High-yield overview
3 main typesA homolateral, B isolated, C divergent
Type Aall metatarsals displaced same direction — lateral most common
Type Bpartial incongruity — B1 medial or B2 lateral column
Type Cdivergent displacement — medial and lateral columns move apart
Critical Must-Knows
- Hardcastle/Myerson classifies Lisfranc injuries by displacement pattern and directly informs whether to pursue anatomic ORIF or consider primary arthrodesis.
- Type A (homolateral): all five metatarsals displace laterally or medially together; usually requires ORIF with trans-articular screws or plates to restore the keystone of the second tarsometatarsal joint.
- Type B (isolated/partial): only part of the tarsometatarsal joint is unstable; B2 lateral column injuries are the most common and often need targeted fixation of the affected rays.
- Type C (divergent): medial and lateral columns displace in opposite directions; high-energy patterns frequently involve significant comminution and may favour primary arthrodesis of the medial column.
The classification examiners want
Hardcastle/Myerson is an injury-pattern classification, not a severity score. Type A and C injuries almost always require open anatomic reduction and internal fixation. Type B injuries may be subtle on plain films; weight-bearing radiographs or CT are mandatory to confirm stability. In high-energy divergent (Type C) injuries with comminution of the medial column, primary arthrodesis of the first and second tarsometatarsal joints should be considered rather than attempting fixation of irreparable joints.
The Hardcastle/Myerson Classification System
The classification divides tarsometatarsal injuries into three patterns based on the direction and extent of metatarsal displacement relative to the cuneiforms and cuboid.
| Type | Pattern | Displacement | Typical Mechanism |
|---|---|---|---|
| A | Homolateral (total incongruity) | All five metatarsals displace in the same direction (usually lateral) | Direct crush or indirect axial load with foot plantar-flexed |
| B1 | Isolated medial | First metatarsal or medial column displaces medially | Low-energy twisting or inversion |
| B2 | Isolated lateral | Second to fifth metatarsals displace laterally; first remains stable | Most common pattern; axial load with foot pronated |
| C1 | Divergent partial | Medial column displaces medially, lateral column laterally | High-energy; often with intercuneiform instability |
| C2 | Divergent total | Complete medial and lateral column dissociation | Catastrophic energy; frequent associated injuries |
Mnemonic
A B C — All, Bits, Crash apartThe three main patterns
Mnemonic
Medial border of second metatarsal base must align with medial border of middle cuneiform on AP viewRadiographic signs of instability
Mnemonic
Fix most, fuse when comminuted or medial column destroyedFix or fuse decision
Clinical Pearl
The keystone of the Lisfranc joint is the second tarsometatarsal articulation; it is recessed between the medial and lateral cuneiforms and provides the primary bony stability. Loss of this keystone in any pattern mandates anatomic reduction and rigid fixation to prevent late collapse and post-traumatic arthritis.
Treatment Implications and Decision Making
| Type | Recommended Treatment | Fixation Method | Key Consideration |
|---|---|---|---|
| A (Homolateral) | Anatomic ORIF in all cases | Dorsal plates or trans-articular screws (3.5 mm or 4.0 mm) across first, second and third TMT joints | Restore the second TMT keystone first; protect with a spanning external fixator if severe swelling |
| B1 (Medial isolated) | ORIF if unstable on weight-bearing views | Single screw or small plate from first metatarsal to medial cuneiform | Check for associated medial column ligamentous injury |
| B2 (Lateral isolated) | ORIF of unstable rays | Trans-articular screws from second, third and fourth metatarsals to respective cuneiforms/cuboid | Fourth and fifth TMT joints tolerate slight incongruity better than medial column |
| C (Divergent) | ORIF or primary arthrodesis | Medial column arthrodesis if comminuted; lateral column usually fixed | High-energy pattern; screen for compartment syndrome and associated fractures |
Caution
Anatomic reduction within 2 mm of the second tarsometatarsal joint is the strongest predictor of good outcome. Malreduction greater than 2 mm leads to post-traumatic arthritis in over 50 percent of patients at five years. If the joint surface is destroyed, primary arthrodesis gives more predictable pain relief than attempted fixation of comminuted fragments.
