Ankle FracturesSteven A. Olson, MD, FACS

Bruce French, MD

Epidemiology • Most common weight-bearing skeletal injury• Incidence of ankle fractures has doubled since the 1960’s• Highest incidence in elderly women• Unimalleolar 68%• Bimalleolar 25%• Trimalleolar 7%• Open 2%

Ankle Anatomy

• Complex joint comprising the articulation of the tibia and fibula with the foot at the talus

• Talar dome tibial plafond are trapezoidal (2.5 mm wider anteriorly)

• Intrinsic stability arises from congruous bony articulations and muscular forces across the ankle

• Extrinsic stability arises from the medial and lateral ligament complex and capsule

• Relatively thin soft tissue envelope

Osseus Anatomy

Lateral Ligamentous Anatomy

Medial Ligaments

Syndesmosis

Ankle Biomechanics• Tri-plane motion• The load bearing force in stance phase of gait is

4 times the body weight• Normal ROM:

~20 degrees of extension ~40 degrees of flexion

• At least 10 degrees of dorsiflexion (extension) is needed for normal gait

• 1 mm of lateral talar shift decreases tibio/talar surface contact up to as much as 40%

History

Consider the relevant factors of the injury• Mechanism of injury• Time elapsed since the injury• Soft-tissue injury• Has the patient ambulated on the ankle?• Patient’s age / bone quality• Associated injuries• Comorbidities

Physical Exam• Neurovascular exam • Note obvious deformities• Pain over the medial or lateral malleoli• Palpation of ligaments about the ankle• Palpation along course of the entire fibula• Pain at the ankle with side to side compression

of the tibia and fibula (5cm or more above the joint) may indicate a syndesmotic injury

• Examine the hindfoot and forefoot

Radiographic Evaluation• Plain Films

AP, Mortise, Oblique views of the ankleImage the entire tibia to knee jointFoot films when tender to palpation

Common associated fracture are:5th metatarsal base fractureCalcaneal fracture

Anteroposterior View

Quantitative analysisTibiofibular overlap<10mm is abnormal - implies syndesmotic injury

Tibiofibular clear space >5mm is abnormal - implies syndesmotic injury

Talar tiltTalar tilt>2mm is considered abnormal

Consider a comparison with radiographs of the normal side if there are unresolved concerns of injury

Mortise View

•Foot is internally rotated and AP projection is performed •Abnormal findings:

medial joint space wideningtalocural angle <8 or >15 degrees (comparison to normal side is helpful)tibia/fibula overlap <1mm

Syndesmotic Injury with Deltoid

Ligament Rupture

Talocural angle

Medial joint space widening

< 1 mm overlap

Lateral View

•Posterior mallelolar fractures•Anterior/posterior subluxation of the talus under the tibia•Angulation of distal fibula•Talus fractures•Associated injuries

Other Imaging Modalities

• Stress Views of the AnkleEvaluate integrity of the syndesmosis -

• CTHelps to delineate joint involvementAids in pre-operative planningEvaluate hindfoot and midfoot if needed

• MRIIdentify ligament and tendon injury and well as talar dome

lesionsSyndesmosis injuries

Understanding Ankle Fracture Classification

Major Classification systemsLauge-HansenWeberOTA

Lauge-HansenBased on cadaveric studyFirst word refers to position of foot at time of injurySecond word refers to force applied to foot relative

to tibia at time of injury

Remember the injury starts on the tight side of the ankle! The lateral side is tight in supination, while the medial side is tight in pronation.

Lauge-Hansen

In each type of fracture there are several stages of injury.

Not every fracture fits exactly into one category.

Supination-External Rotation

1

23

4

Stage 1 Anterior tibio- fibular ligament

Stage 2 Fibula fx

Stage 3 Posterior malleolus fx or posterior tibio-fibular ligament

Stage 4 Deltoid ligament tear or medial malleolus fx

SER Fractures

Classic short oblique fibula fracture. Begins at the mortise anteriorly and extends posterior-proximal. The SER fibula fracture is ideal for a posterior lateral antiglide plate.

The medial injury can be a fracture or a deltoid ligament tear, or a combination of both.

SER Stage 2 injuries are stable and can be managed closed.SER Stage 4 injuries are unstable and require operative fixation.

SER FracturesBimalleolar Fractures - Unstable

“Soft-Tissue SER 4 - Unstable

SER-2 vs. SER-4 How To Decide?

