Lisfranc Injuries

HPI:  
Middle aged female presents with right foot pain after "twisting" her foot. 

Physical Exam:
Swelling present over the dorsum of the foot.  No overlying laceration or abrasions.  Palpable DP and PT pulses with intact sensation in SP, DP and tibial nerve distributions.  Tenderness present over the base of the 2nd metatarsal.  Unable to bear weight on RLE. 

Radiology: demonstrates oblique fracture at the base of the 2nd metatarsal

Management:
We placed the patient in a well padded posterior leg splint and patient was instructed to not weight bear on her RLE.  She was given follow up with orthopedics in 10 days for re-evaluation once swelling improves.  

Discussion:

• Lisfranc injuries do NOT have to involve fractures.  Patient's may have a purely ligamentous injury.  Injury has the potential to be unstable given that the entire Lisfranc joint complex (tarsometatarsal articulation, intermetatarsal articulation and intertarsal articulations) is analogous to a keystone in a stone arch.  
• Obtain weight-bearing XR's of the foot to determine if there is instability (defined as displacement > 2 mm) as this will help determine whether or not surgery will be needed
• Nonoperative treatment includes cast mobilization for 8 weeks whereas operative treatment will typically be an ORIF
• Always rule out compartment syndrome in these patients as the swelling can be severe.

Key Points:

• Can be a purely ligamentous injury
• Mechanism is typically caused by a indirect rotational force and axial load through a hyperplantar flexed forefoot
• Early orthopedics consult needed given possible operative management for an unstable fracture