A 27-year-old man arrives with a muddy sneaker half-laced and a rapidly swelling midfoot after his motorcycle tipped at low speed. He says the foot “folded” when he planted it, and the plantar surface is beginning to discolor beneath the arch. His toes are warm, but he cannot bear weight and winces when the forefoot is gently compressed. The radiographs are not yet in the room, and the decision about whether this foot can wait remains unresolved.
— What’s your move? Read on.
Before you read
- How do you recognize a Lisfranc injury when plain films are subtle?
- Which fractures require reduction, operative fixation, or prolonged non-weight-bearing?
When to Think of It
Suspect injury after axial loading, plantarflexion, crush, twisting, or a fall onto the forefoot. Look for plantar ecchymosis, midfoot swelling, inability to bear weight, focal metatarsal tenderness, shortening/rotation of a toe, or a widened gap between the first and second metatarsals. A “sprain” with disproportionate midfoot pain is Lisfranc until excluded.
Sick or Not Sick
Sick vs. not sick is primarily threatened neurovascular status or irreducible/open deformity vs. stable, closed injury. The call that matters most: does the foot require immediate reduction and orthopedic intervention, rather than routine splinting and follow-up?
The First Fifteen Minutes
- Expose the entire foot; document dorsalis pedis/posterior tibial pulses, capillary refill, temperature, sensation, and toe movement before and after immobilization.
- Obtain AP, lateral, and oblique foot radiographs; add weight-bearing views only if safe and tolerated. Obtain CT for suspected Lisfranc injury or complex fracture when radiographs are nondiagnostic.
- For significant pain: fentanyl 50–100 micrograms IV/IN, repeat 25–50 micrograms every 5 minutes IV as needed, because μ-opioid analgesia rapidly blunts severe nociceptive pain. Monitor ventilation.
- For a cooperative patient needing manipulation: ketamine 1 mg/kg IV, repeat 0.25–0.5 mg/kg as needed, because dissociative analgesia preserves spontaneous ventilation and facilitates reduction. Dose varies by local sedation protocol; check institutional guidance. Alternatively, propofol 0.5–1 mg/kg IV, followed by 0.25–0.5 mg/kg increments, provides rapid sedation but can cause apnea and hypotension; use only with airway-capable monitoring.
- Open wound or gross contamination: give cefazolin 2 g IV (3 g if ≥120 kg) promptly, because early gram-positive coverage reduces infection risk; add broader coverage for farm, water, or heavily contaminated wounds per protocol.
- If deformity, skin tenting, absent pulse, or progressive neurologic deficit is present: urgent reduction under analgesia/sedation, then repeat and document neurovascular examination. Do not delay reduction for advanced imaging.
- Tetanus prophylaxis: Tdap or Td 0.5 mL IM if indicated; for dirty wounds with unknown/incomplete vaccination, add tetanus immune globulin 250 units IM, because passive antitoxin bridges inadequate immunization.
Definitive Care & Disposition
Apply a well-padded posterior splint, often with a stirrup component, and keep the foot elevated. Nondisplaced, stable fractures may receive protected or non-weight-bearing immobilization with orthopedic follow-up. Displaced, angulated, rotated, multiple, open, intra-articular, or Lisfranc injuries need urgent orthopedic consultation; unstable Lisfranc injuries generally require operative fixation after swelling permits, while open injuries require irrigation/debridement and antibiotics. Admit if reduction is unstable, perfusion is threatened, the injury is open, swelling is severe, pain is uncontrolled, or social circumstances make non-weight-bearing unsafe.
How This One Kills
The dangerous miss is a subtle Lisfranc disruption diagnosed as a midfoot sprain, followed by weight-bearing; displacement and ligament failure produce chronic arch collapse and post-traumatic arthritis.
The Differential — What Else Looks Like This
- Lisfranc ligament injury — plantar ecchymosis or first–second metatarsal malalignment; confusing it with an isolated metatarsal fracture causes missed instability.
- Compartment syndrome — escalating pain with passive toe stretch and tense compartments; confusing it with ordinary swelling delays fasciotomy.
- Turf toe/plantar plate injury — plantar first-MTP tenderness without fracture alignment abnormality; confusing it with a displaced fracture leads to incorrect immobilization or missed soft-tissue injury.
- Sesamoid fracture — focal plantar first-MTP pain; confusing it with a metatarsal shaft injury misdirects imaging and weight-bearing advice.
The Second-Day Story
Older adults, patients with neuropathy, and partially treated injuries may have little pain or no memorable trauma. A diabetic patient may present only with swelling, warmth, or inability to walk. Compare both feet, inspect the plantar surface, obtain weight-bearing imaging when safe, and maintain a low threshold for CT when the mechanism and examination disagree with plain films.
Back to Our Patient
Back to the 27-year-old man with the muddy sneaker and plantar ecchymosis: the trigger presentation is axial-loading midfoot trauma with inability to bear weight, so Lisfranc injury and metatarsal fracture must be assumed until excluded. His pulses and toe sensation are intact, making him currently stable, but the plantar bruising makes the injury high risk rather than a routine sprain. He receives IV fentanyl, foot radiographs followed by CT showing tarsometatarsal malalignment, and a well-padded non-weight-bearing splint; because the injury is unstable, orthopedics admits him for operative planning.
Patient Presentation to Attending
How you’d present this patient on the floor — tight, pertinent positives and negatives, no rambling
“This is a 27-year-old man with high-risk midfoot trauma after his motorcycle tipped while his planted foot twisted, now with severe swelling, inability to bear weight, and plantar ecchymosis. He has no open wound, but has marked tarsometatarsal tenderness and pain with forefoot stress; dorsalis pedis and posterior tibial pulses, capillary refill, sensation, and toe movement are intact. There is no compartment firmness or pain out of proportion at this time. Initial foot films are concerning for first–second metatarsal malalignment, and CT confirms an unstable Lisfranc injury. I gave IV fentanyl, immobilized him without weight-bearing, and consulted orthopedics for admission and operative management.”
Study Directive
Draw the Lisfranc joint complex and label the “fleck sign.” Review three foot radiograph sets and identify metatarsal alignment, displacement, and open injury features. Practice a complete pre- and post-reduction neurovascular exam, then state admission criteria from memory.
Recent Literature
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Review or guideline Acute Lisfranc injury management
Provides a current framework for recognizing acute Lisfranc instability, choosing appropriate imaging, and arranging timely operative referral to prevent chronic midfoot pain and deformity.