Chronic Lameness Flashcards
What are some chronic lameness conditions in the horse?
- Osteoarthritis (Join synovitis)
- Navicular Dx
- Chronic Laminits
What is the most common cause of lameness in horses?
Osteoarthritis
What factors to consider with OA?
- Use of horse
- OWner’s expectation
- Age
- Severity
- N° of joint affected
- Risk of lamainits
- Other systemic dx
- Owner’s financial situation
- Associated soft tisue damage
Consequences of OA?
detail what steroids to use when?
INTRA-ARTICULAE ADMIN
Side effects of Corticosteroids?
- Laminitis (BEWARE if suspicious of endocrine dx)
- Iatrogenic Joint infection (low incidence)
- Periarticular cellulitis (diffuse swelling, hot painful)
- Joint flare - aseptic synovitis
- Deleterious effects on cartilage (MPA)
- SLows healing of joint injury
Describe the use of NSAId for OA ?
- Analgesic - SMOAD
- Improves joint mobility
- Inhibition of COX (COX 2 esp inflammation)
- Side effects due to COX 1 inhibition -> Gi ulceration, RDCn renal but Therapeutic effects due to COX 2
What do we HAVE to keep in mind abotu using NSAIDs?
- Narrow safety margin
- Not for competition animals
describe Phenylbut use?
- Most commonly used
- Cost effective –
86p/sachet - Oral or IV
administration - 2.2 mg/kg PO BID
- NOT COX selective
What is the FEI Detection TIme for Phenylbut?
7 days
What other options for NSAIds?
- > Suxibotazone (more palatable)
-> Firocoxib IV or PO
- 3mg/kg SID loading dose then 1 mg/kg SID maintenance
- COX 2 selective!
- FEI detection 14 days
What topical NSAID?
Diclofenac Cream - topical application BID
- licensed in UK not US
(equivalent in UK for humans is voltarol)
What other management considerations for OA?
- Weight management → Diet
- Recommendations: restrict forage to 1.5% bodyweight +
balancer in feed - Housing and environment
- Nutraceuticals
-> Weak scientific evidence for in vivo efficacy
-> Lots of anecdotal evidence
-> Chondroitin sulphate and glucosamine
-> Hyaluronic Acid
-> Green lipped mussel
-> Boswellia
-> Devil’s claw – controlled substance under FEI
Biphosphonates - how do they work?
- DMOAD
- Osteoclast inhibitors – bind to osteoclasts which in turn
decreases osteoblast activity and bone turnover - Reduce rate of bone resorption
- Reduce bone pain
What evidence for use of Biphosphonates?
- Bone spavin
- Navicular dx
- Thoracolumbar pain
Duration fo action for biphosphonates?
Approx 6 months
Risks associated with biphosphonates?
Colic and renal tox
give examples of biphosphonates
- Tiludronate -> admin via saline infusion intravenously over 30 mins ; licensed for bone spavin
- Clodronate -> Admin IM over 3 sites; licensed for navicular dx
Describe used of Sodium hyaluronate (HA)
- Glycosaminoglycan
- Component of articular cartilage and synovial fluid
- Local anti-inflammatory effect and chondroprotective
How do we admin HA?
- Intravenous(40mg) Repeated weekly for 3 treatments
- SMOAD + DMOAD [Kawcak et al, 1997]or Intra-articular (20mg/joint)
- Flare rate of 12%
- Does not result in a substantial enough reduction in lameness when used alone
Best use of HA?
Acute/mild to moderate synovitis
describe polysulfated glycosaminoglycans?
Increase HA synthesis, stimulate cartilage matrix synthesis, decrease matrix
degradation
when are P O L Y S U L F A T E D G L Y C O S A M I N O G L Y C A N S used ?
- Most commonly used intramuscularly →
- Improves lameness and stride length [White et al, 1996]
- 7 treatments(500mg) every 4 days for 28 days
- Can be given intra-articularly
- Associated with higher incidence of joint sepsis
best use for polysulfated glycosaminoglycans?
synovitis
Pentosan Polysulfate used? (Cartrophen)
DMOAD
Stimulate synthesis of proteoglycans in extracellular matrix
→Healthier cartilage
→Stimulates increase production
of hyaluronic acid
→Lubricates and stabilises the
joint
→Anti-inflammatory
What orthobiologics/regen medicine options?
- Polycrylamide Hydrogel
- Interleukin 1 receptor antagonist (IRAP)
- Platelet Rich Plasma and alpha 2 macroglobulin
- Stem Cells
Describe Polyacrymide Hydrogel ?
