AAOS Comprehensive Orthopaedic Review

Section 6 - Trauma

Chapter 60. Fractures of the Ankle and Tibial Plafond

I. Fractures of the Ankle

A. Epidemiology

 

1. Fractures of the ankle are among the most common injuries requiring orthopaedic care.

 

2. Ankle fractures vary from relatively simple injuries with minimal long-term effects to complex injuries with severe long-term sequelae.

 

3. Population-based studies have identified an increase in the incidence of ankle fractures. Data from Medicare enrollees suggest the rate of ankle fractures in the United States averages 4.2 fractures per 1,000 Medicare enrollees annually.

 

4. Rates of surgery vary depending on type of fracture.

 

a. For isolated lateral malleolar fractures, the surgical intervention rate is approximately 11%.

 

b. For trimalleolar fractures, the surgical intervention rate is 74%.

 

5. Risk factors for sustaining an ankle fracture include age, increased body mass, and a history of ankle fractures.

 

6. The highest incidence of ankle fractures occurs in elderly women.

 

7. Isolated malleolar fractures account for two thirds of ankle fractures.

 

B. Anatomy of the lower leg

 

1. Osseous anatomy and ligaments of the ankle joint (

Figure 1)

 

a. The osseous anatomy of the ankle provides stability during weight bearing with mobility in plantar flexion.

 

b. The ankle joint behaves like a true mortise in dorsiflexion.

 

c. Stability is achieved by articular contact between the medial malleolus, the fibula, the tibial plafond, and the talus.

 

d. The talar dome is wider anteriorly than posteriorly, such that as the ankle dorsiflexes, the fibula rotates externally through the tibiofibular syndesmosis to accommodate the talus.

 

e. The lateral malleolus is surrounded by multiple strong ligaments.

 

i. These include the tibiofibular ligamentous complex of the interosseous membrane and syndesmotic ligaments (anterior inferior tibiofibular ligament, posterior inferior tibiofibular ligament, and the inferior transverse ligament).

 

ii. These ligaments are responsible for stability of the ankle in external rotation.

 

iii. In addition, the lateral collateral ligaments of the ankle, including the anterior and posterior talofibular ligaments and calcaneofibular ligaments, provide support and resistance to inversion and anterior translation of the talus relative to the fibula.

 

2. Medial malleolus

 

a. The medial malleolar surface of the distal tibia has a larger surface anteriorly than posteriorly.

 

b. The posterior border of the medial malleolus includes the groove for the posterior tibial tendon.

 

c. The medial malleolus includes the anterior colliculus, which is larger and extends approximately 0.5 cm distal to the smaller posterior colliculus.

 

d. The deltoid ligament provides medial ligamentous support of the ankle.

 

i. The important deep component of the deltoid ligament arises from the intercollicular groove and posterior colliculus.

 

ii. The deep layer of the deltoid ligament is a short, thick ligament inserting on the medial surface of the talus.

 

[Figure 1. The osseous anatomy and ligaments of the ankle joint. A, Anterior, posterior, and lateral views of the tibiofibular syndesmotic ligaments. AITFL = anterior inferior tibiofibular ligament, PITFL = posterior inferior tibiofibular ligament, ITL = inferior transverse ligament, IOL = interosseous ligament. B, The lateral collateral ligaments of the ankle and the anterior syndesmotic ligament. Sagittal plane(C) and transverse plane (D) views of the medial collateral ligaments of the ankle.]

iii. The superficial deltoid ligament arises from the anterior colliculus of the medial malleolus.

 

3. Tendinous and neurovascular structures

 

a. Posterior group

 

i. The posterior group includes the Achilles and plantaris tendons.

 

ii. Immediately lateral to the Achilles tendon lies the sural nerve.

 

b. Medial group

 

i. On the medial side of the ankle, the flexor tendons—including the tibialis posterior, the flexor digitorum longus (FDL), and the flexor hallucis longus—(FHL) course posterior to the medial malleolus.

 

ii. The posterior tibial artery and tibial nerve lie between the FDL and FHL tendons.

 

iii. The saphenous vein and nerve course superior and anterior to the tip of the medial malleolus and are at risk during surgical repair of malleolar fractures.

 

c. Anterior group

 

i. On the anterior aspect of the ankle, the extensor retinaculum contains the extensor tendons, including the tibialis anterior, extensor hallucis longus (EHL), extensor digitorum longus (EDL), and peroneus tertius.

 

ii. Between the EHL and EDL lie the deep peroneal nerve and the anterior tibial artery.

 

iii. The superficial peroneal nerve crosses the ankle anterior to the lateral malleolus, superficial to the extensor retinaculum.

 

iv. Because the superficial peroneal nerve may cross from the lateral compartment to the anterior compartment at varying levels, care must be exercised to avoid injury to this nerve in the treatment of fibular fractures.

 

d. Lateral group

 

i. On the lateral side of the ankle, the peroneal tendons are contained by a stout retinacular structure posterior to the fibula.

 

ii. The peroneus longus is more external to the peroneus brevis.

 

iii. Lateral approaches to the ankle can injure the superficial nerve more proximally and the sural nerve more distally.

