Ankle Dislocation Reduction 

The ankle is a unique modified saddle joint that, together with the subtalar joint, provides range of motion in several physical planes while maintaining stability. The ankle's complex function as a pivoting structure positioned to bear almost the entire weight of the body leaves it vulnerable to tremendous forces of injury. Pure dislocation without associated fracture was thought to be rare;^[1] however, several cases of isolated ankle dislocation without fracture have recently been reported.^{[2, 3, 4, 5, 6, 7, 8]}

The combined movement in the dorsiflexion and plantarflexion directions is greater than 100°; bone-on-bone abutment beyond this range protects the anterior and posterior ankle capsular ligaments from injury. The anterior and posterior ankle capsular ligaments are relatively thin compared with the medial and lateral ankle ligaments. See the image below.

For more information about the relevant anatomy, see Ankle Joint Anatomy.

Dislocation of the ankle usually occurs with fractures of the malleoli or of the posterior aspect of the tibia because the ankle’s ligamentous structures are, in most cases, stronger than the osseous architecture. In addition to a strong association with fractures, ankle dislocations are often open because of the thin layer of tissue that lies over the malleoli. Posterior dislocation of the talus is the most common form of ankle dislocation, although medial, anterior, lateral, and superior dislocations have been well described. Individuals at increased risk for ankle dislocation injuries include those with a history of prior ankle fractures, ankle sprains, weakness of the peroneal muscles, malleolar hypoplasia, or ligamentous laxity such as may occur with Ehlers-Danlos syndrome and other connective tissue disorders.

An ankle dislocation represents a high force traumatic injury that often occurs in vehicular collisions or sports that involve jumping. The clinician must, therefore, examine the patient thoroughly for additional injuries. The energy of the traumatic insult usually either forces the ankle into a position of plantar flexion or strikes the ankle while it is already in a resting position of plantar flexion. Once in plantar flexion, all capsular ligaments of the ankle (with the exception of the posterior talofibular ligament) are stretched and, therefore, more susceptible to structural failure. In addition, plantar flexion brings the smaller surface area of the posterior edge of the talus into the mortise of the ankle, which makes translational forces on the talus more likely to dislodge it from the joint.

Injuries that cause subsequent inversion of the ankle lead to posteromedial displacement and tears in the anterior talofibular and calcaneofibular ligaments. Eversion injuries are more likely to produce lateral dislocations and rupture of the talotibial ligament and medial joint capsule. Inversion injuries are more common as a result of axial loads from falls from significant height.

The rupture of the ankle’s capsular structures is often severe, and the risk of infection secondary to open injury is often significant; however, prompt reduction and, when warranted, operative debridement and repair usually lead to excellent functional recovery and long-term prognosis. Immediate recognition and early reduction of the dislocated ankle are essential, as delayed reduction may lead to subsequent loss of range of motion and increased morbidity.

Evaluation of the ankle injury must sufficiently demonstrate that the dislocation is of the ankle joint, since subtalar dislocations may have presentations similar to those of dislocated ankles but are reduced with a different method.^[9] Applying the ankle reduction technique to a subtalar dislocation may lead to further injury and morbidity, and the 2 injuries may be clearly differentiated from each other radiographically. In addition to aiding in initial diagnosis, radiography helps to identify the anatomy of the fractures associated with ankle dislocations and should be attained both before and after reduction. Further means of identifying subtalar dislocations on the physical examination are described in the Pearls section.

• A traumatic ankle dislocation without associated neurovascular compromise and that has been elucidated by radiographic views of the ankle

  • Such dislocations may or may not have an associated fracture and may or may not be open injuries.
• A traumatic ankle dislocation with associated neurovascular compromise

  • These injuries may be evident by an open or closed ankle deformity with obvious malpositioning of the distal foot.
  • In the context of neurovascular compromise, radiographic studies may be delayed until after the reduction. In such cases, the clinical presentation must assure the clinician that this is an ankle, rather than subtalar, dislocation (see Pearls).

