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Lameness diagnostic in the horseDr. Tóth Péter

Lameness diagnostic in the horseDr. Tóth Péter

SZIU, Faculty of Veterinary Sciences, Large Animal Clinic

Definition of lameness(claudication)

Definition of lameness(claudication)

• Structural or functional disorder in one or

more limbs and related structures

Functional anatomyFunctional anatomy

• Hoof, navicular region

• Tendons, ligaments,

• tendon sheath, bursae

Phases of the stridePhases of the stride

• Supporting phase

• landing

• loading

• Stance

• Breakover • heel lift

• toe pivot

• Swinging phase

Phases of the stride -SwingPhases of the stride -Swing

• Swinging phase

• Flexion (caudal)

• Extension (cranial)

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Normal gait (by Sue Dyson)Normal gait (by Sue Dyson) Overextension in the fetlock jointOverextension in the fetlock joint

Overextension in the coffin jointOverextension in the coffin joint Mechanism of the hoofMechanism of the hoof

Arc of foot flightArc of foot flight

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Plaiting hind limb(bilateral ilial stress fracture)Plaiting hind limb

(bilateral ilial stress fracture)Interference forms at the trotInterference forms at the trot

• A: front limb to front limb

• B: ipsilateral front to hind

• /C: pacer (diagonal limbs)/

• D: ipsilateral hind to front

I. Causes of lameness 1.I. Causes of lameness 1.

Trauma

I. Causes of lameness 2. I. Causes of lameness 2.

Congenital

I. Causes of lameness 3.I. Causes of lameness 3.

Acquired

I. Causes of lameness 4.I. Causes of lameness 4.

Infection

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I. Causes of lameness 5.I. Causes of lameness 5.

Metabolic disturbances

I. Causes of lameness 6.I. Causes of lameness 6.

Circulatory disorders

Aortoiliac thrombosisAortoiliac thrombosisI. Causes of lameness 7.I. Causes of lameness 7.

Nervous system

??

II. Causes of lamenessII. Causes of lameness

• Pain

• Mechanical

• Paralytic disorders

Classification of lamenessClassification of lameness

• Supporting limb lameness

• Swinging limb lameness

• Mixed lameness

• Complementary lameness

• Untipical lameness

• Special lameness

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Supporting limb lamenessSupporting limb lameness

• Cranial phase is longer

• Head and neck movement

• The problem is usually lower

• Worse in inside circle

Swinging limb lamenessSwinging limb lameness

• Cranial phase is shortened

• It is evident during motion

• Usually the problem is higher

• Worse in outside circle

Swinging limb lameness-(bicipital bursitis)

Swinging limb lameness-(bicipital bursitis)

Mixed lamenessMixed lameness• Disturbance in function of different structures

involved in supporting and swinging phase

Compensatory lamenessCompensatory lamenessUneven distribution of weight on another limb

Severe left hind limb lameness(med. femorotibial osteoarthritis)

Severe left hind limb lameness(med. femorotibial osteoarthritis)

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Untipical lamenessUntipical lameness

• When more than one limb is effected

Concurrent left hind right front limb lameness

Concurrent left hind right front limb lameness

Special lamenessSpecial lameness

• E.g. rupture of peroneus tertius

• Upward fixation of the patella

• DDFT rupture

Patella fixationPatella fixation

3 primary causes of upward patellar fixation:

1, Lack of fitness: Lack of quadriceps and/or biceps femoris muscle tone results in an inability to quickly pull the patella up and off of the medial

femoral trochlea.2, Straight or upright pelvic limb conformation: This places the medial

femoral trochlea further distad in closer proximity with the patella, facilitating patellar fixation.

3, Excessive distal patellar ligament length: This places the patella proximad in closer proximity with the medial femoral trochlea, where it

can inadvertently "catch" or "lock"

Patella fixationPatella fixation StringhaltStringhalt

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Fibrotic myopathyFibrotic myopathyDegree of lamenessDegree of lameness

• Grade I. : very mild

• Grade II.: mild

• Grade III.: moderate

• Grade IV.: sever

• Grade V.: very sever (non weight bearing)

Character of lamenessCharacter of lameness

• unchanging

• Changing

• Improving during training/examination

• Intermittent

Order of lameness examinationOrder of lameness examination

• Anamnesis

• Visual examination

• Palpation

• Provocating tests

• Diagnostic analgesia

• Perineural, intrasynovial, infiltration

• Supplementary diagnostic aids

• Puncture, laboratory evaluation, etc.

