Lisfranc Injury

Patients present with a twisting or axial-load mechanism, often with the foot plantar-flexed. Midfoot pain is typically disproportionate to apparent injury, with inability to bear weight or severe pain on toe-off. Patients frequently describe a bad foot sprain that is slow to settle - the classic presentation of a missed Lisfranc.

Examination:

• •Dorsal midfoot swelling and tenderness over the TMT joint complex
• •Plantar ecchymosis (plantar bruising sign): almost pathognomonic when present
• •Pain on palpation of the 2nd TMT joint
• •Neurovascular and skin assessment is essential in any significant midfoot injury
• •Supportive provocation tests (none are stand-alone diagnostic):

- Midfoot squeeze test: compressing the metatarsal heads reproduces midfoot pain - Pronation-abduction test: heel held fixed, forefoot passively pronated and abducted to recreate the mechanism - Piano-key test: downward pressure on the metatarsal heads may reproduce pain or demonstrate instability

Differential diagnoses:

• •Midfoot sprain without Lisfranc injury
• •Metatarsal stress fracture: gradual onset, specific metatarsal tenderness
• •Cuboid syndrome: lateral midfoot pain
• •Navicular stress fracture: medial midfoot or N-spot tenderness (high-risk stress fracture site)
• •Charcot neuroarthropathy: insensate foot (diabetic), swelling disproportionate to pain - a critical do-not-miss in diabetes
• •Gout or septic arthritis of the midfoot

Ottawa Foot Rules help decide who needs initial X-rays in undifferentiated foot trauma, but they do NOT safely exclude Lisfranc when clinical suspicion remains despite normal films. Any clinical suspicion mandates appropriate imaging.

Plain radiographs: weight-bearing AP, oblique (30 degrees), and lateral foot views. Weight-bearing views are preferred when tolerated; non-weight-bearing films commonly miss subtle injuries. Bilateral comparative weight-bearing radiographs are a core tool: subtle unilateral diastasis or alignment loss declares itself against the uninjured side. Consider repeat bilateral weight-bearing films at 10 to 14 days if initial films are normal but suspicion persists.

Key radiographic signs:

• •Fleck sign on AP: avulsed bony fragment in the space between 1st and 2nd metatarsal bases - effectively pathognomonic of Lisfranc ligament avulsion
• •Diastasis greater than 2 mm between 1st and 2nd metatarsal bases (a useful exam threshold rather than a sole diagnostic criterion)
• •Loss of alignment: medial border of the 2nd metatarsal with medial border of the middle cuneiform (AP); medial border of the 4th metatarsal with medial border of the cuboid (oblique)
• •Dorsal displacement of the metatarsal bases on the lateral view

CT (or weight-bearing CT where available) provides superior bony detail and detects occult fractures and subtle articular incongruity. It is useful when weight-bearing views are equivocal or the patient cannot tolerate standing films, and is often used for surgical planning. MRI is useful when X-rays and CT are equivocal and there is concern for purely ligamentous injury. Stress radiographs (e.g. under anaesthetic) are less commonly used in UK practice and are specialist investigations.

If initial imaging is normal but stability remains uncertain, fracture clinic or foot and ankle follow-up with repeat weight-bearing imaging is appropriate - do not simply reassure.

UK-facing practice is informed by BOFAS foot and ankle guidance, generic NICE fracture and sprain guidance, and local orthopaedic pathways. The key principle is early recognition of instability and restoration of anatomical alignment; non-anatomical reduction increases the risk of post-traumatic midfoot arthritis and poor outcome.

Acute phase (0 to 48 hours): protection (below-knee backslab or CAM boot), elevation, and analgesia (pragmatically paracetamol, with NSAIDs - oral or topical - as appropriate to patient risk and contraindications). Non-weight-bearing until definitive imaging and review. Severe, high-energy, or grossly displaced injuries may require urgent closed reduction and temporary stabilisation (cast, K-wires, or external fixation) while soft tissues settle. Open injuries follow the open-fracture pathway (urgent IV antibiotics, orthoplastic assessment per BOA/NICE guidance).

