Not just an foot/ankle sprain: Lisfranc Injuries

17 Dec

 Lisfranc joint complex= the entire tarsometatarsal articulationlis1

 

Lisfranc joint= articulation of the 1st and 2nd metatarsals with the 1st and 2nd cuneiforms

 

Why we should care:

*Up to 20-40% of these injuries are missed on initial visit. 

*Chronic pain and disability are fairly common with Lisfranc injuries. 

*Operative management is sometimes needed.

 

History: Direct or indirect trauma, can be low energy.  Most have midfoot pain, swelling and difficulty bearing weight. These are not sensitive features.

 

Exam:

* TTP at the 1st and 2nd metatarsal bases or remainder of Lisfranc joint complex

* Pain with passive abduction and pronation of forefoot when hindfoot is held flexed (specific for tarsometatarsal injuries)

* Plantar ecchymosis

* Of course perform neurologic and vascular exams.  Also consider and evaluate for a compartment syndrome of the foot.

 

XR findings (order AP, lateral, and oblique views):

 lis2AP or oblique views:

  1. 1.    Medial border of the 2nd metatarsal base and 2nd cuneiform (red line) form a straight line (as do the medial border of the 4th metatarsal base and cuboid)
  2. 2.    Lateral border of the 3rd metatarsal base and lateral border of the lateral cuneiform should form a straight line.
  3. 3.    >2 mm diastasis or >1 mm side to side difference between the metatarsal bases is abnormal (yellow asterix)
  4. 4.    “Fleck sign” or an avulsed bone fragment is a sign of ligamentous injury (yellow asterix)
  5. 5.    Cuneiform or metatarsal fracture

 

 

lis3Lateral views:

  1. 1.    A metatarsal shaft should never be more dorsal than its respective tarsal bone (red arrow)

*** If initial x-ray is normal but suspicion is high, order a weight bearing AP view to assess the 1-2 interval of the metatarsals and/or obtain a comparison x-ray of the contralateral foot. 

 

Management:

* If available, orthopedics consultation

* If not available, consider closed reduction if appropriate.  Then apply bulky dressing and posterior splint with very close ortho follow up

* Some mild lisfranc injuries are treated with casting and non-weight-bearing.  Others go on to require surgery such as reduction and fixation (2 mm of displacement and/or greater than 15 deg of talometatarsal angulation typically require surgery). 

 

Submitted by H. Groth.

 

Sources: Cvetanovich, Greg; Lieberman, Gillian. “Imaging of Lisfranc Injury”. Lecture at Beth Isreal Deaconess Medical Center November 2011; Nunley, JA. “Classification, investigation, and management of midfoot sprains: lisfranc injuries in the athlete”. Am J Sports Med 2002; 30:871-878; Perron, Andrew D; Brady, William J.; Keat, Theodore E. “Orthopedic pitfalls in the ED: Lisfranc fracture-dislocation” Amer J of Emerg Med 2001; 19(1): 71-75; Tintinalli’s Emergency Medicine; Wheeless’ Textbook of Orthopedics.

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