Lameness and Hoof Surgery Flashcards
How long does it take for the entire hoof to grow?
1 year
How much hoof grows per month?
6mm
How much the hoof appear?
Perpendicular and parallel to the ground and symmetrical
How should the sole of the hoof appear?
Parallel and symmetrical
What instruments do you use to pull shoes?
Shoe puller
Clinch cutter
Hammer
Nail puller
What instruments do you use for Hoof trimming?
Hoof nippers
Hoof knife
Rasp
What breed is allowed to have a longer toe?
Standardbreds
Why do we leave the toe longer on Standardbreds?
Increase stride length and will allow the horse to pace faster
What is wrong with a horse that comes up lame after shoeing?
Nail bound
Sidebones
Calcified hoof cartilages seen in older or carriage horses due to microfractures created by each step causing concussion destabilizing the area
Why would you use a Full bar shoe?
Eliminate the hoof mechanism to allow for fracture healing
How do you shoe for Navicular disease?
Elevate the heel
Why do you elevate the heel in treating navicular disease?
Elevating the heel allows the deep flexor tendon to put minimal pressure on the navicular bone
Break over
the moment the toe touches the ground
How do you shoe a horse to facilitate break over?
Rocker toe shoe
How would you shoe for a Ruptured flexor tendon?
Shoe with elongated heels
What clinical sign do you see with superficial digital flexor tendon rupture?
Fetlock drops
What clinical sign do you see with deep digital flexor tendon rupture and superficial digital tendon rupture?
Fetlock drops and toe points up
What clinical sign do you see with all flexor tendon rupture?
Leg is on the ground
What are the clinical signs of Puncture wounds or Solar abscess?
Lameness
Thumping digital pulse
Draining tract at coronary band
Swelling
How do you diagnose Puncture wound or solar abscess?
Hoof testers
Sterile probe draining tract
Radiography
How do you treat Puncture wounds or solar abscess?
Establish drainage
Tetanus: toxoid/antitoxin
Antiseptic solution
Bandage
Keratoma
abnormal keratinization in response to chronic injury
What are the clinical signs of Keratoma?
Lameness
Fistulous tract at coronary band
Deviation of white line
How do you treat a Keratoma?
Use periosteal elevators to remove that section from the hoof
Necrosis of the Collateral Cartilage (Quittor)
Chronic purulent inflammation of collateral cartilage
What are the clinical signs of Necrosis of the Collateral Cartilage (Quittor)?
Lameness
Localized pain over cartilage
Chronic suppurative sinus tract
How do you treat Necrosis of the Collateral Cartilage (Quittor)?
Surgical excision of necrotic cartilage
Thrush
Degenerative condition of the frog
What are the clinical signs of Thrush?
Fetid odor
Undermined frog
Black discharge with sulci of frog
Draft horses
How do you treat Thrush?
Removal of all loose horn
Caustic agents: Copper sulfate
How do you treat Angular Limb Deformities?
Dalmer shoes
Laminitis
Inflammation of the laminae of the foot
Chronic Laminits
after 48 hours of continual pain or when rotation of the distal phalanx occurs
What are the clinical signs of Laminitis?
Shifting weight to hind feet Unwilling to walk Sinking in at coronary band Non-parallel growth rings Sole abscess
What is a sign of several bouts of laminitis?
Non-parallel growth rings
Obel grade 1
No lameness at walk, short stilted gait at trot
Obel grade 2
Stilted gait at walk, foot can be lifted
Obel grade 3
Reluctant to walk, resists lifting foot
Obel grade 4
Refuses to move, may become recumbent
What do you see on radiographs with chronic laminits?
Bone remodeling "ski-tips" Distal marginal fractures Osteolysis Osteomyelitis Rotation Sinking Radiolucent lines
What are risk factors for Laminitis?
Pony Fat Horse Late summer High carbs Non-weightbearing lameness
What are the treatment options for chronic laminitis?
Therapeutic shoeing: Dorsal hoof wall resection, Heart bar shoe, or Reversed horse shoe
Deep digital flexor tenotomy
Euthananasia
What causes tendon laceration?