• X-ray, Ultrasonography, Scintigraphy, CT, MRI

AnamnesisAnamnesis

• How long has the horse been lame?

• What is the cause of the lameness?

• Has been rested or exercised?

• Worm out?

• Treatment?

• When was the horse shod???

AnamnesisAnamnesis

• How long has the horse been lame?

•What is the cause of the lameness?

• How did it happened?

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AnamnesisAnamnesis

• Is he still in work

• Does he worm out of the lameness?

AnamnesisAnamnesis

• Previous treatments? What was the result?

AnamnesisAnamnesis

•When was the horse shod???

Visual examination at restVisual examination at rest

• At a distance (all directions)

• Conformation

• Body condition

• Positure

• Atrophy, assymetry

• Close observation

• Hoof

• Swelling, distension etc.

Visual examinationVisual examination

At rest

Visual examination at exercise 1. Visual examination at exercise 1.

• How to handle the horse?

• Should be held loosely with their heads

• Exercised as slowly as necessary

• Selection of surfaces

• Hard surface (listen, visualisation, think)

• On gravel

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Visual examination at exercise 2.Visual examination at exercise 2.

• Watch all limbs! Which limb is lame?

• Degree, character, type etc.

• Walk, little circle, trot, galopp

Visual examination at exercise 3. Visual examination at exercise 3.

• the horse should be exercised under sattle or

whatever is necessary (driving, racing, jumping,

etc.)

Visual examinationVisual examination

• at exercise

Supllementary diagnostic aidsSupllementary diagnostic aids

RTG

US

Arthroscopy

CT, MRI

Synovia analysis

What you are able to perform also at the stables

What you are able to perform also at the stables

• Anamnesis

• Viual examination

• Palpation

• Provocating tests

• Diagnostic anaesthesia

PalpationPalpation

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Provocating testsProvocating tests Diagnostic analgesiaDiagnostic analgesia

•perineural

•Intrasynovial

Diagnostic analgesiaDiagnostic analgesia

• Purpose

• Find the site of pain

causing lameness

• Confirm suspected site

of pain

Why could the site not optimally anesthetised?Why could the site not optimally anesthetised?

• Bad technique

• Variation of periferial nerve anatomy

• Local anaesthetic diffuses proximally

• 70-80% pozitivity is a pozitive result!

• Deep bony pain is difficult to anaesthetise

• You can not block out all intraarticular pain

• Mechanical lameness

What kind of local anaesthetics should we use?What kind of local anaesthetics should we use?

• Less irritant

• Mepivacaine• Prilocaine• Bupivacaine

• More irritant• Lidocaine

Effect durationEffect duration

• Fast acting about 2 hour duration• Mepivacaine and prilocaine

• Slower acting about 4 hour duration• Bupivacaine

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Diagnostic analgesiaRestraint

Diagnostic analgesiaRestraint

• Depends on horse

• Minimal restraint is less stressful

• Good handler is essential

• Position yourself safely

Diagnostic analgesiaRestraint

Diagnostic analgesiaRestraint

• Physical• Twitch

• Reliable handler

• No effect on result

Diagnostic analgesia restraintDiagnostic analgesia restraint

• Sedation • Small doses• Xylazine• Detomidine/butorphanol

• Safer• Affect result in higher doses

Diagnostic analgesia restraintDiagnostic analgesia restraint

• Leg position• On ground

• Held by clinician

• Held by assistant

Diagnostic analgesia patient preparationDiagnostic analgesia patient preparation

• Perineural analgesia• Clean procedure• Clip if hairy• Antiseptic scrub until

clean• Povidone iodine• Chlorhexidine

• Alcohol with swab then spray

Diagnostic analgesia patient preparationDiagnostic analgesia patient preparation

• Intrasynovial• Aseptic procedure• Clip• 5 minute antiseptic

scrub• Alcohol wash• Sterile gloves• Fresh bottle of

anaesthetic

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Diagnostic analgesia procedureDiagnostic analgesia procedure

• 18-25 gauge needles• Use fine needles when possible

• Length depends on site

• Quantity of anaesthetic depends on site

(try to keep it on minimum!)

