Hunter's Bump

1. What’s Your Diagnosis?

2. Hunter’s Bump = Sacroiliac Luxation

3. Sacroiliac Joint
✤ Attachment of the hind legs to the spine
✤ Non-mobile joint
✤ Transfers hind limb propulsive forces to
the vertebral column
✤ Prominence of the tuber sacrale occurs
when muscles/ligaments holding the SI
in place are torn

4. Hunter’s Bump

5. Diagnosis of SI Subluxation
✤ Musculoskeletal examination and gait analysis to determine if painful
✤ Hunter’s Bump can be chronic or acute:
✤ If the luxation is chronic but stable, the horse may not be painful.
✤ If the luxation is acute and unstable, hind end lameness is usually evident
✤ A Hunter’s Bump is evidence of SI disease.

6. Diagnosis of SI Subluxation
✤ Subluxation and pain can occur prior to visible
development of Hunter’s Bump
✤ lack of Bump does not rule out SI pain
✤ Ideally we would like to identify SI strain prior to
full luxation and visible changes to the pelvis
✤ Nuclear Scintigraphy(Bone Scan) - intravenous
injection of radioactive material and detection of
"hot spots" by use of a gamma camera.

7. Treatment for SI Subluxation
✤ Rest and controlled rehabilitation
typical for any soft tissue injury
✤ Ultrasound guided injection of
Steroids into SI joint to reduce
inflammation and pain