|
http://upload.orthobullets.com/topic/7030/images/AP_moved.jpg
http://upload.orthobullets.com/topic/7030/images/mechanism illustration_moved.jpg
http://upload.orthobullets.com/topic/7030/images/illustration - anatomy_moved.jpg
http://upload.orthobullets.com/topic/7030/images/lateral_moved.jpg
http://upload.orthobullets.com/topic/7030/images/lisfranc dorsal dislocation.jpg
Introduction
  • A condition characterized by disruption between the articulation of the medial cuneiform and base of the second metatarsal
    • unifying factor is disruption of the TMT joint complex
    • injuries can range from mild sprains to severe dislocations
    • may take form of purely ligamentous injuries or fracture-dislocations
    • ligamentous vs. bony injury pattern has treatment implications
  • Epidemiology
    • incidence
      • account for 0.2% of all fractures
    • demographics
      • more common in the third decade
      • more common in males
  • Mechanism & Pathoanatomy
    • causes include MVAs, falls from height, and athletic injuries
    • mechanism is usually caused by indirect rotational forces and axial load through hyperplantar flexed forefoot 
      • hyperflexion/compression/abduction moment exerted on forefoot and transmitted to the TMT articulation
      • metatarsals displaced in dorsal/lateral direction
  • Associated conditions
    • proximal metatarsal fractures or tarsal fractures
      • Lisfranc equivalent injuries can present in the form of contiguous proximal metatarsal fractures or tarsal fractures
  • Prognosis
    • missed injuries can result in progressive foot deformity, chronic pain and dysfunction
      • tarsometatarsal fracture-dislocations are easily missed and diagnosis is critical
Anatomy
  • Osteology 
    • Lisfranc joint complex consists of three articulations including
      • tarsometatarsal articulation
      • intermetatarsal articulation
      • intertarsal articulations
  • Ligaments
    • Lisfranc ligament  
      • critical to stabilizing the second metatarsal and maintenance of the midfoot arch
      • An interosseous ligament that goes from medial cuneiform to base of 2nd metatarsal on plantar surface 
      • Lisfranc ligament tightens with pronation and abduction of forefoot
    • plantar tarsometatarsal ligaments
      • injury of the plantar ligament between the medial cuneiform and the second and third metatarsals along with the Lisfranc ligament is necessary to give transverse instability. 
    • dorsal tarsometatarsal ligaments
      • dorsal ligaments are weaker and therefore bony displacement with injury is often dorsal
    • intermetatarsal ligaments
      • between second-fifth metatarsal bases
      • no direct ligamentous attachment between first and second metatarsal
  • Biomechanics
    • Lisfranc joint complex is inherently stable with little motion due to
      • stable osseous architecture
        • second metatarsal fits in mortise created by medial cuneiform and recessed middle cuneiform, "keystone configuration"
      • ligamentous restraints
        • see individual ligaments above
  • Columns of the midfoot
    • medial column
      • includes first tarsometatarsal joint
    • middle column
      • includes second and third tarsometatarsal joints
    • lateral column
      • includes fourth and fifth tarsometatarsal joints (most mobile)
Classification
  • Multiple classification schemes described
    • none proven useful for determining treatment and prognosis
Physical Exam
  • Symptoms
    • severe pain
    • inability to bear weight
  • Physical exam
    • inspection & palpation
      • medial plantar bruising
      • swelling throughout midfoot
      • tenderness over tarsometatarsal joint
    • motion & stability
      • instability test
        • grasp metatarsal heads and apply dorsal force to forefoot while other hand palpates the TMT joints
          • dorsal subluxation suggests instability
          • if first and second metatarsals can be displaced medially and laterally, global instability is present and surgery is required
        • when plantar ligaments are intact, dorsal subluxation does not occur with stress exam and injury may be treated nonoperatively
    • provocative tests
      • may reproduce pain with pronation and abduction of forefoot
    • compartment syndrome
      • always check for compartment syndrome and take compartment pressures if high suspicion
Imaging
  • Radiographs
    • recommended views
      • AP, lateral, obliques
      • stress radiograph
        • may be helpful to show instability when non-weight bearing radiographs are normal and there is high suspicion
      • weight-bearing radiographs with comparison view
        • may be necessary to confirm diagnosis
    • findings
      • five critical radiographic signs that indicate presence of midfoot instability
        1. disruption of the continuity of a line drawn from the medial base of the second metatarsal to the medial side of the middle cuneiform
        2. widening of the interval between the first and second ray
        3. medial side of the base of the fourth metatarsal does not line up with medial side of cuboid on oblique view
        4. metatarsal base dorsal subluxation on lateral view
        5. disruption of the medial column line (line tangential to the medial aspect of the navicular and the medial cuneiform)
