Foal Angular Limb Deformities Flashcards
What is a lateral deviation in the frontal plane of the limb called?
Valgus
What is a medial deviation in teh frontal plane of the limb called?
Varus
what side should you apply pressure when correcting a Valgus deformity?
valgus deformity –>lateral deviation, therefor apply pressure on the medial side
What are some causes of Valgus deformity?
1) periarticular laxity
2) incomplete ossification of the carpal bones
3) hypothyroidism
4) limb confirmation
- over loading
- phyeal trauma or infection
5) multifactorial
T/F Valgus deformity is also known to occur in twins?
True
How would you diagnose Valgus deformity in a horse?
1) Observation
2) limb manipulation
3) Radiographs (long, narrow cassettes
If you can manually correct Valgus deformity in a young horse what does this suggest?
joint laxity, correctable
What type of radiographic view would you want to Diagnose a angular limb deformity?
long, narrow cassettes in :
DORSOPALMER view
What regions can be affected with angular limb deformity?
1) carpus/ tarsus
2) metacarpal/ metatarso pharyngeal joints
What locations (pivot point) can limb defomities occur in?
1) the growth plate
2) joint space
How do we obtain the pivot point?
After radiographs….
1) cellulose acetate overlay
2) bisect long bone axis
3) deviation at each joint space
What is the pivot point?
the point where the two long bone axis intersect
How do you calculated the deviation?
Pivot point + angle = deviation
How do you treat angular limb deformities
1) Conservative
2) surgical (more severe forms)
What are some conservative treatment for limb deformities?
1) stall rest
2) hoof trimming
3) external support (splint / cast)
What are some surgical treamtents for limb deformities?
1) hemicircumferential periostal transection and elevation (HCPTE)
- periosteal stripping
2) Growth retardation (temporary transphyseal bridging TTP)
- sqrews, wires
- staples
3) corrective osteotomy (-ectomy)
What type of Shoes can be used to correct angular limb deformities?
- for valgus
- for varus
Treatment + Dalmer shoes
for Valgus–> use toed out
for Varus–> use toed in
What are the 2 techniques that need to be acomplished during surgical treatment?
1) growth acceleration
2) growth retardation
What is a growth acceleration technique?
1) HCPTE (periosteal stripping)
can be done in the field quickly (xylazine and ketamine)
What is a growth retardation technique?
*want to stop the growth plate from growing
1) using surgical screws and wire
- one hole distal to the growth plate
- one hole proximal to the growth plate
- circlage wire in figure 8 configuration
on the oposit side the growth continues to happen resulting in straighteing out
make sure to radiograph 2 weeks later?
Following a growth retardation techinique how long after should you radiograph again?
2 weeks
When do you use corrective osteoectomy?
When there is no more growth plate to retard or accelerate growth for correction
- procedure is used to cut the bone and straighten things out
What are some forms of corrective osteoectomy
1) closing wedge-requires plates and screws
2) step ostectomy-take out wedge and put it in other leg
3) dome saw
T/F: with Valgus deformities there is a certain degree of outward rotation of the feet
TRUE
And we see inward rotation with various
T/F: Hypoplasia of the proximal sesamoid bones is part of the multifactorial complex implicated in development of angular limb deformities in foals
FALSE
Hypoplasia of the carpal and tarsal bones contribute to the multifactoral complex of angular limb deformities
T/F: the limb can usually be straightened in foals with Hypoplasia of the carpal bones
TRUE
Which view is especially useful in identifying tarsal bone Hypoplasia?
LATEROMEDIAL radiographic view
T/F: delayed ossification of the epiphysis can cause carpal angular limb deformities in NEWborn foals
TRUE
T/F: Congenital HYPOthyroidism has been implicated as a cause of delayed ossification of the carpal and tarsal cuboidal bones
TRUE
Foals with tarsal bone Hypoplasia tend to present with what angular limb deformity and appearance?
Valgus and sickle-hocked appearance
Are Foals with angular limb deformities usually lame?
NO
What happens if a foal with cuboidal bone hypoplasia is left untreated?
It becomes manually irreducible deformity within 2 weeks
Angular limb deformities most often originate within the carpal, tarsal, __________joint regions?
Metacarpo or metatarsophalangeal
FETLOCK
T/F: in most foals born with mild to moderate angular limb deformities, spontaneous resolution occurs within 2-4weeks of life
TRUE
To avoid development of a contracted foot in a foal, glue-on shoes should not be left on for longer than _________?
2 weeks
How often should tube casts be changed to allow rapid growth in foals?
10-14days
1-2weeks
When is Corrective ostectomy or osteotomy performed?
Generally after cessation of physical growth
IS HCPTE as effective as Stall confinement alone, in correcting carpal angular limb deformities?
YES it is as effective
What should foals with carpal bone hypoplasia be treated with ?
-Splint bandaging
Or
-Tube casting
What is the best treatment for a 6 weeek old foal with significant VARUS deformity caused by asymmetric growth at the distal metatarsal growth plate in the left hindlimb?
1) Surgery
2) Corrective trimming
3) shoeing and confinement
HCPTE temporarily increases longitudinal growth on which aspect of the deformity?
Concaved
When is Trans Physeal Bridging used?
Primarily used in :
1) young foals with SEVERE angular deformities
2) miniature foals
3) foals with significant limb deformity after the rapid growth phase
What is required as post op treatment for a foal that had HCPTE?
CONFINEMENT
