Intro and investigation of lameness Flashcards
Outline approach to the lame horse
History (Anamnesis) • Observation from a distance: – Symmetry – Posture – Conformation • Palpation – Incl. hoof testers • Gait Observauion / Movement – Baseline – Addiyional Movement • Selected Examination Steps – Manipulations – Flexion Tests • Diagnostic Analgesia • Diagnostic Imaging • Treatment
Name 2 objective tests
- kinetics
- kinematics (motion of points, bodies and systems/ groups of bodies without consideration of the causes of motion)
What are the 2 types of observation?
- subjective
- objective (kinetic and kinematic)
What basic info is important in the hx?
• SIGNALMENT – Sex, Breed, Age*, Use
• CURRENT LAMENESS: What is the problem?
– hx of trauma
– Duration of lameness
– Deterioration or improvement, circumstances
– Effects of exercise
– Management Changes
• Changes in shoeing or related changes
• Changes in training or performance intensity
• Changes in stable/working/turn-out surface
• Changes in housing
• Changes in health & diet
• Current medication and response, response to rest
• Past Lameness Problems
Specifc aspects of hx that are important in a lameness work up
TYPE OF SPORTING ACTIVITY – Level of Competition (past, current, intended) • ADDITIONAL SOURCES – Images / Video tapes – Records – Diagnostic Imaging – Discussion with others
Where might chronic porgressive OA affect the older horse? 8
– PIP joint – DIP joint – MCP joint – Carpometacarpal joint – Coxofemoral joint – FemoroRbial joints – Tarsus – Previous injury (retired racehorses)
What should you observe from a distance?
- symmetry, posture and conformation
- poor conformation doesn’t necessarily mean lameness
- significant variations usually obvious
What should you palpate?
- SDFT origin and insertion
- distal sesamoidean ligaments
- digital pulses
- hoof testers
- tendons (loaded and unloaded)
What are you looking for when palpating joints?
- distension
- temperature
- pain
- ROM
What should you palpate along equine back?
- back
- pelvis (tuber coxae adn tuber ischii)
What is limb movement composed of? 2
horse’s travel and action
Define a horse’s ‘travel’
- flight of a single hoof in relation to other limbs
- often viewed from side or behind
Define a horse’s ‘action’
– Overall description of gait characterisyics
– Takes into account joint flexion, stride length, suspension and other qualities – Variation between different types and breeds
What are the phases of an equine stride?
- landing
- slide
- loading
- stance
- breakover (heel lift and toe pivot)
- swing
Describe gait - walk
- Even rhythm four-beat gait
* Not very suitable to recognise subtle lameness
Describe gait - pace
- Two-beat lateral gait
– Ipsilateral fore- and hindlimbs elevate alternatively
– Viable gait for STB racehorses and some other breeds
– Considered an impure gait for most “normal” horses
Describe canter
- Three-beat gait with lead preference
– Difficult to identify subtle lameness
– Useful for back/rider/saddle associated problems
Describe trot
- Two-beat diagonal gait
• Steadiest and most rhythmic gait in most horses
Which gait is preferred for a lameness exam?
trot
If you are in doubt as to the location of a lameness, what can you do?
- palpation
- nerve and joint blocks
What should you determine with gait observation/ movement?
- is the animal lame? which legs?
2. How lame (grading system, will i be able to appreciate a difference with diagnostic analgesia)
Goal - lameness exam
localise the source of lameness in the limb(s) to allow for targeted diagnostic imaging and tx (helps cost and specificity)
Name 2 lameness grading scales
- American Association of Equine Practitioners (AAEP, scale 0-5)
- Wyn-Jones scale (0-10)
- doesn’t matter which scale you use so long as you use one scale consistently
Outline the AAEP lameness grading scale
0:Lameness not perceptible under any circumstances
1:Lameness difficult to observe and not consistently
apparent, regardless of circumstances (e.g. weight
carrying, surface, circling, inclines, hard surface etc.)
2:Lameness is difficult to observe at a walk or when
troqng in a straight line but consistently apparent
under certain circumstances (e.g. weight carrying,
surface, circling, inclines, hard surface etc.)
3:Lameness consistently observable at a trot under all
circumstances
4:Lameness is obvious at a walk
5:Lameness produces minimal weight-bearing in moRon
and/or at rest or a complete inability to move
Outline the Wyn-Jones lameness grading scale
Grade 0: Sound.
Grade 2/10: Lameness hard to detect at walk or trot.
Grade 4/10: Lameness barely detectable at walk, easy to see
at trot.
Grade 6/10: Easily detectable lameness at walk.
Grade 8/10: Hobbling at walk. Unable/unwilling to trot.
Grade 10/10: Non weight-bearing
What does a fetlock drop suggest? Exception?
Usually more on opposite (sound) fore- or hind
limb
• Exception: Tendon or Suspensory Ligament damage
When might changes in limb stride be noted?
cranial and caudal phase of stride
Is it easier to recognise TL or HL lameness?
forelimb
Signs of forelimb lameness - 3
• HEAD NOD/ HEAD ELEVATION
– Head down when opposite forelimb hits ground
– Head up when lame forelimb hits ground
• ASYMMETRICAL contraction pectoral mm.
• SOUND/CONCUSSION
– Harder landing on sound limb → louder noise
How can HL lameness be recognised? 4
• PELVIC HIKE
– Affected side down when lame HL hits ground
– Affected side up when opposite HL hits ground
– Greater excursion on lame HL
• ELEVATION OF TUBER CALCIS
– Higher on sound side
• DRIFTING
– Horse moves away from lame limb
– Lame limb tracks under body (most often) or is posted out
• SOUND
– Harder landing on sound limb → louder noise
What additional factors need considering when assessing lameness? 5
• SURFACE – Soft vs. hard • CIRCLE • Different GAITS – Severe lameness/Suspected Fracture (walk) – Gallop (rarely) • UNDER SADDLE – Owner& separate rider (?) • HIGH-SPEED TREADMILL – STB Pacers & Trolers
How does a slow motion video affect grading score?
tends to increase grading score as it looks more severe than normal speed
T/F: radiographic signs of change on fetlock and stifle can cause lameness
True
How reliable is the tuber calcis elevation for evaluating HL lameness?
not so reliable
What is meant by drifting?
horse runs obliquely (e.g. L HL brought b/w front limb tracks)
What can a short stride length indicate?
- either TL or HL lameness, easier to appreciate when HL lame as a greater distance b/w the toe of the HL and the toe of the TL when the lame HL is weight-bearing
What can reduced fetlock drop be a sign of?
- TL or HL lameness
- observe how close the fetlock drops towards the ground
- reduced fetlock drop is associated with the lame limb d/t reduced loading
- easiest to observe at walk
What parts of the history do you need? (SA)
- signalment (including use)
- current lameness (hx of trauma, duration of lameness, deterioration or improvement, circumstances, effects of exercise, management changes
- past lameness problems
How should you observe gait? (SA)
- patient moving towards, away and across you
- circling and turning (exaggerate abnormalities)
- which limb is problem, concentrate on this (characterise and score)
What manipulation should be done? (SA)
Move joint and limb in a controlled fashion to determine:
- ROM/ abnormal mvt
- pain related to mvt
- load or unload specific structures in limb
What is your overall assessment/ future decisions based on? (SA)
- add up findings from exam
- does patient have locomotor abnormality?
- is it a problem to patient/ owner?
- anatomical location known?
- how to investigate further
What are the objective parts of the lameness exam?
- observation at rest
- observe gait
- palpate to recognise anatomical abnormalities
- manipulate to locate functional abnormality