 

C. Surgical approaches to ankle fractures

 

1. Direct lateral approach to the fibula

 

a. Commonly used to stabilize lateral malleolar fractures

 

b. The dissection is anterior to the peroneal tendons at the level of the ankle mortise.

 

c. Proximally, the peroneal tendons must be dissected to expose the fibula.

 

d. The dissection plane is between the peroneus tertius anteriorly and the peroneus longus and brevis posteriorly.

 

e. The superficial peroneal nerve should be considered when more proximal dissection is required for fibular fracture.

 

f. The posterior aspect of the lateral malleolus can be approached through this incision; this requires reflection of the peroneal tendons away from the posterior surface of the fibula to facilitate placement of internal fixation on the posterior surface of the fibula.

 

2. Posterolateral approach to the ankle joint

 

a. The posterolateral approach exists between the peroneal tendons and the Achilles tendon.

 

b. Direct exposure of the posterior aspect of the tibia is accomplished by elevating the FHL tendon away from the posterior aspect of the tibia in the deep portion of this incision.

 

c. This approach is useful for stabilizing a posterior malleolar fracture using direct reduction techniques.

 

3. Anteromedial approaches to the medial malleolus

 

a. The medial malleolus can be approached through a longitudinal incision directly over the malleolus; the saphenous nerve and vein are frequently encountered.

 

b. A slightly more anterior incision facilitates direct inspection of the ankle joint and talar dome.

 

c. Using a more posteromedial incision, the posterior tibial tendon and neurovascular bundle can be elevated to access the posteromedial portion of the medial malleolus.

 

4. Percutaneous incisions

 

a. In addition to the lateral, posterolateral, and medial approaches, a variety of percutaneous incisions can be used to facilitate hardware placement.

 

b. An anterior percutaneus incision often is used to facilitate indirect fixation of a posterior malleolar fracture.

 

c. Blunt dissection and placement of retractors and soft-tissue sleeves are required to avoid injury to the neurovascular structures surrounding the ankle.

 

D. Mechanism of injury

 

1. Most ankle fractures are low-energy, rotational injuries.

 

2. Ankle fractures also occur commonly in sports, usually secondary to a rotational mechanism.

 

3. Fractures with a significant axial loading mechanism are more severe and often result in tibial plafond fractures.

 

4. Associated injuries

 

a. Common with malleolar fractures

 

b. Fractures of the talar dome occur in a substantial portion of ankle fractures and are known to compromise long-term outcome.

 

c. Associated osseoligamentous injuries such as avulsive injuries of the anterior inferior tibiofibular ligament may occur.

 

d. Avulsion fractures in which the anterior inferior tibiofibular ligament avulses from the distal tibia (Chaput tubercle) or fibula (Wagstaffe tubercle) may occur and result in associated external rotation instability.

 

e. With adduction-type ankle injuries, impaction injury to the medial distal tibia may occur.

 

i. To restore ankle joint congruency, this impaction injury may require treatment in addition to the malleolar fracture.

 

ii. This injury pattern should be considered in particular when the medial malleolar fracture has a vertical orientation and is associated with a transverse distal fibular fracture.

 

f. The lateral articular surface can be impacted in a pronation-abduction type of mechanism. Reduction and stabilization of the lateral articular impaction can be difficult and may also result in significant long-term outcome problems.

 

E. Clinical evaluation

 

1. Clinical evaluation should include a description of the mechanism of injury.

 

2. An evaluation of medical comorbidities, especially diabetes mellitus, is important. Physical examination should include a thorough inspection for communicating open wounds.

 

a. An open ankle fracture is most commonly associated with an open medial wound with a punctate or transverse laceration in communication with the ankle joint.

 

b. These fractures should be considered as surgical emergencies.

 

3. An examination for deformity of the foot relative to the leg and the direction of displacement to the foot should be performed.

 

4. The complete circulatory and neurologic examination should be documented, including assessment of the superficial peroneal, deep peroneal, sural, and posterior tibial nerves, which can be examined using light touch and sharp/dull discrimination.

 

5. The condition of the skin must be considered.

 

6. Soft-tissue swelling should be assessed because it will affect surgical timing.

 

7. Fracture-dislocations should be reduced to avoid isolated skin and soft-tissue ischemia.

 

8. In patients without dislocation, the ankle should be palpated for areas of tenderness.

 

9. Ottawa ankle rules

 

a. The Ottawa ankle rules assist physicians in deciding when it is appropriate to obtain radiographs in adults with ankle injuries.

 

b. These guidelines are sensitive for ankle fracture, and they reduce the number of radiographs taken, along with associated costs.

 

c. According to these rules, ankle radiographs are needed only if there is pain near the malleoli and one or more of the following conditions is present:

 

i. Age 55 years or older

 

ii. Inability to bear weight

 

iii. Bone tenderness at the posterior edge or tip of either malleolus

 

10. Physical examination and instability

 

a. Although physical examination of acute ankle injuries is important, the ability to detect instability by physical examination alone has been questioned.

 

b. This is particularly the case for isolated lateral malleolar fractures, in which it is often difficult to determine the degree of instability of the ankle.