      • lateral  
        • non weight-bearing radiographs may show dorsal displacement of the proximal base of the first or second metatarsal  
      • AP  
        • malalignment of medial margin of the second metatarsal base and the medial edge of the middle cuneiform diagnostic of Lisfranc injury 
        • may see bony fragment (fleck sign) in first intermetatarsal space 
          • represents avulsion of Lisfranc ligament from base of 2nd metatarsal
          • diagnostic of Lisfranc injury 
      • oblique
        • malalignment of fourth metatarsal and cuboid
  • CT scan
    • useful for diagnosis and preoperative planning
  • MRI
    • can be used to confirm presence of purely ligamentous injury
Treatment
  • Nonoperative
    • cast immobilization for 8 weeks 
      • indications
        • no displacement on weight-bearing and stress radiographs and no evidence of bony injury on CT (usually dorsal sprains)
        • certain nonoperative candidates
          • nonambulatory patients
          • presence of serious vascular disease
          • severe peripheral neuropathy
          • instability in only the transverse plane
  • Operative
    • open reduction and rigid internal fixation 
      • indications
        • any evidence of instability (> 2mm shift)    
        • favored in bony fracture dislocations as opposed to purely ligamentous injuries
      • outcomes
        • anatomic reduction required for a good result
    • primary arthrodesis of the first, second and third tarsometatarsal joints
      • indications
        • purely ligamentous arch injuries  
        • delayed treatment 
        • chronic deformity
      • outcomes
        • level 1 evidence demonstrates equivalent functional outcomes and decreased rate of hardware removal or revision surgery compared to primary ORIF   
        • primary arthodesis is an alternative to ORIF in patients with any evidence of instability with possible benefits
        • medial column tarsometatarsal fusion shown to be superior to combined medial and lateral column tarsometatarsal arthrodesis
    • midfoot arthrodesis
      • indications
        • destabilization of the midfoot's architecture with progressive arch collapse and forefoot abduction
        • chronic Lisfranc injuries that have led to advanced midfoot arthrosis and have failed conservative therapy
Technique
  • General Surgical Considerations
    • equipment
      • fluoroscopy and radiolucent table
      • small fragment and mini fragment sets (2.0mm-4.0mm screws)
      • reduction clamps, k-wires, dental pick, Homan retractors
      • small battery powered drill
    • timing of surgery
      • emergently only if
        • the presence of compartment syndrome
        • open injury
        • irreducible dislocations
      • delay operative treatment until soft tissue swelling subsides (up to 2-3 weeks)
      • if grossly unstable and in presence of significant soft tissue swelling consider early external fixation
  • Open reduction and rigid internal fixation
    • approach
      • single or dual longitudinal incisions can be used based on injury pattern and surgeon preference
      • longitudinal incision made in the web space between first and second rays
      • first TMT joint is exposed between the long and short hallux-extensor tendons
    • reduction & fixation
      • reduce intercuneiform instability first
      • fix first through third TMT joints with transarticular screws
        • screw fixation is more stable than K-wire fixation 
    • postoperative care
      • early midfoot ROM, protected weight bearing, and hardware removal (k-wires in 6-8 weeks, screws in 3-6 months
      • gradually advance to full weight bearing at 8-10 weeks
      • if patient is asymptomatic and screws transfix only first through third TMT joints, they may be left in place
      • preclude return to vigorous athletic activities for 9 to 12 months
  • Primary arthrodesis of the first, second and third tarsometatarsal joints
    • arthrodesis & fixation
      • expose TMT joints and denude all joint surfaces of cartilage
      • use cortical screws to fuse joints
    • postoperative care
      • apply cast or splint for 6 weeks
      • progress weight bearing between 6 and 12 weeks in removable boot
      • full weight bearing in standard shoes by 12 weeks post-op
  • Midfoot arthrodesis
    • arthrodesis & fixation
      • expose TMT joints and midfoot  and remove cartilage from first, second, and third TMT joints
      • add bone graft
      • reduce the deformity using windlass mechanism
      • variety of definitive fixation constructs exist
    • postoperative care
      • touch down weight bearing in a cast for 6 weeks
      • begin weight bearing at 10 weeks if evidence of healing is noted on radiographs
Complications
  • Posttraumatic arthritis
    • most common complication
    • may cause altered gait and long term disability
    • treat advanced midfoot arthrosis with midfoot arthrodesis
  • Nonunion
    • uncommon
    • revision surgery indicated unless patient is elderly and low demand
 

Please rate topic.

Average 4.2 of 61 Ratings

Technique Guides (1)
Questions (24)
EVIDENCE & REFERENCES (30)
VIDEOS (4)
CASES (5)
GROUPS (1)
Topic COMMENTS (28)
Private Note