see: [Rosen - Lisfranc injury](x-devonthink-item://6C060DB4-FEA0-4FE3-AF5D-87933674890F?page=20&start=2798&length=53&search=Lisfranc%20(Tarsometatarsal)%20Fractures%20and%20Dislocations), [Core radiology - Lisfranc fracture-dislocation](x-devonthink-item://C1EF00FD-576C-4C41-AE08-CA966611F572?page=1009), [High risk and low incidence diseases: Lisfranc injury.](bookends://sonnysoftware.com/ref/DL/265355) [AFP - lisfranc injuries](https://www.racgp.org.au/afp/2017/march/lisfranc-injuries) don't confuse with *Jones fracture* (transverse fracture of base of 5th metatarsal) > **Lisfranc injuries** refer to any fracture, dislocation, or ligamentous injury at the tarsometatarsal joint > > ==XR findings include:== > - **separation btwn base of 1st and 2nd metartarsal** (most common) > - *Fleck sign* -- bony fragment btwn medial cuneiform and 2nd metatarsal > - lateral displacement of 2nd metatarsal with respect to middle cuneiform > - \>2mm widening btwn medial cuneiform and 2nd metatarsal > - \>1mm widening btwn first and 2nd metatarsals or medial and middle cuneiform and metatarsals > - **fracture of 2nd metacarpal base** *virtually pathognomonic* of occult lisfranc injury > - on lateral view, dorsal subluxation of metatarsals at the tarso-metatarsal joint, talometatarsal angle >15 deg, reduced plantar distance btwn medial cuneiform and 5th metatarsal >![[Pasted image 20240322191730.png]] ![[83EA2A77-06E8-4A11-A5AD-CD8BE41C2562.jpeg]] C1 - medial cuneiform, M2 - base of 2nd metatarsal, M3 - base of 3rd metatarsal, Red - dorsal Lisfranc ligament, Blue - interosseous Lisfranc ligament, Green - plantar Lisfranc ligament. ![[Pasted image 20240322193115.png]] - midfoot is divided into two columns: - medial column contains navicular, cuneiforms, and first three tarso-metatarsal joints - lateral column contains cuboid and 4th and 5th tarso-metatarsal joints (see diagram below) - the midfoot is a vital bridge btwn the hindfoot and the forefoot. injuries to the midfoot have the potential to dramatically affect the individual's daily function, including the ability to stand and walk. - eg untreated midfoot injuries in diabetics can lead to **charcot's foot** (collapse of the midfoot arch) and lifelong complications with ambulating. - the **lisfranc ligament** runs between the lateral base of the medial cuneiform and the medial base of the second metatarsal. - injuries to this ligament range from sprains to fracture-dislocations, w/ 2nd metartarsal fractures particularly common *the usual mechanism of injury* for sprains is a low-velocity indirect force *plantarflexion with an axial load* (eg jumping over an obsticle) seen with more significant injuries - eg motorcycle or trip over a pothole **mechanisms of lisfranc injury in image below:** A. fall onto the plantar flexed foot B. direct blow on the heel, in kneeling position C. crush injury D. forced inversion or eversion of the forefoot ![[Pasted image 20240322193441.png]] **causes** - fractured base of second metatarsal (most common) - cuboid fracture - medial cuneiform fracture # Normal Foot XR ![[Pasted image 20240322185151.png]] ![[Pasted image 20240322193216.png]] # Diagnosis lis franc injury ![[Pasted image 20240322193652.png]] ***Mechanism:*** Lisfranc injuries should be considered in any patient presenting with midfoot pain in the setting of a high or low-energy mechanism of injury. - Low energy mechanisms are more common, and occur when a *rotational* or axial force is transmitted to a stationary plantar-flexed foot. - most common is missteps, falls, and sports injuries. can also occur when stepping down intoa hole, stepping off a curb, missing a step while descending a flight of steps, or stepping on the heal of another person while the foot ins plantar-flexed. - windsurfing and horseback riding are concerning mechanisms of injury, as the forefoot is held in a fixed position while teh body is thrown - High energy mechanisms