Limitations and Modern Context
- It is a descriptive classification, not prognostic. Hardcastle/Myerson does not quantify energy or cartilage damage; two Type C injuries can have very different outcomes depending on the degree of comminution and soft-tissue injury.
- CT is essential for surgical planning. Plain radiographs underestimate the extent of comminution and intercuneiform instability; every suspected Lisfranc injury should have a CT scan with coronal and sagittal reformats before definitive fixation.
- Weight-bearing radiographs remain the gold standard for stability. Up to 20 percent of injuries are missed on non-weight-bearing films; a gap greater than 2 mm between the first and second metatarsal bases on weight-bearing AP view indicates instability even if the Hardcastle pattern appears subtle.
- Primary arthrodesis versus ORIF debate. Recent series suggest primary arthrodesis of the medial column in high-energy Type C injuries reduces re-operation rates for post-traumatic arthritis, but Level-1 evidence is still lacking.
- The classification does not address pure ligamentous injuries. Low-energy pure ligamentous Lisfranc injuries (Myerson Type B2) may be missed on static imaging and require stress fluoroscopy or MRI for diagnosis.
Evidence Base
Evidence
Dislocations and fracture-dislocations of the tarsometatarsal joints
Hardcastle PH, Reschauer R, Kutscha-Lissberg E, et al. • J Bone Joint Surg Br (1982)
Key Findings:
- Original description of three displacement patterns in 119 patients
- Homolateral, isolated and divergent groups showed distinct radiographic appearances and outcomes
- Anatomic reduction correlated strongly with return to pre-injury function
Clinical implication: Established the foundational classification still used today for surgical decision-making in Lisfranc injuries.
Limitation: Pre-CT era; relied on plain radiographs only.
Source: J Bone Joint Surg Br 1982;64(3):349-56
Evidence
Tarsometatarsal joint injuries: a classification and management algorithm
Myerson MS, Fisher RT, Burgess AR, et al. • Foot Ankle (1986)
Key Findings:
- Modified Hardcastle classification into A, B1, B2, C1, C2 subtypes
- Emphasised the importance of the second tarsometatarsal keystone
- Proposed treatment algorithm based on displacement pattern
Clinical implication: Refined the classification into the form used in current practice and linked pattern to fixation strategy.
Limitation: Retrospective review without long-term functional scores.
Source: Foot Ankle 1986;6(5):225-42
Evidence
Outcome of surgically treated Lisfranc injuries
Kuo RS, Tejwani NC, Digiovanni CW, et al. • J Bone Joint Surg Am (2000)
Key Findings:
- Anatomic reduction within 2 mm associated with good to excellent results in 80 percent
- Malreduction greater than 2 mm led to post-traumatic arthritis in 60 percent
- Primary arthrodesis considered when greater than 50 percent articular surface comminuted
Clinical implication: Quantified the critical reduction threshold that still guides modern fixation goals.
Limitation: Mixed injury patterns; no randomisation between fixation and fusion.
Source: J Bone Joint Surg Am 2000;82(11):1609-18
Evidence
Primary arthrodesis versus ORIF for Lisfranc injuries
Ly TV, Coetzee JC • J Bone Joint Surg Am (2006)
Key Findings:
- Prospective comparison showed lower re-operation rate with primary arthrodesis in high-energy injuries
- Type C divergent injuries with medial column comminution benefited most from fusion
- ORIF group had higher rates of symptomatic post-traumatic arthritis requiring later fusion
Clinical implication: Supports selective use of primary arthrodesis for comminuted Type C injuries rather than attempting fixation.
Limitation: Single-centre; relatively small numbers.
Source: J Bone Joint Surg Am 2006;88(3):514-20
Evidence
Weight-bearing radiographs in the diagnosis of subtle Lisfranc injuries
Nunley JA, Vertullo CJ • Am J Sports Med (2002)
Key Findings:
- Weight-bearing films detected instability missed on non-weight-bearing views in 25 percent of cases
- Medial border of second metatarsal to middle cuneiform alignment greater than 2 mm indicates surgical injury
- Classification alone underestimates pure ligamentous injuries
Clinical implication: Mandatory weight-bearing or stress radiographs before accepting a stable classification.
Limitation: Did not correlate findings with Hardcastle subtype outcomes.