• After block

• Brief walk out post block then stand still

• Too much walking could give a false positive

Diagnostic analgesia procedureDiagnostic analgesia procedure

• Evaluate • 5-10 minutes• 20-30 minutes• 60 minutes

• Intrasynovial analgesia• Usually acts more

quickly • Shorter duration

Diagnostic analgesia procedureDiagnostic analgesia procedure Diagnostic analgesia procedureDiagnostic analgesia procedure

• Post block• Sterile wrap• (5-10 min)

Diagnostic analgesia: Fore limbStrategy

Diagnostic analgesia: Fore limbStrategy

• No clinical suspicion as to site of pain• Block from distal to

proximal

• Use regional blocks

• Differentiate with intrasynovial blocks later if necessary

Perineural analgesia: forelimbPerineural analgesia: forelimb

• 1. Ramus pulvinus (low palm dig block)

• 2. prox palm digit block (deep volar)

• 3. low palmar block (middle volar)

• 4. four point block

• 5. high palmar block (subcarpal)

• 6. subcarpal block

• 7. Ulnar block

• 8. Medianus et musculocutaneus block

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Low palm digit block (ramus pulvinus)Low palm digit block (ramus pulvinus)

Ross and DysonRoss and Dyson

• 23 g 1.5 cm needle• 1.5 ml anaesthetic

• At level of collateral cartilages

Ross and Dyson

• Structures

anaesthetised• Palmar foot• Toe• DIP joint• +/- distal DDFT lesions• Occasionally PIP joint

Low palm digit block (ramus pulvinus)Low palm digit block (ramus pulvinus)

Prox palm digit block (deep volar)Prox palm digit block (deep volar)

Ross and Dyson

• 23 g 1.5 cm needle

• 1.5 ml anaesthetic

• 2-3cm proximal to

collateral cartilages

Ross and Dyson

Prox palm digit block (deep volar)Prox palm digit block (deep volar)

• Structures anaesthetised• Palmar foot• Toe• DIP joint

• +/- distal DDFT lesions• Occasionally PIP joint

• 22-23 G 1.5 cm needle

• 3 ml loc anaesthetic

• At level of prox

sesambones

Ross and Dyson

Low palmar block (middle volar)Low palmar block (middle volar)

Ross and DysonJ. Walmsley Anglia

Low palmar block (middle volar)Low palmar block (middle volar)

• Structures anaesthetised• As for PDB (proximal

pastern)

• Sometimes includes • Fetlock joint (MCP) • Sesamoid bone locally

• Does block distal DDFT lesions

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In case of positive low or prox palm digit analgesiaIn case of positive low or prox palm digit analgesia

Differentiate structures

with:

• DIP block

• Navicular bursa block

• PIP block

Distal interphalangeal joint analgesiaDistal interphalangeal joint analgesia

• Aseptic procedure

• 19g 3cm needle

• 6 ml anaesthetic

• Dorsal or palmar

approach

Distal interphalangeal joint analgesiaDistal interphalangeal joint analgesia

• Structures anaesthetised

with 6 ml• DIP joint• Dorsal sole (toe)• (not the heel)

• 10 ml anaesthetic• Blocks heel as well

Navicular bursa analgesiaNavicular bursa analgesia

• Aseptic procedure

• Radiographic control

• 19g 7cm needle

• 3.5 ml anaesthetic

• 0.5 ml iohexol contrast

solution

• Structures anaesthetised• Navicular bursa• Dorsal sole (toe)• Navicular bone • Navicular ligaments• (not the heel)

• 30 minutes: DIP joint

Navicular bursa analgesiaNavicular bursa analgesia Proximal interphalangeal joint (PIPJ)Proximal interphalangeal joint (PIPJ)

• Dorsal approach• 21g 2.5cm needle

• 5 ml anaesthetic

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PIPJPIPJ

• Palmar approach• 21g 2.5cm needle• 5 ml anaesthetic

PIPJPIPJ

• Structures

anaesthetised• PIP joint

4 point block (N. digit. palm., nn. metacarpales)4 point block (N. digit. palm., nn. metacarpales)

Ross and Dyson

• 23 g 1.5 cm needle

• 1.5 -3 ml anaesthetic

• Palmar digital nerves

• Palmar metacarpal

nerves

4 point block4 point block

• Structures anaesthetised

• As for PDB plus:

• Metacarpophalangeal (MCP) region

• PD nerve only • Useful for annular

ligament analgesia

Positive 4 point block:Positive 4 point block:

• Differentiate structures with: -

• MCP analgesia

• Digital sheath analgesia

Metacarpophalangeal analgesiaMetacarpophalangeal analgesia

Ross and Dyson

• Dorsal and palmar approaches

• 19-22g 3-4cm needle

• 10 ml anaesthetic

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Ross and Dyson

• Dorsal approach• Easier

• Articular cartilage easily traumatised

Metacarpophalangeal analgesiaMetacarpophalangeal analgesia Metacarpophalangeal analgesiaMetacarpophalangeal analgesia

Ross and Dyson

• Palmar approach

• Between suspensory ligament and MC3

• Sometimes difficult to be sure of centesis

Prof. Jean M. Denoix

Metacarpophalangeal analgesiaMetacarpophalangeal analgesia

Prof. Jean M. Denoix

• Structures anaesthetised• MCP joint

• Subchondral bone pain slow to respond

• 30 minutes may anaesthetise:• distal suspensory branches• sesamoids

Digital flexor tendon sheath (DFTS) analgesia

Digital flexor tendon sheath (DFTS) analgesia

• 20g 2.5cm needle

• 10-15ml anaesthetic-

• Proximal approach

Digital flexor tendon sheath (DFTS) analgesia

Digital flexor tendon sheath (DFTS) analgesia

• 20g 2.5cm needle

• 10-15ml anaesthetic-

• Distal palmar

approach

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Digital flexor tendon sheath (DFTS) analgesia

Digital flexor tendon sheath (DFTS) analgesia

• Structures anaesthetised• Digital sheath• Local structures with

time• Annular ligament

• Often only a partial improvement

High palmar blockHigh palmar block

• 20g 3cm needle

• 5ml in each site

• Palmar nerves

Subcarpal blockSubcarpal block

• Structures anaesthetised• Whole metacarpal region

• 65% chance of penetrating carpometacarpal (CMC) joint

• Dorsal branches must be anaesthetised to block the skin dorsally

Lateral palmar analgesiaLateral palmar analgesia

• More specific for suspensory ligament

origin

• 22g 1.5cm needle

• 5ml anaesthetic

• Less chance of blocking the CMC

joint

Suspensory ligament origin infiltrationSuspensory ligament origin infiltration

• Specific for suspensory ligament lesions

• 19g 5cm needle • 10 ml anaesthetic

• From lateral• Include palmar metacarpal

nerves

Positive subcarpal analgesiaPositive subcarpal analgesia

• Perform middle carpal

joint analgesia

• Can diffuse around

palmar nerves and block

metacarpal structures

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• Dorsal pouches

• Medial or lateral

• 19g 3cm needle

• 5ml anaesthetic

• Check in 5-10 minutes

Middle carpal and antebrachiocarpal analgesia

?

• Remember• Subcarpal analgesia and middle carpal joint analgesia

may block the same structures

• Clinical findings may help to differentiate

N. ulnaris analgesiaN. ulnaris analgesia

N. medianus

N. ulnaris

N. palm.lat

• 18g 4cm needle

• 10-15ml anaesthetic

• 10 cm prox from accessory carpal bone

N. medianus analgesiaN. medianus analgesia

N. medianus analgesiaN. medianus analgesia

• 5 cm below elbow joint, medial side

• caudomedial surface of radius

• jusst cranial from m. flex. carpi radialis

• 10 ml loc anaesthetic

•A. and v. is locaated caudally from it

•Fals positive response because of elbow joint

•possible

N. musculocutaneus analgesiaN. musculocutaneus analgesia

• Branch for skin

• Seldom necessary

• 4x3 ml

• V. cephalica cran. caud.

• V. ceph. access. cran. caud.

v. cephalica

v. cephalica acc.

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Elbow analgesiaElbow analgesia

• Cranial or Caudal pouch

• 19g 9cm needle • 25ml anaesthetic

• NB radial nerve• Lat ulnar bursa not adviced (communicates just in 37%)•• Cran approach: signs of radial paresis • Method: infront of collat lig 2/3 distance between

humerus epicondyle and tub radii in cranial diretion

• Caud method: infront of olecranon caud fron epicondyle long needle, may need skin loc anaesthesia

Shoulder joint analgesiaShoulder joint analgesia• 19g 9cm needle

• 25ml anaesthetic

• Wait 30 minutes

• Inbetween tub majus pars cran et

caud humeri

• infront of infraspinatus insertion

Bicipital bursa analgesiaBicipital bursa analgesia

• 19 G 9cm needle

• 20ml loc anaesthetic

• Poncture under ultrasonographic controll adviced

• 4cm dist. and 6-7 cm caudal from tub. majus pars cranialis

humeri

Thank you for your attention!Thank you for your attention!