2.8 Equine Tendon and Ligament Disease Flashcards
What are common signs of equine tendon and ligament injury?
- reduced weight bearing with reduced joint extension: stiff tendon
- hyperextension of the metacarpophalangeal joint when standing
- swelling of the metacarpal area
- edema of the limb
- pain on palpation
- tendon laxity on palpation
Review equine limb tendon anatomy
note that the annular ligament and manica flexoria are sheathes that cover the flexor tendons; manica flexoria is an extension of the SDFT that wraps the DDFT; the annular ligament is a fibrous band that wraps around both flexor tendons. Both the MF and the AL are near the fetlock (metocarpophalangeal joint)
How do you diagnose tendon and ligament disease?
(1) palpation and visualization of the clinical signs
(2) ultrasonography to confirm diagnosis
- both the affected limb and the normal limb
- can use a stand-off pad (SDFT is close to the skin)
- assess ~7 days after injury to give prognosis
(3) other
- +/- scintigraphy
- +/- diagnostic analgesia
What are the most common tendinopathies of the horse?
(1) SDFT tendinopathy
- most common
- palmar metacarpal swelling
- US core lesion (hypoechoic)
(2) DDFT tendinopathy
- digital sheathe or navicular bursa
(5) accessory ligament (of the DDFT) desmitis
- proximal and lateral metacarpal swelling
- dorsal to SDFT
- lameness often absent
(3) proximal suspensory ligament desmitis
- most common site in sport horses
- over extension of metacarpophalangeal joint
- proximal metacarpal/tarsal swelling
(4) suspensory body and branch desmitis
- often bilateral, concurrent splint bone fractures
(6) tenosynovitis
- inflammation of the tendon sheathe
(7) annular ligament syndrome (ALS)
- thickening of the palmar or plantar annular ligament (PAL >2mm) which may or may not also involve the digital sheath and other associated structures
(8) intra-thecal tendon tears
How do you choose treatment for tendonitis in the horse?
many old treatments are deleterious or have no effect; few evidence-based treatment choices - must choose based on:
- tendon pathology
- phase of tendon healing (acute, subacute, chronic)
What is the acute inflammatory phase of equine tendonitis?
0-2 weeks
- pain, heat, swelling, lameness
- hemorrhage, edema
treatment
- minimize inflammation: cold therapy, compression, short-acting steroids (beware laminitis), NSAIDs
What is the subacute inflammatory phase of equine tendonitis?
1 week - 6 months
- reduction or absence of lameness
- resolution of inflammation
treatment:
- promote fibroplasia
- optomize scar organization
What is the chronic inflammatory phase of equine tendonitis?
3 - 18 months
- tendon size decreases
- tendon less pliable
- reduced fetlock extension (contractures)
treatment:
- premote remodelling: controlled, ascending exercise
- prevent re-injury
What is the specific therapy for proximal suspensory desmitis?
extracorporeal shock wave therapy
for hindlimb PSD that is not responding to conservative management:
- fasciotomy and neurectomy
What is the specific therapy for intra-thecal tendon/ligament issues?
use a scope to debride and remove torn tissue
- hindlimb (manica flexoria tears): good prognosis (70-80%)
- forelimb (DDFT tears): poorer prognosis (20-40%)
What are the developmental diseases of the equine tendon?
