ANKLE FRACTURES

PRESENTED BY

SPENCER F. SCHUENMAN D.O.

GARDEN CITY HOSPITAL

ANATOMY The ankle is a complex joint

consisting of three distinct functional articulations. Tibia and fibula Tibia and talus Fibula and talus

Each of these articulations are reinforced by a group of ligaments

ANATOMY CONT.

The tibia and fibula form a mortise which provides a constrained articulation for the talus.

The articular surface of the distal tibia (plafond) and the mortise is wider superiorly and anteriorly to accommodate the wedge shaped talus. This provides some intrinsic stability

especially during weight bearing.

ANATOMY CONT.

Ankle stability is provided by a combination of three factors. Bony architecture The joint capsule Ligamentous structures (three

distinct groups) Syndesmotic ligaments Medial collateral ligaments Lateral collateral ligaments

Syndesmotic Ligaments

Comprised of 4 ligaments Anterior

tibiofibular Posterior

tibiofibular Transverse

tibiofibular Interosseous

Medial Collateral

Superficial and deep Deltoids

Posterior tibiotalar

Tibiocalcaneal Tibionavicular

Lateral Collateral

Anterior Talofibular ligament (weakest)

Posterior Talofibular ligament

Calcaneofibular Ligament

Tendons and Neurovascular Structures

Thirteen Tendons, two major arteries and veins, and five nerves cross the ankle joint

Four groups of Tendons Posterior

Achilles and Plantaris Tibialis Posterior Flexor Digitorum Longus Flexor Hallucis Longus

Innervated by Tibial Nerve

Tendons and Neurovascular Structures

Anterior Tibialis Anterior Extensor Digitorum Longus Extensor Hallucis Longus Peroneus Tertius

Innervated by Deep Peroneal nerve Peroneus Longus and

Brevis Innervated by Superficial

Peroneal nerve

Neurovascular Bundles

Anterior N/V bundle Anterior Tibial artery and Deep

Peroneal nerve Lies anterior between the EHL

and Tib. Ant.. Superficial Sensory Nerves

Saphenous nerve-ant. to med. malleolus

Superficial Peroneal nerve-ant to midline dorsal foot

Sural nerve-post to the fibula

Posterior N/V bundle

Ankle Biomechanics A lateral talar shift of 1mm will decrease

surface contact by 40% and a 3 mm shift results in a >60% decrease.

The fibula is essential to providing lateral stability, and maintaining congruency between the talus and the plafond.

A minimum of 10 degrees of dorsiflexion and 20 degrees of plantarflexion are required for normal gait.

Clinical Evaluation

Assess the neurovascular status Assess the condition of the soft

tissues Always palpate proximal and

midshaft fibula for tenderness Reduce a dislocated ankle

immediately to prevent pressure or impaction injuries to the talar dome

Radiographic Evaluation

AP-Look for talar shift (medial joint widening) and syndesmotic disruption

Lateral- The dome of the talus should be centered under the tibia and congruous with the tibial plafond. Also posterior malleolus fxs can be identified.

Mortise- Taken in 15-20 degrees of internal rotation to offset the rotation of the malleoli. You should see a symmetric joint space on all sides.

Classifications-Lauge-Hansen Four patterns, based on pure injury

sequences, each subdivided into stages of increasing severity

System takes into account (1) the position of the foot at the time of injury; (2) the direction of the deforming force.

Based on cadaveric studies The patterns may not always reflect

clinical reality.

Supination-adduction (SA)

Accounts for 10-20% of malleolar fxs

The only type assoc. with medial displacement of the talus

I. Fibula fx transverse

II. Med. Malleolus vertical fx or disruption

Supination-external rotation (SER)

Accounts for 40-75% of malleolar fxs

I. Disruption of ant talofibular ligament

II. Spiral oblique fx fibula

III. Disruption PTF lig or post malleolar fx

IV. Deltoid disruption or Med malleolar fx

Pronation-abduction (PA)

Accounts for 5-20% of malleolar fxs

I. Transverse fx med malleolus or rupture of deltoid

II. Rupture of syndesmotic lig or avulsion fx

III. Transverse or short oblique fibular fx at or above joint line

Pronation-external rotation (PER)

Accounts for 5-20% of malleolus fxs

I. Transverse fx med malleolus or rupture of deltoid

II. Disruption of ant tibiofibular lig with or without avulsion fx

III. Spiral fx above level of syndesmosis (3-5cm proximal)

IV. Rupture of post tib/fib lig or post malleolus

Classifications-Weber Types A,B, and C Based o the level of the fibular fx: the more

proximal, the greater the risk of syndesmotic disruption and associated instability

A. Fx below the level of the syndesmosis, avulsion fx resulting from supination of foot.

B. Oblique or spiral fx caused by ext rotation, begins near or at the level of the syndesmosis

C. Fx of fibula above the syndesmosis with almost always assoc med malleolus fx

Weber Classification

Fracture Variants Maisonneuve fracture- originally described as and ankle

injury with a fracture of the proximal third of the fibula. An external rotation-type injury. Resemble PER fxs.

