Phillip D Jones, DVM, MS

Diplomate American College of Veterinary Surgeons

NAVICULAR SYNDROME AND HEEL PAIN IN THE PERFORMANCE HORSE

OUTLINE

• Causes for caudal heel pain

• Diagnostics and therapies

• Shoeing recommendations

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

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

NAVICULAR SYNDROME

• Important PE findings -contracted heels -atrophied frog-small foot compared with body size

NAVICULAR SYNDROME

• Medical therapy -shoeing changes-anti-inflammatory medications -rest

• Surgical therapy- PD neurectomy (criteria! & complications!)

DIAGNOSTICS

• Localization

• Palmar Digital Nerve block-Mepivacaine: 1 -1.5ml /nerve

DIAGNOSTICS

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

ADD NORMAL NB

Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008

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 12-40 month follow up.

SHOEING

• Key points:

• Correct and maintain dorsopalmar and lateromedial balance

• Ease breakover

• Maintain heel mass

• Protect palmar aspect of the hoof from concussion

MEDICAL THERAPIES

• Intra-articular injection

• Intra-bursal injection

• Tilduronic acid (Tildren)

• NSAID’s

• Isoxuprine-2.2% oral bioavailability

TREATMENT

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

TREATMENT

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

FRACTURE

Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008

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

BIPARTITE

Dyson- Radiographic Interpretation of the Navicular Bone. EVE 2008

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