Angular and Flexural Limb Deformities

Question 1

What are some growth abnormalities that occur in foals?

Answer 1

Angular Limb Deformities
Tendon and Ligament Laxity
Flexural Deformity (Contracted Tendons)

Question 2

What is the definition of an angular limb deformity?

Answer 2

Lateral or medial deviation to the long axis of the bone in the frontal plane

Question 3

What is the name of the ALD described by a lateral deviation distal to the point pivot point?

Answer 3

Valgus

Question 4

What is the name of the ALD described by a medial deviation distal to the point pivot point?

Answer 4

Varus

Question 5

Who commonly gets ALD?

Answer 5

Foals - younger ones, all breeds and either sex

Question 6

Which limb is the most common location for ALD?
Which site most common for ALD?
What is the most common defomrity?

Answer 6

Front limbs
Carpus, Fetlock, Tarsus
Carpal valgus, then fetlock varus

Question 7

What causes congenital ALD?

Answer 7

Ligamentous Joint Laxity
-Worse on weight baring, shift while moving and windswept

Incomplete endochondral ossification of cuboidal bone (premature or dysmature)

Question 8

What are some perinatal factors that contribute to ALD?

Answer 8

-Intrauterine mispositioning
-Over-nutrition of mare
-Hypoplasia of cuboidal bones
(Premature, dysmature, hypothyroidm, OC)
-Incomplete development MT/MC

Question 9

What are some causes of acquired ALD?

Answer 9

-Asynchronous longitudinal growth of physis or physeal dysplasia (genetic, nutritional, physeal or physitis)
-Traumatic luxation or fracture of physis, epiphysis or crapal/tarsal bone

Question 10

What factors should be considered in ALD?

Answer 10

-Inciting cause
-Physis growth
-Bone increase response to increase load

Question 11

How do you go about evaluating ALD cases?

Answer 11

Signalment, HX, visual exam, physical exam, rads, is one present, has it changed over time, define it and what joints are involved

Question 12

What type of history questions help with ALD?

Answer 12

When did they notice it? Has it worsened? Any lameness? Trimming?

Question 13

What are some key parts of your ALD visual exam?

Answer 13

-Watch while standing and walking
-front and back/multiple limbs
-Multiple site on limb
-Estimate degree pivot point
-Lameness in limb or contralateral
-Look at mare

Question 14

On your visual exam you notice the toe is deviated medially…what deformity will that most likely be?

Answer 14

(Fetlock) Varus

Question 15

What is key when examining the joints and degree of angulation?

Answer 15

Need to be standing directly in front of the joint in question

Question 16

What should be included in your physical exam?

Answer 16

Palpate joint laxity, observe angulation when flexed, evaluate hoof balance, palpate both limbs for heat, pain, swelling and crepitus

Question 17

What should you observe on your radiographs?

Answer 17

Pivot Point
Mild: <5
Severe: >15

Question 18

Is mild carpus valgus protective for carpal injury?
If so what does that make carpal varus?

Answer 18

Yes it is
Makes it bad

Question 19

What may you find on a radiograph of an angular limb deformity?

Answer 19

Metaphysis - flaring and sclerosis
Growth Plate - indistinct physis, irregular width
Epiphysis - wedge shape, fracture lines
Cuboidal - abnormal shape, hypoplastic, collapsed, subluxated
MT/MC - shorter or wider joint space
Bone cotes - diaphyseal remodeling
Ulna/fibula - complete

Question 20

What are treatment goals for ALD?

Answer 20

Improve the conformation
Halt worsening angulation
prevent DJD
Improve athletic performance

Question 21

More intervention is needed if…

Answer 21

the foal is older and the deformity is more sever

Question 22

What are some non-surgical treatments for ALD?

Answer 22

Stall rest and revaluate 2wks
Tube cast, splint or brace
Corrective trimming, hoof extension and shoeing

Question 23

Prognosis ALD?

Answer 23

Hypoplastic cuboidal bones - poor athletic
Tendon and ligament laxity - good

Question 24

What is sickle hock conformation?

