Equine Tendon and Ligament Disease Flashcards
What are the types of tendon injury?
‘Percutaneous’ - laceration or penetration
‘Subcutaneous’ - Strain or displacement
What are the causes of overstrain injury in equids?
Sudden overextension - DDFT
Preceding tendon degeneration with superimposed sudden overextension - SDFT, SL
What is a typical history of a horse with a tendon injury?
There is usually a preceding intense period of exercise, although signs can be delayed.
What is the area most prone to injury in the equine limb?
Weight bearing tendons on the palmar aspect
Describe the stance and gait in a clinical evaluation for diagnosis in equine tendon injury…
MCPJ extension decreased with: - reduced weight-bearing (pain) - fibrosed (stiff) tendons increased with severe SDFT/SL injuries
Elevated toe
- DDFT rupture (bears weight and the toe lifts, pathognomic)
What do you need to look at during palpation in the lame horse?
Observation - site of metacarpal swelling
Palpate - weight bearing (it is not possible to elicit pain in the standing horse as you can’t squeeze the tendons), limb lifted
Some area difficult to palpate - proximal SL in hindlimb
Assess BOTH LIMBS
What is the role of diagnostic ultrasonography in the lame horse?
Diagnosis - affected limb and normal limb
Assessment of severity - around 7 days after injury in order to assess the prognosis
What equipment do you need to perform diagnostic ultrasonography on equine tendons and ligaments?
7.5+ MHz linear transducer
Describe superficial digital flexor tendinopathy…
Palmar metacarpal swelling
Initial lameness variable
Pain on palpation
‘Core’ lesion on ultrasound
What is the typical history of a horse with suspensory ligament desmitis or proximal suspensory desmitis?
Lameness variable in degree
Acute or insidious onset
What are the clinical signs of suspensory ligament desmitis or proximal suspensory desmitis?
Confirmation (hindlimb)
Straight hock, overextending MTP joint (unknown which comes first)
Lameness
Often lamer with the limb on the outside of a circle
Proximal MC/MT swelling, this can be very transitory, so there may be none or very little when you arrive or palpate. Swelling is variable and there can be medial palmar vein distension (although this can occur with any soft tissue injury at this location).
Pain on palpation
Describe the ultrasonography of suspensory body and branch desmitis…
Branches need imaging from medial and lateral aspects
Focal or generalised lesions
Enlargement
Peripligamentar fibrosis is very common
Bilateral involvement is common
Describe the radiography of suspensory body and branch desmitis…
Often concurrent bony abnormalities; attachment sites on bones that may occur in response.
What is another name for the DDFT?
Inferior check ligament
Describe the signs of desmitis of the DDFT..
Swelling in the proximal metacarpal region
Dorsal to the SDFT
Lameness is variable, but often absent
Ultrasonography shows a general enlargement
Describe ultrasonography of intra-thecal tendon tears…
Ultrasonographic diagnosis is difficult
Lateral or medial echogenic “material”
Oblique views
MF instability in longitudinal view
Contrast tenography
Describe the lameness of annular ligament syndrome…
Mild to moderate
Minimally responsive to rest
Occasionally irregular gliding of tendons
What is the importance of the synovium?
Important for frictionless movement of tendon over the joints.
What can cause dysfunction of the digital sheath?
“Idiopathic” distension
Penetrating injuries - sepsis
Non-septic inflammation (primary and most secondary)
What are the three phases of tendon healing?
- Acute (inflammatory) phase
- Subacute (fibroplasia) phase
- Chronic (remodelling) phase
What are the clinical signs of the acute inflammatory phase of tendon healing…
0-2 weeks Lameness Pain on palpation Heat Swelling
Describe the pathology in the acute inflammatory phase of tendon healing…
Haemorrage
Inflammation
- Neutrophils
- Macrophages and monocytes
- Increased blood flow
- Oedema
- Proteolytic enzymes
What is the rational treatment for the acute phase of tendon healing?
Minimise inflammation
How can inflammation be minimised in the acute phase of tendon healing?
Physical therapy
Application of cold (ice)
Compression
MCP joint support (rest!)
Medication \+ Short acting steroids -- only with 24/48 hours systemically or peritendinously -- beware of laminitis \+ NSAIDs -- analgesia
Surgery
- Percutaneous tendon splitting
knife
- Needles (possible to combine with intra-tendinous medication)
What are the clinical signs of the subacute, reparative phase of tendon healing?
1 wk - 6 mons
Reduction or absence of lameness
Resolution of signs of inflammation
Tendon still palpably enlarged and soft
Signs of reinjury if exercised too early
What is the pathology of the subacute, reparative phase of tendon healing?
Angiogenesis
Fibroplastia
What is the treatment rationale for subacute, reparative phase of tendon healing?
Promote fibroplasia
Optimise organisation of scar
What is the pathology of the chronic remodelling phase of tendon healing?
3 - 18 months
Collagen transformation from type III to I
Crosslinking
Thicker collagen fibres
What can extracorporeal shockwave therapy be used for?
Proximal suspensory desmitis
What are the possibly aetiologies of flexural limb deformities?
Congenital
- Uterine malpositioning
- Common digital extensor tendon rupture
Acquired
- Part of developmental orthopaedic disease
- Pain (OCD etc)
How can you treat carpal flexural deformity?
Exercise and physiotherapy
Tube cast
Surgery
How can you treat flexural limb deformities?
Exercise
Shoeing
Splints
Surgical release
Describe the two types of distal interphalangeal joint flexural deformities…
Type 1
Dorsal hoof wall is less than vertical
Type 2
Dorsal hoof wall is past vertical
How would you treat type 1 DIP joint flexural deformity?
Exercise and physiotherapy
Toe extension shoe
Surgery (desmotomy of the ALDDFT, DDFT tenotomy)
How would you treat type 2 DIP joint flexural deformity?
Usually needs surgery
Desmotomy of ALDDFT
DDFT tenotomy
What are the types of tendon laxity?
Congenital
Acquired (secondary to casting)
How can you treat metacarpophalangeal joint flexural deformity?
Exercise or physiotherapy
Tow extension and raised heel shoe
Splint or braces
Surgery