 

c. In patients with an isolated fibular fracture without talar shift, the ankle should be palpated directly over the deltoid ligament for swelling, ecchymosis, and tenderness as a clue to potential deltoid ligament injury; however, the value of this maneuver to predict ankle instability is comparatively limited.

 

d. Stress examination of isolated fibular fractures without talar shift has been advocated recently as a more sensitive examination of ankle instability.

 

F. Radiographic evaluation

 

1. Standard radiographs of the ankle include mortise, AP, and lateral views.

 

a. The mortise view is obtained by internal rotation of the patient's leg by approximately 15° such that the x-ray beam is perpendicular to the transmalleolar axis.

 

b. The AP radiograph is obtained with the x-ray beam in line with the second ray of the foot.

 

c. If there is any suggestion of proximal tibial or fibular pain or tenderness or swelling and pain in the foot region, the radiographic evaluation should include full views of the tibia and fibula and foot.

 

2. Important considerations on standard radiographic views (

Figure 2)

 

a. The subchondral bone of the tibia and fibula should form a continuous line around the talus on all views.

 

b. The talocrural angle (the angle between a line drawn perpendicular to the distal articular surface of the tibia and a line connecting the lateral and medial malleoli) should be 83° ± 4° or within 5° of the contralateral ankle on the mortise view.

 

c. The medial clear space (the distance between the medial articular surface of the medial malleolus and the talar dome) should be ≤4 mm and should be equal to the superior clear space between the talus and the distal tibia on the mortise view.

 

d. The tibiofibular clear space (the distance between the medial wall of the fibula and the tibial incisural surface) should be ≤6 mm on the mortise view.

 

[Figure 2. Radiographic appearance of the normal ankle on the mortise view. A, The condensed subchondral bone should form a continuous line around the talus. B, The talocrural angle should be approximately 83°. C, The medial clear space should be equal to the superior clear space between the talus and the distal tibia and ≤4 mm on standard radiographs. D, The distance between the medial wall of the fibula and the incisural surface of the tibia, the tibiofibular clear space, should be ≤6 mm.]

3. In the case of an ankle with an isolated fibular fracture and medial tenderness without evidence of initial talar displacement, a stress view has been recommended.

 

a. This may be performed by simple gentle external rotation of the foot with the ankle in dorsiflexion and the leg stabilized, or by supporting the patient's leg with a pillow or cushion and allowing the ankle to rotate with the force of gravity.

 

b. In these situations, a widening of the medial clear space of ≥5 mm may occur. This may be indicative of ankle instability secondary to medial ligamentous injury in conjunction with the fibular fracture.

 

G. Classification—AO/Weber and Lauge-Hansen classifications

 

1. AO/Weber classification (

Figure 3)

 

a.

Ankle fractures are classified based on the location of the fibular fracture.

b.

The degree of instability depends on the location of the fibular fracture.

c.

Weber A fracture

 

i.

Occurs when the fibular fracture is located distal to the tibiofibular syndesmosis

 

ii.

Injury usually occurs according to an inversion mechanism.

 

[Figure 3. AO/Weber classification of ankle fractures. The staging is determined completely by the level of fibular fracture. Type A occurs below the plafond; type C starts above the plafond.]

[

Table 1. Lauge-Hansen Classification of Ankle Fractures]

 

iii.

Because of the infrasyndesmotic location, Weber A fractures are less likely to result in instability.

 

iv.

Indications for surgery are therefore dependent on the status of the medial ankle.

d.

Weber B fracture

 

i.

Most common type of ankle fracture

 

ii.

Includes a fibular fracture beginning at approximately the level of the ankle syndesmosis (the anterior inferior tibiofibular ligament) and extending proximal and posterior

 

iii.

May be associated with ankle instability, depending on the status of the medial side of the ankle

e.

Weber C fracture

 

i.

Associated with a fibular fracture above the level of the ankle syndesmosis

 

ii.

Usually occurs with an external rotation mechanism

 

iii.

Weber C ankle fractures are generally unstable because they are usually associated with medial injury.

 

2. Lauge-Hansen classification (

Figures 4 and

5)

 

a. Roughly corresponds to the Weber classification

 

b. In the Lauge-Hansen classification, the ankle fracture is classified according to the mechanism of injury.

 

i. Two variables are described, the first being the position of the foot and the second relating to the deforming force applied to the ankle.

 

ii. In a cadaveric study, most ankle fracture patterns were reproduced by placing the foot in either supination or pronation and then applying deforming forces in abduction, adduction, or external rotation.

 

iii. When the foot is supinated, the medial deltoid ligament is relaxed and the initial injury is lateral.

 

iv. When the foot is pronated, the deltoid ligament is tense, and the initial injury occurs medially as either a medial malleolar fracture or deltoid ligament disruption.

 

c. The Lauge-Hansen classification describes four major fracture types—supination-adduction (SAD), supination-external rotation (SER), pronation-external rotation (PER), and pronation-abduction (PAB). In each of these, the initial injury is followed in a predictable sequence of further injury to other structures around the ankle (Table 1).

 

d. As in the Weber classification, the Lauge-Hansen classification requires that particular attention be paid to the specific characteristics of the fibular fracture.

