fmCase 4 Flashcards
Differential of inversion ankle injury
- Sprain
- Distal fibula fracture
- Talar dome fracture (may be missed in XR, possible cx avascular necrosis)
- Peroneal tendon tear (persistent pain posterior to lateral malleolus)
- Subtalar injury (dislocation of talocalcaneal and talonavicular joints)
- Tendonitis (posterior tibialis): first pain worsens with activity, then constant discomfort, then chronic with worse during day or after exercise
Compartment syndrome signs/symptoms
6 p’s:
- pain (hallmark) out of proportion
- pallor
- pulselessness
- paresthesia (most reliable)
- poikilothermia
- paralysis
Ankle injury important history items
Usual MOI is plantar flexion and inversion
Lateral sprain more common
H/o previous ankle sprain is risk factor
H/o snap or tear is NOT diagnostically significant (only is in acute knee injury)
Patient seeking immediate help and non-weightbearing more likely to have severe injury
Most often damaged ligaments in inversion ankle injury
- Calcaneofibular: inversion test
- Anterior talofibular (most easily): anterior drawer test
- Posterior talofibular
Crossed-leg test
Detects high ankle tibiotibular syndesmotic sprain: patient sitting with one leg crossed over, apply pressure to medial knee. high ankle sprain will produce pain.
Grading ankle sprains
Grade I: stretching/small tear; slight functional loss; mild swell/tenderness; no instability
Grade II: incomplete tear; functional impairment and difficult weight bearing; tender and swollen; ecchymosis; instability with stopping point.
Grade III: complete tear; cannot bear weight x4 steps; swollen >4cm; ecchymosis; instability withOUT stopping point
Less likely differential of ankle injury
- Tarsal tunnel syndrome (tibial nerve)
- Syndesmotic injury (interosseus membrane and AITF ligament; ankle squeeze test)
- Joint infection
- Ankle arthritis (tibiotalar joint)
- Tibial fracture
- Pathologic fracture (metastatic disease)
- Achilles tendon rupture (popping/snappy sound at injury)
Ottawa Rules to determine XR need for adult with acute ankle or mid foot injury
XR if:
- Pain in malleolar zone AND either
- Bony tenderness along distal 6 cm of posterior edge of malleolus, or
- Inability to bear weight both immediately and in ED
XR foot if:
- Midfoot region pain AND either:
- Bony tenderness at navicular bone or base of 5th metatarsal, or
- Inability to bear weight both immediately and in ED
Ankle sprain management
RICE N
- Rest x 72 hr only, then exercises (motion, stretch, balance, proprioception), avoid sandals
- Ice 10 min x several times
- Compression tape/ elastic wrap/ semi-rigid ankle (latter best for return to sports or work and less instability)
- Elevation
- NSAIDs
