Midfoot Fractures

Jenny Jefferis

What is a midfoot fracture?

Fracture of the midfoot involving the: Tarsometatarsal joint

(Lisfranc Fracture) Cuneiforms Tarsal navicular bone Cuboid bone

What is a Lisfranc Fracture?

Between the tarsal and metatarsal bones The 1st & 2nd metatarsal articulates with

the medial cuneiforms and are the keystones of the foot

Supplies stability between the midfoot & forefoot during gait

Lisfranc Fracture

Frontal view of the foot shows fracture/ dislocation in the tarsometatarsal joint (Lisfranc's joint) with dislocations of the 1st through 5th metatarsals

Various fractures of the tarsal navicular bone include: Cortical avulsions

Most common Results from twisting forces on the mid foot

Fracture of the tuberosity May involve the post. tibial tendon

Bony fractures Stress fractures

Tarsal Navicular Fracture

Frequently have posttraumatic arthritis & discomfort in all phases of gait

Requires immobilization in a non-weight bearing short leg cast

Cuboid Fracture

Known as nutcracker fractures because the cuboid is cracked like a nut b/w the 5th metatarsal & the calcaneous as the forefoot is forced into abduction.

Cuneiform Fracture

Uncommon Usually occur w/ high-

energy injuries Open reduction &

internal fixation is recommended

Mechanism of Injury

3 common causes Twisting of the forefoot

Often occur during vehicle accidents when the foot is abducted Axial loading of a fixed foot

Occurs when falling on an extremely dorsiflexed foot or axial loading from body weight, stepping off a curb

Crushing To the dorsum of the foot Usually in industrial accidents

Clinician should be aware of compartment syndrome & injury to the dorsal pedis artery

Treatment GoalsAlignment-Restoring the alignment with the cuneiforms

-Important for normal weight bearing-Load distribution of the foot-To maintain the medial arch of the foot

Restoring the length & alignment of:cuneiformscuboid

navicular

Treatment Goals

Stability Stable fixation of the navicular & cuboid

Allows effective transfer of weight from the hind foot Helps with eversion & inversion of the subtalar jt.

A stable reconstruction of the Lisfranc joint Important in maintaining the medial arch of the foot & a

pn free and secure gait

Range of Motion

Motion Normal Functional

Ankle Plantar Flexion

45° 20 °

Ankle Dorsiflexion

20-25 ° 10 °

Foot Inversion 35 ° 10 °

Foot Eversion 25 ° 10 °

Muscle Strength

Invertors Tibialis Anterior Tibialis Posterior

Evertors Peroneus Longus Peroneus Brevis

Dorsiflexors Tibialis Anterior Toe extensors

Plantar Flexors Gastrocnemius Soleus Tibialis Posterior

Peroneous Longus weaknesscan result from severe dislocationsof the Lisfranc Fracture because this muscle inserts on the 1st metatarsal & 1st cuneiform

Time of Bone Healing

Tarsometatarsal or Lisfranc Fracture 8-10 weeks

Tarsal Navicular 6-10 weeks

Cuboid & Cuneiform Fracture 6-10 weeks

Duration of Rehabilitation

Tarsometatarsal or Lisfranc Fracture 8 weeks- 4 months

Tarsal Navicular Acute Fx:6 wks- 4 months Delayed union, nonunion, or stress fx: 6 wks- 4

months Cuboid & Cuneiform Fracture

6 wks- 4 months

Treatment Methods Tarsometatarsal or Lisfranc

Fx: Cast:

Biomechanics: stress-sharing device

Mode of Bone Healing: Secondary, with callus formation

Indications: May be treated w/ a short leg cast for 6 wks. May bear weight when pn free.

Treatment Methods Open Reduction & Internal

Fixation Biomechanics: stress-shielding

device w/ screw fixation Mode of healing: Primary, w/ rigid

fixation Indications: Pt placed in a weight

bearing cast for 6 wks. Unprotected weigh bearing is not recommended until screws are removed at least 10-12 wks after surgery.

Treatment Methods Closed Reduction &

Percutaneous Pinning Biomechanics: Stress-sharing

device w/ pin fixation Mode of bone healing:

Secondary, w/ callus formation Indications: Kirschner-wire

fixation. Placed in a non-weight bearing short leg cast after fixation. Wires removed at 6 wks, followed by protective weight bearing.

Treatment Methods

Tarsal Navicular Fx Cast

Biomechanics: stress-sharing device Mode of bone healing: Secondary, w/ callus formation Indications: May be placed in a short leg cast.

Cortical avulsion fx: short leg walking cast, 4-6 wks. Tuberosity fx: Short leg walking cast, 4-6 wks.

Treatment Methods

Open Reduction & Internal Fixation Biomechanics: Stress-shielding device w/ rigid

fixation Mode of bone healing: Primary, w/out callus

formation Indications: To avoid severe deformity & arthritis,

must be treated w/ reduction & rigid fixation

Treatment Methods

Cuboid & Cuneiform Fx Cast

Biomechanics: Stress-sharing device Mode of bone healing: Secondary w/

minimum callus formation Indications:

Cuboids: closed in a weight bearing cast Cuneiforms: short leg cast, immobilized

because of ligamentous damage

Treatment Methods

Open Reduction Internal Fixation Biomechanics: stress-shielding device Mode of bone healing: primary, w/ rigid fixation Indications:

open reduction & internal fixation for any amount of displacement, followed by a 6 wk. period of non-weight bearing.

Special Considerations of the Fx

Age Joint stiffness particularly w/ navicular fx’s Active Pts. Also are probe to jt. Stiffness w/ a navicular fx

Articular Involvement Posttraumatic arthritis & fusion Limited pronation & supination

Location or possible Open Fractures

Damage to the dorsal pedis artery Open fx must undergo irrigation, debridement, & intrevenous antibiotics Always a possibility of compartment syndrome

Tendon & Ligament Injuries Extensor tendons should be inspected for possible damage

Gait Stance Phase

60% of gait cycle Heel Strike

↑ pn from inversion to eversion Foot-Flat

Painful b/c of injured bones of the medial arch Mid-Stance

Painful as foot is moving from neutral to eversion Push-Off

Pt may limit plantar flexion Cycle is shortened

Swing Phase 40% of gait cycle Not affected by any of these fxs b/c foot is not in contact w/ ground

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