 

e. The Lauge-Hansen classification was first designed to assist in determining the forces required to obtain and maintain a closed reduction of an ankle fracture; however, this classification continues to assist with understanding the mechanism of injury of rotational ankle fractures.

 

H. Nonsurgical treatment

 

1. Nonsurgical treatment of ankle fractures remains the standard of care in many situations.

 

2. In stable fibular fractures without associated medial injury, closed treatment leads to excellent function in most cases.

 

a. When the fracture is stable, a short leg cast or functional brace can be applied for 4 to 6 weeks.

 

b. Weight bearing is permitted when symptoms allow.

 

[Figure 4. Lauge-Hansen classification of ankle fractures. Drawing shows the sequence of injury when the foot is supinated (SER and SAD injuries). Tib-fib = tibiofibular.]

   

 

[Figure 5. Lauge-Hansen classification of ankle fractures. Drawing shows the sequence of injury when the foot is pronated (PER and PAB injuries). Tib-fib = tibiofibular.]

   

 

c. Prolonged immobilization and casting is not necessary.

 

d. Some studies have reported good results using a simple supportive high-top shoe or elastic bandage.

 

3. Unstable fractures

 

a. With an unstable fracture, nonsurgical treatment requires frequent follow-up.

 

b. Radiographic confirmation that the talus has remained reduced in the mortise is required.

 

c. Casting and non-weight bearing for a minimum of 4 weeks is required to prevent the ankle from displacing; even so, maintaining the reduction is difficult and has several disadvantages.

 

i. Prolonged casting presents challenges for elderly or infirm patients.

 

ii. As swelling diminishes, the reduction may be lost.

 

iii. Despite the disadvantages, in selected cases such as neuropathic patients or patients too unwell to tolerate surgery, casting is useful.

 

I. Surgical treatment

 

1. General issues

 

a. Surgical treatment is indicated for unstable ankle fractures.

 

b. Distal tibiofibular diastasis also requires reduction and fixation.

 

c. The timing of surgery is important.

 

d. A closed reduction may assist with the resolution of swelling and help to avoid further articular damage.

 

e. Temporary immobilization and elevation are useful for allowing swelling to resolve.

 

f. At the time of surgery, perioperative antibiotics are required, and a pneumatic tourniquet to assist with visualization of the surgical field is helpful.

 

2. Lateral malleolus

 

a. Fixation of the fibular fracture is usually performed before treatment of the medial or posterior malleolus or syndesmosis. Fixation of the fibula provides stability to the ankle and restores length. Exceptions to the "fibula first" strategy:

 

i. When the fibular fracture is extensively comminuted, in which case stabilization of the medial side first may assist with positioning the talus within the mortise, therefore helping to achieve an anatomic reduction of the fibula

 

ii. In many supination-adduction mechanisms, fixation of the fibula provides assistance with stability but is not adequate to reduce the talus within the mortise.

 

b. Reduction of the fibula may be achieved directly, or indirectly with traction or a push/pull distraction technique.

 

c. Typically the fibular fracture is stabilized with a one third tubular plate, contoured to the lateral or posterolateral fibula with an additional lag screw to provide fracture compression.

 

d. Use of a posterior antiglide plate is useful for a very distal fibular fracture, a fracture associated with a posterior dislocation, or osteopenic bone.

 

e. A posterior plate provides stable fixation in antiglide or buttress mode, even without the use of distal screws.

 

f. The proximal portion of the plate is fixed with bicortical screws placed from posterior to anterior.

 

i. Should screws be needed in the distal fragment, they can be placed from posterior to anterior without penetrating the ankle joint.

 

ii. A lag screw can be placed from posterior to anterior through the plate or, alternatively, from anterior to posterior.

 

iii. Long oblique fractures of the fibula can be stabilized with lag screws only.

 

iv. At minimum, two screws placed at least 1 cm apart are required.

 

v. Additional lag screws or a greater span between the screws provides more stable fixation.

 

3. Medial malleolus

 

a. The medial malleolus can be stabilized using a variety of techniques, depending on the fracture pattern.

 

b. Most fractures are oblique and can be stabilized with two 4.0-mm partially threaded cancellous screws.

 

i. Exceptions include the anterior colliculus fracture, which can occur with a deep deltoid ligament rupture.

 

ii. Stabilizing the anterior colliculus may not restore ankle stability.

 

c. Vertical shear fractures can be associated with articular impaction that may require reduction and bone grafting; as well, antiglide or buttress plate fixation of the vertical shear fracture may be necessary.

 

4. Posterior malleolus

 

a. Posterior malleolar fractures involving >25% of the articular surface, or associated with posterior subluxation following fixation of the fibula, require reduction and fixation.

 

b. The posterior malleolus can be reduced using either direct or indirect techniques.

 

c. The posterolateral approach described previously is useful for directly visualizing the extra-articular fracture line and facilitates placement of a posterior-to-anterior lag screw or buttress plate.

 

d. If indirect reduction is used, a reduction tenaculum is placed posteriorly through the fibular incision and anteriorly through a separate small anterior incision.

 

i. Care should be taken to spread the soft tissues and avoid injuring the vulnerable anterior structures.

