Flexural deformities Flashcards
Which anatomical plane do they occur in?
- the sagittal plane
– therefore assessed by viewing from the side
Are they more common in the fore or hindlimbs?
- Forelimbs
More commonly unilateral or bilateral?
- bilateral
Laxity vs Contracture
- laxity = hyperextension
– joint sinking towards the ground - contracture = hyeprflexion
– joint flexed
Is congenital hyperextension common?
- yes
Which part of the limb is usually affected by congenital hyperextension?
- the distal limb: fetlock and phalangeal joints
Clinical signs of congenital hyperextension
- elevated toe
- palmar/plantar fetlock is sunken
Cause of congenital hyperextension
- flaccidity of flexor muscles after birth
Tx of congenital hyperextension
- usually self corrects within a few weeks
– confine to a small grass pen
– want a firm surface for them to stand on, whilst getting exercise so a small grass pen is good - skin abrasions may occur on palmar/plantar fetlock
– protect with bandages - glue on heel extension shoes may be required (if doesn’t resolve on its own)
What can congenital hyperflexion cause?
- dystocia
- inability of the foal to stand (due to inability to get its leg straight)
Where does congenital hyperflexion occur?
- coffin joint
- pastern joint (rarely)
- fetlock
- carpal joints
- tarsal joints
Congenital hyperflexion – medical treatment
§ Light exercise – spontaneously resolve in a few days.
– If a mild problem and the foal is able to weight bear and walk around
§ 3g oxytetracycline in 500ml saline slow IV.
→ within a few days of birth (usually within 48h, definitely within 1wk of birth)
→ inhibits tractional structuring of collagen fibrils.
→ tendons & ligaments more susceptible to elongation during normal weight bearing.
§ Toe extensions and heel reduction.
→ stretches musculotendinous unit during weight bearing.
§ NSAIDs (and omeprazole)
– As stretching of the tendons is painful
§ Splints or casts.
→ encourages relaxation of the musculotendinous unit.
Why when giving NSAIDs to a foal must you also give omeprazole?
- Bigger risk of GI ulceration, so must give omeprazole as a gastro-protectant
Congenital hyperflexion – surgical treatment
- if medical tx fail – rarely required
Acquired hyperflexion - cause
§ Pain cause flexion withdrawal reflex and subsequent muscle contraction.
Pain due to:
1) Rapid bone growth with tendons unable to keep up
→ functional shortening of tendons
→ resulting tension in tendon is painful
2) Specific injury e.g. osteochondrosis, fracture, septic arthritis, foot abscess
Another term for acquired coffin joint contracture
- Club foot
Acquired coffin joint contracture - age affected and why
§ 1-4 months old
→ Metacarpal / tarsal bones growing rapidly
→ Functional shortening of DDFT (as it can’t grow at the same speed as the metacarpal/tarsal bones)
Acquired coffin joint contracture - stages
§ Stage 1: dorsal hoof wall has not past vertical – good prognosis
§ Stage 2: dorsal hoof wall has progressed past vertical – guarded prognosis
Acquired coffin joint contracture – medical management
§ Toe extensions and heel reduction.
→ stretches DDFT musculotendinous unit during weight
bearing.
§ NSAIDs (and omeprazole).
§ Reduce foals growth rate by reducing nutrition → reduce feed to foal and mare
– reduce mares milk by reducing her nutrition
– reduce creep feeding to the foal itself
→ early weaning
§ Address other causes of pain
– e.g. osteochondrosis or fracture
§ Suitable for stage 1 only
Acquired coffin joint contracture stage 1 – surgical management
- Desmotomy of the accessory (check) ligament of the DDFT
→ proximal cannon under short G.A.
→ good prognosis as an athlete
– sectioning the check ligament reduces some of the tension and pull of the DDFT on the pedal bone
Performed in addition to medical therapies
Acquired coffin joint contracture stage 2 – surgical management
- Tenotomy of DDFT
→ mid cannon or palmar pastern
→ guarded prognosis as an athlete
– partly because it is harder to correct the deformity and also because sectioning of the DDFT creates problems on its own
Performed in addition to medical therapies
Acquired fetlock joint contracture - age affected and why
§ 10-18 months old
→ Radius / tibia growing rapidly
→ Functional shortening of SDFT and suspensory ligament.
– As their growth can’t keep up with that of the bones
Acquired fetlock joint contracture - stages
§ Stage 1: Fetlock remains behind vertical
§ Stage 2: Fetlock positioned in front of vertical, but can move behind vertical during weight bearing.
§ Stage 3: Fetlock positioned in front of vertical always.
Acquired fetlock joint contracture – medical management
§ Toe extensions
– to increase the stretch of the tendons
§ NSAIDs (and omeprazole)
– for the pain
§ Reduce foals growth rate by reducing nutrition → reduce feed to foal and mare
→ early weaning
§ Splint (or bandage) to force fetlock into extension
§ Address other causes of pain
§ Suitable for stages 1 only.
Acquired fetlock joint contracture – surgical management
§ Careful palpation under G.A. with limb in full extension reveals which structure(s) is causing contracture.
§ Procedure performed depends on structure(s) involved and severity
§ Performed in addition to medical therapies
Acquired fetlock joint contracture – surgical management if SDFT causing contracture
Mild → Desmotomy of the accessory (check) ligament of the SDFT
Stages 2 or 3 → SDFT Desmotomy (guarded for athletic use)
Acquired fetlock joint contracture – surgical management if DDFT causing contracture
Mild → Desmotomy of the accessory (check) ligament of the DDFT
Stages 2 or 3 → DDFT Desmotomy (guarded for athletic use)
Acquired fetlock joint contracture – surgical management if suspensory ligament causing contracture
→ Suspensory ligament Desmotomy (guarded for athletic use)
