(2) Lecture 13: High Ankle Sprains Flashcards
Main factor in preventing talar eversion
FIBULA is main factor in assisting DELTOID ligament in preventing talar eversion
Fractures from Eversion/external rotation MOI
- Deltoid
- Ant. inf. tib-fib
- Fracture
Can injure
- deltoid ligament
- anterior inferior tib fib ligament
- fibula
- tibia
Fibula assists deltoid ligament to prevent talar eversion
Healthy ankle injury
Eversion and external rotation WITHOUT deltoid ligament tear
MOI: in a skate or ski boot
- may have noticeable deformity
- no pain on palpation over deltoid lig or malleoli
- no deformity? +ve squeeze and/or ER tests on lower leg
Course of action for Tib and Fib fractures
- stabilize joint
- monitor for shock
- transport to hospital
Syndesmosis sprain
aka High ankle sprain
- common in sports w/ boots (skiing, hockey)
- one of most difficult to treat
MOI
- EVERSION/EXTERNAL ROTATION w/ DORSIFLEXION (planted foot)
- forced external rotation w/ simultaneous internal rotation
- immediate superior ankle pain
Groups of supporting structures btwn tibia and fibula
- superior-posterior
- interosseous membrane
- anterior inferior tibiofibular lig
Ankle Syndesmosis Functional Anatomy
- ankle in neutral position = AITFL is OBLIQUE to both tibia and fibula
Ankle Syndesmosis in Dorsiflexion
- fibula externally rotates and moves superiorly
- EXTERNAL ROTATION of fibula increases tension in these structures
- interosseous and AITFL are PERPENDICULAR now
Anatomy of Syndesmosis Injuries
- talus is WIDER ANTERIORLY than posteriorly
- during dorsiflexion , wider aspect of talus is JAMMED btwn tibia and fibula (stops dorsiflexion going further)
- if foot is forced into dorsiflexion and/or talar eversion/ER, it will stress structures holding tib and fib together
Assessment Keys for Syndesmosis Injuries
Diagnosis of exclusion
Rule out everything else
- fracture (Ottawa ankle + ER test)
- medial ankle injury
- lateral ankle injury
- Appropriate MOI?
- positive special tests? (squeeze test, ER and dorsiflexion test, stabilization test)
- tenderness over AITFL, interosseous memb
NO ONE test is definitive
Squeeze test
Squeeze Test
Compress proximal tibia and fibula
positive test = pain at level of AITFL
all structures must be severely compromised
External Rotation and Dorsiflexion Test
Stabilize lower leg w/ one hand
- passively dorsiflex and externally rotate the foot
LOWEST FALSE POSITIVE RATE
This would be “go-to” test
Stabilization Test
Tightly apply a few layers of athletic tape just above ankle jt to stabilize distal syndesmosis
Then test patient’s function
- stand, walk, toe raise, jump
Subjective Assessment of Ankle Syndesmosis
MOI: forced dorsiflexion + eversion
- pain just superior to ankle jt
- didn’t hear/feel a crack but maybe a “POP”
- not much swelling
Pain
- normal: 6/10
- with walking: 9/10
- walking on toes: 7/10
Objective Assessment of Ankle Syndesmosis
- heel-raised gait pattern (walking on toes) on that side
- no significant swelling/deformation
STTT
- pain w/ active + passive movements into dorsiflexion and eversion
- EMPTY END FEEL into DORSIFLEXION
- no pain w/ resisted movements
