Orthopaedic Problems in Developing Yearling Flashcards
Define yearling
A yearling is a horse in the first year of its life as of 1st of January
Describe Yearling Prep Process
Begins 8-10 weeks pre-sale
- Used to being handled
- Exercise for strength
- Diet increase in energy for optimal growth
Detail the exercise / role of vet
- Exercise program should not be started until vet evaluation
- Physical or conformation problems can be exacerbated by forced exercise
- Risk that exercise can cause lameness issues
Detail Diet /role of vet
- Ration evaluation very important
- Excess energy leads to rapid growth and increased body fat
- > More pressure on joints, tendons and muscle
-> More prone to developmental orthopaedic disease - Deficiencies, excesses and imbalances of nutrients result in increased incidence and
severity of developmental orthopaedic diseases
Wha deficiencies/excess/imbalance do we see?
- Deficient- Ca, P, Cu, Zn
- Excess- Ca, P, Zn, I, Fl, heavy metals lead and cadmium
- Imbalance- Ca:P ratio
PRe-sale screening?
Xray ->
* Spring- animals being considered for sale later in the year
* 36 views→ fetlock, carpus, hocks, stifles
* Radiographs allocated a grade 1-4.
Surgical interventions?
- Any lesions requiring surgery can be dealt with allowing
ample time for sales prep - Some undergo surgery on non-clinically significant lesions
→ attempt to prevent negative impact of future sales price
What conditions does Developmental Orthopaedic Disease encompass?
- Osteochondrosis (OCD or Osseous Cys like lesions)
- Physitis
- Angular Limb Deformities
- Flexural Limb deformities
- Cervical Vertebral Stenotic Myelopathy
Describe Osteochondrosis?
- Focal disturbance in endochondral ossification resulting in a
thickened area of articular cartilage - Thickened areas of cartilage are complicated by the
development of fissures extending to the articular surface
Describe OCD
- Fragments separates from adjacent subchondral bone
→ Become mineralised/calcified
→ Joint ‘Mice’ - Focal or multifocal failure
Osseous Cyst Lesions (subchondral bone cysts)
- Retention of a focal area of degenerate cartilage within the
subchondral bone - Occur on weight bearing surfaces of the joint
Pathogenesis of Osteochondrosis
- Multifactorial
- Polygenic
- Environment & Susceptibility Important
Factors to Osteochondrosis?
- Body size & growth rate
- Nutrition high plane
- High phosphorous diet
- Copper deficiency
- Gender -> males? - Genetic predisp
- Exercise
- Trauma
- Toxins
Clinical Presentations and Lesion Distribution Osteochondrosis
- Young animals -> asymptomatic picked up at sales rads
- Joint effusions -> less evident with cysts
- +/- lameness
- Reduced activity
- Postural abn
- Stiffness
- Predilection sites (often bilat)
Locations of lesions in tarsocural (hock) joint?
- DIRT(distal intermediate ridge of tibia)
- Lateral trochlear ridge of talus
- Medial malleolus of tibia
- Medial trochlear ridge of talus
- Lateral malleolus of tibia
Femoropatellar (Stifle) Locations?
- Lateral and medial femoral trochlear ridge.
- Lateral facet of the patella
Metacarp/tarsophalangeal (fetlock) joint ?
- Mid-saggital ridge
- Condyle of MC3 or MT3
Scapulohumeral (shoulder) locations?
- Glenoid fossa
- Humeral head
Anatomy of talus
What would we see on Xray with osteochondrosis?
- Flattening of joint surface
- Mineralised cartilage flap seen
within subchondral bone defect - Presence of joint mice
- Subchondral Bone Cysts
- Joint Effusion
- *Predilection sites
Consequences long term of OC/OCD?
Predisp to OA
→Free floating fragments can result in extensive cartilage damage
→Joint mice may become lodged in synovial membrane
Conservative management for OC/OCD?