• Radiographic evidence of a subtalar, rather than ankle, dislocation^[9]
• Clinical evidence of a subtalar, rather than ankle, dislocation in the absence of radiographic studies (See Pearls for a description of clinical evidence.)^[9]
• Failed attempts at closed reduction despite optimal conditions

• Oxygen supply
• Bag-valve mask
• Oxygen saturation monitor
• Wall suction, suction tubing, and Yankauer suction catheter
• Intravenous catheter (≥ 20 ga)
• Medications as needed for procedural sedation
• Normal saline (0.9% NaCl)
• Rolls of 4-in Webril, 3-4
• Stockinette, 5 in
• Rolls of 6-in plaster, 2-3
• Rolls of 4-in elastic bandage (eg, Ace wrap)

Because of the application of procedural sedation, ankle reduction is usually performed with the patient in the supine position to provide immediate access to the patient's airway for bag-mask ventilation, if needed. The reduction is performed with the ipsilateral knee in a position of flexion, thus relieving tension on the Achilles tendon and making reduction easier. Proper positioning can be accomplished through the following steps:

• Bring the patient toward the foot of the bed until the knee hangs off in a flexed position. The reduction must then be performed with the clinician sitting at the foot of the bed at the patient's feet.
• Have an assistant grasp the ipsilateral leg at the proximal tibia and fibula and bring the knee and hip into a position of flexion. This requires the assistant to hold the leg in this position for the duration of the reduction. The patient may be turned slightly on his or her side so that the ipsilateral leg is not held straight into the air but, rather, is braced against the bed in a position of flexion.

Obtain and document a thorough preprocedure history, including a history of prior injuries and surgeries, the mechanism of trauma, the amount of time that has elapsed since the traumatic event, a description of the presenting symptoms, prior medical allergies and reactions, any subjective loss of strength or sensation, and the patient’s age in reference to skeletal maturity.

Perform and document a thorough physical examination, noting ecchymoses, swelling, pallor, abrasions, lacerations, paresthesias, weakness, notable deformities of the ankle or foot, presence and character of the dorsalis pedis and posterior tibial pulses, the exact position in which the ankle and distal foot are held, and a comparison examination of the contralateral ankle. Emphasis should be placed on assessing the neurovascular status of the distal foot. Carefully explore all areas of skin overlying the ankle joint for dermal compromise that may make the injury an open dislocation.

If the ankle injury is associated with lacerations of the skin in the area of the ankle joint, the injury is likely an open injury; tetanus prophylaxis and antibiotic coverage of skin flora should be given.

Assess the patient for additional injuries, particularly life-threatening injuries that may have resulted from the high-force trauma that caused the ankle dislocation. Follow Advanced Trauma Life Support (ATLS) protocols, when deemed appropriate. Continue management of the ankle dislocation as soon as proper evaluation and resuscitation of the patient have insured hemodynamic stability.

Obtain radiographs of the patient's ankle, choosing the type of radiograph that may be performed and evaluated in the shortest duration of time. Prereduction films are often a valuable source of information; however, if significant neurovascular compromise is present and radiography would delay the time until reduction can be attempted, prereduction films do not have to be obtained. Choices of radiographic techniques include the following:

• Anteroposterior (AP) and lateral views of the ankle are the most common and efficient means of radiographic assessment. These 2 views usually provide an excellent depiction of the direction of the dislocated talus and show the presence of most associated fractures. Additional views add little to the initial evaluation of the dislocated ankle and are usually more appropriate in the postreduction setting.
• A CT scan of the ankle, while superior to flat plate radiographs in revealing small fracture fragments, is usually not the test of choice since it cannot be performed portably and may delay the time to reduction. Such a test should only be considered if neurovascular compromise is not present and the scan can be quickly performed and evaluated.

Explain the procedure, benefits, risks, alternatives, and complications to the patient or the patient’s representative and obtain signed informed consent for both the procedure and sedation. Ask the patient or the patient’s representative if he or she would like others to be present for the procedure.

