The foot Flashcards
Key points to hoof anatomy
Foot hangs in suspension off the dorsal hoof wall - laminae
Digital cushion faily susceptible to penetration
Differential diagnoses for acute, severe, unilateral lameness
Subsolar abscess
Pedal bone fracture
Solar bruising
Simple solar bruising is common and due to blunt sole trauma.
Can vary from contusion to haemorrhage.
Tissues become inflamed, vascularity increases, oedema develops.
Risk factors for solar bruising
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
Treatment for solar bruising
NSAIDs and rest
Shoeing changes can be preventative
Subsolar abscessation
The most common cause of acute severe lameness
Form between the sensitive and non-sensitive tissues
- white line
- seat of corn
- frog
Signs of subsolar abscessation
Increased digital pulses
Sensitivity on hoof testers
Treatment of subsolar abscessation
Paring knife -> drainage
Foot bandaging (poulticing) to achieve or maintain drainage
NSAIDs
Foot penetrations
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
Causes of recurrent or persistent foot abscesses
Keratoma
Septic pedal osteitis
Pedal bone fracture
Keratoma
Space occupying mass growing down the length of the hoof which requires a hoof wall resection to remove
Septic pedal osteitis
A severe clinical condition and is a therapeutic challenge
Resorptive lesions on radiorgaphy - lysis of bone
Pedal bone fracture
Will improve much slower than an abscess
Navicular Syndrome/Palmar Heel Pain/Podotrochleitis
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
Ossified collateral cartilages
over diagnosed!
But a true focus of lameness in some cases
Associated with collateral ligament injuries -> common aetiology
Foot balance is key
Basic imaging modalities for soft tissue injuries
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
Examples of bony evidence of soft tissue injury
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
Transcuneal 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
MRI of the equine foot
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
Core lesions of DDFT
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
Sagittal splits of DDFT
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
Dorsal border of the DDFT
Dorsal border fibrillation
Often causes bursitis and adhesion formation
More of a degenerative pathology rather than acute injury
Management can be surgical or medical
Treatment of DDFT injuries
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
Impar ligament disease
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).
What can a foot with dorsopalmar/dorsoplantar foot imbalance cause?
increased/decreased loading of palmar/plantar soft tissues:
SDFT, DDFT, SL, DSIL….
What will poor lateromedial imbalance cause?
Increased loading of lateral and medial soft tissue structures:
Collateral ligaments, navicular suspensory ligament
Bar shoes
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.
Pads and packing material for hooves
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
Graduated pads and shoes
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
