changes in opacity

Question 37

Define osteophytes.

Answer 37

An outgrowth of bone at the margin of the articular surface Smoothly marginated homogenous bone proliferation. Such as in Osteoarthritis

Question 38

Describe enthesophytes.

Answer 38

A focal proliferation of new bone to form a bony spur at an enthesis (the site of tendon, ligament, joint capsule, or fascia attachment to bone). e.g. due to Trauma, inflammation Look very similar to osteophytes but are located outside the joint.

Question 39

Describe osteoarthritis on radiography.

Answer 39

Increased subchondral opacity. Bone formations (osteophytes, enthesophytes). Bone remodeling in bone margins. Periarticular calcification Is a Degenerative change and a Common finding in older animals. NB Poor correlation of radiographical and clinical findings. Meaning can be severe changes in xrays but not much reaction clinically and vice versa

Question 40

Describe the shoulder joints on radiography.

Answer 40

Remember Clavicles in cats, and Sometimes rudimentary ones seen in large dogs, they look like poorly mineralized structures. Calcified opacities around or within the shoulder joint are commonly seen, majority of them are incidental findings though. NB The Supraglenoid tubercle's physis in immature dogs, can be misidentified as fracture.

Question 41

identify

Answer 41

rudimentary clavicle of dog

Question 42

identify

Answer 42

NB The Supraglenoid tubercle's physis in immature dogs, can be misidentified as fracture. (left image) rudimentary clavicle in right image

Question 43

identify

Answer 43

fracture of supraglenoid tubercle

Question 44

identify

Answer 44

fracture of humeral head from two angles

Question 45

Describe luxation/Subluxation of the shoulder.

Answer 45

Congenital or acquired Can occur in any direction Medially mostly congenital, toy breeds. Lateral mostly in large breeds due to trauma.

Question 46

Define Osteochondrosis.

Answer 46

OC - Abnormality of endochondral ossification. - The cartilage of the epiphysis fails to form subchondral bone → thickened abnormal cartilage → prone to injury. Symptoms: Pain, swelling, and stiffness at the affected joint, but usually without significant structural damage like detachment.

Question 47

Osteoarthrosis is

Answer 47

another term for OA. Osteoarthritis (OA) is a degenerative joint disease involving cartilage loss. It develops over time due to wear and tear.

Question 48

define Osteochondritis dissecans

Answer 48

OCD is a subtype of OC. Cartilage is fissured and forms a cartilage flap → that can: - Stay in place, granulation tissue will hinder it. OR: or dislodge and resorb, or remain as a free body (“joint mouse”/"loose body"), or grow and eventually ossify. Secondary osteoarthrosis even if primary treatment successful. - Classical site – humeral head - Medial humeral condyle - Distal femoral condyle Symptoms: More severe symptoms, including severe pain, joint locking, catching, and limited movement, especially if the fragment detaches fully.

Question 49

Difference between osteochondrosis and osteochondrosis dissecans?

Answer 49

OCD is a subtype of OC. OC is A general term referring to a group of disorders that affect the development and growth of bones, particularly at the growth plates in children and adolescents. OCD is a more specific and advanced form of osteochondrosis where a segment of bone and its covering cartilage become unstable and can separate from the underlying bone.

Question 50

Osteochondrosis dissecans findings on radiography. (exam q!)

Answer 50

Flattening or an irregular, radiolucent subchondral defect of variable size involving the caudal aspect of the humeral head. Subchondral sclerosis surrounding the defect. Osteoarthritis in chronic cases. Often bilateral → both shoulders should be controlled!

Question 51

identify

Answer 51

OCD, Osteochondrosis dissecans

Question 52

Describe the elbow joint on radiography.

Answer 52

Mediolaterally imaged the following can be seen: - Congruency of joint surfaces - Coronoid process - Osteophytes Craniocaudal/anterior-posteriorly the following can be imaged: - Osteophytes - Defects of humeral medial condyle - Luxation/subluxation

Question 53

elbow mediolateral in flexion, you can spot what 3 pathologies:

Answer 53

- ununited anconeal process - osteophytes - flexor enthesopathy

Question 54

Incidental finding in the elbows.

Answer 54

sesamoids Usually Large breed dogs Laterally or craniolaterally to medial head on radius

Question 55

What do you see

Answer 55

Condylar fractures Lateral: most common Medial: rare Y or T: fracture line goes through and between condyles..

Question 56

identify

Answer 56

elbow luxation normal elbow here as example

Question 57

identify

Answer 57

Congenital luxation of the radius

Question 58

Describe elbow dysplasia.

Answer 58

Abnormal development, including - MCD (Medial coronoid disease) Fragmented coronoid process (FCP) - OCD (osteochondritis dissecans) - Incongruity - UAP (Ununited anconeal process)

Question 59

UAP?

Answer 59

Ununited anconeal process a condition in which a bony protuberance within the elbow becomes detached from the ulna. This loose, bony fragment causes pain and lameness and contributes to articular damage within the elbow joint.

Question 60

FCP?

