L16 lisfranc & midfoot inj

Fractures and Dislocations of the Mid-foot Including

Lisfranc Injuries

Arthur K. Walling, MDClinical Professor Of OrthopaedicsDirector Foot and Ankle Fellowship

Florida Orthopaedic InstituteTampa, Florida

Lisfranc’s Joint Injuries

• Any bony or ligamentous injury involving the tarsometatarsal joint complex

• Named after the Napoleonic-era surgeon who described amputations at this level without ever defining a specific injury

Anatomy

• Lisfranc’s joint: articulation between the 3 cuneifoms and cuboid (tarsus) and the bases of the 5 metatarsals

• Osseous stability is provided by the Roman arch of the metatarsals and the recessed keystone of the second metatarsal base

Anatomy

• Lisfranc’s ligament: large oblique ligament that extends from the planter aspect of the medial cuneiform to the base of the second metatarsal (there is no transverse metatarsal ligament from 1 to 2)

Anatomy

• Interosseous ligaments: connect the 2 thru 5 metatarsal bases both dorsal and plantar (stronger and larger)

• Secondary stabilizers: plantar fascia, peroneus longus, and intrinsincs

Anatomy

• Four Major Units1. 1st MT – Medial Cuneiform: 6 degrees of Mobility2. 2nd MT – Middle Cuneiform > Firmly Fixed3. 3rd MT – Lateral Cuneiform > Firmly Fixed4. 4th – 5th MT – Cuboid: Mobile

Anatomy

• Associated Structures:1. Dorsalis pedis artery – courses between 1st and 2nd metatarsal bases2. Deep peroneal nerve: runs alongside the artery

Incidence

• Generally considered rare ( 1 per 55,000 people per year or 15/5500 fractures )

• As index of suspicion increases, so does incidence

• Approximately 20% of Lisfranc’s injuries may be overlooked ( especially in polytraumatized patients )

Mechanisms of Injury

• Trauma: motor vehicle accidents account for one third to two thirds of all cases ( incidence of lower extremity foot trauma has increased with the use of air bags )

• Crush injuries• Sports-related injuries are also occurring

with increasing frequency

Mechanisms of Injury - Direct

Direct Injuries: force is applied directly to the Lisfranc’s articulation. The applied force is to the dorsum of the foot.

Mechanisms of Injury - Direct

Direct Injuries: plantar displacement is more common, but dorsal displacement can also occur.

Open fracture/compartment syndrome/soft tissue injury greater

Mechanisms of Injury - IndirectIndirect injuries: more common than direct and result from axial loading or twisting. Metatarsal bases dislocate dorsally more often than plantarly.

Mechanism of Injury - Indirect

• Typical of athletic injury

• Axial loading to plantar flexed foot results in hyper-plantar flexion and ligament rupture

• Rarely associated with open injury or vascular compromise

Mechanism of Injury - Indirect

• Twisting injuries lead to forceful abduction of the forefoot, often resulting in a 2nd metatarsal base fracture and/or compression fracture of the cuboid (“ nut cracker”)

Associated Fractures

• Base of 2nd metatarsal• Avulsion of navicular• Isolated medial

cuneiform• Cuboid

Classification

• Quenu and Kuss (1909): Homolateral, Isolated, and Divergent1. Modified by Hardcastle in 19822. Further modified by Myerson in 1986

• Fail to encompass all injury patterns especially crush injuries

• Guide treatment but do not establish prognosis

ClassificationQuenu and Kuss (1909)

HOMOLATERAL: most common


ISOLATED


DIVERGENT: least commom

ClassificationHardcastle (1982)

Homolateral or Total Incongruity:

• All 5 metatarsals displace in common direction

•Fracture base of 2nd common


Isolated Partial Incongruities:

• Displacement of 1 or more metatarsals away from the others


Divergent:

• Lateral displacement of lesser metatarsals with medial displacement of the 1st metatarsal

• May have extension of injury into cuneiforms or talonavicular joint

ClassificationMyerson (1986)



Diagnosis

• Requires a high degree of clinical suspicion1. 20% misdiagnosed2. 40% no treatment in the 1st week

• Be wary of the diagnosis of “midfoot sprain”

Clinical Findings

• Midfoot pain with difficulty in weight bearing

• Swelling across the dorsum of the foot

• Deformity variable due to possible spontaneous reduction

Clinical Findings

• Ecchymosis may appear late

• Local tenderness at tarsometatarsal joints

• Gentle stressing plantar/dorsiflexion and rotation will reveal instability

Clinical Findings

• Check neurovascular status for compromise of dorsalis pedis artery and/or deep peroneal nerve injury

• Asses for possible COMPARTMENT SYNDROME

Radiographic Evaluation

• AP, Lateral, and 30° Oblique X-Rays are mandatory

• AP: The medial margin of the 2nd metatarsal base and medial margin of the medial cuneifrom should be alligned


• Oblique: Medial base of the 4th metatarsal and medial margin of the cuboid should be alligned


• Lateral: The dorsal surface of the 1st and 2nd metatarsals should be level to the corresponding cuneiforms


• Standing views provide “stress” and may demonstrate subtle diastasis

• Comparison views are very helpful• Associated fractures:

1. Base of 2nd metatarsal2. Avulsion navicular3. Isolated medial cuneiform4. Cuboid


• Additional imaging:1. True stress views or fluroscopy2. CT Scans3. Bone scan – for persistent pain with no radiographic findings4. If suspicious: repeat x-rays and keep looking

Treatment

• Early recognition is the key to preventing long term disability

• Anatomic reduction is necessary for best results: displacement of >1mm. or gross instability of tarsometatarsal, intercuneiform, or naviculocuneiform joints is unacceptable