 

ii. A percutaneous anterior-to-posterior screw can then be inserted in lag mode, using fluoroscopic control.

 

e. Partially threaded screws require care to insert so that the screw threads cross the fracture line for smaller posterior fragments.

 

5. Tibiofibular syndesmosis

 

a. Injuries to the tibiofibular syndesmosis are common with rotational ankle injuries.

 

b. Following fixation of the lateral malleolus, all external rotation and eversion ankle fractures should be evaluated fluoroscopically because syndesmotic instability may be present.

 

c. Although more common with higher fibular fractures, approximately one third of SER-type ankle fractures are associated with syndesmotic instability after fibular fixation.

 

d. The syndesmosis is typically stabilized with one or two screws inserted from the fibula into the tibia. The most distal screw should be inserted at the superior margin of the syndesmosis.

 

e. An accurate anatomic reduction of the syndesmosis is required; overcompression and widening of the syndesmosis as well as anterior translation of the fibula can occur.

 

f. Achieving an accurate reduction is even more critical when only syndesmosis fixation is used, such as for a proximal fibular fracture associated with interosseous membrane disruption, ankle instability, and fibular shortening. In this instance, an accurate restoration of fibular length and alignment is required before placement of the syndesmosis screw.

 

g. A variety of implants have been used successfully to stabilize the syndesmosis, including one or two screws, 3.5-mm and 4.5-mm screws, and bioabsorbable implants.

 

h. Screws can engage either three or four cortices.

 

i. Screws that engage all four cortices may be more likely to break.

 

ii. The indications for screw removal remain controversial; however, it seems most important to leave the screws in long enough to ensure ligamentous healing has occurred to prevent redisplacement.

 

6. Pearls and pitfalls are listed in

Table 2.

 

J. Rehabilitation

 

1. Following fracture fixation, the limb is placed in a bulky cotton dressing incorporating a plaster splint.

 

2. Progression to weight bearing is based on the fracture pattern, stability of fixation, patient compliance, and philosophy of the surgeon.

 

K. Complications

 

1. Nonunion

 

a. Nonunion is rare and usually involves the medial malleolus when treated closed, associated with residual fracture displacement, interposed soft tissue, or associated lateral instability resulting in shear stresses across the deltoid ligament.

 

b. If symptomatic, it may be treated with open reduction and internal fixation or electrical stimulation.

 

c. Excision of the fragment may be necessary if not amenable to internal fixation and the patient is symptomatic.

 

2. Malunion

 

a. The lateral malleolus is usually shortened and malrotated.

 

b. Widened medial clear space and large posterior malleolar fragment are most predictive of poor outcome.

 

c. The medial malleolus may heal in an elongated position, resulting in residual instability.

 

3. Wound problems

 

a.

Skin edge necrosis occurs in 3% of patients.

b.

Risk is decreased with minimal swelling, no tourniquet, and good soft-tissue technique.

 

[Table 2. Pearls and Pitfalls of Ankle Fractures]

c.

In fractures that are operated on in the presence of fracture blisters or abrasions, the complication rate is more than doubled.

 

4. Infection

 

a. Occurs in <2% of closed fractures

 

b. Leave implants in situ if stable, even with deep infection. The implant may be removed after the fracture unites.

 

c. May require serial debridements with possible arthrodesis as a salvage procedure

 

5. Posttraumatic arthritis

 

a. Occurs secondary to damage at the time of injury, altered mechanics, or as a result of inadequate reduction

 

b. Rare in anatomically reduced fractures, with increasing incidence with articular incongruity

 

6. Reflex sympathetic dystrophy (rare)—May be minimized by anatomic restoration of the ankle and early return to function.

 

7. Compartment syndrome of foot (rare)

 

8. Tibiofibular synostosis—Associated with the use of a syndesmotic screw and is usually asymptomatic.

 

9. Loss of reduction—Found in 25% of unstable ankle injuries treated nonsurgically.

 

10. Loss of ankle range of motion



II. Tibial Plafond Fractures

A. Epidemiology

 

1. A plafond fracture is a distal tibial fracture with intra-articular extension.

 

2. Tibial plafond fractures account for less than 10% of lower extremity injuries.

 

3. The average patient age is 35 to 40 years.

 

4. These injuries are more common in males than in females.

 

5. The most common mechanisms of injury include motor-vehicle collisions or falls from a height.

 

6. These fractures appear to be increasing in incidence, similar to other severe lower extremity fractures.

 

B. Anatomy

 

1. In the distal part of the calf, the medial border of the tibia lies directly subcutaneously, with a thin layer of skin and subcutaneous tissue covering the bone.

 

2. Anterior to the tibia lie the tendons of the anterior compartment as well as the anterior tibial vessels and deep peroneal nerve.

 

3. The fibula sits laterally and relatively posterior to the tibia; in general, only one quarter to one third of the fibula sits anterior to the midline of the tibia.

 

4. In the posterolateral position lie the peroneal tendons. Directly posterior to the tibia lie the flexor tendons, the Achilles tendon, and the posterior tibial artery and nerve.

 

5. Fracture anatomy

 

a. Fractures of the tibial plafond assume a varying course within the cartilage of the distal bone.

