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 Goals Alignment- 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: cuneiforms cuboid 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 ° Foot Eversion 25 °

Muscle Strength Invertors Evertors Dorsiflexors Plantar Flexors Tibialis Anterior Tibialis Posterior Evertors Peroneus Longus Peroneus Brevis Dorsiflexors Toe extensors Plantar Flexors Gastrocnemius Soleus Peroneous Longus weakness can result from severe dislocations of 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

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 Heel Strike Foot-Flat Mid-Stance Push-Off 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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