Ankle Fracture Tips

Mitchell Goldflies

Ankle Anatomy

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

• Talar dome tibial plafond are trapeziodail (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 thing soft tissue envelope

Ankle Biomechanics

• Tri-plane motion• Load bearing force in stance phase of gait is 4 times

body weight• Normal ROM:

– - 20 degrees of extension– - 40 degrees of flexion

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

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

Radiographic Evaluation

• Plan Films– AP, Mortise, Oblique views of ankle– Image entire tibia to knee– Foot films when tender to palpation– Common associated fractures:

• 5th metatarsal base fracture• Calcaneal fracture

Anteroposterior View

Quantitative analysis• Tibiofibular overlap

– <10 mm is abnormal – implies syndesmotic injury

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

• Talar Tilt– >2 mm is considered abnormal

Consider a comparison with radiogrpahs 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 widening– Talocrural angle <8 or>15 degrees

(comparison to normal side is helpful_– Tibia/finula overlap <1mm

Lateral View

• Posterior malleolar 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 Ankle– Evaluate integrity of the syndesmosis

• CT– Helps to delineate joint involvement– Aids in pre-operative planning– Evaluate hindfoot and midfoot if needed

• MRI– Identify ligament and tendon injury and well as talar – Syndesmosis injuries

Understanding Ankle Fracture Classification

• Major Classification system

• Lauge-Hansen

• Weber

• OTA

Lauge-Hansen

• Based on cadaveric study• First word refers to position of foot at

time injury• Second word refers to force applied to

foot relative to tibia at time of injuryRemember 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

Stage 1 Anterior tibia-fibular ligament

Stage 2 Fibula fx

Stage 3 Posterior malleolus fx or posterior tibia-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-proiximal. The SER fibula fracture is ideal for a posterior lateral antiglide plate.

• The medial injury can be fracture or a deltoid figament 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 Fractures

• Bimalleorlar Fractures – Unstable

• Soft-Tissue SER 4 - Unstable

A Comparison of Physical Findings (swelling, Tenderness, Ecchymosis

and Stress X-ray)• Swelling and Eccymosis Scale

– None– Mild– Moderate– Severe

Stress Radiograph

• Performed if mortise reduced on initial films– No talar subluxation– Medical clear space 4mm or less

• Ankle in neutral dorsiflexion• External rotation stress

– @ 8 lbs– Ankle positioned in Mortise view for stress

radiograph

Instability = SE 4

Medical clear space > 4mm

At least 1mm more than superior joint space

Any talar subluxation

Supination Adduction

• Stage 1 Fibula fracture is transverse below mortise.

• Stage 2 Medical malleolus fracture is classical vertical pattern.

• Marginal impaction is common at the medical edge of the platform

SAD

• Only 2 injuries stages

• Medial 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 Rotation

• Stage 1 Deltoid liagment 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

PER

• Proximal spiral fibula fracture

• Must x-ray knee to ankle to asses injury

• Syndesmosis is disrupted in most cases

• Epiponym Maisonneuve Fracture

• Restoration of the mortise and syndesmosis are the keys to treatment

• The 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 tibia-fibular ligament

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

PAB

• Fibula fracture typically distal ½ of fibula. Plating of fibula may be helpful.

• Medial malleolus fx can be difficult to purchase with standard screws. Tension bond fixation may be helpful

Weber Classification

• Based 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

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

syndsmosis– Patient whose overall condition is unstable

and would not tolerate and operative procdure

• Management:– Below the knee cast 4-6 weeks– Follow with serial x-rays and transition to

walking boot or short-leg walking cast

Surgical Indication

• Instability– Talar subluxation

• Malposition– Joint incongruity– Articular stepoff

Operative Fixation

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

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 syndemosis

Posterior Malleolus Fracture

• Internal fixation is done with lag screws typically• The screws can be put in from anterior or

posterior • Attempt to visualize the plaford prior to reduction

of the fibula is difficult because the posterior malleolus if often attached to the distal fibula. Generally reducing the fibula and dorisglexing the ankle are the final steps in reduction. Occasionally a posterior approach may be necessary for reduction.

Lateral Fixation

• Antiglide plating

• SER fibula patterns

• Can add log screw

• Posterolateral

Syndesmotic Fixation

• It has been traditionally thought to dorisflexion when inserting a syndesmotic screw to prevent malreduction of the morise by over tightening the joint

• However Dorisflexion is not necessary

• Cannot Over tighten when the syndesmosis is reduced

• Make sure syndesmosis is anatomic!

Syndesomtic Screws Controversies

• 3.5 mm vs 4.5 mm screw(s)

• 3 corticies vs 4 corticies

• Retain vs Removal

• Every surgeon has their own protocol. No consensus un 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 care• Low grade open results similar to closed

fractures• High grade open results have increased costs

increased number of complications and poorer overall outcomes

Soft Tissue Problems

• Dislocation with kin 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

Disbetic Ankle Fractures

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

• Significant 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 rehabilitration 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 boot– Not study shows a significant– Difference between the treatments

– In general early return of motion– Is preferred when the fixation– Is stable and the patient can comply– With post-operative recommendations\

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 scres and has maximal mechanical stability

• Consider an intramedullary screw if there is not adequate distal bone

Outcome

• Position of the mortise at union and stability 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 talarshift treated conservatively 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 stiffness– 41% have reduced dorisflexion (Lindsjo, Clin,

Orthhop, 1985)

Results

• Predictors of worse results– Bimallelor fracture– Anterolateral impaction injuries of the tibial plafond– Large posterior malleolar fragments– Talar don’t injuries– Talus fractures– Associated foot/ ankle injuries– Delay in fixation– Age >50 years– Diabetes mellitus

Complicatoins

• Malunion– Usually associated with shortened or

malroated distal fibula– Failure to reduce the syndesmotic injury– Treated with fibular lengthening and/or

derotational osteotomy +/- sydesmotic fixation– Good results with fibular osteotomy to prevent

arthrosis– Ankle fusion for advanced arthrosis or

osteomy failure

Complications

• Non-union– Usually involving the medial malleolus due to

soft tissue (i.e. posterior tibial tendon) interposition

– Treated with electrical stimulation, ORIF, bone graft, or excision of fragment

– Patient may have co-morbidities such as diabetes, peripheral vasuclar diesase or smoking

– Noncompliance and premature weight bearing

Complications

• Wound problems– Edge 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

• Infection– Occurs in less than 2% of closed fractures– Increased incidence in Diabetics, Age >50

and Alcoholics– Treated with antibiotics– Implants usually left in place to maintain

stability for optimal soft tissue perfusion – May require serial debridements +/- VAC

dressing– Arthrodesis used as a savage 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 ot

ankle implant

Complications

• Compartment Syndrome– Can occur in immediate postoperative period– Treated with fasciotomie followed by delayed closure

or skin graft

• Complex Regional Plan Syndrome Type I (RSD)– Minimized by appropriate reduction and early return to

function

• Tibiofibular synotosis– Associated with syndesmotic screw use and is usually

asymptomatic

Summary

• Careful clinical and radiographic evaluation• Restoration of ankle joing anatomy

– Fibular length– Syndesmotic stability– Neutral varus/valgus orientation

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

• Prepare patient for possible development of post traumatic arthrosis