Lecture 7 Flashcards
Ottawa rules for ankle x-rays
- Pain in the malleolar zone and one of the following:
- Bone tenderness at posterior edge or tip of lateral malleolus (distal 6 cm)
- Bone tenderness at posterior edge or tip of medial malleolus (distal 6 cm)
- Inability to bear weight immediately and in the ER for 4 steps
- (Bearing weight counts even if there is a limp)
Ottawa rules for foot x-rays
- Pain in the midfoot zone and one of the following:
- Bone tenderness at base of 5th metatarsal
- Bone tenderness at the navicular
- Inability to bear weight immediately and in the ER for 4 steps
- (Bearing weight counts even if there is a limp)
Clinical judgement can overrule concrete rules. The following can prevent adequate palpation:
- Altered foot/ankle sensation
- Large amounts of swelling
- Other painful injuries
- Altered mental state of patient
Treatment of lateral ankle sprain with avulsion fracture of 5th metatarsal tuberosity
- Usually conservative with protected weightbearing boot/cast
- Surgery may be warranted depending on degree of displacement of fractured fragment or % of articular surface involved
5th metatarsal tuberosity (styloid process)
- Atttachment of fibularis brevis and lateral band of plantar aponeurosis
- Well vascularized
- Avulsion fracture can result from inversion ankle injuries
Have to differentiate avulsion fracture from
- Other 5th met frx
- Apophysis
- Os vesalianum (.1-1% prevalence)
Apophysis of the 5th metatarsal
- 2ᵒ ossification center
- Normally seen ages 10-16 yrs
- Appears 12 yrs boys and 10yrs girls
- Fuses within 2-4 years after appearance
Apophysis of the 5th metatarsal is located
- Laterally
- Oriented longitudinally
Most commonly fractured metatarsal
- 5th metatarsal
- Tuberosity most common
Proximal fractures of 5th metatarsal
- Tuberosity (zone 1): avulsion fractures
- Metaphysis/metadiaphyseal jxn (zone 2): Jones fractures
- Proximal diaphysis (zone 3): stress fractures
- All cause lateral foot pain and difficulty walking
Tuberosity (zone 1): avulsion fractures
- Also known as pseudo-Jones fractures
- Plantarflexion inversion injury
- Well vascularized by multiple metaphyseal arteries
Metaphysis/metadiaphyseal jxn (zone 2): Jones fractures
- Transverse frx through the base (~1.5-3cm from tuberosity tip)
- Caused by forefoot adduction
- Can occur when pivoting and foot rolls onto the lateral border
Jones fractures are susceptible to
- Nonunion and delayed union
- Watershed area of blood supply between:
- Nutrient artery that enters and supplies the diaphysis
- Metaphyseal vessels that supply the apophysis
Jones fracture treatment requires
- Periods of non-weightbearing
- Often require surgical intervention
Proximal diaphysis (zone 3): stress fractures
- Caused by repetitive microtrauma
- Susceptible to delayed union and nonunion
- Requires period of non-weightbearing, often surgical intervention is required