Answer 24

Incomplete ossification of tarsal bones, collapse dorsal aspect of cartilage template, abnormal conformation, OA and lameness

Question 25

If the horse has a varus deformity, which way should the extension go for correction?

Answer 25

Extension Lateral (Extension medial for valgus)

Question 26

How should you correctively shoe foals?

Answer 26

Glue ons, limit normal growth, day on day off, second set if needed, hoof nipper or rasp off

Question 27

What are some surgical treatments for ALD?

Answer 27

-Periosteal transection and elevation -Transphyseal bridging -Wedge Ostectomy

Question 28

What are some things to remember about transphyseal bridging?

Answer 28

Very effective, restrict exercise to prevent implant failure, second surgery to remove the implant, local infection and scarring, can overcorrect

Question 29

When should you treat and when does the physis close of the following joints: MCP/MTP: Carpus: Tarsus:

Answer 29

MCP/MTP: 30d, 120d Carpus: 4m, 18m Tarsus: 4m, 21m

Question 30

How long should you wait to know if your conservative treatment is working?

Answer 30

no more than 3 weeks for MCP, no more than 3 months for carpus or tarsus

Question 31

What is the rule on prognosis for ALD?

Answer 31

The more distal the pivot point the poorer the prognosis

Question 32

How do you prevent ALD?

Answer 32

Owner education, monitor, proper feeding, look at mare and stallion conformation, foot trim and rasp on schedule, avoid excessive exercise

Question 33

When should fetlocks be treated by?

Answer 33

2 months of age

Question 34

What is the general process for fixing ALD?

Answer 34

Address inciting cause, restrict exercise, trim and rasp, hoof extension, transphyseal screw, periosteal transection and elevation

Question 35

What are tendon and ligament laxity also known as?

Answer 35

Digital hyperextension deformities

Question 36

Where are tendon and ligament laxity commonly found?

Answer 36

more in hind limbs

Question 37

What is the cause of tendon laxity?

Answer 37

Lack of exercise, systemic illness, bandage or casting

Question 38

What is a sign of tendon and ligament laxity?

Answer 38

No weight on toe, walk on heel bulb

Question 39

How can you acquire a tendon and ligament laxity?

Answer 39

Hoof overgrowth Bandaging or casting

Question 40

What are some conservative ways that tendon and ligament can resolve?

Answer 40

Moderate exercise, trimming and rasping feet, shoe, light bandage to protect skin

Question 41

Treatment for Tendon and ligament laxity?

Answer 41

Heel extension, controlled exercise, no splint or bandage

Question 42

What is a flexural limb deformity?

Answer 42

length disparity between tendons and bones, tendon normal on ultrasound

Question 43

Contracted tendons are

Answer 43

rare

Question 44

Where does FLD or hyperflexion of a joint commonly occur?

Answer 44

DIJ, MCP, Carpus

Question 45

Which limb do flexural deformities typically occur in?

Answer 45

Front

Question 46

What causes FLD?

Answer 46

Congenital: uterine mispositioning, genetic, teratogen, disease of mare, locoweed, Sudan grass

Question 47

What causes AFLD?

Answer 47

Growth disparity between bones, tendons and ligaments Pain - flexion withdraw reflex (physis, OCD, septic arthritis, wounds, hoof pain, contralateral limb overload)

Question 48

What is critical to assess when it comes to a foal with FLD?

Answer 48

Can it nurse

Question 49

How do you know the horse has a DIJ FLD?

Answer 49

Walk on toe, cant put heel on ground, club foot, excessive toe wear

Question 50

How do you know you have a metacarpophalangeal joint (fetlock) FLD?

Answer 50

Upright or knuckled over, DJD, reducible or non

Question 51

How do you know you have a carpal FLD?

Answer 51

Buckling or flex at carpus

Question 52

Treatment FLD?

Answer 52

Congenital: assist nursing, increase exercise, NSAID, Oxytet, Toe extension shoe, splint or cast, surgery DJI - Hoof trim, rasp, lower heel, avoid trimming toe Carpus- splint or cast