Hindlimb Lameness overview

Do medial and lateral femorotibial joint sacs communicate?

no

The medial femorotibial and femoropatellar joint sacs communicate what percent of the time?

80%

The lateral femorotibial and femoropatellar communicate what percent of the time?

20%

Where do osteochondrosis lesions most commonly occur?

lateral trochlear ridge of the femur

Where do subchondral bone cysts commonly occur?

distal medial femoral condyle

Osteochondral lesions develop _________ to improper ossification of growing articular cartilage

secondary

If osteochondrosis is symptomatic, what is the best thing to do?

arthroscopic procedure

Where is the 2nd most likely place for osteochondrosis to develop?

distal intermediate ridge of the tibia

First and second most likely location for bone cysts?

medial femoral condyle, distal MC3, proximal to MC1)

Would you expect a lot of effusion in bone cysts?

typically no

Your hors woke up from anesthesia in a crouched position, with inability to fully extend hindlimbs. What happened?

damage to femoral nerve, vet causes this. Patient stretched their nerve while asleep

What should you do to treat the femoral nerve?

sedate or anesthetize until nerve function returns

Is it normal to not be able to extend the horse hindlimb?

yes, this is normal. Should be extremely difficult to extend the horses hindlimb

What apparatus prevents hock extension when stifle is flexed?

reciprocal

WHat makes up the reciprocal apparatus?

fibularis tertius, superficial digital flexor

What would allow the hock to be extended when the stifle is flexed? prognosis?

fibularis tertius rupture, good prognosis

How would we fix a fibularis tertius tear? What is important about the head?

tie up in stall, but let the horse lower its head every few hours to expel mucous that may have accumulated in the nares of the horse

Could you also place a cast on a patient to treat a fibularis tertius tear?

yes

If a horse is unable to extend its hock on its own, what has torn?

SDF

Prognosis for SDF tear in foals? Adults?

good, poor

What are the common causes for a locking patella?

laxity or stretching of middle and medial patellar ligaments

What is the normal stifle angle?

135 degrees

What are the two clinical manifestations of a locking patellar?

prolonged or intermittent

Will the horse have to be helped to disengage the patella in prolonged fixation?

yes

WHat are the two forms of intermittent patellar fixation?

beginning of stride, end of stride

How to test for upward fixation?

manually lock in upward

How can you unlock the patella?

back the horse up, sharp blow to lateral limb

What was the old treatment for patellar fixation? why is this not done?

cut medial patellar ligament, caused 10-40% lameness

New treatment for patellar fixation?

inject a counter-irritant or have the horse run up hills or in soft footing

What is medial patellar desmoplaty?

similar to tendon splitting, several incisions made in ligaments

What is the goal of treatment for patellar fixation?

roughen and thicken the middle and medial patellar ligaments

What injection is used to thicken the middle and medial patellar ligaments?

2% iodine in oil

What is it called when there is hyper-flexion of hind limb as each stride is initiated?

stringhalt

WHat are the 3 causes of stringhalt?

faulty input from stretch receptors, scarring of lateral tendon sheath, ingestion of hypochoeris radicata

If the cause of stringhalt was lateral digital extensor scaring, what would you do?

LDE tenectomy

What is fibrotic myopathy and what does it affect?

a fibrous/bony scar that affects the semitendinosus muscle and fascia

How would you fix fibrotic myopathy?

semitendinosus tenotomy

What is bone spavin?

fusion of joints seen with ankylosis(more so joint space narrowing)

What is bog spavin?

tibiotarsal joint effusion

What is curb?

inflammation of long plantar ligament

How to tell difference in bog spavin vs thoroughpin?

In bog spavin, effusion will go dorsally. If thoroughpin, will go distally