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Emergency Med > 9 - Lisfranc's Injury > Flashcards

9 - Lisfranc's Injury Flashcards

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1
Q

Key learning points

A
  • Define the key tarsal-metatarsal joint anatomic landmarks used to assess injury
  • Describe the radiographic features of TMTJ injury
  • Compare the evidence based treatment recommendations and the evolution of treatment recommendations
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2
Q

Anatomy

A
  • Lis franc’s joint (3 Cuneiforms, Cuboid, Bases of metatarsals 1-5)
  • Intrinsic Osseous Stability is provided by the Roman arch of the metatarsals and the recessed keystone of the second metatarsal base
  • Further stability is provided by ligaments
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3
Q

Ligament anatomy

A
  • Inter-osseous ligaments connect metatarsals 2 - 5 at the bases (Both dorsal and plantar)
  • No transverse metatarsal ligament from the first to the second
  • Plantar ligaments are stronger and larger
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4
Q

Lis franc’s ligament

A
  • Strong oblique ligament from the plantar aspect of the medial cuneiform to the base of the second metatarsal
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5
Q

Associated structures

A
  • Dorsalis pedis artery courses between 1st and 2nd metatarsal bases
  • Deep peroneal nerve runs alongside the artery
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6
Q

Lis franc’s injury

A
  • Fracture and dislocation of the tarso-metatarsal joint complex
  • May be a pure dislocation due to ligament rupture only (Primarily Ligamentous)
  • May involve fractures of the metatarsals and the cuneiforms (Intra articular and/or Extra articular)
  • Lots of variability
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7
Q

Classifications of lis franc’s injuries

A
  • Quenu and Kuss (1909) – Homolateral, Isolated, and Divergent
  • Modified by Hardcastle in 1982
  • Further modified by Myerson in 1986
  • Fail to encompass all injury patterns especially crush injuries and do not establish prognosis
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8
Q

Reality of classifications

A

o Lots of them

o Do they really help? No

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9
Q

What MUST you evaluate in a Lis Franc’s injury?

A

o Angulation & Translocation

o Transverse & Sagittal displacement

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10
Q

What may hide a true deformity?

A

Spontaneous reduction
o **Does it match the other side?
o **Careful attention to the “key-stone”

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11
Q

Subtle Lis Franc’s deformity

A

The subtle ones are the toughest

  • Often missed in the ED
  • History and physical exam is key
  • Alignment of the second metatarsal base medially is an important radiographic finding
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12
Q

Mechanism of injury

A
  • Trauma
    o Motor vehicle accidents account for one third to two thirds of all cases
    o Incidence of lower extremity foot trauma has increased with the use of air bags
  • Direct or Crush injuries
  • Sports-related injuries are also occurring with increasing frequency
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13
Q

Mechanism of injury - indirect force

A
  • More common than direct
  • Result from axial loading or twisting
  • Metatarsal bases dislocate dorsally more often than plantar
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14
Q

Advanced imaging

A
  • CT and MRI are unlikely to be helpful with either diagnosis or treatment
  • Must be suspicious due to the possibility of spontaneous reduction
  • Stability is key Do a Stress test***
  • Comparison to the other foot
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15
Q

Clinical questions for treatment of TMTJ dislocation

A
  • Reduction vs. No Reduction?
  • Closed Reduction with Pin vs. Open Reduction?
  • Wires vs. Screws?
  • ORIF vs. Fusion?
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16
Q

Example

A
  • Positional changes from unstable Lis franc’s causes severe progressive functional abnormalities
  • Angular and Translational

Notes on x-ray
o “Skinny” joint on the lateral view – no normal joint space
o Sign of degenerative joint disease
o Subchondral sclerosis
o This is a sign of DJD
o 2nd metatarsal is set back behind joint of 1st metatarsal
o 1st metatarsal should be parallel to talar neck line on the lateral view (“Meary’s line”)

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17
Q

** KEY POINTS **

A
  • TMTJ stability and alignment is important for function
  • Arthrodesis is the most stable option for repair with the lowest revision rate
  • There is no good argument from a surgical or functional standpoint for “Joint Preservation” in the TMTJ
  • Locking plates provide a stable, load bearing construct that tolerates external stresses better than traditional AO techniques
  • Must prioritize deformity correction in both acute and late reconstructions
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18
Q

Case study - alignment on x-ray

A
  • Base of second metatarsal is not lined up with the intermediate cuneiform
  • This is how you know that there is a dislocation
  • On an AP x-ray this is the most reliable clue to why there is an injury and this is not just normal anatomy
19
Q

Case study - fracture

A
  • Fracture of base of 2nd metatarsal
  • Evulsion of Lis Franc’s ligament which goes from base of 2nd metatarsal to medial cuneiform
  • All the cortices of the joint line up,
  • If you have the evulsion, you have a severe instability and it needs to be addressed
20
Q

Case study - dislocation, no fracture

A
  • Base of the 1st metatarsal and medial cuneiform
  • No fracture, so this is a purely ligamentous
  • Much worse than a fracture
  • Worse prognosis
21
Q

Classifications

A

Classifications = not important, not clinically relevant

22
Q

Case study - 3rd metatarsal fracture

A
  • Base of the 3rd metatarsal is fractured
  • Do a contralateral x-ray to be able to compare
  • To get a lateral film will tell you if there is any sagittal plane deviation
  • Stress test shows you that there is a severe injury
  • Substantial dislocation is present
  • Advanced imaging is not necessary
  • The key to a Lis Franc’s injury is restoring stability – do not worry about restoring “function”
  • CT and MRI are unlikely to be helpful with either diagnosis or treatment
  • Must be suspicious due to the possibility of spontaneous reduction
23
Q