 

b. Fractures may include an impaction of the anterior articular surface, posterior articular surface, or both, as well as central impaction of the articular surface, depending on the exact direction of injury.

 

c. Careful evaluation of the direction and orientation of the fracture patterns is essential when determining the optimal surgical approach.

 

C. Surgical approaches

 

1. Ruedi and Allgower described surgical approaches to the distal tibia and fibula: open reduction and internal fixation of the fibula using a lateral approach, and open reduction and internal fixation of the tibia through a medial approach. Over time, this surgical technique has evolved to avoid some of the soft-tissue complications potentially associated with open reduction and internal fixation.

 

2. Some approaches to the distal tibia include skin incisions that do not pass directly over the thin subcutaneous skin of the medial subcutaneous border of the tibia.

 

3. The anterolateral approach may be useful, particularly when fractures are impacted in valgus and when the fibula is intact or is associated with a very proximal injury.

 

a. The anterolateral approach incision is just lateral to the anterior compartment tendons and neurovascular structures and crosses the ankle.

 

b. This incision may be long or short as necessary to facilitate reduction.

 

c. The superficial peroneal nerve may be at risk with this incision and needs to be carefully avoided.

 

d. The skin incision for the anteromedial approach may be placed more anteriorly just adjacent to the anterior tibial tendon to avoid placing this incision directly over the subcutaneous border of the tibia.

 

e. The presence of soft-tissue injury and blisters may preclude the use of an anteromedial approach.

 

f. When performed, the anteromedial approach should be done with great care to avoid unnecessarily risking further soft-tissue compromise.

 

4. The lateral incision to the fibula is placed slightly more posteriorly in the case of a tibial plafond fracture. This facilitates a larger skin bridge between the fibular incision and that used for placement of tibial fixation.

 

a. Placement of the incision posterior to the peroneal tendons may facilitate visualization, reduction, and fixation of the posterior articular surface of the tibia as well.

 

b. This incision courses between the peroneal tendons and the Achilles tendon, care must be taken to protect the sural nerve.

 

5. External fixation is also described for fractures of the ankle and distal tibia.

 

a. The medial subcutaneous border of the tibia is a safe position for wires, and transfibular wires may be safe.

 

b. If spanning temporary external fixation is used, the external fixation pins should be placed remote from the fracture site to avoid interference with definitive internal fixation.

 

D. Mechanism of injury

 

1. Axial compression—Fall from a height

 

a. The force is directed axially through the talus into the tibial plafond, causing impaction of the articular surface; may be associated with significant comminution.

 

b. If the fibula remains intact, the ankle is forced into varus with impaction of the medial plafond.

 

c. Plantar flexion or dorsiflexion of the ankle at the time of injury results in a primarily posterior or anterior plafond injury, respectively.

 

2. Shear—Skiing accident

 

a. This mechanism is primarily torsion combined with a varus or valgus stress.

 

b. It produces two or more large fragments and minimal articular comminution.

 

c. There is usually an associated fibular fracture, which is usually transverse or short oblique.

 

3. Combined compression and shear

 

a. These fracture patterns demonstrate components of both compression and shear.

 

b. The vector of the two forces determines the fracture pattern.

 

E. Clinical evaluation

 

1. Clinical evaluation of fractures of the tibial plafond includes an examination of the neurologic and vascular status of the entire limb.

 

2. It is useful to examine the stability and alignment of the ankle joint, observing the orientation of the ankle, including its length, alignment, and rotation.

 

3. The skin may be placed at risk by bone fragments causing pressure on the skin and soft-tissue envelope, and therefore areas of blanching, abrasion, and contusion should be examined.

 

4. Large blood-filled fracture blisters should be noted, as they frequently preclude immediate open reduction and internal fixation.

 

F. Radiographic evaluation

 

1. Plain radiographs

 

a. Standard radiographs of the ankle include AP lateral, and mortise view radiographs centered on the joint.

 

b. The AP view demonstrates the amount of articular impaction and shortening; the lateral view also demonstrates articular incongruity and is useful for determining the position of the posterior articular segment.

 

c. Full-length views of the entire tibia and fibula rule out more proximal injury and assess the extent of metadiaphyseal involvement.

 

2. Computed tomography

 

a. CT is very useful for tibial plafond fractures.

 

b. CT aids in identifying fracture fragments not seen on plain radiographs, assists in determining the extent of articular comminution, and is critical for planning surgery and guiding surgical approaches.

 

c. CT may assist the surgeon in determining whether a fracture can be reduced percutaneously or whether an open approach is required.

 

d. If temporary external fixation is planned, a CT scan done following application of the external fixator and realignment of the limb provides the best information.

 

G. Classification

 

1. There is no universally accepted classification of tibial plafond fractures.

 

2. Important characteristics to consider include articular and metaphyseal comminution, shortening of the tibia resulting in proximal displacement of the talus, impaction of individual or multiple joint fragments, and associated soft-tissue injury.

 

3. A wide variation in fracture patterns can result, related to the position of the foot and the precise direction and magnitude of the force applied.

 

4. The Ruedi-Allgower classification considers three variations of tibial plafond fractures (

Figure 6).

