Flashcards in Cartilage Development and Joint Dx (Pead) Deck (23):
What is a "joint" composed of? (tissue wise)
- joint capsule
- ynovial membrane
- synovial fluid
What zones does the end of a juvenile long bone consist of?
- physis (growth plate)
- epiphysis (covered in cartilage)
> cancellous bone to spread the load
Wht may be seen at the end of an adult longn bone?
" suture line" where growth plate closed (not a physis)
Why do limb deviations result?
- damage to the physis, eg.
> ridge within joint
> bridging of bone across the physis
What are lateral and medial deviations of the limbs referred to as?
- valgus deformity = lateral deviation of the distal limb
- varus deformity = medial
Whicch way will the limb deviate if physis is demaged?
Towards the side of damae
Is it normal for the epiphysis to expand during growth?
What is "osteochondrosis"? eg?
- term for a group of conditiions affecting the developing cartilage and its supporting bone
> OCD (osteochondrosis dessicans)
> Subchondral bone cyts (SBC)
> Peri-aritcular fx/fragmentation
- NB. human medical textbooks this refers to a more specific dz
Most common eg. of peri-articular fragmentation/fx?
- detachment of chondral or oseteochondral fragment fromt he peri-aritcular area
- eg. canine elbow (frag/fx of MEDAL CORONOID PROCESS) FCP/FCMP
What is osteochondrosis initiated by?
- vascular problem in the epiphysis
- failure of normal cartilage bone succession
Outline the pathogenesis of osteochondrosis dessicans
- section of wedge of epiphysis does not turn into bone, emain cartilagenous
- fissures develop
- wedge stuck down by fibrous repair tissue
- OR break off and float into joint capsule, causing abnormal wear elsewhere in the joint
How does a subchondral bone cyst form?
- excessive cartilage in one section of the bone
- beins ossifying again
- isolated area of cartilage bubble under the surface (weak spot) changes loading of the joint, might be painful, unstable etc.
> most common horses
Where is osteochondrosis commonly seen?
- OCD, FCP fragmented choronoid proces), UAP (ununited anconeal process)
- esp. elbow shoulder, stifle, tarsus + otehrs
- OCD, SBC
- stifle, tarsus, MCP, PIP, DIP, shoulder, elbow, carpus
- OCD esp hip
> broiler chickens
- OCD stifle
> all fast growing, high performance, YOUNG patients
Presentation of ocd?
+- joint effusion
- often bilateral
- - varibale lameness
- subclinical dz possible
- large, young, fast growing, purebred
- excericse intolerant
- partially responsive to analgesia
- partially responsive to rest
- Pain on MANIPULATION of affected joint
First plan of action for investigating joint dz?
Tx of joint OCD? (juvenile,d evelopmental dz)
- fragment removal
- encourage repair (fibrocartilage, rarely get hyaline cartilage back)
> generally prognosis variable
- related to formation OA
- shoulder forms little OA (so prognosis is good) cf. elbow (prognosis poor)
How does OA differ in animals to humans?
> humans commonly aging process
> animals 2* to 1* predisposing disease
- worsened or exacerbate by age
How can fragented medial choronoid process by visualised?
- NEeds CT
Tx elbow elbow medial choronoid process fragent?
- fragment removal
- encourage repair
> novel tx that change anatomy
> prognosis complicated
- depends on degree of OA
- may need salvage (salvage procedure/joint replacement)
What must you be careful of when manipulating joints?
- holding bones t oo tightly
- panosteitis can be confused for joint pain
How does osteochondrosis lead to OA?
- direct cartilage damage
- incongruency, mechanical incompetence
- cycle of reaction
- often temporarily stabilises in young adult
Prog for OCD/O in a young animal?
Not likly to excercsie maximally but otherwise life prog good! Dont be too negativve with owners.