Neonate orthopaedic disease Flashcards
6 neonatal orthopaedic diseases
1) Incomplete ossification of cuboidal bones
2) Septic arthritis / physitis / osteomyelitis (SAPO)
3) Physitis
4) Physeal fracture
5) Angular Limb deformity
6) Flexural deformity
Incomplete ossification of the carpus - which bones?
- radial, intermediate, ulnar, 2nd, 3rd, 4th carpal bones
Incomplete ossification of the tarsus - which bones?
- central 2nd, 3rd, 4th tarsal bones
Skeletal formation in utero (re cartilage ossification)
▪Skeleton formed as a cartilage in utero
▪Normally ossify in last 2-3 months of gestation (months 9-11)
Which foals are affected by incomplete ossification of cuboidal bones?
- premature/dysmature foals
What can cause incomplete ossification of cuboidal bones?
During gestation:
- placentitis
- colic
- abnormal positioning
How do bones ossify/mineralise? (i.e. which direction?)
- from the centre outwards
What can incomplete ossification of cuboidal bones cause at birth?
- peri-articular laxity
Treatment of incomplete ossification of cuboidal bones
▪Excess exercise may cause damage to soft cartilage
▪Lead to joint and limb malformations
Therefore,
▪ Restrict exercise
▪ Splint limbs if laxity exists
▪ Wait for bones to ossify
▪ Keep in with nice soft bed
▪ Gradually decrease splints and increase exercise as the bones get stronger
Radiographic findings of incomplete ossification
- curved edges of bone
- big spaces where bone should be that are cartilaginous
What is physitis?
= Inflammation of the physis (growth plate) at the end of a long bone
Closure time of the distal radius
24 months
Closure time of the distal metacarpus (M3)
6-9 months
Closure time of the distal tibia
17-24 months
Closure time of the distal metatarsus (M3)
9-12 months
When will the growth phase of the distal metacarpus be active up until?
4 months
When will the growth phase of the distal radius be active up until?
18-20 months
When will the growth phase of the distal tibia be active up until?
18-20 months
When can physitis occur?
- anytime until closure of the growth plates
Does most of the long bone growth happen during resting or load bearing in foals?
- resting
Physitis potential triggers
▪Rapid growth
- specific growth phases / increased feed intake
▪Trauma to the physis (? type 5 Salter-Harris injury)
- indirectly through exercise, e.g. running up and down the fence line all day following the mare
- indirectly through severe contra-lateral limb lameness (increased weight bearing in non-lame limb)
- directly through external injury
▪Genetic predisposition
Clinical signs of physitis
▪ Heat
▪ Swelling
▪Pain on palpation ▪Possibly lameness
Signalment of physitis
▪Distal metacarpus 3-6mo foals
▪Distal radius yearlings
▪Commonly bilateral
Physitis - radiographs
- Widening of the growth plates
- Sclerosis around the growth plates
- Periosteal new bone with bridging
– Risk of angular limb deformities (ALD)
Physitis - tx
- Exercise restriction
- Analgesia (as a painful and inflammatory condition, meloxicam is the best option for foals)
- Correction of underlying cause (e.g. reduce feed intake, etc)
Salter-Harris fracture type 1
- Fracture happens across the growth plate
- Doesn’t go into the bone above or below
- Made of cartilage hence a weak point
Salter-Harris fracture type 2
- Fracture goes across the growth plate and exits through the metaphysis
Salter-Harris fracture type 3
- Fracture goes across the growth plate and goes through the joint surface
Salter-Harris fracture type 4
- Fractures of the epiphysis extending through the articular cartilage, epiphysis, physis and metaphysis
- i.e. doesn’t start across the physis
Salter-Harris fracture type 5
- Crushing of the growth plate - epiphysis crushed into the physis
What is the most common physical fracture?
- Salter-Harris type II
Physeal fracture tx
▪Conservative management - cast coaptation & confinement ▪Surgical correction – internal fixation
▪Damage to physis creates risk of growth deformities
- ALD or flexural deformity
– ALD if 1 side of the bone stops growing but the other side doesn’t
Why are the front legs more commonly affected by physitis?
- because they bear more weight than the back legs
Most common cause of a Salter-Harris type II fracture
- being trodden on by the mare
