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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
Return to Lower Extremity
Index