Bone Spavin Flashcards
Common cause of hindlimb lameness
Bone spavin
A bone spavin is DJD of which joints?
Distal intertarsal and tarsometatarsal joints (DIT, TMT)
Which aspect of the joint is affected by a bone spavin?
Medial
What predisposes to bone spavin?
Poor conformation (osteoarthritis)
What is normal pelvic limb conformation
Hips, hock, fetlock all in line anperpindicular to ground
Hindlimb too far cranial
Camped under
How should the cannon bone be relative to the ground?
Perpendicular to the ground
Hip and hock aligned but fetlock too far cranial
Sickle hocked
Medial deviation of the hocks
Cow hocked
What type of performance horses is bone spavin more common in?
Western
How many joints does the tibiotarsus (hock) joint have?
4
Little ledge for the man to sit on which splint bone in which view?
MT4 DLPM
DLPM highlights which aspects of the bones?
Dorsomedial and palmarlateral
Small osteophytes on rads
Grade 1 and grade 2 bone spavin
Medium osteophyte on rads
Grade 3 bone spavin
Large osteophyte on rads
Grade 4 bone spavin
What causes bone spavin?
Chronic repetitive compression, torsion and shear strains
What nerve block do you use to dx a bone spavin?
High 4-point
Which joint is not strained in a spavin flexion test?
fetlock
How long do you hold a spavin flexion test?
90sec
What is the DI modality of choice for bone?
CT
What is the surgical treatment for bone spavins?
Ankylosis
Why does medical management of a bone spavin usually work?
Low motion, high compression joint
What medical treatments can you do for bone spavin?
IA steroids/chondroprotectives/anti-inflammatories, corrective shoeing, exercise adaptation
Decreases rotational and shearing forces on the hock joint
Cunean tenectomy
Where do you transect the tendon for a cunean tenecotmy?
Medial aspect of limb
What are two methods of TMT/DIT joint ankylosis?
Mechanical and chemical
What mechanical methods can you use for joint ankylosis?
Drill, Nd:YAG/diode laser
What chemical can you use to destroy the cartilage in a joint for an ankylosis?
70% ethanol
What approach do you use for trans-articular drilling?
Medial approach distal to cunean tendon
At what angle should the drill tracts diverge from each other?
30*
When do most drilled ankylosis joints heal by?
7.5mo post-op
Destroys cartilage by superheading and vaporizing synovial fluid
Laser facilitated ankylosis
Promotes partial ankyloses but yields less pain and discomfort post-op
Laser facilitated ankylosis
Why would you do contrast rads prior to IA injection of 70% ethanol for ankylosis?
Make sure the joints don’t communicate
How soon after IA 70% ethanol does lameness resolve in horses w/bone spavin?
3mo (86% of the time)
What volume of 70% ethanol do you use for ankylosis?
3mL
