Tendon and Ligament injuries

Question 1

SDFT tendonitis

• common (2)
• types (2)
• pathogenesis

Answer 1

• mid metacarpus
• common in race horuses
• degeneration: accumulation of microdamage –> weakened tendon –> major injury at normal loading
• acute overload: normal tendon, excessive overload (uncommon)

Pathogenesis:

inflammation only –> stretching and slipping of fibres –> fibre rupture –> tendon rupture

Question 2

SDFT tendonitis

-CS (3)

Answer 2

• localised swelling (possible oedema and heamorrhage), heat and pain
• lameness
• sinking of fetlock

Question 3

SDFT tendonitis US

• how
• looking for (5)
• core lesion

Answer 3

• 7.5-10mHz: good resolution but not a deep penetration
• confirms sturctures involved
• echogenicity
• CSA % and lesion
• longitudinal fibre pattern
• oedema

core lesion:
haematoma (anechogenic) –> granulation tissue (anechogenic) –> fibrous tissue ( hypo–>hyperechogenic as it matures)

Question 4

SDFT tendonitis Repair

Answer 4

Acute = inflammatory phase (2-4w post injury)
• limit inflammatory response→ further tendon damage & minimise scarring
1. Box rest
2. Application of cold
3. Firm and even bandaging between cold therapy
4. NSAIDs

Subacute = repair phase (1-3m post injury):
• encourage collagen production, longitudinal fibre orientation, prevent formation of restrictive adhesions
• promote restoration of normal tendon architecture & prevent re-injury
• Box rest & passive motion, then gradually increasing periods of walking in hand
– Start with 5 minutes twice daily
–Swimming

Chronic = remodelling phase (>3m post injury)
• promote remodelling & prevent re-injury
• Gradually increasing exercise (Do not turnout for 4-6m, no fast work 6-10m)
• Return to full exercise
– depends on US appearance
– Prolonged convalescence required (9-13m)

Question 5

SDFT tendonitis monitoring healing (4)

Answer 5

US!
• Used to tailor exercise programme to healing
• 2-3 monthly exams, timed to coincide with imminent increase in exercise level
• Aim for continuing ↓ in CSA of tendon & lesion, ↑ echogenicity, ↑ fibre alignment (

Question 6

Other treatments for SDFT tendonitis

Answer 6

• Platelet-rich plasma
- Source of growth factors, attract resident stem cells → tissue regeneration
- Acute & subcute phase
• Stem cells
- modulate local inflammatory response and attract resident stem cells
• Hyaluronic acid (HA) – tendon sheath
• Polysulphated glycosaminoglycan

Question 7

DDFT injuries (3)

Answer 7

• tendonitis/tears more common in FL>HL: FL carries more weight than HL
• Fetlock region: subject to compression
lacerations most common in pastern

Question 8

Distension of digital flexor tendon sheath

• what
• associations (3)
• chronic CS (4)

Answer 8

• Synovitis of sheath (tenosynovitis)
• May be associated with:
➢ SDFT or DDFT injury
➢ Annular ligament desmitis
➢ Subcutaneous fibrosis (chronic phase)
•  Fetlock canal is inelastic " potential for compartment-like syndrome

• Chronic, low grade synovitis, horse not lame is common
– Frequently bilateral or quadrilateral distension
– Look for subcutaneous fibrosis at back of fetlock
– Potential for a compartmental syndrome

Question 9

Distension of digital flexor tendon sheath

• Investigation (3)
• Tx
  - -> first (3)
  - -> second (4)

Answer 9

Investigation:
• Diagnostic local anaesthesia
• Ultrasonography
• Radiography, tenoscopy

Acute synovitis
– Intrasynovial corticosteroid (triamcinolone acetonide, Adcortyl™), HA
– Rest, cold, bandaging

No response to medical Tx/synovitis complicated by other injury “ tenoscopy
– Debridement of tendon lesions
– Desmotomy of annular ligament
– Controlled exercise begun soon after surgery to avoid restricting adhesions
– Intrasynovial HA

Question 10

Suspensory ligament desmitis (3)

Answer 10

• Proximal ligament, body or branches may be injured
• Hindlimb proximal ligament injuries
– Important cause of mild-moderate (2-3/5) unilateral/bilateral hindlimb lameness

Question 11

HL proximal suspensory desmitis

• what
• predisposition
• Dx (2)
• Tx (3)

Answer 11

• Desmopathy
– Degenerative condition vs body & branch injuries (strain following acute overlload)
– Do not see acute inflammatory signs
– Lameness relates to development of compartment syndrome with nerve compression
• Straight hocks predispose

Dx:
diagnostic local anaesthesia:
• Infiltration; plantar metatarsal nerves; tibial nerve; deep branch of the lateral plantar nerve

Tx: 
• Medical treatment
– Local infiltration with corticosteroid
– Shockwave therapy
• Fasciotomy & neurectomy