A promising alternative with a long duration of action
- Integrates into joint capsule and tissue via vessel in growth
- Creates a cushion like effect in the joint
- Preservation of joint cartilage and aid regeneration
Describe use of IL-1 Receptor antagonist PRotein (IRAP) ?
- Aim: block action of pro-inflammatory cytokine IL-1
- used in humans for many years to manage OA
Protocol for use of IL-1 IRAP
- Protocol: 3 injections 7-10 days apart
- Used most often in chronic progressive OA
Describe Platelet RIch lasma use?
- Autologous biological product prepared from whole blood
- Enrichment of platelets and degranulation to release
growth factors - Evidence to support use in younger patients for joint
tissue healing
→ acute traumatic injuryD
Describe use of Alpha 2 Macroglobulin -
- Alpha2EQ
- Naturally occurring protein in blood
- Anti-inflammatory with multimodal mechanism of action
- Can be used with other treatments/pre-treatment
stem Cells - two types?
- Bone marrow derived Mesenchymal Stem cells
- Chondrogenic induced Mesenchymal stem cells
Describe Bone marrow derived MEsenchymal Stem clels?
Bone marrow aspirated from sternum
Cultured over several weeks
Promote repair and regeneration
May participate in repair of cartilage
May be beneficial in cases with intra-articular
soft tissue injuries to promote healing
Describe Chondrogenic induced mesenchymal stem cells?
Derived from equine allogenic peripheral blood
No need to wait for cultures – comes ready to use
Cost – timing/storage
If all else fails what surgical options for OA?
- arthrodesis
- Neurectomy
What different conditions encompass Navicular syndrome ?
o Navicular Bone Pathology
o Navicular Bursitis
o Navicular suspensory desmitis ( collateral sesamoidean ligament)
o Distal Sesamoidean Impar Desmitis
o DDFT injury/tear or adhesions of the DDFT
What are the mainstays of Navicular syndrome?
- Rest
- Anti-inflammatories
- Bone metabolism medications
Describe the ‘Rest stage’
- Dependant on degree of soft tissue damage
- Box rest with hand walking
- If DDFT affected: more prolonged → up to 12 months
describe the use of Anti-inflammatories ?
- Most common long term, palliative medical treatment
- Intra-articular: Distal interphalangeal joint-> Corticosteroids (TA and MPA)
- Intra thecal: Navicular bursa-> More effective clinically?; Corticosteroid +/- hyaluronic acid
What can be used for aspect 3 of treatment -> bone metabolism medications?
- Bisphosphonates
- Treat bone pain
- Inhibit osteoclast activity and bone resorption
IM injection OR?→Intravenous regional limb perfusion :
no scientific to support this currently
How can we use remedial farriery for navicular syndrome
- Dependant on confirmation of the foot
- Optimise foot balance
- Often have long toe and low, underrun heels, contracted heels
Step 1 of Remedial farriery?
- Correct and maintain dorsopalmar and mediolateral balance
* Correct hoof pastern axis
* Elevate heel with wedge (2° - 4°)
Step 2 of Remedial farriery?
- Ease of breakover achieved by shortening and/or rolling the toe
* Decreases the work of moving the foot
Step 3 of Remedial farriery?
- Maintenance of foot and especially heel mass
Step 4 of Remedial Farriery?
- Protect palmar aspect of foot from concussion
Types of shoes → aim to move weight bearing axis
* Egg bar shoe
* Heart bar shoe – central support shoe
* Natural balance
* Leverage Reduction Shoe
* Frog support
* Remove shoes??
Other medications for navicular syndrome?
- Isoxuprine
- Warfarin
- Botulinum Toxins
Detail use of Isoxuprine?
Peripheral vasodilator, dec blood viscosity and platelet aggregatiion
-> Inc in distal limb circulation
Use fo warfarin?
dec blood viscosity HOWEVER ischaemic pathogenesis largery disproved therefore NO LONGER COMMONLY USED
detail Botulinum toxins
-> interference with pain pathway reducing lameness
- Prelim studies suggest improvement in lameness intra-thecal injection)
- More ivestigation required to evaluate dosage and long term efficacy
Navicular bursoscopy?
- Fibrillation or tearing of DDFT visible on MRI
→Assess and debride lesions → reduce inflammation
Palmar digital neurectomy?
- Effective but potential for complications
- Horse cannot compete under FEI rules
- British Dressage - pre-2023 couldn’t compete
- 2024/25 can be signed competition legal by vet