Prepare for and perform procedural sedation as described in Anesthesia.

Position the patient as described in Positioning.

Posterior talus dislocations are reduced by performing the following steps:

• First, hold the foot in a position of plantar flexion, thus recreating the position of the initial injury.
• Second, apply axial traction to the ankle by having an assistant grasp the distal foot and provide constant force to fatigue the musculature of the extremity.
• Third, grasp the distal tibia with one hand and create posterior traction proximal to the dislocation. At the same time, place the other hand on the posterior heel of the foot, distal to the injury, and create persistent anterior pressure. This maneuver effects reduction after a few moments. See image below.

  Ankle posterior.

Anterior talus dislocations are reduced by performing the following steps:

• First, hold the foot in a position of plantar flexion, thus recreating the position of the initial injury.
• Second, apply axial traction to the ankle by having an assistant grasp the distal foot and provide constant force to fatigue the musculature of the extremity.
• Third, while anterior traction is being applied to the distal tibia, grasp the foot at a point distal to the injury and create both axial traction and a posterior force. This posterior pressure effects reduction after a few moments. See image below.

  Ankle anterior.

Lateral talus dislocations are reduced by performing the following steps:

• First, hold the foot in a position of plantar flexion, thus recreating the position of the initial injury.
• Second, apply axial traction to the ankle by having an assistant grasp the distal foot and provide constant force to fatigue the musculature of the extremity.
• Third, grasp the distal tibia with one hand and create lateral traction proximal to the dislocation. At the same time, place the other hand on the posterior heel of the foot, distal to the injury, and create persistent medial pressure. This maneuver effects reduction after a few moments.

Medial talus dislocations are reduced by performing the following steps:

• First, hold the foot in a position of plantar flexion, thus recreating the position of the initial injury.
• Second, apply axial traction to the ankle by having an assistant grasp the distal foot and provide constant force to fatigue the musculature of the extremity.
• Third, grasp the distal tibia with one hand and create medial traction proximal to the dislocation. At the same time, place the other hand on the posterior heel of the foot, distal to the injury, and create persistent lateral pressure. This maneuver effects reduction after a few moments.

After each reduction attempt, repeat the neurovascular examination to ensure that blood flow has been maintained and no new sensory or motor compromise has occurred.

• If reduction has been achieved but neurovascular compromise is apparent after reduction, emergent operative management is indicated.
• If neurovascular compromise is present but reduction has not been achieved, operative management may be needed to reduce the injury, and limited future attempts should be made. If reduction cannot be accomplished after 2-3 attempts under optimal conditions, operative management should not be delayed further.

Once reduction is achieved and the neurovascular status of the limb is stable, apply a long leg posterior splint with a sugar-tong component, which immobilizes the joint in a position of 90° of flexion. All efforts should be made to avoid applying any material that may become constricting to the ankle, since remarkable swelling may take place in the postreduction period. The distal foot and toes should be left open to allow serial neurovascular checks.

Repeat radiography may now be attained to assess the adequacy of the reduction and document any associated fractures. Flat plate radiography may consist of repeat AP and lateral views at the minimum; a mortise or additional view may be added to further describe the condition of the joint. A CT scan of the ankle may provide additional information as to the presence of smaller fractures and the position of fracture fragments.

Long-term orthopedic follow-up should be arranged in conjunction with the orthopedic specialist who will continue to manage this patient’s case. Many patients require surgical intervention for associated fractures of the ankle, and admission to the hospital may be needed for open fractures. If outpatient management is deemed appropriate, the patient should follow up in the next 2-3 days. Outpatient instructions should include the following:

• The patient should not bear weight on the affected ankle until instructed otherwise upon follow-up with orthopedics. The ankle should remain in the splint at all times, and instructions as to the care of the splint must be given.
• The patient should return for emergent care immediately if pain increases; if the skin color of the distal foot changes; or if any numbness, weakness, or change in temperature is experienced in the injured leg.
• The patient should understand instructions for pain medicine as deemed appropriate. Narcotics, nonsteroidal antiinflammatory drugs (NSAIDS), or both are usually warranted.