Trauma
Overloading
Infection
What tendons in the Fore limb are prone to laceration?
Common digital extensor tendon
Lateral digital extensor tendon
What tendons in the Hind limb are prone to laceration?
Long digital extensor tendon
Lateral digital extensor tendon
How do you treat Tendon laceration?
Corrective shoeing
Bandage
Cast
Surgery
What suture pattern is used to fix tendons?
Locking loop
What do you observe during a lameness exam?
Stride Foot flight arc Path of the foot flight Foot strike Joint angels Gluteal excursion
What is the rule for fore limb lameness?
“Head Down on Sound”
Head Appears to rise when lame limb weight bearing
Observing Hind Limb lameness
Head goes down with lame limb weight bearing
Increased gluteal excursion in lame limb - “Hip Hike” or “Hip Drop”
Grade 1 Lameness
Difficult to observe, inconsistent
Grade 2 Lameness
Difficult to observe in a straight line but consistently apparent under certain circumstances
Grade 3 Lameness
Consistently observable or a trot under all circumstances
Grade 4 Lameness
Obvious lameness with marked head, nod, hitching, shortened stride
Grade 5 lameness
Minimal weight bearing/ non weight bearing and inability to move`
What 5 pathognomonic lameness’ are diagnosed at the walk?
Peroneus tertius rupture Upward fixation of patella Stringhalt Fibrotic myopathy Sweeney
What is the clinical sign of Peroneum Tertius Rupture?
Simultaneous extension of the hock and flexion of the stifle
How do you treat the Upward fixation of the patella?
Exercise
Medial Patellar Desmotomy
What medication will cause a lameness to change?
Xylazine
What are the different methods of Local Anesthesia?
Perineural block
Regional
Direct infiltration of site
IA
What local anesthetics are used for Lameness exam?
2% Lidocaine
2% Mepivacaine
0.5% Bupivacaine
When would you use Bupivacaine for lameness?
Shoeing manipulations/therapeutic effect
What structures are anesthetized by the Palmar Digital Nerve Block?
Entire Sole Navicular apparatus Soft tissues of heel Coffin joint Digital portion of DDFT
What structures are anesthetized by the Abaxial Nerve Block?
Foot P2 Distopalmar P1 Proximal and distal interphalangeal joints Distal SDFT and DDFT Distal Sesamoidian ligament Digital annular ligament
What nerves are blocked by Low 2-point nerve block?
L/M palmar metacarpal n.
L/M palmar n.
Where do you perform the Low 4 point nerve block?
Between Palmar MCIII and MC II and IV
Between SL and DDFT
What structures are anesthetized by the High 4-Point Nerve Block?
Suspensory ligament
Flexor tendons
MCIII and MCIV
Where do you perform the High 4 point nerve block
Below carpus in groove between suspensory and DDFT
What are the indications for Nuclear Scintigraphy?
Lameness site cannot be determined Lameness is localized but not detectable with radiographs or US Multiple limb lameness Intermittent lameness Upper limb/pelvic lameness Suspect fracture not seen on rads
What is important to know about Nuclear Scintigraphy?
The animals must be isolated because they are radioactive
Leave for 24-48 hours and detect radiation levels before handling the animal
What is a disadvantage of Nuclear Scintigraphy?
Not very specific
poor anatomic detail
What would you use if the lameness cannot be determined with radiographs or US?
MRI
Crimp pattern of the tendon
Allows for “stretch” of tendon
Load applied, lose crimp
Followed by a linear phase of stretching
How long can a tendon rupture?
can extend 12-20% before rupture
Tendon Repair
Scar tissue formation resulting in less elastic tendon
Tendonitis
Inflammation of a tendon most commonly from overuse but can be from infection or traumatic injury
What causes tendon injuries?
Overstrain
Percutaneous Trauma
Overstrain
Sudden overload or strain induced
What causes strain induced Overstrain?