Stable / undisplaced injury (Nunley-Vertullo Stage I): non-weight-bearing in a CAM boot typically for 6 weeks. Repeat weight-bearing radiographs at around 2 to 3 weeks to exclude evolving instability before loading. Progressive weight-bearing and rehabilitation thereafter, guided by symptoms, under fracture clinic or foot and ankle follow-up. Return to sport broadly 3 to 4 months, criteria-based.

Unstable injury (Nunley-Vertullo Stage II or III, fracture-dislocation, or demonstrated instability): urgent orthopaedic or foot and ankle referral. ORIF and primary arthrodesis of the medial and middle columns are both accepted definitive options; the choice depends on injury pattern and surgeon judgement. Primary arthrodesis is a valid alternative, particularly in selected purely ligamentous patterns. The lateral column is usually stabilised temporarily (e.g. K-wires) to preserve motion. Hardware practice varies: bridge plates are sometimes retained; flexible constructs are designed to be left in place; rigid crossing screws are sometimes removed electively (commonly around 4 to 6 months when removal is chosen).

Chronic or missed injury: midfoot arthrodesis is typically required once post-traumatic arthritis has developed.

Referral: FCP or advanced practitioner physiotherapist or GP for initial triage; urgent orthopaedic referral for any suspected Lisfranc with displacement, positive fleck sign, instability, or inability to weight-bear; same-day assessment for open injury, neurovascular compromise, suspected compartment syndrome, or grossly displaced injury; SEM or foot and ankle clinic for persistent midfoot pain after apparently stable presentation.

Timelines are broad guides only; progression is criteria-based and highly variable by stability, operative construct, sport, and symptoms.

• •Phase 1 (0 to 6 weeks): non-weight-bearing in CAM boot, swelling and pain control, gentle ROM of ankle and toes, maintain proximal conditioning
• •Phase 2 (6 to 12 weeks): progressive weight-bearing as tolerated (or per post-operative protocol), graded calf and intrinsic foot strengthening, proprioception
• •Phase 3 (3 to 6 months): progressive loading, single-leg balance, running progression, sport-specific drills
• •Phase 4 (return to sport): criteria-based with pain-free weight-bearing, repetitive single-leg heel raise without pain, symmetrical single-leg hop distance and mechanics, restoration of symmetrical dynamic arch height, completion of sport-specific drills, and psychological readiness

A rigid carbon plate or stiff-soled insert can offload the midfoot during early return to activity.

• •BOFAS Hyperbook: Lisfranc Injury - UK specialty consensus on diagnosis, classification, and the principle that any instability requires anatomical reduction.
• •Nunley and Vertullo (Am J Sports Med 2002) - athletic Lisfranc classification (Stage I-III) driving the operative versus non-operative decision in SEM populations.
• •Myerson / Quenu-Kuss classification - the high-energy fracture-dislocation framework (type A total incongruity, type B partial, type C divergent).
• •NICE NG38 (Fractures - non-complex) - UK assessment and management framework including weight-bearing radiograph principles and follow-up for uncertain stability.
• •BOA Standards (BOASts) - open-fracture and orthoplastic pathway for any open midfoot injury; IV antibiotics within 1 hour.

• •Suspect Lisfranc in any bad foot sprain that is slow to settle, any midfoot injury with plantar ecchymosis, and any foot injury with inability to weight-bear. Approximately 20 percent are missed on initial presentation - clinical suspicion is the principal safeguard.
• •Mechanism is axial load or twist of a plantar-flexed foot (equestrian stirrup, footballer with heel stepped on) or high-energy trauma.
• •The 2nd metatarsal base keystone and the Lisfranc ligament are the anatomical core of the injury; there is NO intermetatarsal ligament between the 1st and 2nd metatarsal bases.
• •Always obtain weight-bearing AP, oblique, and lateral radiographs. Bilateral comparison views are a core tool. Non-weight-bearing films miss subtle injuries.
• •Fleck sign on AP is effectively pathognomonic; diastasis greater than 2 mm between 1st and 2nd metatarsal bases is a useful exam threshold.
• •Nunley-Vertullo classification (SEM): Stage I non-operative; Stage II and III typically operative. Non-anatomical reduction increases the risk of post-traumatic midfoot arthritis - any instability needs urgent orthopaedic referral.