Of note, 10-20% of subtalar dislocations are irreducible by closed methods and require operative intervention. Radiographs of the ankle, including anteroposterior (AP), lateral, and mortise views, may quickly and reliably differentiate between ankle and subtalar dislocations.

Isolated subtalar dislocations have been reported.^[11]

Anterior dislocations of the talus are associated with loss of a palpable dorsalis pedis pulse due to impingement from the displaced talus. This represents a vascular emergency, since the true status of the artery cannot be accurately assessed while the ankle remains dislocated.

Use of a Doppler ultrasound may aid in establishing that some blood flow is present; however, without the presence of a palpable pulse, emergent reduction is required to restore blood flow.

If adequate reduction cannot be achieved, or if reduction has not restored the presence of a palpable pedal pulse, emergent operative management is indicated.

Lateral subtalar dislocations are rare but have been reported. These can also occur with bimalleolar fractures.^[12]

An ankle injury with dislocation must be differentiated from a subtalar dislocation, since an attempt to reduce a subtalar dislocation with ankle reduction techniques are likely to be unsuccessful and may lead to further injury of the involved articular structures. Subtalar dislocations are rare (< 2% of large joint dislocations) and are the result of high-force mechanisms of injury directed at the forefoot. The following chart compares presentations of ankle and subtalar dislocations.^[9]

Table. Differentiating Features for Ankle Dislocation and Subtalar Dislocation (Open Table in a new window)

Irreducible dislocation

• Osseous fragments, capsular ligaments, and ruptured tendons, as well as foreign bodies, may all become interposed in the anatomic joint space and make closed reduction impossible.
• Repeat forceful attempts at reduction can cause additional soft tissue injury and iatrogenic fractures and can convert a closed injury into an open injury if the skin around the ankle is ruptured.
• Concurrent fracture of the anterior calcaneal process may make closed reduction of a subtalar dislocation impossible.^[13]

Surgical intervention

Surgical intervention should be considered in the following scenarios:

• Failure to reduce the injury despite 2-3 attempts under optimal conditions
• Increasing tension or tenting of the skin in a closed injury during reduction attempt
• The presence of multiple other intraarticular fractures or subtalar dislocation demonstrated by radiography, in a neurovascularly intact injury
• Amputation of the foot distal to the injury

Conversion of a closed injury to an open injury

• During closed reduction, if the skin over the ankle joint is ruptured (particularly over the malleoli), the injury has been converted into an open injury.
• Tetanus prophylaxis and antibiotic coverage of skin flora should be administered.
• If necessary, the wound should be surgically debrided.

Patient Education and Consent

Consent should be obtained from the patient or family member.^[10] The reason the procedure is being performed (suspected diagnosis); the risks, benefits, and alternatives of the procedure; the risks and benefits of the alternative procedure; and the risks and benefits of not undergoing the procedure. Allow the patient the opportunity to ask any questions and address any concerns they may have. Make sure that they have an understanding about the procedure so they can make an informed decision.

The patient should be counseled about the risks of vascular or neurologic complications, soft tissue injury, or creation of additional fractures. The patient should also be counseled that the reduction may not be successful and that additional procedures and or surgery may be necessary.

Discuss how these risks can be avoided or prevented (eg, proper positioning, ensuring that the patient remains as still as possible during the procedure, adequate analgesia).

Anesthesia

Anesthesia for reduction of an ankle fracture or dislocation is usually performed by methods of procedural sedation, if the reduction is not taking place in the operating room under general anesthesia. Regional ankle blocks should not be attempted because of the difficulty in application in the context of distorted ankle anatomy and the subsequent loss of a reliable neurological examination.

If possible, one clinician should be responsible only for the procedural sedation and should not take part in the reduction attempt but, rather, ensure that sedation and hemodynamics remain optimal. For more information, see Procedural Sedation.