Fetlock - MCP/MTP Flashcards
Five routine radiographs of the fetlock
Lateral, flex lateral, DP, DLPMO, DMPLO
Purpose of the flex lateral
Expose sagittal ridge, most common sight of osteochondrosis in the fetlock
Purpose of slight downward angle of DP of fetlock
Separate the proximal sesamoids from the joint
Three important soft tissue structures on the lateral view of the fetlock and how to differentiate
Fetlock joint capsule, branches of suspensory ligament, digital sheath of the flexor tendons
Differentiate joint effusion/synovitis from digital sheath effusion/synovitis based on location in reference to suspensory branches
Joint cranial to, sheath caudal to
Oblique views of the fetlock are good for evaluating what three things
Dorsoproximal eminences and Palmar/plantar processes of P1
Abaxial margins of sesamoids
DJD in the fetlock joint
Early -3
Late -3
Always look for…
Early – increased intracapsular soft tissue (effusion and/or synovial proliferation), osteophyte production, enthesophyte production
Late – narrowing of the joint space, cystic areas of subchondral demineralization, ankylosis
Inciting cause
Fetlock DJD – Locations
osteophyte production
enthesophyte production
O– Most prominent along the dorsal medial and dorsal lateral margins of the joint as seen in the oblique views
E– Distal aspect of collateral fossa – Superimposed on DP
Sesamoiditis definition
Commonly seen in
Radiographic findings – 3
Chronic repetitive trauma of suspensory ligament may result in tearing of the attachment of suspensory ligament branches at the abaxial margin of the sesamoid bone and causes remodeling of the proximal sesamoid Bones
Young race horses, +/- lameness
– Enlarged vascular channels
– Ill defined lysis
– enthesiopathy of Suspensory ligament branches and sex more than ligaments
Osteomyelitis of the proximal sesamoid bones
Most often occur at blank and concurrently with blank
Clinically appear blank and prognosis is blank
Articular surface of the axial margin and concurrently with septic Tenosynovitis of the flexor sheath and/or septic arthritis of the fetlock
Severely lame and guarded prognosis
Three parts of the proximal sesamoid bones
Cause and prognosis based on fracture location
Apex – Best, secondary to strain placed on the suspensory apparatus
mid body – poor, racing injury
Basilar – poor, there a bed race horse, avulsion fracture at attachment site of distal sesamoidean ligament
Dorsoproximal P1 osteochondral fragment
Pathogenesis
Side that is more common
Developmental or hyperextension of fetlock
Medial
Palmar/plantar P1 fragments
Etiology, common breed, Common location, clinical presentation
Best view to appreciate this injury
Unknown, standardbreds and thorough breads, metatarsophalangeal joint, may not see any lameness or lameness only at high-speed
Oblique
MC/MT III fracture
Most often seen in…
Side most often affected
Two views to appreciate fracture
Racehorses
Lateral
125DP “Bucket shot”, flexed DP, want to superimpose sesamoids over MCP/MTP to provide contrast to appreciate fracture line
Osteochondrosis definition
Disturbance in process of Endochondral ossification
Osteochondritis dessicans definition
When osteochondrosis disturbance leads to semi-loose or loose fragments in the joint