SER-2

Negative Stress view

External rotation of foot with ankle in neutral flexion (00)

Stable Treatment FWBAT

+ Stress View

Widened Medial Clear Space

SE-4SE-4

A Comparison of Physical Findings (Swelling, Tenderness, Ecchymosis) and

Stress X-raySwelling and Ecchymosis Scale

None

Mild

Moderate

Severe

Tornetta et al

Tenderness9 Locations recordedVisual scale

0 - None10 - Worst

MedialMedial

LateralLateral

Joint lineJoint line

Performed if mortise reduced on initial filmsNo talar subluxationMedial clear space 4mm or less

Ankle in neutral dorsiflexionExternal rotation stress

@ 8 lbsAnkle positioned in Mortise view for stress

radiograph

Stress Radiograph

Stress Radiograph - Technique

Instability = SE 4

3 mm3 mm

6 mm6 mm

Medial clear space > 4mm

At least 1mm more than superior joint space

Any talar subluxation

Medial Tenderness – No Correlation with Instability

Mild Moderate Severe

SE 2 67% 20% 13%

Stress (+) SE 4 50% 22% 28%

SE 4 50% 12% 38%

Bimalleolar 23% 41% 36%

0%10%20%30%40%50%60%70%

SE 2 Se 4

Mild Moderate Severe

Medial Swelling – No Correlation to Instability

Mild Moderate Severe

SE 2 38% 37% 25%

Stress (+) SE 4 21% 44% 35%

SE 4 13% 31% 56%

Bimalleolar 36% 50% 14%

0%

10%

20%

30%

40%

50%

60%

SE 2 Stress (+) SE 4 SE 4 Bimalleolar

Mild Moderate Severe

Stress ExaminationEffective method of diagnosing Stable SER-267 SE2…all healed without displacementMedial tenderness

NO!!

EcchymosisNO!!

`

Tornetta et al

Supination Adduction

1

Stage 1 Fibula fracture is transverse below mortise.

Stage 2 Medial malleolus fracture is classic vertical pattern.

Marginal impaction is common at the medial edge of the plafond.

2

SAD

Only 2 injury stagesMedial fracture may require a buttress screw

or plate to prevent fracture displacement.Marginal impaction needs reduction and

fixation with bone graft and implants.

Pronation-External RotationStage 1 Deltoid

ligament tear or medial malleolus fx

Stage 2 Anterior tibio-fibular ligament and interosseous membrane

Stage 3 Spiral, proximal fibula fracture

Stage 4 Posterior malleolus fx or posterior tibio-fibular ligament

341 2

PER

Proximal spiral fibula fractureMust x-ray knee to ankle to assess injurySyndesmosis is disrupted in most cases Epiponym Maisoneuve FractureRestoration of the mortise and syndesmosis are the

keys to treatmentThe fibula must be have length and rotation restored

Pronation-Abduction

Stage 1 Transverse medial malleolus fx distal to mortise

Stage 2 Posterior malleolus fx or posterior tibio-fibular ligament

Stage 3 Fibula fracture, typically proximal to mortise, often with a butterfly fragment1

2 3

PABFibula fracture typically in distal 1/2 of fibula.

Plating of fibula may be helpful.Medial malleolus fx can be difficult to purchase with

standard screws. Tension band fixation may be helpful.

Weber ClassificationBased on location of fibula fracture relative to mortise.

Weber A fibula distal to mortise Weber B fibula at level of mortise Weber C fibula proximal to mortise

Concept - the higher the fibula the more severe the injury

Classification

Lauge-Hansen meets Weber

Weber A Pronation Abduction

Weber B Supination External Rotation

Pronation AbductionWeber C Pronation External Rotation

OTAAlpha-Numeric Code 4=Tibia 3=Distal B= Partial Articular Fx

43B1 43B2

Common Names of Fracture Variants

• Maisonneuve FractureFracture at the proximal 1/3 of the fibula - PER IV

• Volkmann FracturePosterior malleolus fracture

• Wagstaffe FractureAnterior fibular tubercle avulsion fracture by the anterior inferior

tibiofibular ligament (AITF)• Tillaux-Chaput Fracture

Avulsion of the anterior lateral tibia due to the AITF• Collicular Fractures

Avulsion fracture of distal portion of medial malleolusInjury may continue and rupture the deep deltoid ligament

Initial Management• Closed reduction (conscious sedation may be necessary)• Compression dressing, splint, elevate• May take unstable fracture to OR if soft tissues not overly

edematous (i.e. skin wrinkles absent, fracture blisters present).• Otherwise, wait for soft tissue to

settle.• Pain control

Nonoperative Treatment

• Indications:Nondisplaced stable fracture with intact

syndesmosisPatient whose overall condition is unstable and

would not tolerate an operative procedure

• Management:Below the knee cast for 4-6 weeksFollow with serial x-rays and transition to

walking boot or short-leg walking cast

Nonoperative Treatment•Clinical example

SER injuryTreated in walker boot WBAT

Films 4 months post injury show healed stable mortise

Less than 3 mm displacement of the isolated fibula fracture with a reduced ankle mortise do not require surgery

