21. Joint Disease Flashcards
How does joint space thickness vary over time in the presence of joint disease?
- Typically:
EARLY: Expansion (effused)
LATE: Collapse (due to cartilage degradation)
=> Later phase rarely dx due to lack of weight bearing rx and variable projection angles
Radiographic features of JOINT DISEASE
Image with examples…
List three examples of large accumulations of articular or periarticular mineralisation?
1) Intraarticular OSTEOCHONDROMA
2) Meniscal mineralisation (cats)
3) “Pseudogout” - calcium pyrophosphate deposition disease (dogs)
List three distinct categories of articular calcified bodies?
1) Avulsed fragments -> articular or periarticular bone
2) Osteochondral components of disintegrating joint surface
3) Small synovial osteochondromas
Pathophys of osteophyte formation?
- Degradation of articular cartilage
- Degradation products -> synovial hyperplasia
- Synovial hyperplasia -> Osteophyte (initially cartilage, later ossified)
=> Bony outgrowths at periphery of articular cartilage
What are entheses?
- INSERTION of tendon, ligament, joint capsule, or fascia TO BONE
Enthesophyte = Bony spondylopathy at enthesis
Common entheses of carpus x 5
Main enthesis of shoulder x 3
Main entheses of stifle X 5
What is Vacuum phenomenon? What are the posible causes of intrarticular gas (4 broad categories)?
- Vacuum = Intrarticular diffusion of nitrogen from ECF following negative pressure
In what % of shoulder with humeral head OCD radiographs is vacuum phenomenon seen?
20%
NOT a feature in normal contralateral radiographs!
List 4 clinical conditions associated with intraarticular gas
- Osteochondrosis
- Degenerative IVDD
- Vertebral instability
- DJD
Sites of sesamoids in the dog TABLE
What % of feline menisci have mineralisation in stifle rads? Which site most commonly affected?
46%
Cranial horn, medial meniscus
=> % mineralisation significanly associated with degree of cartilage damage in medial femoral and tibial condyles. THEREFORE associated with medial compartment DJD
MCP sesamoid fragmentation is associated with which bones and which breeds?
2nd and 7th MCP sesamoids
ROTTIS (several large breeds)
=> up to 44% in one group of rottis; 73% in one group up to 12mo with CS associated in 65%
Another group: cause of FL lameness in 50% young rottis
Transverse fragmentation of the digital sesamoids reported in which breed?
Racing greyhounds -> possibly fracture is cause
What is the most common example of sesamoid displacement? Which breeds are predisposed?
Patella luxation!
Toy breeds and Devon Rex
What are these
Iliopubic sesamoids!
What are the three most frequent locations of canine DJD?
- Hips (dysplasia
- Shoulder
- Stifles
What is the incidence of shoulder and stifle DJD reported at rx / necropsy?
Shoulder: 33-50%
Stifle: 20%
What are the two sesomoids of the tarsus!! Odd….
Lateralplantar tarsometatarsal sesamoid
Intra-articular tarsometatarsal sesamoid
What is the most reliable feature to assess for grading of stifle DJD?
- Number and size of osteophytes
=> other features less reliable e.g. effusion, sclerosis, mineralisation
What is the timeline of onset of osteophytosis after cranial cruciate transection?
- Commence as early as 3 days -> margins of femoral trochlea seen radiographically at 2 weeks
Prox / dist fem trochlea -> femoral and tibial condyles and patella
Enthesophytes: CrCr and collateral
List 3 specific views that can be used to identify early trochlear osteophytes?
1) Flexed mediolateral
2) Craniomedial - caudolateral
3) Caudomedial - craniolateral
What feature is the strongest indicator of coxofemoral DJD? What measure is used to evaluate this feature? Normal values?
- Joint subluxation
- DISTRACTION INDEX:
DJD varies with breed and DI
Unlikely to develop DJD if
<0.3 in GSD
<0.4 in lab / Rotti
Radiographic signs of DJD
BOX
Causes of OA in cats
3x primary
7 x secondary
BOX
What are the earliest recognisable signs of hip dysplasia? And how are they manifested radiographically?
