Osteochondrosis
Osteochondrosis presents in animals that are? Signalment Please
Young, fast growing, large, pure breeds
Common CS and signalment
Pain, stiffness post rest, muscle atrophy, lameness
Old, big dogs, and TB horses
Typical CSs
Lameness, pain, Enlarged LNs, +- lung CSs
Types
Infectious and non-infectious (immune-mediated (erosive or not) and neoplastic)
What is it?
an infection of the cortex and medulla
Name two clinical signs
bilateral lameness and muscle atrophy
Why can it occur
secondarily to trauma, aging, infection and non-infectious inflammation, developmental dysplasia and OCD
Signalment and common locations for Osteosarcoma
Old large breed dogs, occasionally young ones
close to stifle away from elbow in metaphsyeal areas
old cats in hindlimb and good prognosis after amputation
Regardless of type what are some common clinical signs
Painful swollen joint, lameness, exercise intolerance, stiffness and if systemic or infectious pyrexia
Common CS
Lameness, heat, swelling, pain, febrile
Best practice for diagnosis and what could you see
radiographs and see flap/fragment at articular surface
Best Diagnostics
Radiographs for new bone deposition, narrow joint space
synovial fluid analysis for low viscosity, few neutrophils, low WBC
intrasynovial analgesia to estimate treatment effect
Best way to diagnose
Potential causes of infectious/septic arthritis
Bacteria (Staph, strepp, pasteurella)
Borriela (lyme disease)
Rickettsial (ehrlichiosis)
Protazoal (leishmania)
How can it occur?
Secondary to a surgery, or a trauma/laceration
Why does OCD occur?
Vascular injury causes cartilage at articular surface to detach or there is a problem with cartilage growth which affects bone growth
good treatment options
weight control, physiotherapy, NSAIDS (cox2 inhibition), intrarticular corticosteroids, joint supplements, surgery
Treatment
Limb amputation (4mo survival)
amputation + chemo (12-14 mo survival)
Radiotherapy and NSAID only palliative
Euthanize
Causes of non-erosive immune mediated polyarthritis
persistent antigenic stimulation causing abnormal B & T cell interaction which produces an AB/Ag complex which deposits in synovium and stimulates neutrophils and macrophages chemotaxis, hypersensivity type III
Diagnostics
radiographs, FNA+cytology to determine if bacterial, biopsy, culture and sensitivity
Treatment plans
Pain management, surgery to remove fragment
OCD in shoulder=better prognosis than if in elbow
Beware of secondary Osteoarthritis
Pathomechanism
loss of cartilage homeostasis stimulates matrix metaloprotinase (MMP) cytokines
synoviocytes release prostoglandins, MMP and cytokines causing more cartilage damage and DJD
Important consideration
Has it metastasized to lungs as in 90% of cases
causes of immune-mediated erosive polyarthritis
chronic synovitis leads to protease and collagenase causing proliferative granulation tissue (pannus) and erosion
Treatment plan
start on broad spectrum antibiotics, change to more specific ones after culture and sensitivity, surgical cleaning, remove any implants that are there