1. Navicular Syndrome and Heel pain in the performance horse
Phillip D Jones, DVM, MS
Diplomate American College of Veterinary Surgeons

2. Outline Causes for caudal heel pain Diagnostics and therapies
Shoeing recommendations

3. Caudal heel pain Navicular syndrome
Degenerative process that changes the bone-initiation and progression of the disease is a result of excessive and prolonged forces of compression on the bone
Important factors- signalment, conformation, and use

4. Navicular syndrome Mild to moderate intermittent lameness
Insidious onset
Perceived as shoulder lameness
Poor confirmation
Bilateral lameness
Lameness switches to contralateral limb after unilateral PD block

5. Navicular syndrome
Important PE findings -contracted heels -atrophied frog -small foot compared with body size

6. Navicular syndrome
Medical therapy -shoeing changes -anti-inflammatory medications -rest
Surgical therapy- PD neurectomy (criteria! & complications!)

7. Palmar Digital Nerve block -Mepivacaine: 1 -1.5ml /nerve
Diagnostics
Localization
Palmar Digital Nerve block -Mepivacaine: ml /nerve

8. Diagnostics

9. Navicular syndrome
Changes within the navicular bone edema vascular stasis enlargement of the nutrient foraminae cyst-like medullary areas subchondral bone changes changes in the flexor surface fragmentation of the distal border

10. Add normal NB

17. Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008

18. Shoeing Correct or preserve dorsopalmar and lateromedial foot balance
Hoof pastern angle should be straight
Foot trimmed to maintain heel mass and shorten toe to facilitate breakover
Elevation of heel may relieve pressure from DDFT on palmar aspect of navicular bone
Egg bar shoe: greater surface area disperses forces Of 55 horses with navicular disease 53% had permanent pain relief of lameness after egg bar shoes in month follow up.

21. shoeing
Key points:
Correct and maintain dorsopalmar and lateromedial balance
Ease breakover
Maintain heel mass
Protect palmar aspect of the hoof from concussion

22. Medical therapies Intra-articular injection Intra-bursal injection
Tilduronic acid (Tildren)
NSAID’s
Isoxuprine -2.2% oral bioavailability

23. Treatment

24. Caudal Heel Pain Desmititis of the collateral ligaments.
Tendonitis of the DDFT at 3 possible locations: -insertion -palmar to the navicular bone -proximal to the navicular bone
Desmitis of the impar ligament.
Desmitis of the distal annular ligament.
Synovitis in the distal interphaleangeal joint.
Synovitis in the navicular bursa.
Cystic lesion in the second phalanx

26. Treatment

27. Shockwave
Extracorporeal shock wave -generates a pulse wave within the body
Encourages growth mediators and other cytokines integral to the healing process
Offers temporary pain relief

28. Fracture
Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008

31. Bipartite Navicular Bone
Develops as 2 separate centers of ossification that never unite
Unilateral or bilateral
Broad well defined lucent line between the 2 pieces
Horse may be clinically normal, or have episodic lameness in full athletic function
No history of acute lameness as in fracture

32. Bipartite
Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008

33. ?