CH 11 Joints Flashcards
Why are sesamoids sometimes not seen on radiographs?
They may not be mineralised.
They start out as cartilage and then (most of the time) ossify, becoming radiographically visible.
Absence of mineralization of the medial fabella and popliteal sesamoid is more prevalent in _________ cats than in ________ cats (Arnbjerg and Heje, 1993).
fill in the blanks with either: domestic or pedigree
Absence of mineralization of the medial fabella and popliteal sesamoid is more prevalent in domestic cats than in pedigree cats (Arnbjerg and Heje, 1993).
Mineralization of the supinator sesamoid is reportedly present in ___% of cats (Wood et al., 1995) and ___% of dogs (Wood et al., 1985).
40 (cats)
30 (dogs)
Which sesamoid does the elbow have?
Sesamoid in the tendon of origin of the supinator muscle
Which sesamoid does the carpus have?
Sesamoid in the tendon of origin of the abductor pollicis longus muscle
Which sesamoids does the stifle have?
Patella - tendon of insertion of quadriceps muscle
Fabellae - lateral and medial origin of gastrocnemius muscle
Popliteal - tendon of popliteus muscle
Which sesamoids does the stifle have?
Lateral plantar tarsometatarsal
Intra-articular tarsometatarsal
Which sesamoids do the metacarpo-/ metatarsophalangeal joints have?
Paired palmar/plantar sesamoid bones (tendons of insertion of the interosseous muscles)
Single dorsal sesamoid
(in the extensor tendons)
In which stage of arthroses is scintigraphy particularly useful - early or late?
early, when only soft tissue inflammation is present.
a) normal
b) reduced joint space (between femoral head and cranial acetabular margin)
c) increased joint space (it’s V-shaped); incongruent joint
3 causes of reduced joint width
artifact (beam not centred properly)
cartilage attrition
muscle contracture
What is the theory behind vacuum phenomenon?
Nitrogen diffuses from extracellular fluid into the joint space, when there is negative pressure (either naturally e.g. IVDD, shoulder OCD, or induced e.g. traction during stress radiography)
What is the initiating factor for osteochondrosis?
Local ischaemia > failure of the the cartilage to mineralise
Which joint(s) is(are) more commonly affected by congenital luxation?
Shoulder and elbow
manually compressed and distracted coxofemoral joint - is this a normal amount?
No, this is excessive, and indicates joint laxity and poor joint congruity.
Cartilage cells have reduced proliferation and differentiation with which vitamin imbalance?
Hypervitaminosis A
What is the radiographic lag time of hypervitaminosis A following the start of the inciting cause?
10 weeks
Usually (historically?) seen in older cats, caused by eating a liver-based diet
Which is true of Hypervitaminosis A:
A. It causes osteopenia
B. The changes are most apparent in the lumbar vertebrae.
C. The shoulder and elbow joints have the most pronounced changes.
D. It causes widened physes.
A. It causes osteopenia.
C. The shoulder and elbow joints have the most pronounced changes.
Most pronounced in cervical spine, and shoulder and elbow (cranial part of the cat)
There is marked ankylosing spondylopathy and periarticular enthesopathy.
Physeal thickening is a feature of:
A. Hypervitaminosis A
B. Nutritional secondary hyperparathyroidism
C. Renal secondary hyperparathyroidism
D. Rickets
Rickets - it is one of the defining features. Consequently, there is also metaphyseal flaring and cortical thinning.
Put these in the correct chronological order of occurrence during development of osteoarthrosis:
- Formation of osteophytes and enthesophytes
- Increased subchondral opacity
- Calcification in and around the joints.
- Bony remodelling of normal joint contours
- Increased subchondral opacity
- Bony remodelling of normal joint contours
- Formation of osteophytes and enthesophytes
- Calcification in and around the joints.
What is the most common primary joint neoplasm? what are some others?
Most common: synovial cell sarcoma
Others:
- Histiocytic sarcoma (shorter survival when comapred to SCS - Craig et al., 2002)
- Synovial myxoma
- Malignant fibrous histiocytoma
- Fibrosarcoma
- Chondrosarcoma
What are synovial cysts? (where do they arise from, are they benign or malignant)
They are benign (but can become very large), and arise from the synovium or tendon sheath or bursa
What is typical of joint neoplasms that is rare with other neoplasms?
Invasion of bone on either side of a joint (polyostotic)
In which species is villonodular synovitis more reported?
Horses
7yr Oriental cat
There is a arge continuous zone of proliferative new bone and several smaller osseous bodies at the medial aspect of the stifle in the region of the medial collateral ligament and medial joint capsule. Surgical exploration and histopathological diagnosis were consistent with synovial osteochondromatosis.
Which of these is autosomal dominant?
A. Mucopolysaccharidosis
B. Osteochondrodystrophy of Scottish Fold cats
C. Alaskan Malamute chondrodysplasia
D. Avascular necrosis of the femoral head
E. Incomplete ossification of the humeral condyle
B. Osteochondrodystrophy of Scottish Fold cats
Why would villonodular synovitis be confused with a neoplasm?
Because the fibrous mass that develops with this condition, can secondarily result in adjacent bone destruction
How might rodenticide toxicity or von Willebrand’s disease affect a joint?
It can cause haemarthrosis (bleeding into the joint space). This can (chronically) damage the cartilage and subsequently the subchondral bone.
Which signalment is overrepresented by calcinosis circumscripta?
young large-breed dogs, esp. GSD
old cat
Hypervitaminosis A; extensive ankylosing spondylopathy of the cervical vertebrae and arthrosis of the shoulder joint (both typical locations)
Dog
fragmented MCP