include MVA or motorcycle accidents and crush injuries ***Exam:*** - can use [[Ottawa Ankle Rule]] in adults and paediatrics. - if no bony tenderness at base of 5th metatarsal or at the navicular, and the pt can bear weight immediately after injury and in the ED, unlikely Lis Franc injury - signs of lisfranc injury: - significant pain elicited by *torsion of the midfoot* - pain on passive dorsiflexion or plantarflexion - classically, pts present with midfoot pain and swelling and inability to weight bear. - **plantar echymosis** (see above image) is strongly suggestive of a lisfranc injury - *Piano key test* : head of each metatarsal is moved while midfoot is held firm. - *pronation-abduciton test* (stress test) : one hand the abduct and pronate the forefoot while using hte other hand to stabilise the hindfoot. pain along the medial midfoot is a positive test. - stress lisfranc by having pt plantar flex the foot while adducting first digit. pain with these tests suggests lisfranc injury - squeeze test: pressure across TMT joint ***Imaging:*** - X-Ray: ideally bilateral weight-bearing AP, lateral, and 30 deg oblique views of foot - bony displacement of 1mm or greater btn the bases of the 1st and 2nd metartarsals is considered unstable - **CT is recommended** when radiographic imaging is equivocal b/c better delineation of bony structures and dx of occult fractures of subluxations that can be missed on plain films ![[Pasted image 20240322191837.png| classification of Lisfranc injuries by direction of displacement of metatarsals with respect to the midfoot. Direction of displacement is indicated by arrows]] ## examples ![[Pasted image 20240322190805.png| lis franc injury showing fleck sign]] ![[Pasted image 20240322192544.png|Lisfranc injury with fractures of the bases of the second through fourth metatarsals, including a fragment suspicious for an avulsion from the Lisfranc ligament at the second metatarsal base]] ![[Pasted image 20240322192652.png| step-off at the tarsometatarsal joint]] ![[Pasted image 20240322193006.png| lisfranc fracture-dislocation with homolateral dislocation at the lisfranc joint, with fracture of the base of the second metatarsal]] ![[Pasted image 20240322194035.png|oblique view of lisfranc injury]] # Complications - associated vascular compromise, especially **dorsalis pedis** at medial/medial plantar anastomosis - an important branch of the dorsalis pedis artery passes btwn first and second metatarsals to form plantar arch; trauma to this can cause significant haemorrhage leading to [[Compartment syndrome]], or less commonly vascular compromise of the forefoot - injury to [[Neurovascular assessment|deep peroneal nerve]] - long term biomechanical problems due to lateral drift of 3rd, 4th, and 5th metatarsals. - first metatarsal may drift medially with the medial cuneiform. - arthritis - associated fractures of the tarsal bones (navicular, cuboid, and cuneiforms) are also common # Treatment - <1mm is non-weight-bearing splint, rest, ice, elevation, ortho follow up, likely 4 weeks cast - fracture displacement, associated dislocation, or evidence of compartment syndrome requires emergent intervention and ortho consultation Patients with high-energy or displaced Lisfranc injury are managed surgically. - Orthopedic consultation, either in the ED or outpatient in 24 to 48 hours, is appropriate. Such patients can be immobilized in a well-padded lower leg splint and should be nonweightbearing. - Patients with significant pain, swelling, or those with signs of compartment syndrome, require emergent orthopedic assessment. - Patients with nondisplaced but suspected ligamentous Lisfranc injury should have urgent outpatient orthopedic consultation within 48 hours arranged. These patients should be placed in a well-padded splint and should be nonweightbearing. # OSCE - [Lis fran Cabrini 2024 OSCE](x-devonthink-item://C855B92E-016F-4357-BA5E-2CB37ACA11A9)