Answer 60

Fragmented coronoid process is a developmental defect of one of the coronoid processes, two small bony protrusions on the end of the ulna within the elbow joint. In this condition, one of the coronoid processes develops a fissure or crack and separates from the rest of the bone.

Question 61

normal on the left so what do you see in the right image?

Answer 61

FCP, Fragmented coronoid process is a developmental defect of one of the coronoid processes, two small bony protrusions on the end of the ulna within the elbow joint. In this condition, one of the coronoid processes develops a fissure or crack and separates from the rest of the bone.

Question 62

identify

Answer 62

elbow dysplasia yellow arrows: osteophytes

Question 63

identify

Answer 63

UAP Ununited anconeal process a condition in which a bony protuberance within the elbow becomes detached from the ulna. This loose, bony fragment causes pain and lameness and contributes to articular damage within the elbow joint.

Question 64

identify

Answer 64

incongruity too much space between the joint surfaces in all 3 images = elbow dysplasia

Question 65

Review pelvic anatomy.

Answer 65

Question 66

Extended VD pelvis view means..

Answer 66

the patellas are also in the image and they're rotated to position in the center of the femurs.

Question 67

identify

Answer 67

VD flexed view “Frog position” Conscious patient with painful hips. Cranial and caudal aspect of femoral head and neck should be visible.

Question 68

What is Flückiger technique?

Answer 68

VD pelvis image, but femurs at the angle of 60 degrees from the table. Allows you to see Subluxation of the hips.

Question 69

Difference between fabellas and sesamoids?

Answer 69

the fabella is a specific sesamoid bone found in the knee, while sesamoid bones refer more broadly to small bones located in various parts of the body, typically in joints under high mechanical stress.

Question 70

identify pathology

Answer 70

hip joint subluxation

Question 71

identify

Answer 71

incidental finding of anal glands filled with air

Question 72

identify pathology

Answer 72

chronic hip luxation (dislocation) with osteophyte development

Question 73

identify pathology

Answer 73

Avascular necrosis of femoral head - Young dogs - Small and toy breeds legg-calve-perthes disease

Question 74

identify

Answer 74

Feline capital metaphyseal osteopathy sorta like the cat version of -legg-perthes' Young male neutered cats mostly. Extensive lysis and bone remodeling of the neck. Secondary fractures

Question 75

Describe hip dysplasia.

Answer 75

Primary changes are - Laxity of hip joints - Lack of formation of the acetabulum - Poor coverage of the femoral head Secondary changes, - Subchondral sclerosis at the cranial acetabular margin, moves laterally over time. - Osteophytes at the caudal aspect of the femoral neck (Morgan’s line). - Periarticular osteophyte formation on the cranial effective acetabular rim and dorsal acetabular margin.

Question 76

identify

Answer 76

hip dysplasia

Question 77

Incidental findings/normal variations of the femoral head. (4)

Answer 77

Broomstick-conformation Plump conformation CCO (Morgan’s line) Puppy line

Question 78

Broomstick-conformation is

Answer 78

incidental/normal variation in the femoral head shape. A slender femoral neck merges without clear demarcation with the smaller femoral head. German shepherd (a)

Question 79

Plump conformation is

Answer 79

incidental/normal variation in the femoral head shape without signs of dysplasia. Rottweiler (b).

Question 80

CCO (Morgan’s line) is

Answer 80

is a bone formation in the caudolateral region of the femoral neck indicative of joint instability. in large or heavy dogs, a subtle Morgan’s line is often visible in normal joints. CCO = caudolateral curvilinear osteophyte

Question 81

Puppy line is

Answer 81

found in young dogs, a thin straight line can be visible in the region of the Morgan’s line. This so-called puppy line disappears at the age of approximately 18 months.

Question 82

Review mediolateral dog stifle joint anatomy.

Answer 82

Review craniocaudal dog stifle joint anatomy.

Question 83

Review mediolateral cat stifle joint anatomy.

Answer 83

Review craniocaudal cat stifle joint anatomy.

Question 84

identify pathology

Answer 84

stifle trauma

Question 85

CCLR (Cranial crucial ligament rupture) on radigoraphy. (3)

Answer 85

Can be seen: - Compressed infrapatellar fat pad - Distal displacement of popliteal sesamoid - Osteophyte development if chronic/ time has passed since rupture. Evaluate both sides!

Question 86

Grading of CCLR.

Answer 86

Not official grading. Describes how the knee develops from time from rupture.

Question 87

identify

Answer 87

Patella luxation

Question 88

Describe Scottish fold - osteochondrodysplasia.

Answer 88

Autosomal dominant gene so its inherited. All individuals are affected but severity can vary. - Is Bilateral - symmetrical carpal and tarsal ankylosis - Any joint can be affected - Painful condition!

Question 89

identify

Answer 89

Erosive polyarthropathy (rheumatoid arthritis) image of a dog

Question 90

identify

Answer 90

Feline digit-lung syndrome Primary neoplasia in lungs that causes Lytic changes in digital bones. We dont know why this happens in cats.

Question 91

identify

Answer 91

Hyperthrophic osteopathy in dogs Primary neoplasia in thorax or abdominal cavity that affects long bones. Makes them "hairy".