La Ortho - Angular Defomrity Flashcards
Valgus deformity
Limb deviates laterally
Distal to reference point
Varus deformity
Deviates medially
Distal to reference point
ALG causes
Perinatal factors
Acquired
Windswept ALD
Tarsal valgus and tarsal varus
Perinatal facots
Maternal illness during pregnancy
Periarticular laxity
Incomplete ossification of cuboidal bones
Acquired factors
Unbalanced nutrition
Excessive exercise/trauma
- asymmetrical physeal growth
Specific prenatal factors
Periarticular laxity
Cuboidal bone hypoplasia
Teratogenic insults
Placentitis
Hormonal /nutritional imbalance
Specific postnatal factors
Poor limb conformation
Excessive growth rate
Physeal injuries
Overload due to contralateral limb lameness
Visual exam
Keep perspective of where youre located vs where the foal is located
Always check multiple directions/views to achieve a proper diagnosis
Periarticular laxity
Soft tissues around joint are too elastic
Can be manually corrected
Radiographs will appear normal
Treating periarticular laxity
Exercise restriction - stall confinement
Excess loading will lead to pathologic loading
Treating severe cases of periarticular laxity
Severe cases
Tube casts
Splint bandages
Orthotic devices
- goal is to support structures while bone straightens
Incomplete ossification
Premature/dysmature
>1 joint affected
May lead to permanent ALD without protection
Can be manually corrected
Radiographs abnormal
Treating incomplete ossification
Exercise restriction
External support for periarticular laxity
Improve in 2-4 weeks
Reradiograph to follow
asymmetric physeal growth
Metaphysis or epiphysis
Present at birth but more common to develop in growth
Radiographs are abnormal - one side of metaphysis is hypertrophic = different lengths
Manually correction is NOT possible
Cause for APG
???
Unbalanced nutrition
Rapid growth
Trauma - path forces/fracture
Osteochondrosis
Osteomyelitis
Treating APG
Exercise restriction - in all cases! Goal is to prevent physeal trauma
Mild to mod cases - balance foot for equal loading mechanics
Severe - surgery to balance
Goal for balancing foot
Hoof wall development to be equal on both sides
Corrective shoes for APG
Trim every 2 weeks
Maintain symmetric shape - can add acrylic for shape
Conservative management
Catching early = very good prognosis
Failure to catch or treat - abnormal loads placed on limb just progresses the deformity
When is it ideal to act for APG
Prior to 2 months for fetlock
4 months for tarsus
6 months for carpus
When does the majority of growth occur for various bones?
Fetlock - 2 months
Tarsus - 4 months
Carpus - 6 months
When does the physeal close in various bones?
Fetlock - 3 months
Tarsus - 1-2 years
Carpus - 1-2 years
When is it ideal for conservative management for APG?
Fetlock - 2-3 wks
Tarsus - >6 wks
Carpus - <2-3 months
Flexural limb deformity
Deviation in sagittal plane
- laxity or deformity
Occurrence of flexural limb deformity
Can occur in metacarpophalangeal joint, distal interphalangeal joint, carpal joints
Common in young foals
What causes FLD
Congenital - laxity & deformity
Acquired - deformity
Congenital
Flexural laxity - flexor muscle flaccidity
Flexural deformity - lack mobility in affected joint, painful
Acquired FLD
Flexural deformity
Nutrition - too rapid growth, bone outgrows soft tissue
Pain - flexion withdrawal reflex, muscle contraction over time = Flexural deformity
Flexural laxity
Muscle laxity - toes off ground, fetlock on ground, back at knee
Controlled exercise
Balance foot
Light bandages - protect legs - DO NOT provide support, make muscle tendon unit work to strengthen it
Extended heel shoes
Risk with bandaging FLD
Too much support = more laxity
Flexural deformity
May not be able to stand - esp with carpus
FPT is common due to no nursing
Cant straighten
Oxytetracycline in FLP
Deformity
Given IV inhibits myofibroblast contraction - allows muscle to relax and have better prognosis
Bandaging flexural deformity
Want to protect/relax muscle tendon unit
Must change frequently, pressure sores are common
Bandages come all the way to the ground - unlike in laxity
Toe extensions w FD
Toe extensions are common, when FD is on distal interphalangeal jt
Increases tensile forces of DDFT
Distal check ligament desmotomy
DF in distal interphalangeal joint
Releases load & transfers weight to DDFT
Proximal check ligament desmotomy
P3 is normal, fetlock is not
FD in metacarpophalangeal joint
Lengthen muscle/tendon unit
Releases tension w forward bend so leg relaxes back to a more normal stance
