The foot

Question 1

Key points to hoof anatomy

Answer 1

Foot hangs in suspension off the dorsal hoof wall - laminae

Digital cushion faily susceptible to penetration

Question 2

Differential diagnoses for acute, severe, unilateral lameness

Answer 2

Subsolar abscess
Pedal bone fracture

Question 3

Solar bruising

Answer 3

Simple solar bruising is common and due to blunt sole trauma.

Can vary from contusion to haemorrhage.

Tissues become inflamed, vascularity increases, oedema develops.

Question 4

Risk factors for solar bruising

Answer 4

Surface: uneven or highly concussive surfaces

Shoeing/farriery: barefoot horses will be more prone, long shoeing interval (particularly corns)

Activity type: horses used for hacking will be more likely

Activity level: repetitive concussive forces

Conformation: horses with flat foot and low heel conformation

Question 5

Treatment for solar bruising

Answer 5

NSAIDs and rest

Shoeing changes can be preventative

Question 6

Subsolar abscessation

Answer 6

The most common cause of acute severe lameness

Form between the sensitive and non-sensitive tissues
- white line
- seat of corn
- frog

Question 7

Signs of subsolar abscessation

Answer 7

Increased digital pulses

Sensitivity on hoof testers

Question 8

Treatment of subsolar abscessation

Answer 8

Paring knife -> drainage

Foot bandaging (poulticing) to achieve or maintain drainage

NSAIDs

Question 9

Foot penetrations

Answer 9

Often involve nails from fencing and stabling.

Radiography with the nail in situ can help locate its tip

MRI is the accepted gold standard

Treatment can vary from poulticing to navicular bursoscopy depending on extent of injury

Question 10

Causes of recurrent or persistent foot abscesses

Answer 10

Keratoma

Septic pedal osteitis

Pedal bone fracture

Question 11

Keratoma

Answer 11

Space occupying mass growing down the length of the hoof which requires a hoof wall resection to remove

Question 12

Septic pedal osteitis

Answer 12

A severe clinical condition and is a therapeutic challenge

Resorptive lesions on radiorgaphy - lysis of bone

Question 13

Pedal bone fracture

Answer 13

Will improve much slower than an abscess

Question 14

Navicular Syndrome/Palmar Heel Pain/Podotrochleitis

Answer 14

Truly an MRI diagnosis, but radiography can identify navicular bone changes

Associated with disease of the DDFT, impar ligament, navicular suspensory ligament

Often responds to mediation of the DIPJ or navicular bursa

Farriery is a key factor in successful management

Question 15

Ossified collateral cartilages

Answer 15

over diagnosed!

But a true focus of lameness in some cases

Associated with collateral ligament injuries -> common aetiology

Foot balance is key

Question 16

Basic imaging modalities for soft tissue injuries

Answer 16

Radiography
- identifies evidence of soft tissue disease

Transcutaneal ultrasound
- small window through the frog to visualise a section of the DDFT and DSIL, requires careful foot preparation and overnight soaking
- proximal navicular bursa visible between heel bulbs

Question 17

Examples of bony evidence of soft tissue injury

Answer 17

Navicular bone changes seen with DDFT disease

Ossified collateral cartilages are associated with collateral ligament disease

Enthesiopathy seen with impar ligament disease and collateral ligament disease

Question 18

Transcuneal ultrasound

Answer 18

Small window through the frog to visualise a section of the DDFT and DSIL
○ Requires careful foot preparation and overnight soaking

Proximal navicular bursa visible between heel bulbs

Question 19

MRI of the equine foot

Answer 19

Standing low-field MRI is an investment à >£1000 for a single foot

Benefits of MRI:
○ Likely definitive diagnosis/diagnoses
○ More accurate prognostication
○ Guided specific medical treatments
○ Specific indications for farriery

Question 20

Core lesions of DDFT

Answer 20

Seen with various severities

Found at different locations along the length of the tendon
§ Tend to do worse more distally

Can propagate proximally/distally with time
§ Care with neurectomy due to this - should do MRI before

Question 21

Sagittal splits of DDFT

Answer 21

Often seen at the level of the navicular bone

Often propagate proximally/distally with time
§ Especially after neurectomy

Involve tendon surface so can lead to adhesion formation and bursitis

Lameness often severe but very variable

Question 22

Dorsal border of the DDFT

Answer 22

Dorsal border fibrillation

Often causes bursitis and adhesion formation

More of a degenerative pathology rather than acute injury

Management can be surgical or medical

Question 23

Treatment of DDFT injuries

Answer 23

Intrabursal medications:
§ Biologics in the acute phases of injury
§ Corticosteroids to manage long-term signs

Navicular bursoscopy:
§ Indicated for all lesions seen to communicate with the bursa
§ Sagittal splits and dorsal fibrillation particularly
§ Can break down adhesions surgically
§ Debride fibrillated tissues which are drivers for synovitis
§ Only box rested for a week or two

Question 24

Impar ligament disease

Answer 24

The ligament itself is utterly indistinct with a complete loss of the normal architecture.

Pedal bone – at the insertion of the impar ligament there are two osseous cyst-like lesions in the cortex of the pedal bone.

The largest of which extends approximately 6mm into the bone (white arrow).

Question 25

What can a foot with dorsopalmar/dorsoplantar foot imbalance cause?

Answer 25

increased/decreased loading of palmar/plantar soft tissues:
SDFT, DDFT, SL, DSIL….

Question 26

What will poor lateromedial imbalance cause?

Answer 26

Increased loading of lateral and medial soft tissue structures:
Collateral ligaments, navicular suspensory ligament

Question 27

Bar shoes

Answer 27

The heart bar shoe has been the mainstay of providing pedal bone support in a variety of conditions.

There are three main benefits here:
* Some load is transferred from the hoof wall to the sole
* Independent movement of the heel bulbs is reduced and therefore reduces stress to tissues in the heel region
* Better loading of the heel region can stimulate better quality heel growth

Although some new techniques have come along, you will still see these shoes with good success.

Question 28

Pads and packing material for hooves

Answer 28

Pads, often with raised profiles where the frog sits to allow some transfer of force to the solar tissues and pedal bone

Resins and impression materials can be injected into the space between the pad and sole to reduce concussion, directly transfer force across the whole sole and support the pedal bone

Question 29

Graduated pads and shoes

Answer 29

Lame horses e.g. DDFT tear within the foot
- reduces the strain on the DDFT

Should only be used in the short term to prevent progression of poor foot conformation