- Should always be considered in horses younger than 18 months as
esions can improve radiographically and presumably heal - Dietary modification- reduction in dietary energy intake
-> reduce growth rate
-> reduce body weight - Rest
- Analgesia
What does surgical management involve? Pg?
Arthroscopic debridement of lesions and removal of cartilage flaps
Prognosis dependent on site and severity of lesion and presence of
secondary Degenerative Joint Disease
What does surgical management depend on?
- Age: lesions may heal in younger animals
- Presence of joint effusion
- Frequency and severity of lameness:
- if there are clinical signs of lameness - surgery is often indicated
- Radiographic appearance of lesion:
- Appearance of large defects or joint mice- surgery is indicated
Osseous cyst like lesion treatment?
- Rest & systemic NSAIDs- 4-6 weeks box rest
- Corticosteroids intraarticular or intralesional
- Surgical options including debridement and translesional screws
Physitis = ?
Inflammation of the growth plate
What lesion is physitis causing?
When does this happen?
Compression lesion which arises due to greater weight bearing on medial or lateral
aspect of limb
* Often occurs secondary to angular limb deformity
Where do we commonly see physitis ?
medial aspect of distal radius
→secondary to carpal varus limb deformity
when do we see physitis ?
- Fetlocks at 3-6 months
- Distal Radius 8 months – 2 years
Clinical presentation of physitis?
- Firm, warm and painful enlargement of the growth plate
- Most commonly on medial aspect
- May resent limb flexion and exhibit signs of pain when pressure applied
across growth plate - Bilateral lameness may be evident (Stiffness)
If untreated, what happens with physitis ?
Growth ceases on affected side
* →the angular limb deformity is exacerbated
* →the growth plate will close prematurely
* →results in permanent conformational defects
Physitis on xray?
- Irregularly thickened Growth plate
- Metaphyseal sclerosis
- Periosteal new bone formation
Tx for Physitis?
- Box rest
- NSAIDs
- Assess nutrition
- Reduction in bodyweight
- Treatment of any underlying Angular Limb Deformity
- Corrective trimming/hoof extensions
How would we assess nutrition?
- Restrict grain intake
- Ensure sufficient protein intake
- Correct mineral intake- Ca:P balance and sufficient Cu
and Zn
Prognosis Physitis?
Good provided condition was not too severe as to result in permanent conformation defects
Describe Angular Limb deformities
- Congenital or Acquired
- Distal portion of limb deviates laterally (VALGUS) or medially (VARUS)
Causes of Angular Limb Deformities?
- in utero malposition
- Hypothyroidism
- Trauma
- poor conformation
- excessive joint laxity
- defective endochondral ossification
Which joints affected?
- Carpus affected most frequently (distal radius) and most commonly carpus valgus.
- Fetlock (distal MCIII/MTIII) and tarsus (distal tibia) also affected
CLs of angular l Def?
- Most foals asymptomatic except if severe deviation
present - Epiphyseal/Physeal dysplasia –deviation cannot be
corrected manually - Ligamentous laxity- deviation can be corrected manually
Dx of ALD?
o Clinical examination and visualisation of deviation
o Dynamic Assessment
o Radiographs to determine precise site and cause
ALD - Conservative tx?
- Rest
- Corrective farriery
- Extracorporeal Shock Wave Therapy in foals >2weeks
- SPlint/Cast
How to correct with farriery for valgus vs varus?
- Valgus- trim lateral hoof wall +/- place extension medially
- Varus- trim medial hoof wall +/- place extension laterally
What two options for surgical tx of ALDs?
- Periosteal Transection and Elevation
- Bridging of the Physis on the convex side of the limb
Describe Periosteal Transection and LEevation
- Releasing incision into periosteum
- Hemi-circumferential transection with elevation of triangular flaps of
underlying periosteum - Performed on concave side of limb
- Increases growth of that side
Describe Bridging of the Physis on the convex side of the limb
- Transphyseal Bridge
- Transphyseal Screw
- Transphyseal Staple
Prognosis?