Instability

A
  • Do you need to reduce it?
  • Open or closed? Closed reduction should always be tried first according to literature
  • Joint NEEDs to be stabilized, one way or another
24
Q

Elevated first ray

A
  • 1st ray elevation leads to forefoot supination, leading to compensation via hind foot pronation
  • Hallux limitus will occur
  • Additional stress on the lateral metatarsal heads
  • Reduces weight bearing on the medial foot
  • Hind foot pronation leads to medial rotation of the knee
  • Midfoot abduction leads to a rotational equilibrium leading to pronation of the foot
25
Q

Small shift equals big deformity

A
  • Even when it is just a “little bit off” it is a big problem because it will get worse 100% of the time
26
Q

Reduction vs no reduction

A
  • Instability is well known to result in progressive collapse biomechanical dysfunction and painful arthrosis
  • All studies that compare accurate reduction to mal position show better outcome for accurate reduction
27
Q

Percutaneous fixation

A
  • Instability remains
  • Imperfect reduction – there’s no way to get it perfect
  • Intraarticular fractures need to be perfect
  • Studies do not support the use of percutaneous fixation
  • Highly variable
  • Inadequate reduction leads to continued instability and further damage
  • Almost everyone recommends ORIF
  • 100% of patients had DJD of TMTJ regardless soft reduction
28
Q

Screws or pins

A
  • Incomplete stability after ORIF
  • Loss of reduction after pin removal
  • High incidence of DJD
  • High rate of revision surgery
  • ORIF needs revision because they will fail, even with the best options we have
  • 3 operations is not uncommon
29
Q

Arthrodesis vs ORIF

A
  • Even though the evidence is compelling that you need stability and arthrodesis, some still say you need to try ORIF first
  • Arthrodesis has much better results
30
Q

ORIF stats

A
  • 15 of 20 had loss of correction, arthrosis and or pain

- 16 out of 220 needed hardware removal and secondary surgery

31
Q

Ligamentous injury ****

A

ORIF
o Dorsal instability
o Medial second metatarsal base fracture
o Much more stable
o This is because the dorsal ligaments are the only ones that are torn, but they don ‘t even matter
o Plantar ligaments are still intact and they are strong

Arthrodesis
o Plantar instability
o Pure ligamentous instability with dislocation
o Less reliable

Fracture
o Better outcome than if it is purely ligamentous

32
Q

ORIF - Henning 2009

A

Prospective randomized study of patients presenting with Lis franc’s fracture dislocation
o ORIF vs primary arthrodesis of 1-2-3
o Follow up for 1 year
o 94% fusion rate in the arthrodesis group
o ***Found similar short term stability …

33
Q

ORIF vs complete TMTJ - Muiler 2002

A
  • ORIF did better functionally than complete TMTJ arthrodesis 1-4
  • Only fuse 1-2-3
34
Q

Late or revision arthrodesis - Rammelt 2008

A
  • We can always fuse it later, but no one actually wants 2-3 operations
  • We can talk people into it, but we should not be doing this
  • Primary arthrodesis had better functional results, less complicated recovery than secondary arth
  • Medial column fusion gave better result than fusion of all 5 joints
  • It is a much harder operation
35
Q

ORIF

A
  • 2nd and 3rd surgeries common
  • High DJD in first 5 years
  • No post op advantage
36
Q

Case study

A
  • Evulsion fracture off of the medial cuneiform (or 2nd metatarsal), but looks more like medial cuneiform
  • Lateral deviation of base of 2nd metatarsal (possibly – very subtle)
  • Implication of the evulsion fracture is that it is an intraarticular and involves
  • Lis Franc’s is more plantar than dorsal, so it is the most important
  • If it is truly unstable with a stress test, arthrodesis of 1-2-3 is the best treatment option
  • Alignment is key for arthrodesis
  • Align the 2nd with intermediate cuneiform and
37
Q

Case study

A
  • Joint space is diminished 2-5, joint space is irregular in 1
  • Treatment is arthrodesis
38
Q

SUMMARY

A
  • Closed pinning and ORIF – high failure rates and high revision rates
  • Consider adjacent joint degeneration
39
Q

Alignment

A
  • 1st ray is elevated
  • Leads to hallux limitus
  • It causes degenerative changes of the first MPJ with arthritic changes
40
Q

Surgical technique

A
  • 2 incisions
  • Only make incision over 4 and 5
  • Fuse 1-2-3
  • Lateral incision is much more lateral than you would think
  • Need to know the anatomy “associated anatomy slide on DP
  • Not fusing 4 and 5, just debriding it
41
Q

Diagnosis

A
  • Hard to diagnose
  • Just as bad as leaving it, is fusing it in an abnormal position
  • The key is that they come in and they are subtle, they don’t do a stress test
  • Stress test – thumb pressure on cuboid, hand pressure on 1st metatarsal
42
Q

Review

A
  • Type II= slip of the physis and fracture of the shaft
  • Non-articular and has robust
  • Relax the patient and reduce it closed
43
Q

Steps for reduction of fracture

A
  • Anesthesia
  • Increase deformity
  • Traction
  • Reduce deformity
  • Maintain reduction (screws, immobilization, cast, etc.)

Emergency Med (14 decks)

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