Surgical IndicationsInstability

Talar subluxation

Malposition

Joint incongruity

Articular stepoff

Surgical IndicationsInstability

Talar subluxation

Malposition

Joint incongruity

Articular stepoff

Medial Approach to the Ankle

LATERAL

ANTERIOR

AnteromedialAnterolateral

Lateral

Operative Fixation

In general when a bimalleolar ankle fracture is operated it is helpful to open the medial side prior to lateral fixation. This allows better visualization of the mortise to assess cartilage damage and remove osteochondral fragments.

Case Example20 yo male falls while running - sustains ankle injury

Diagnosis SER Stage 4

Incisions

Lateral

Fibula

Medial

Post. Tib Artery

Medial ApproachInitial approach to medial malleolus allows better inspection of talus and tibial plafond. The fibula is still unstable allowing improved visualization to the joint.

Chondral defect on talar domeChondral defect on talar domeTibial Plafond

Medial Malleolus

Lateral Plating

Fracture reduced with plate in this example Fracture reduced with plate in this example or with screws alone into plate proximallyor with screws alone into plate proximally

Drill Screw HoleDrill Screw Hole

Posterior Malleolus Fracture> 25% of joint surface involved on lateral of ankle is

typical indication for fixation. The fragment is often larger than that seen on lateral view.

The fracture is nearly always associated with the pull of the posterior tib-fib ligament. So the fragment is nearly always larger laterally than medially, and it is typically obliquely oriented.

The fracture typically involves the incisura, where the fibula articulates with the tibia to form the syndesmosis.

Posterior Malleolus FractureInternal fixation is done with lag screws typically.The screws can be put in from anterior or posterior.

Attempt to visualize the plafond prior to reduction of the fibula is difficult because the posterior malleolus is often attached to the distal fibula. Generally reducing the fibula and dorsiflexing the ankle are the first steps in reduction. Occasionally a posterior approach may be necessary for reduction.

Lateral Fixation

Antiglide plating

SER fibula patterns

Can add lag screw

Posterolateral

approach

Antiglide Plating

Posterolateral IncisionPosterolateral Incision

FibulaFibula

Antiglide Plating

PeronealsPeroneals FractureFracture

Antiglide Plating

Slide Plate DistallySlide Plate Distally

Antiglide Plating

Push Plate Posteriorly ProximallyPush Plate Posteriorly Proximally

Antiglide Plating

Fracture Reduced With Clamp in this example Fracture Reduced With Clamp in this example or with screws alone into plate proximally or with screws alone into plate proximally

Fill Screw HolesFill Screw Holes

Lag ScrewLag Screw

Antiglide Plating

Screws Only - Lateral Fixation

Screw only

Young patients < 40

Non-comminuted Fracture

2 Screws

Greater than 1 cm apart

> 45!> 45!

Screw Only Fixation

Screw Only FixationOver 100 cases

No hardware failure

2% lateral irritationIncisional

Compares favorably with direct lateral plating

Tornetta et al

Syndesmotic Injury

Syndesmotic Injury – Minimally Invasive

Fibular location identicalFibular location identical

True lateralsTrue laterals

Syndesmotic Injury - Minimally Invasive

Syndesmotic Injury

Accurate Reduction Accurate Reduction isis

ParamountParamount

Weber C / PER 4

Short!

Treatment Must Maintain Length

Still Short!Still Short!NormalNormal

SideSide

Postop & F/U

Before Fixation After Fixation

4343°42°42°

Cadaveric Study of Syndesmodic Screws Compressing Mortise

Syndesmotic FixationIt has been traditionally taught to dorsiflexion when

inserting a syndesmodic screw to prevent malreduction of

the mortise by over tightening the joint

However Dorsiflexion is not necessary

Cannot Overtighten when the syndesmosis is reduced!Make sure syndesmosis is anatomic!

Tornetta et al

Syndesmodic Screws Contoversies

3.5 mm vs 4.5 mm screw(s)3 corticies vs 4 corticiesRetain vs Removal

Every surgeon has their own protocol. No consensus in literature on these points!