Repetitive microtrauma - a phase of molecular degeneration which progressively weakens the tendon
where do you find the most serious percutaneous trauma?
Palmar aspect of the pastern/metacarpus
Which tendons are most prone to injury?
SDFT
SL
What are the predisposing factors for tendonitis?
Increased stress on tendon/ligament Poor/deep ground surface Inadequate training and muscle fatigue Poor conformation Poor hoof care Improper bandaging/boots
What is the best tool for diagnosing tendonitis?
Ultrasound
What type of probe should be used for diagnosing tendonitis?
7.5-12 MHz linear transducer
What do you see on Ultrasound with Acute tendonitis?
Enlargement
hypoechogenicity
Reduce striated pattern
changes in shape, margin or position
What so you see on ultrasound with chronic tendonitis?
variable enlargement
echogenicity
irregular striated pattern - fibrosis
What is the treatment for tendonitis?
cold therapy, rest, and controlled exercise program
Compression and coaptation
NSAIDs
What is the goal of treatment for Tendonitis?
Restoration of the tensile strength of the tendon without peritendinous granulation tissue and adhesions Reduce inflammation Speed healing/return to work Increase tensile strength Decrease risk of re-injury
What are other non-surgical treatments for tendonitis?
Intra-lesional injections
Electro shock wave therapy
Therapeutic Ultrasound
Laser
What is used for Intralesional injections?
Platelet Rich Plasma
Stem cells
Bone marrow
How does Shock Wave Therapy help tendonitis?
Increases Vascularization
and growth factors in the area
Surgical repair of tendonitis
Suturing tendon
Superior check desmotomy
Annular ligament desmotomy
What are the two layers of the synovial membrane?
Subintimal
Intimal
What is contained in the subintimal layer o the synovial membrane?
Blood supply and innervation
What is contained in the intimal layer o the synovial membrane?
Synoviocytes
Subchondral bone
“Shock absorber”
More deformable than cortical bone
Articular Cartilage
specialized extracellular matrix that distributes compressive loads
Used to define the health of the joint and create a joint surface
Aggregans
forms aggregates with HA
Protects collagens from damage
What is the backbone of the cartilaginous matrix?
Hyaluronic acid
What provides a sponge-like shock absorbing effect?
Glycosaminoglycans
What are the gross cartilage changes associated with Osteoarthitis?
Yellow Fibrillate Dull Ulcerated Pitted
What are the changes associated with Joint disease?
Sclerosis
Osteophyte formation
Enthesiophyte formation
What are the clinical signs of Osteoarthritis?
Lameness
Joint pain
Decreased range of motion
Joint effusion
What are the goals of treatment of joint disease?
Reduce/ minimize inflammation
Slow progression of degeneration
Reduce/eliminate pain
Restore synovial fluid to normal
What are the options to manage joint disease?
Chondroprotectives Corticosteroids NSAIDs Blood based products Cell based treatments
What are the chondroprotective agents?
Hyaluronic acid
Polysulfated glycosaminoglycans
Polyglycan
Pentosin Gold plus Halo
What does Sodium Hyaluronate/ Hyaluronic acid do?
Provides viscoelasticity, boundary lubrication Modulates chemotactic response Scavenges free radicals Increases production of endogenous HA Decreases degradation of aggrecan
What is the most efficacious way of administering HA?
Intra-articularly
Polysulfated Glycosaminoglycans
inhibit degradative enzymes
Reduction of synovial effusion
Counteracts deleterious effects of IL-1
How does Adequan work?
up regulation of glycosaminoglycans and collagen synthesis
Decrease in inflammatory mediators
Improvements in synovial membrane
What should you add with Adequan?
Antimicrobial
Polyglycan
Post surgical lavage
What is the most effective for mild synovitis/capsulitis?
HA
What is the most effective for severe synovitis/capsulitis or chronic OA?
PSGAGs (Polysulfated Glycosaminoglycans)
Why use Triamcinolone acetonide?
Chondroprotective effects
What with wrong with using Methylprednisolone acetate?
deleterious effects on articular cartilage