- Synovial effusion, synovitis, round ligament hypertrophy and perifoveal cartilage erosion
=> LAXITY (precipitated by effusion)
PennHIP vs OFA
Which 2 features of bicipital tenosynovitis can be seen radiographically?
- Chondromalacia of bicipital groove and osteophytes at margin
- Mineralisation of tendon
Features of hypervitaminosis A
- Dietary oversupplementation (e.g. bovine liver), more often cats
- Can happen in 10 weeks.
- Connective tissue disorder
- CS: Obtundation, apprehension, reluctance to jump, hypersensitive to neck palp, lame
- Rx: Ankylosing spondylopathy of cervical and cranial thoracic vertebral column, and periarticular entehsopathy / DJD of shoulder and elbow
- NON-REVERSIBLE!
Features of mucopolysaccaridosis
- Tissue accumulation of GAGs
- MPS VI best studied
- Normal to short legged dwarfs with facial dysmorphism
TWO PHENOTYPES:
Less severe -> Shoulder and stifle DJD
Classical -> Dwarfism and dysmorphia
Rx: Epiphyseal dysplasia,osteopaenia, distortion of subchondral bone, ST mineralisation, vertebral malformation (Small and square bodies, elongated pedicles, malformed processes), new bone around process and anklyosising spnodylopathy;
Features of scottish fold chondro-osseous dysplasia (SFCOD)
- Auto dom -> association with folded ears
- Defective cartilage formation
- Rx: Joints and entheses, and some long bones (MC, MT and phalanges) affected
=> Large enthesophytes around joints, ankylosis arthropathy
=> Malformed bones in manus / pes (short and fat)
=> Vertebral malformations in tail -> short and wide caudal vert. spondylopathy
What is the typical progression of joint sepsis radiographically?
- Initially: Effusion and periarticular swelling
- Later: Subchondral and perichondral bone destruction
TABLE OF POLYARTHROPATHIES x 10 GROUPS!!!
Features of rheumatoid arthritis
- Dogs and cats
- Severe, progressive, EROSIVE polyarth
Rx include:
1) Subchondral bone destruction and cyst
2) Joint space narrowing
3) Progressive decreased opacoty of epiphyses
4) Destruction of subchonral and perichondral bone
5) Mushrooming of ends of metacarp/tars = SC bone collapse
6) Joint sublux / lux
+- Other features of OA
Features of hypertrophic osteopathy
- Generalised osteoproductive disorder of periosteum -> LONG AND SHORT TUBULAR BONES
- Usually caused by intrathoracic mass or cardiopulmonary disease. Abdo masses (particularly urinary) have been described
- Pathophys not understood
- TYpically distal, progressing proximally
- Periosteal surface nodular or spiculated
Features of villonodular synovitis
- Intracapsular joint disorder
- Nodular synovial hyperplasia -> may reflect response to trauma
- HORSES AND DOGS
- Carpus, hip, stifle
- Rx: ST swelling, erosion of bone at chondrosynovial junction +- cyst-like with opaque border.
=> In people, femoral lesions like “Apple core”
Features of synovial osteochondromas
- Islands of cartilage -> pedunculated / seperated
- Dogs and cats, BURMESE over-represented
- Rx: usually well-deinfed, rounded, often multiple mineralised intrarticular nodules
=> Can cause severe lameness, reported in dogs
DDx in cats: Mild MPS 6 and hypervit A
Features of synovial sarcoma
- Uncommon in dog, rare in cat -> Tends to be medium to large breeds, middle age
- Stife and elbow MOST COMMON
- Rx: Either side of joint, ST mass / partially calcified, spiculated periosteal response, erosion cortical none. MAY APPEAR NON-AGGRESSIVE INITIALLY
- Locally invasive and potential to metastasise -> lungs in approx 50%
Table of intraarticular calcified bodies
