History
Jacques LisFranc De St-Martin (1790 - 1847)
General Surgeon in Napoleonic army
Mechanism
High energy
1. Twisting / Abduction injury of forefoot
- original description is fall from horse with foot caught in stirrups
- MVA
2. Axial Loading
A Extrinsic axial compression applied to heel
B Extreme ankle equinus with axial loading of body weight
3. Direct Crushing
- to dorsum of mid-foot
- greatest risk of compartment syndromes and open fractures
Classification
A: Quenu & Kuss; Modified by Hardcastle (JBJS 1982)
1. Homolateral
- all 5 metatarsals displaced in same direction
- most common
2. Isolated
- only 1st MT injured / displaced
3. Divergent
- 1st MT displaces medially
- other 4 MT displace laterally
- least common
B: Myerson
https://www.ncbi.nlm.nih.gov/pubmed/3710321
A: Total incongruity (medial or lateral)
B: Partial incongruity
B1: Medial
B2: Lateral (most common)
C: Divergent displacement
C1: Partial
C2: Total
Anatomy
Bony Stability
1-3 MT articulate with cuneiforms
4 & 5 articulate with cuboid
Bases of MT wider dorsally than plantar
- form 1/2 of Roman arch
2nd MT is keystone of transverse MT arch
- medial cuneiform is recessed proximally
- mortise provided for base of second
Ligamentous stability
Lis Franc ligament
- plantar structure
- 1 cm long x 0.5 cm diameter
- base 2nd MT to medial cuneiform
- avulsion as 'fleck fracture'
Note: no intermetatarsal ligament from 1st MT to 2nd
Mobility (Sagittal)
Medial Column (1st MT) - 3.5 mm
Middle Column (2/ 3) - .6mm
Lateral Column (4/5) - 13mm
Examination
Swelling and pain
- out of proportion
- must suspect Lis Franc
Brusing plantar aspect foot
- indicative of Lis Franc Ligament rupture
Signs compartment syndrome
X-ray
Fleck sign
- avulsion of LF from base of 2nd MT
- can be only sign of isolated Lis Franc Injury
Diastasis between 1st & 2nd MT
- may need to perform bilateral weight bearing stress view
AP / Assess medial column
- medial border 1st MT should line up medial border medial cuneiform
- medial border of 2nd MT should line up with medial border middle cuneiform
Internal Oblique 30o / Assess lateral column
- medial border 3rd MT line up with medial border lateral cuneiform
- medial border of 4th MT line up with medial border cuboid
CT scan
Confirm displacement of MT from respective joints
Identify fleck sign
Identify dorsal displacement of metatarsals
Compression fractures / nutcracker of cuboid
MRI
Confirm oedema or tear of Lis Franc ligament
Bone brusining tarsometatarsal ligaments
Subluxation of ligaments
Intraoperative
Curtis stress views
Hindfoot stabilised & forefoot pronated/ abducted
Prognosis
Residual pain & stiffness with non-anatomical reduction
- 2° OA
- progressive planovalgus
Management
Non Operative
Sprains with no displacement
- 6/52 in NWB SLPOP
- close serial follow up
- strapping/ medial arch support 6/12
Operative
Indications
Any displacement
Closed Technique
Indication
- isolated Lis Franc with diastasis
- early diagnosis and treatment
Technique
- longitudinal traction
- reduction first intermetatarsal joint
- percutaneous fixation screws
- from medial cuneiform to 2nd metatarsal
Open Technique
Timing
- wait for swelling to reduce
- may take 2 - 3 weeks
Goal
- reduced and stabilise all MTJ that are injured
First incision
- dorsal
- between 1st and 2nd MT
- lateral to EHL
- protect branches of SPN
- dorsalis pedis and DPN are in this intermetatarsal space
- very difficult to identify
Reduction
- clean out joint
- reduce first and second metatarsal to cuneiforms
- check AP reduction
Provisional fixation
- K wire 1st MT to medial cuneiform
- K wire 2nd MT to intermediate cuneiform
- K wire medial cuneiform to base 2nd MT
- +/- K wire medial to intermediate cuneiform if unstable
- insert 4.0 mm cannulated screws
2nd incision between 3rd and 4th MT if required
- reduce 3rd and 4th MTPJ
- K wire / screw 3rd MT to lateral cuneiform
- Fix 4th and 5th to cuboid with K wires
- 5th K wire usually inserted percutaneously
- check with oblique view
- may use screw / k wire to 3rd MTPJ
Post op
Strict NWB for 8/52
- Lis Franc ligament takes time to heal
Removal of K wires at six weeks
Screw removal
- no sooner than 4/12
- broken screws rarely bothersome
Complications
Compartment Syndrome
Open fracture
- closed reduction and hold with external fixator
Midfoot Arthritis
- can develop later
- require midfoot fusion
- some surgeons advocate primary fusion if joint surfaces very damaged / comminuted