Open Ankle Fractures

Treat with appropriate antibiotics pre-op and 48 hr post-op

I & D with immediate ORIF if clean wound ORIF and Ex Fix if severe soft tissue damage

present to allow for wound careLow grade open results similar to closed fracturesHigh grade open results have increased costs

increased number of complications and porer overall outcomes

Soft Tissue Problems• Dislocation with skin compromise

Immediate reduction required!If the talus is not reduced beneath the plafond, there is increased pressure on the skin and increased risk of skin breakdown, that all may lead to wound breakdown and infection

10% have skin slough when a timely reduction is not obtained

Diabetic Ankle Fractures

• Neuropathy, nephropathy, retinopathy and PVD increase the risk of complications (Marsh, OTA, 2003)

• Significant risk for amputation 6% for closed injuries (Marsh, OTA, 2003)43% for open fractures (White, OTA, 2003)

• Increased risk of superficial and deep wound infections• Increased risk of malunion/nonunion• Transarticular fixation with tibial-calcaneal nail has

been proposed (Jani, OTA, 2003)• Healing and rehabilitation time may be as much as

double the non-diabetic patient

Postoperative Care• Compression dressing/splint or cast• Drain?• Ice and elevation• Non weight-bearing with progression to weight-

bearing based on fracture pattern, stability of fixation, patient compliance and philosophy of the surgeon

• Early ROM • Late removal of symptomatic hardware as needed

Postoperative Care•Casting vs. Removable Boot with early ROM

May have some wound problems with bootNo study shows a significantdifference between the treatments

In general early return of motion is prefered when the fixation is stable and the patient can complywith post-operative recomendations

Osteopenic Ankle Fractures•Increased incidence with older population•Poor hardware fixation with an increased risk of failure of fixation•May augment fixation with k-wires•Periosteum preserving technique with bridge plating in comminuted fibula fractures•Use of an anti-glide plate to get a better screw purchase from posterior to anterior screws and has maximal mechanical stability•Consider an intramedullary screw if there is not adequate distal bone

Outcome

Position of the mortise at union and stabiltiy of talus are critical factors!

Obtain an anatomic reduction

Hold to union

If loss of position is noticed,

re-reduce if possible

Results• Stable ankle fractures without lateral talar shift treated

conservatively have 90% good to excellent results• Operative fixation of unstable ankle fractures have 85-

90% good to excellent results• 2 year follow up

80-90% have unlimited ability to work, walk and participate in leisure activities

20-30% report swelling or stiffness41% have reduced dorsiflexion ( Lindsjo, Clin Orthop, 1985)

ResultsPredictors of poorer results

Bimalleolar fractureAnterolateral impaction injuries of

the tibial plafondLarge posterior malleolar

fragmentsTalar dome injuriesTalus fracturesAssociated foot/ankle injuriesDelay in fixationAge > 50 yrDiabetes Mellitus

Complications•Malunion

Usually associated with shortened or malrotated distal fibula Failure to reduce the syndesmotic injuryTreated with fibular lengthening and/or derotational osteotomy +/- syndesmotic fixationGood results with fibular osteotomy to prevent arthrosisAnkle fusion for advanced arthrosis or osteotomy failure

Complications

• Non-unionUsually involving the medial malleolus due to soft

tissue (i.e. posterior tibial tendon) interpositionTreated with electrical stimulation, ORIF, bone

graft, or excision of fragmentPatient may have co-morbidities such as diabetes,

peripheral vascular disease or smokingNoncompliance and premature weight bearing

Complications

• Wound problemsEdge necrosis (3%)Dehiscence

Risk is decreased by minimizing swelling, not using a tourniquet, and careful atraumatic soft tissue handling

ORIF on the presence of fracture blisters and larger abrasions have more than twice the average wound complication rate

Complications

• InfectionOccurs in less than 2% of closed fracturesIncreased incidence in Diabetics, Age > 50, and

AlcoholicsTreated with antibioticsImplants usually left in place to maintain stability

for optimal soft tissue perfusionMay require serial debridements +/- VAC dressingArthrodesis used as a salvage procedure

Complications•Post traumatic arthrosis secondary either to articular damage at the time of injury or inadequate reduction resulting in abnormal mechanics.

Treated with NSAIDs, AFO, ankle fusion or ankle implant

Complications• Compartment Syndrome

Can occur in immediate postoperative period.Treated with fasciotomies followed by delayed closure

or skin graft• Complex Regional Pain Syndrome Type I (RSD)

minimized by appropriate reduction and early return to function

• Tibiofibular synostosisassociated with syndesmotic screw use and is usually

asymptomatic

Summary• Careful clinical and radiographic evaluation• Restoration of ankle joint anatomy

Fibular lengthSyndesmotic stabilityNeutral varus/valgus orientation

• Delay ORIF until the surrounding soft tissue swelling and blisters have resolved

• Prepare patient for possible development of post traumatic arthrosis

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