 

a. Type I fractures—Nondisplaced

 

b. Type II fractures—Displaced but minimally comminuted

 

c. Type III fractures—Highly comminuted and displaced. The comminution and displacement of this classification refers to the articular surface.

 

5. The OTA classification system is more precise (

Figure 7).

 

a. Distal tibial fractures are divided into type A fractures, which are extra-articular; type B, or partial articular fractures; and type C, or total articular fractures.

 

b. Each category is further subdivided into three groups based upon the amount and degree of comminution.

 

c. Other characteristics of the fracture, such as the location and direction of fracture lines or the presence of metaphyseal impaction, are also included in further subdivisions.

 

d. Types B, C1, C2, and C3 are the fractures commonly considered to be tibial plafond fractures.

 

[Figure 6. Ruedi-Allgower classification of tibial plafond fractures.]

6. The soft-tissue injury is also important. The most vulnerable skin for tibial plafond fractures is the anteromedial side of the tibia.

 

a. Grade 0—Closed fractures without appreciable soft-tissue injury.

 

b. Grade 1—Abrasions or contusions of skin and subcutaneous tissue.

 

c. Grade 2—A deep abrasion with some muscle involvement

 

d. Grade 3—Extensive soft-tissue damage and severe muscle injury. Compartment syndrome and arterial rupture are also considered grade 3 injuries.

 

H. Nonsurgical treatment

 

1. Nonsurgical care is less common for tibial plafond fractures than for ankle fractures.

 

2. Indications

 

a. Stable fracture patterns without displacement of the articular surface are treated nonsurgically because nonsurgical treatment of fractures with articular displacement has generally yielded poor results.

 

b. Nonambulatory patients or patients with significant neuropathy may be treated nonsurgically as well.

 

3. Nonsurgical treatment consists of a long leg cast for 6 weeks followed by a fracture brace and range-of-motion exercises versus early range-of-motion exercises.

 

a. Manipulation of displaced fractures is unlikely

 

[Figure 7. OTA classification of distal tibial fractures. Type A fractures are extra-articular, type B are partial articular, and type C are total articular. Types B3, C1, C2, and C3 are the fractures commonly considered tibial plafond fractures.]

   to result in reduction of intra-articular fragments.

 

b. Loss of reduction is common.

 

c. Inability to monitor soft-tissue status and swelling is a major disadvantage.

 

I. Surgical treatment

 

1. Most treatment strategies for tibial plafond fractures currently are related to safe management of the soft tissues.

 

2. Either external or internal fixation is used.

 

3. External fixation—As definitive treatment, uses limited approaches to reduce the articular surface with minimal internal fixation of the joint surface.

 

a. General

 

i. May bridge the ankle or may be localized to the distal tibia

 

ii. External fixation that spans the ankle may involve less disruption of the zone of injury but has the disadvantage of rigidly immobilizing the ankle.

 

iii. External fixation applied to a single side of the ankle joint allows greater motion at the ankle. However, it cannot be used for all fractures, and in this case, the placement of pins and wires will commonly disrupt the zone of injury.

 

iv. An additional alternative includes articulated fixation, which allows some motion at the ankle but may be difficult to apply because the axis of the hinge of the fixator must correspond to the axis of the ankle joint.

 

b. Techniques for application of definitive external fixation

 

i. When using an ankle bridging technique, pins are placed initially in the calcaneus and talar neck while proximal pins are placed in the medial subcutaneous border of the tibia.

 

ii. A fixator is then placed and the articular surface is provisionally reduced with ligamentotaxis.

 

iii. Fracture reduction forceps or clamps can then be placed percutaneously directly over the fracture lines to reduce displaced fragments.

 

iv. Articular fragments are stabilized using lag screws.

 

v. The external fixator is used to maintain length, alignment, and rotation of the extremity and to protect the joint as fracture healing occurs.

 

vi. This technique preserves soft tissues and can be performed on a staged basis if necessary when the zone of injury is felt to be unsafe to tolerate the limited approaches required for reduction.

 

4. Internal fixation

 

a.

General

i. Internal fixation using definitive plate fixation of high-energy tibial plafond fractures continues to evolve.

 

ii. Initial successes using this technique described by Ruedi and Allgower were followed by many reports of failure with the incidence of wound complications approaching 40% in large series of patients sustaining high-energy tibial plafond fractures.

b.

Techniques

i. Various techniques have been recommended for minimizing the complications of plating, including delaying definitive surgical treatment using spanning external fixation until the soft tissues have settled; use of lower profile implants; avoiding anteromedial incisions; indirect reduction techniques that minimize soft-tissue stripping; patient selection based upon the injury pattern as necessary.

 

ii. With consideration of these principles, the rate of wound complications reported in more recent series ranges from 0% to 6%.

 

iii. The use of locked plates and percutaneously applied plates may also be of use to further improve results.

c.

Definitive internal fixation—Performed in stages.

 

i.

Stage 1—Includes fibular plating to regain lateral column length and application of a simple spanning external fixator.

 

 

(a)

Two proximal half-pins placed on the anterior tibia are used.

 

 

(b)

Care should be taken to keep these pins well proximal to the fracture line to avoid compromising definitive fixation.