- Good if treated early and not a severe deformity
- Many cases self-correc
Describe when treatment would be suggested with regards to angle of deformity
Age and Growth plate closure times?
o Fetlock- 6 months
o Carpus- 20-24 months
o Tarsus- 17-24 months
Timing of different interventions?
Describe Acquired Flexural Limb Deformities?
During periods of rapid bone lengthening
* Distal interphalangeal joint- 3-6 months
* Carpal flexural deformity- 1-6 months
* Metacarpophalangeal joint- 9-18 months
Causes of Acquired Flexural Limb Deformities?
- Genetic propensity for rapid growth
- Overnutrition
- Exercise
- Pain
What are the two possible Causes /PathoG of Acquired Flexural Limb Deformities
- Period of rapid boen lengthening
- Pain response during physeal dysplasia
Describe AFLD due to rapid bone lengthening?
- →Potential for passive elongation of tendinous unit is limited by accessory ligaments
- →Discrepancy in length of bone to tendon
Describe AFLD due to pain from dysplasia
- →Altered load bearing on limb
- →Secondary contraction and shortening of musculotendinous unit
- →Limited extension of a region
Clinical Presentation of AFLD in the Distal Interphalangeal Joint
- Prominent bulge at the coronary band
- Increase length of heel relative to toes
- Failure of heel to contact the ground after trimming
→boxy shaped foot
AFLD of the DIP can be recognised in two stages :
Stage 1: the dorsal wall of the hoof does not pass beyond the
vertical.
Stage 2: The dorsal wall of the foot passes beyond the vertical.
Tx for Mild AFLD?
Conservative
* Exercise restriction
* Lowering the heel +/- bevel toe
* Dietary restriction
* Pain control- NSAIDs
* Weaning of foal
* Toe Cap if wearing of toe
excessive
Tx for Severe AFLD? (unresponsive to conservative tx)
Surgery
* Transect Accessory Ligament
of the Deep Digital Flexor
Tendon
* Transect Deep Digital Flexor
Tendon (if hoof angle >90°)
Corrective Farriery
Tx for Metacarpophalangeal/ Metatarsophalangeal Joints AFLD Conservative?
Conservative >
* Eliminate pain with analgesics
* Exercise restriction
* Correction of underlying nutritional problems
* Corrective Farriery
Tx for Metacarpophalangeal/ Metatarsophalangeal Joints AFLD Surgery?
- Desmotomy of accessory ligament of superficial digital flexor tendon
or ALDDFT - MUST treat underlying cause or improvement will only be transient
What is the full name of ‘Wobblers Syndrome’?
Cervical Vertebral Stenotic Myelopathy (CVSM)
Describe CVSM?
- Classified as Grade 1 (developmental) or grade 2 (degenerative)
- Malformation of vertebrae (C2-C5)
- Stenosis of the canal
The spinal cord compression can be …. or ….
dynamic of statis
Who do we see wobblers in ?
- In weanlings and yearlings, commonly overgrowth of articular processes causing
dynamic compression - Seen at 6 months – 3 years of age
- Male horses > female horses.
CLS of CVSM?
- Severity depends on degree of compression.
- Abnormal gait in the front and/or hindlimbs.
- Ataxia.
- Weakness (toe drag, stumbling)
Diagnosis of CVSM?
- Full neuro exam
- Plain radiographs
- Myelography (gold standard)
- CT (+/- myelography)
Conservative Tx for CVSM?
- Diet- reduction in protein and energy to 70% of normal
- Box rest
- Steroids
- NSAIDs
(also in acute compressive or moderate degenerative lesions)
Surgical CVSM TX?
Dorsal Laminectomy or Intervertebral Body Fusion
* Only suited in small percentage
* 1 or 2 sites of compression-dynamic
* Recent onset and mild clinical signs
