Day 4 - Lameness Flashcards
Causes of injuries (7)
- Trauma
Septic synovial sheet/joint → pain and even death - Congenital
Coangulation, Navicular diseases Enlarged synovial channels - Acquired
- Infection - septic joint is an emergency
- Metabolic disturbances - osteoarthritis, clots, hernia, laminitis
- Circulatory disorders - aortoiliac thrombosis
- Nervous system
Mechanical and paralytic disorders
Classification of lameness (6)
- Supporting limb lameness
- Swinging limb lameness
- Mixed lameness
- Complementary lameness
- Untypical lameness
- Special lameness
Severe left hind limb lameness
med. femorotibial osteoarthritis
Provacation tests
find out
Shoulder flexion
Elbow flexion
Carpal flexion
Hock flexion
Navicular flexion
Hip flexion
Stifle flexion
Hock flexion
Navicular flexion
Fetlock flexion test
Shoulder flexion test
Lower limb flexion (?)
Supplementary diagnostic tools in lameness
US, x-ray, arthroscopy, MRI, CT, synovial analysis
Lameness - local ana
irritant, non irritant and long/short acting
Lidocain - irritant
Less irritant
Mepivacaine - short acting
Bupivacaine - long acting (not really used)
Lameness - sedation
Xylasine or Detomidine/butorphanol
Deep digital nerve anesthesia - structures ana
- Palmar foot
- Toe
- DIP joint
- +/- distal DDFT lesions
- Occasionally PIP joint
Abax. Sesamoid Block - structures ana
- as for PDP
- sometimes includes fetlock joint and sesamoid bone
- distal DDFT
Distal interphalangeal joint analgesia - structures at 6 ml and 10 ml
- Structures anaesthetised with 6 ml
- DIP joint
- Dorsal sole (toe)
- (not the heel)
- 10 ml anaesthetic
- Blocks heel as well
Navicular bursa analgesia - structures
- Navicular bursa
- Dorsal sole (toe)
- Navicular bone
- Navicular ligaments
- (not the heel)
- 30 minutes: DIP joint
4 point block (N. digit. palm., nn. metacarpales - structures
- As for PDB plus:
- Metacarpophalangeal (MCP) region
- PD nerve onlyàUseful for annular ligament analgesia
Positive 4 block
Differentiate structures with: -
* MCP analgesia
* Digital sheath analgesia
Metacarpophalangeal joint anesthesia - structures
- MCP joint
- Subchondral bone,
- After 30 min, distal branches of susp. lig and sesamoids
Metacarpophalangeal joint anesthesia - structures
- MCP joint
- Subchondral bone,
- After 30 min, distal branches of susp. lig and sesamoids
Digital flexor tendon sheath (DFTS) analgesia - structures
- Digital sheath
- Local structures with time
- Annular ligament
- Often only a partial improvement
High palmar block - structures
- Whole metacarpal region
Positive subcarpal analgesia - next test
perform middle carpal joint analgesia
N. musculocutaneous
Elbow analgesia
..
Pastern ring block
- induces dorsal branches, and dorsal metatarsal nerves
- Blocks pastern and foot?