 

 

(c)

A 5- or 6-mm centrally threaded pin can be placed across the calcaneus and attached to the proximal half-pins using a combination of struts. This technique is simple to apply and maintains stability and alignment. Extra care is necessary to avoid pressure from bony fragments on soft tissues, prevent shortening, and maintain forefoot positioning.

 

ii.

Typically a delay of approximately 2 weeks then ensues, to allow the soft tissues to settle.

 

iii.

Stage 2—Includes formal articular reduction and internal fixation.

 

 

(a)

Once open reduction and internal fixation is performed, incisions are only as large as required to anatomically reduce the articular surface. Periosteal stripping is performed only at the edges of the fracture to achieve visualization of the reduction while preserving blood supply.

 

[

Table 3. Pearls and Pitfalls of Tibial Plafond Fractures]

 

 

(b)

Precontoured plates may be useful; both anteromedial and anterolateral plates facilitate percutaneous placement. Locking plates may be of benefit, particularly when articular surface comminution is present.

 

 

(c)

Bone grafting with bone graft substitutes or chips of allograft to fill metaphyseal voids was once described as a standard step in fixation of a tibial plafond fracture; however, with less extensive dissection in the metaphyseal region, the indications for grafting have become less routine.

 

5. Pearls and pitfalls are described in Table 3.

 

J. Rehabilitation

 

1. Rehabilitation of tibial plafond fractures is prolonged, and patients should be counseled that weight bearing may be contraindicated for 3 months or more.

 

2. In patients treated by external fixation, the healing time has generally been 12 to 16 weeks.

 

3. Tibial plafond fractures have a significant deleterious long-term effect on patients' ankle function and quality of life. Worse outcomes are seen if complications occur.

 

4. Where possible, motion of the ankle joint should be permitted and facilitated.

 

5. The use of a removable boot or brace may be of benefit as the patient transitions from immobilization and non-weight bearing to mobilization and protected weight-bearing status.

 

K. Complications

 

1. Malunion

 

a. Malalignment of the tibia is relatively common.

 

b. Articular malunion is probably even more common than recognized.

 

c. Series using definitive external fixation have reported an increased incidence of fair or poor articular reduction compared with formal open reduction and internal fixation.

 

d. Angular malalignment may also occur. Loss of alignment following treatment occurs in particular if union is delayed and implant failure occurs.

 

2. Nonunion and delayed union

 

a. The rate of delayed union and nonunion for tibial plafond fractures is difficult to determine because surgical implants obscure radiographic visualization of the fracture.

 

b. Some series report nonunion rates of approximately 5%.

 

c. It is likely that more comminuted fractures, and those with greater devascularization of the fracture fragments, are more likely to lead to nonunion, and for this reason soft-tissue dissection should be minimized.

 

3. Infection and wound breakdown

 

a. Infection and wound breakdown is a devastating complication.

 

b. Wound breakdown is almost always severe and frequently leads to unfavorable outcomes.

 

c. The cost of treating this complication is extremely high because multiple surgical procedures are required and amputation may be the result.

 

d. Although the use of modern techniques of soft-tissue preservation whenever possible appears to have substantially decreased the rate of infection and wound breakdown, some risk of infection and wound breakdown remains, and patients should be counseled regarding this risk before undertaking surgical treatment of the tibial plafond fracture.

 

4. Ankle arthritis

 

a. Significant arthrosis of the ankle joint is common after tibial plafond fractures.

 

i. In one study, arthrosis was found in 74% of patients from 5 to 11 years postinjury.

 

ii. Arthrosis most commonly begins within 1 or 2 years postinjury.

 

b. The presence of radiographic arthritis does not always correlate well with subjective clinical results, and despite the devastating impact to the articular surface and problems associated with fracture of the tibial plafond, arthrodesis is not commonly required until many years after the injury.



Top Testing Facts

1. The talar dome is wider anteriorly than posteriorly.

 

2. The superficial deltoid arises from the anterior colliculus and the deep deltoid from the posterior colliculus of the medial malleolus.

 

3. According to the Ottawa ankle rules, ankle radiographs are indicated if the patient has an ankle injury and is older than 55 years, unable to bear weight, or has tenderness at the posterior edge or tip of either malleolus.

 

4. Fractures of the fibula are usually fixed prior to the medial malleolus, lateral malleolus, or syndesmosis in order to obtain length

 

5. Exceptions to the "fibula first" rule include (1) extensively comminuted fibular fractures in which stabilization at the medial side first may facilitate positioning of the talus within the mortise an d(2) supination-adduction injuries.

 

6. An SER type IV injury is associated with an unstable short oblique fracture at the distal fibula and a medial malleolus fracture or deltoid ligament disruption.

 

7. Posterior malleolar fractures involving >25% of the articular surface should be reduced and stabilized.

 

8. Tibial plafond (pilon) fractures result from either axial compression or shear.

 

9. Internal fixation of high-energy tibial plafond fractures usually should be achieved approximately 2 weeks after the injury, preceded by a period of temporary external fixation.

 

10. The superficial peroneal nerve may be injured when using an anterolateral approach to treat a tibial plafond fracture.



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