Source: Am J Sports Med 2002;30(6):871-8
Exam Viva
Practise clinical reasoning and management decisions out loud
Viva scenarioStandard
Clinical prompt
“A 28-year-old footballer presents after a twisting injury to the foot. Non-weight-bearing radiographs appear normal, but weight-bearing AP shows a 3 mm gap between the first and second metatarsal bases. How do you classify and manage this injury?”
Practical approach
This is a subtle Type B2 (isolated lateral) Lisfranc injury. The weight-bearing radiograph demonstrates instability at the second tarsometatarsal joint even though the first metatarsal remains reduced. I would obtain a CT scan to confirm no fracture and assess the articular surfaces. Management is anatomic ORIF with trans-articular screws or dorsal bridging plates from the second and third metatarsals to the middle and lateral cuneiforms. Post-operatively the patient is kept non-weight-bearing for six weeks then progressed in a boot. The second tarsometatarsal keystone must be reduced to within 2 mm.
Key clinical points
Weight-bearing films are required to diagnose subtle instability
Type B2 is the most common pattern in athletic injuries
Anatomic reduction of the second TMT joint to less than 2 mm step-off
Trans-articular screws or dorsal plates; protect the medial column
Common pitfalls
Dismissing the injury because non-weight-bearing films look normal
Attempting closed reduction without confirming the pattern on CT
Fixing only the obvious displacement and missing intercuneiform instability
Further questions
“What is the keystone of the Lisfranc joint and why does it matter?”
“When would you consider primary arthrodesis instead of ORIF?”
“How do you differentiate a Type B2 from a Type C injury on imaging?”
Viva scenarioAdvanced
Clinical prompt
“A 45-year-old driver is involved in a high-speed motor vehicle collision. Radiographs show divergent displacement of the first metatarsal medially and the second to fifth metatarsals laterally with comminution of the medial cuneiform. Classify the injury and outline your surgical plan.”
Practical approach
This is a Type C2 (total divergent) Lisfranc injury with high-energy medial column comminution. I would first resuscitate and screen for compartment syndrome. CT confirms the divergent pattern and extent of articular destruction. Because greater than 50 percent of the first and second tarsometatarsal joint surfaces are comminuted, I would perform primary arthrodesis of the medial column (first and second TMT joints) using screws and a dorsal plate, while reducing and fixing the lateral column (third to fifth TMT) with trans-articular screws. A spanning external fixator is applied if swelling precludes immediate definitive fixation. The goal is a stable plantigrade foot rather than attempting to salvage destroyed joints.
Key clinical points
Type C2 divergent total incongruity with medial column destruction
Primary arthrodesis indicated when greater than 50 percent articular surface lost
Medial column fused, lateral column reduced and fixed
External fixation first if soft-tissue envelope is compromised
Common pitfalls
Attempting fixation of irreparable comminuted fragments
Ignoring compartment syndrome in the foot
Fusing the lateral column unnecessarily (fourth and fifth TMT tolerate incongruity)
Further questions
“What are the long-term outcomes of primary arthrodesis versus ORIF in Type C injuries?”
“How do you assess cartilage viability intra-operatively?”
“What associated injuries must be excluded in a high-energy Lisfranc dislocation?”
Exam day cheat sheet
Hardcastle/Myerson — Exam Cheat Sheet
The three patterns (A, B, C)
- Type A: all five metatarsals displaced together (homolateral) — usually lateral
- Type B: partial/isolated — B1 medial column only, B2 lateral column (most common)
- Type C: divergent — C1 partial, C2 total; medial and lateral columns move apart
Key radiographic thresholds
- Medial border of second metatarsal base must align with medial border of middle cuneiform
- Step-off greater than 2 mm on weight-bearing AP indicates instability
- CT mandatory for comminution assessment before deciding fixation versus fusion
Fix versus fuse decision
- Fix (ORIF) when articular surfaces intact and reduction achievable within 2 mm
- Fuse (primary arthrodesis) when greater than 50 percent cartilage loss or comminution of medial column
- Type A and B usually fixed; Type C with medial destruction often fused
Critical technical points
- Restore the second tarsometatarsal keystone first — it is recessed and provides primary stability
- Trans-articular 3.5 mm or 4.0 mm screws or dorsal bridging plates
- Non-weight-bearing six weeks then protected weight-bearing; monitor for post-traumatic arthritis