• Goal: obtain or maintain anatomic reduction

Treatment

• Nonoperative: for nondisplaced injuries with normal weightbearing or stress x-rays

• Short leg cast• 4 to 6 weeks

nonweight bearing• Repeat x-rays to rule

out displacement as swelling decreases

• Total treatment 2-3 months

Operative Treatment

• Surgical emergencies:1. Open fractures2. Vascular compromise (dorsalis pedis)3. Compartment syndrome

Operative TreatmentTechnique

• 1 – 3 dorsal incisions:1. 1st incision centered at TMT joint and along axis of 2nd ray, lateral to EHL tendon2. Identify and protect NV bundle


• Reduce and provisionally stabilize 2nd TMT joint

• Reduce and provisionally stabilize 1st TMT joint

• If lateral TMT joints remain displaced use 2nd or 3rd incision(s)

2nd met. Base unreduced

reduced


• If reductions are anatomic proceed with permanent fixation:1. Screw fixation is preferable for the medial column2. “Pocket hole” to prevent dorsal cortex fracture


3. Screws are positional not lag4. To aid reduction or if still unstable use a screw from medial cuneiform to base of 2nd metatarsal

Operative Treatment Technique

5. If intercuneiform instability exists use an intercuneiform screw6.The lateral metatarsals frequently reduce with the medial column and pin fixation for mobility is acceptable

Case ExamplePreop AP

Postop AP

Postop Lateral

Postoperative Management

• Splint 10 –14 days, nonweight bearing• Short leg cast, nonweight bearing 4 – 6

weeks• Short leg weight bearing cast or brace for

an additional 4 – 6 weeks• Arch support for 3 – 6 months

Hardware Removal

• Lateral column stabilization can be removed at 6 to 12 weeks

• Medial fixation should not be removed for 4 to 6 months

• Some advocate leaving screws indefinitely unless symptomatic

Complications

• Post traumatic arthritis1. Present in most, but may not be symptomatic2. Related to initial injury and adequacy of reduction3. Treated with arthrodesis for medial column 4. Interpositional arthroplasty may be considered for lateral column

Complications

• Compartment syndrome• Infection• Complex mediated pain syndrome• Neurovascular injury• Hardware failure

Prognosis

• Long rehabilitation (> 1 year)• Incomplete reduction leads to increased

incidence of deformity and chronic foot pain

• Incidence of traumatic arthritis (0 – 58%) and related to intraarticular surface damage and comminution

Navicular Fractures

• Anatomy: a horseshoe shaped disc sitting between the talus and cuneiforms

• Numerous short ligaments attach dorsally, plantarly, and laterally

• Deltoid attaches medially

Navicular Fractures• Blood supply: because of

the large articular surfaces, vessels can only enter dorsally, plantarly, and thru tuberosity

• Medial and lateral thirds have good blood supply, the central third is largely avascular

• # of vessels decreases with age

Navicular Fractures

• Avulsion fractures: usually dorsal lip (essentially severe sprain)

• Treatment:1. Immobilization & progressive weight bearing2. Excision of fragment if painful

Navicular Fractures

• Tuberosity fractures: avulsion by p. tibial tendon and spring lig.

• Usually minimally displaced

• May have associated calcaneocuboid impaction

• ORIF depending on degree of displacement ( > 5mm.)

Navicular FracturesBody Fractures

• High energy trauma with axial foot loading• Frequently associated with talonavicular

subluxation• CT scans helpful for preop planning• Anatomic reduction essential

Navicular FracturesBody Fractures Classification

• Sangeorzan Type 1: coronal fracture plane


• Sangeorzan Type 2: primary fracture dorsolateral to plantar medial with medial displacement of major fragment and forefoot


• Sangeorzan Type 3: comminution of the body in the sagittal plane with forefoot laterally displaced


• Treatment:1. ORIF if any

displacement2. Anteromedial

incision along medial aspect Tib. Ant.

3. Second anterolateral incission to help reduce lateral fragment


• Treatment cont.:4. May require stabilization or fusion to cuneiforms5. Avoid fusion of essential talonavicular joint if at all possible

Missed navicular fx required orif and primary fusion secondary to arthritis


• Prognosis: With adequate reduction most have good result, but few are “normal”

• Type 3 worst prognosis:1. Only ½ adequately reduced in Sangeorzan series (60% of joint surface)2. 6 of 21 developed ostonecrosis with one collapse

Navicular Stress Fractures

• Incidence: Uncommon• Etiology: repetitive

stress and poor blood supply

• Running most common, but can occur in all patients active in sports

• Diagnosis:Vague arch pain with midfoot tenderness

• Delay in diagnosis common

• X-Rays: AP, Lat., and Oblique

• CT and Bone scans if uncertain

Navicular Stress FracturesTreatment

• Incomplete Fracture: Nonweight bearing cast until healed (variable time)

• Complete fracture or nonunion: ORIF with screws perpendicular to fracture plane with or without bone graft

• Complications: nonunion or persistent pain

Cuboid Fractures

• Isolated fractures are rare

• Most often associated with other fractures &/or dislocations

• Two types of fractures usually seen

Cuboid Fractures

• Avulsion fractures: most common

• Compression fractures: mechanism of injury “nutcracker” axial loading with plantar flexion and forefoot abduction

Cuboid FracturesTreatment

• Isolated and nondisplaced: immobilization 6 to 8 weeks

• Displaced: ORIF1. Often requires bone graft and small plate2. Can use small external fixateur for distraction

Cuneiform Fractures

• Isolated fractures quite rare

• Displacement of these fractures is unusual

• Healing with few complications is likely

• Mechanisms of injury:1. Direct trauma – most common and heal rapidly with nonoperative treatment2. Indirect trauma (Lisfranc variants): ORIF

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L16 lisfranc & midfoot inj