Intro to cases that block to the foot with no localising signs Flashcards
what should you observe on static exam when dealing with a lameness that has been localised to the foot?
Foot conformation:
* Size, shape and symmetry of feet
* Contraction of heel bulbs
* Hoof balance
Unshod or shod
* Type and fit of shoes
* Abnormal ware to shoe
Palpation:
Often no heat, pain or swelling
* Can palpate effusion in the distal interphalangeal joint
what should you observe on dynamic exam when dealing with a lameness that has been localised to the foot?
Walk
* looking for obvious lameness - won’t then do next step
* how the foot land → should be flat not heel / toe / side first
Straight Trot
* most useful gait for assessing lameness
* head nod for unilateral lameness
* short and stiff if bilateral lame
Trot on lunge
* both reins, hard and soft surfaces
* lameness usually worse with on inside and on hard
what nerve block is this? what structures does it anaesthetise?
plamet digital nerve block
ALways numbs:
* Sole
* Heel bulbs
* Palmar & distal P3
* Navicular bone
* Navicular bursa
* Distal DDFT
* Impar ligament
* Palmar DIP joint
Variably numbs:
* Dorsal P3
* Dorsal laminae
* Dorsal DIP joint
* Collateral ligaments of coffin joint
* Distal P2
* Collateral cartilages
what local anaesthetic and how much do you use for equine nerve blocks?
1.5-2ml of mepivacaine
causes less tissue reaction than lignocaine
what nerve block is this?
Abaxial sesamoid nerve block - numbs the digital nerve but higher up
what nerve block is this? what is important with this block?
distal inter-phalangeal joint block
need a sterile approach, should have no resistance when injecting
what are the differential when a horse lameness blocks to the foot with no localising signs?
- DIP joint OA (coffin joint)
- Navicular bone degeneration
- Navicular bursitis
- Fracture of P3 or navicular bone
- DDF Tendonitis
- Impar ligament desmitis
- DIP collateral ligament desmitis
- Hoof imbalance
- Subchondral cystic lesion
- Pedal osteitis
- Mineralisation of lateral cartilage - ‘sidebone’
what 5 radiographic veiws can you take of the equine foot?
- Latero-medial
- Standing dorso – palmar
- Dorsal 60°proximal – palmar distal oblique of pedal bone - upright pedal
- Dorsal 60°proximal – palmar distal oblique of navicular bone - upright navicular
- Palmar 45° proximal – palmar distal oblique of navicular bone - flexor navicular
what structures can you visulise on ultrasound when dealing with foot lameness?
Proximal end of coffin joint collateral ligaments
DDFT between heel bulbs
Insertion of DDFT through frog
describe the hoof pastern axis in each of these legs
what is the normal load bearing balance in horse hooves?
place line through center of p2
what should the angle of the distal phalax be in a horse?
what is more imporntant dynamic hoof balance or standign latero medial hoof balance?
the dynamic hoof balance is more imporntant, the hoof needs to hit the ground evenly and flat when it lands durign striding. Standing posture is less important
what is shown here?
Subchondral cystic lesion
* Osteochondrosis
* Traumatic – part of OA
* Rare
what is shown here?
pedal osteitis
- Irregular lysis of solar margin of distal phalanx
- Occurs following chronic pressure or inflammation within hoof - e.g. repeated concussion / chronic laminitis
- Differentiate from ‘crena’
- normal symmetrical indentation at toe
what is shown here?
mineralisation of lateral cartilage - side bone
- Common incidental finding
- Front feet of older, heavier horses
- Can cause lameness:
- During formation
- If traumatised / fractured
