Equine soft tissue injuries of the distal limb Flashcards
What is strain
the amount a tendon elongates for amount of stress put into it
Curve not linear
Sections of stress strain graph
1 = straightening of tendon crimp, don’t get much deformation
2 = elasticc deformation; tendon absorbs lots of strain before deforming and returns elastic energy
3 = non-elastic deformation; potential for microdamage here
4 = failre/rupture
What safety factor do most equine soft tissues have
only 1.2
What is COMP
Cartilage oligometric matrix peptide
Involves in organising collagen into efficient systems; high early in life esp in middle of SDFT where it needs to be more elastic
What age is COMP high i.e window to make a difference with tendon education
<3 years
Difference in collagen in DDFT between mid metacarpal region and fetlock
In mid metacarpal region, more elastic with lots of type 1 collagen
In fetlock region, it is changing direction and needs to be resistant to compreeion; more type II colagen
What is chondroid metaplasia
Where there is more type II collagen in a tendon so it is more ike cartilage
See this where tendons change direction
Also after injury
What has suspensory ligament evolved from
interosseus muscle; so it has some muscle fibres and fat
Where do most SDFT injuries happen
Mid metacarpal region; mostly forelimb
Where do most DDFT injuries happen
Where it changes direction i.e around fetlock within tendon sheath or around navicular bone wihtin hoof
Where do suspensory ligament injuries tend to happen
At prox origin + insertion onto prox sesamoid bones
Where do check ligament injuries happen and how do they present
IN prox third of forelimb metacarpus on lateral side
Get a pathognomic lateral swelling
What are common soft tissues around stifle that get injured
Cruciate ligament
Medial meniscus
When does most tendon education happe
in the foal so want foal to be active
Why should we refrain from training horses at competition standard too often
Because this puts them in stage 3 of stress/strain graph i.e above threshold for microdamage of tendons
What are the advantages/disadvantages of overreach boots and when should we use them
can stop overreach injuries
But contributes to physiologcal heating effect in tendons so can cause denaturaiton
Only use in horses that tend to overreach
What happens in the remodelling phase o tendon injury
Tendon size decreases
Transformation back to springy type I collage from type III
Why do scar tissue lesions in tendons tend to extend proximally and distally over same cross sectinoal area
Because this section is non-compliant so during tendon stretch there is pulling on the parallel fibres above and below the lesion
What structures are within the digital flexor tendon sheath
DDFT
SDFT
MAnica flexoria
Palmar/plantar annular ligament
what is the manica flexoria
Part of SDFT which forms a tunnel for DDFT to travel through
What is the annular ligament and what happens when it gets injured
= ligament that holds DDFT/SDFT in canal
Very uncompliant tissue
When it is injured and heals, it shortens causing constriction of the tendon sheath, this leads to effusions around flexor tendons and even more compression and inflammaiton
= compartment-like syndrome
How do treat palmar annular ligamnet syndrome
Cut the palmar annular ligament
Characteristics of ultrasound as a diagnostic device for soft tissue injuries
High specificity
Low sensitivity
Why is it. agood idea to do tenoscopy and removal of torn manica flexoria parts
Because they drive tneon injury
What do we see with a peroneus tertius tear
Reciprocal apparatus breaks down
Can extend the tarsus without extending stifle
What is peroneus tertius the antagonist of
SDFT
What horses is locking stifle seen most in
Miniature horses
How to treat locking stifle in mild vs severe cases
mild = rehab
severe = medial patellar ligament desmotomy
Which meniscus is more commonly injured and which aspect
Medial meniscus as cranial aspect
How to diagnose meniscal injuries
arthroscope
U/S can be used for severe ones
What kind of lameness is cruciate ligament injury associated with
Acute, severe lameness rather than degeneration
What can we do to treat refractory cases of soft tissue injury in tarsal region
Neurectomy of deep branch of lateral plantar nerve
+ plantar fasciotomy to allow ligament to swell out
What is a contraindication for neurectomy of lteral plantar nerve for lameness in tarsal region
marked ligament degeneration because the neurectomy can accelerate degeneration
What sort of injuries would be candidates for biological therapies
Need something to inject into
e,g tendon core lesion
injuries within synovial structures
Are bone marrow or adipose derived stem cells better
Bone marrow e.g from sternabrae
How good is platelet rich plasma in soft tissue injury
Seems to heal quicker but just as likely to re-injur so less populat now
What is the only consistently proven practctice to improve soft tissue injuries
Controlled exercise programH
How to do a controlled exercise program
Start early with walking in hand
Increase work gradually over 6-12 weeks
Don’t turn out free until up to canter level work in school
What type of laser has the best effect in soft tissue injury
Class 4
Difference between water treadmill and swimming
Water treadmill provides stress for bones and soft tissue to make them heal
Adds resistance
vs swimming good for aerobic fitness
What sedatino choice would be good for scanning a horse
detomidine; gives 45 mins sedation
+ butorphanol
What frequency probe do we use for tendon scanning
High freq linear probe
This gives good tissue detail (traded off against low depth but this isn’t needed)
What is a lameness with thickening on lateral aspect of prox third of metacarpu s likely to be
Check ligament injury e.g split injury
Large swelling on back of tarsus/carpus localises to where
Digital flexor tendon sheath
Swelling over lateral aspect of distal metacarpu s might be injury to what structure
suspensory ligament (this is where it inserts on prox sesamoids)
Why is the fibre pattern in a torn tendon so poor
Because it is not under tension
See similar finding when a non-weight bearing tendon is scanned
How should shockwave threapy be delivered for best results; weight bearing or not
Non-weight bearing