Curbstone fracture-avulsion fx off the posterior tibia produced by a tripping mechanism.

Leforte-Wagstaffe fracture-anterior fibular tubercle avulsion fracture by the anterior tibiofibular ligament, usually associated with SER fx patterns.

Tilaux-Chaput fracture-avulsion of anterior tibial margin by the ant tibiofibular ligament; counterpart to the LeForte-Wagstaffe fx.

Pediatric Classification-Dias and Tachjian Lauge-Hansen principles correlated with

the Salter-Harris classification Classification simplified by noting the

direction of physeal displacement, Salter-Harris type, and location of the metaphyseal fragment.

The four types of classification aids in determining the proper maneuver for closed reduction.

Supination-inversion (SI)

Grade I- adduction forces avulse the distal fibular epiphysis (Salter I or II)

Grade II- tibial fx, usually SH III or IV

Require ORIF if displaced

High rate of growth disturbances

Supination-plantar flexion (SPL) The plantarflexion

force displaces the epiphysis directly posteriorly, resulting in a SH I or II fx. Fibular fxs are not described with this mechanism.

Supination-external rotation (SER)

Grade I- the external rotation force results in a SH II fx of the distal tibia. Distal fragment is displaced post.

Grade II- with further external rotation, a spiral fx of fibula is produced.

Pronation-eversion-external rotation (PEER) A SH I or II fx of

the distal tibia occurs simultaneously with a transverse fibular fx. A Thurston-Holland fragment, when present is lateral or posterolateral.

Juvenile Tillaux fracture

A SH type III fx involving the anterolateral distal tibia. This takes place in children ages 10-14 when the physis is not yet completely closed.

Triplane fractures A group of

fractures that have in common the appearance of a SH III fx on the AP x-ray and a SH II fx on lateral x-ray.

Treatment

Incidence of posttraumatic arthritis in the ankle is greater than 90% for displaced fxs and less than 10% for those with accurate stable reduction

The goal of treatment is to restore the ankle joint anatomically. Fibular length and rotation must be restored to obtain an anatomic reduction.

Closed Treatment

Only undisplaced, stable fracture patterns with an intact syndesmosis can be treated closed.

If anatomic reduction is achieved with closed manipulation, a short leg cast can be placed for 4-6 weeks.

All fxs should be reduced as well as possible in the emergency room, regardless of eventual treatment.

Open Treatment ORIF is indicated for failure to obtain

or maintain a closed reduction. Widened mortise greater than 1-2

mm should be reduced and fixed if it cannot be stabilized with closed means.

ORIF should be carried out immediately, or, if the soft tissue is in question,wait 4-7 days until swelling subsides.

Open Treatment of the Fibula

Restoration of fibular length and rotation is essential in obtaining an accurate reduction.

The fibula is generally held with a lag screw and a 1/3 tubular plate.

Fractures up to the midshaft should be fixed. Fibula fxs above the syndesmosis generally require a

syndesmotic screw. Cottons test can be performed to test for the integrity of the syndesmotic ligament.

The syndesmotic screw is placed 1.5-2.0cm above the joint under max dorsiflexion.

Treatment of the Medial and Posterior Malleoli Medial malleolar fxs can be held

with one or two cancellous screws perpendicular to the fx line or with tension bands

Indication for fixation of the posterior malleolus are involvement of >25% of the articular surface, >2 mm displacement, or persistent posterior subluxation of the talus.

Treatment of Open Fractures

These require immediate irrigation and debridement in the operating room.

Stable fixation is important prophylaxis against infection and helps soft tissue healing. Reports have shown that immediate internal fixation can

be done with a low incidence of infection Avoid use of a tourniquet, closed surgical incisions, and

leave open wounds open. Repeat debridement every 2-3 days until the wound is

clean, then delayed closure can be performed.

Complications Nonunion-rare; usually the medial malleolus

when treated closed. Malunion Wound problems Infection-<2% of closed fxs; leave implants

alone when stable, even with deep infection. Posttraumatic arthritis-seen with 10% of

anatomically reduced fxs and 90% of malreduced fxs; usually seen by 18 months

Reflex sympathetic dystrophy Compartment syndrome of foot