Low plantar six point
- plantar digital nerve
- plantar metatarsal nerve
- dorsal metatarsal nerve
Blocks all tissues distal to block
If positive; block fetlock and digital sheat
Subtarsal (high plantar)
- plantar and plantar metatarsal nerves
- blocks susp. lig, complete ring block
Energy storing
Positional
SDFT (Support the hyperextended metacarpophalangeal joint during weight-bearing)
Digital extensor tendons
Injuries based on type of horse
Racing thoroughbreds
Show jumpers
Eventers
Dressage
- Racing Thoroughbreds: SDFT in forelimb - mid metacarpal region
- Elite show-jumpers: forelimb SDFT & DDFT injuries
- Elite eventers: forelimb SDFT injuries
- Dressage horses: hindlimb suspensory ligament injuries
Complete rupture, loss of function
Deep digital flexor tendon
- Toe flips up
- If in the metacarpal/metatarsal region and outside the DFTS
- Can heal satisfactorily if immobilized
- If ruptured near the insertion or within the DFTS - poor prognosis
Complete rupture, loss of function
Suspensory ligament
- Fetlock drops - hyperextension
- Grave prognosis
- Degenerative / traumatic / catastrophic
Non-traumatic tendon & ligament injuries
- Tendinitis/tendinopathy
- Desmitis/desmopathy
overstrain injuries
degenerative proc (most common)
Repair of tendon & ligament injuries
No regeneration! (4)
- Intratendinous haemorrhage immediately after injury
- Inflammatory reaction
* Designed to remove damaged tendon tissue - Reparative phase
* Starts within a few days
* Angiogenesis and scar tissue formation - Remodelling phase
* Gradual, incomplete replacement of type III to type I
Superficial digital tendon injury
- Most common site: mid-metacarpal region. Common injury in racehorses and jumpers
- Within the DFTS and the carpal sheath. Less common
- In the pastern region. Often traumatic - overreach
Not US too quickly
Superficial digital tendon injury - Tx (3)
Acute phase
Subacute phase (fibroplastic phase)
Chronic (regenerative) phase
Superficial digital tendon injury - Tx
Actue phase
Aim to minimize inflammation & limit the action of proteolytic enzymes
* Physical therapy – rest, cold, immobilization (Rupert jon to decrease hemorrhage)
* Systemic short-acting corticosteroids in first 24-48 hours
* Never intralesional steroids – calcification!
* NSAID’s – some controversy
* (Surgical treatment – tendon splitting, desmotomy of AL-SDFT)
Superficial digital tendon injury - Tx
Subacute phase
- Progressive mobilization. Should start walking, collagen need to be formed
- Ultrasonographic monitoring
- Regenerative therapies - tendons do not regenerate!
- Mesenchymal stem cell therapy
- Stem cells differentiate into tenocytes, regenerate matrix
- Soup of growth factors – stimulate cell proliferation & matrix synthesis
Superficial digital tendon injury - Tx
Chronic phase
- Controlled exercise
- Regular ultrasonographic monitoring
- to prevent re-injury
- Takes time – at least 6-12 months before returning to full work
Deep digital flexor tendon injuries
- Metacarpal region –> Majority of injuries within the DFTS
- Pastern region - Down to insertion
Most distal part can only be imaged with MRI or CT - Poor prognosis
- Lesions in fetlock - show jumpers
- Limited healing ability of tendons within synovial environment
- Adhesion formation
- Mesenchymal stem cell therapy
- Associated with inf. tenosynovitis
Suspensory ligament injuries
Forelimb proximal suspensory desmitis
- Pain on palpation
- Difficult to palpate most proximal
- Lamer with the limb on outer circle
- Acute
- Reasonable prognosis
- Return to exercise in 3-4 months
- +/- intralesional therapy
- Chronic
- More difficult
- Blister treatment
- Guarded prognosis
Suspensory ligament injuries
Hindlimb proximal suspensory desmopathy
- No localizing signs
- Lamer on outer circle
- But often bilateral
- Degenerative process
- Dressage horses
- Straight hock - predisposes
- Poor success rate, best is surgery
Accessory ligament of the deep digital flexor tendon injuries
- Much more common in the FL than in the HL
- Usually painful on palpation
- Acute cases – rest, cooling, intralesional treatment, regenerative laser, shockwave
- Chronic, non-responsive cases - desmotomy
Collateral ligament injuries
- Can be true sprain injuries
- Rupture results in luxation/subluxation of joint
Digital flexor tendon sheath (DFTS) injuries
Primary and secondary tenosynovitis
If lameness - improvement to low 4-point nb.
Primary tenosynovitis
- Accumulative low-grade trauma
- Direct trauma
- Abnormal force (hyperextension)
- Infectious
Secondary tenosynovitis
- DDF tendonitis
- Damage to the manica flexoria
- Damage to the synovial layers
Distension of the DFTS
Palmar annular ligament syndrome
- Desmopathy of PAL - External trauma and overextension of fetlock
- Chronic inflammation – adhesions, fibrosis
- Perpetuating condition
Inflammation, pressure, stenosis, further inflammation
