Ankle fractures in adults

INTRODUCTION — Ankle fractures are increasingly common injuries that necessitate a careful approach for proper management. Over five million ankle injuries occur each year in the United States alone [1].

This topic review will provide an overview of ankle fractures that result from minor trauma (ie, indirect or low energy fractures), including a basic approach to their evaluation and management. Fibular fractures above the lateral malleolus, tibial fractures, and ankle injuries other than fractures are discussed elsewhere. (See "Fibula fractures" and "Overview of tibial fractures in adults" and "Ankle sprain in adults: Evaluation and diagnosis" and "Non-Achilles ankle tendinopathy".)

EPIDEMIOLOGY AND RISK FACTORS — The incidence of ankle fractures is approximately 187 fractures per 100,000 people each year [1]. Since the mid-1900s, this rate has increased significantly in many industrialized countries, most likely due to growth in the number of people involved in athletics and in the size of the elderly population [1-3].

The vast majority of ankle fractures are malleolar fractures: 60 to 70 percent occur as unimalleolar fractures, 15 to 20 percent as bimalleolar fractures, and 7 to 12 percent as trimalleolar fractures [1,4]. There are similar fracture rates overall between women and men, but men have a higher rate as young adults, while women have higher rates in the 50- to 70-year age group [1,4].

Cigarette smoking and a high body mass index have been associated with ankle fractures [5,6]. In contrast to fractures of the radius and other fractures common among perimenopausal and postmenopausal women, bone density has not been clearly demonstrated to be a major risk factor [7].

CLINICAL ANATOMY — The bony anatomy of the ankle consists of the articulation of the distal tibia and fibula with the talus (figure 1 and figure 2 and figure 3). These bones are held together by the ligaments of the ankle to form a mortise. The weight-bearing portion of the mortise consists of the tibial plafond and the talar dome. The mortise gains its stability from the bony relationships of the ankle and from surrounding structures.

The lateral ligament complex consists of the anterior talofibular ligament, the calcaneofibular ligament, and the posterior talofibular ligament (figure 4). The medial ankle complex consists of the deep and superficial fibers of the deltoid ligament (figure 5). The peroneal tendons, anterior and posterior tibialis tendons, Achilles tendon, and joint capsule provide additional support (figure 6).

The syndesmosis of the ankle refers to the articulation of the distal tibia and fibula (figure 7). Support is provided by the anterior tibiofibular ligament, the posterior tibiofibular ligament, the transverse tibiofibular ligament (posteriorly), and the interosseous membrane, which extends from the ankle proximally. These structures prevent the distal tibia and fibula from separating. Abnormal forces that rotate the talus within the mortise push the tibia and fibula apart and may cause an injury to the syndesmotic ligaments or a fracture.

The motion of the ankle is complex. Although the joint moves primarily in the sagittal plane to enable dorsiflexion and plantarflexion of the foot, motion occurs in several planes. Inversion and eversion of the foot occur mainly at the subtalar joint.

The talar dome is narrower posteriorly. It therefore fits more tightly into the mortise, creating greater joint stability, when the ankle is dorsiflexed [3,8]. The position of the talus in the mortise depends more on the medial supporting structures, which are stronger, than the lateral structures. Therefore, the ankle is better able to withstand forces that stress the medial side of the joint [9].

The posterior tibial artery and tibial nerve run together just posterior and lateral to the medial malleolus (figure 8). The anterior tibial artery (dorsalis pedis in the foot) and deep peroneal nerve run together and cross the ankle joint anteriorly, approximately in the midline, just lateral to the extensor hallucis longus and below the extensor retinaculum.

There is no single, widely accepted definition of the anatomic margins of the lateral malleolus. For the purpose of this review, the lateral malleolus refers to the distal part of the fibula that articulates with the talus and distal tibia. Lateral malleolar fractures are those that lie between the distal tip of the fibula and the most proximal portion of the fibula that lies directly adjacent to the tibia in the tibial groove (image 1).

The lateral malleolus provides stability against excessive eversion of the ankle and foot. The medial malleolus is the most distal part of the tibia and articulates with the medial aspect of the talar dome. The posterior aspect of the distal tibia is commonly referred to as the posterior malleolus. It primarily includes the portion of the tibia where the syndesmotic ligament complex attaches.

MECHANISM OF INJURY

Overview — Ankle injuries that result from bending forces are commonly described as inversion or eversion injuries. Technically, inversion and eversion are motions of the subtalar joint and become supination and pronation when combined with ankle and midfoot motion. Internal and external rotation of the ankle refers to the rotation of the talus within the joint.

Supination (inversion) injuries typically cause distraction of the lateral ankle structures and compression of the medial structures. Pronation (eversion) injuries cause medial distraction and lateral compression. Structures being distracted (or stretched) generally fracture or tear before structures being compressed. As an example, injuries that occur while the ankle is supinated will result in damage to the distal fibula and its associated ligaments, which are being stretched, before any damage occurs to the distal tibia and its deltoid ligament complex.

In addition to bending forces, rotational forces often contribute to ankle injuries by placing further stress on supporting structures and forcing the malleoli apart.

Historically, orthopedists have classified the mechanism of injury using two descriptors. The first describes the position of the ankle at the time of injury; the second refers to the force applied to the ankle that causes the injury. As an example, a "supination/external rotation" injury refers to the ankle in a supinated position with an external rotation force applied to it. These descriptors predict the sequence in which structures are injured and provide the basis for the Lauge-Hansen system of ankle fracture classification used to guide orthopedic decision making. The amount of force sustained during the injury is a third factor, in addition to ankle position and force direction, which determines the type and extent of injury.

Several studies question the accuracy of the Lauge-Hansen scheme [10,11]. A complete discussion of classification systems is beyond the scope of this review and can be found elsewhere [3,9,12].

One classification scheme deserves further mention because of its simplicity and clinical relevance. In this approach, the ankle is conceived as a ring of supporting structures surrounding the talus (figure 9) [8]. Supporting structures may be ligaments or bones. If the ring is broken at one site, the injury is stable and can be managed nonoperatively; if the ring is broken at two or more sites, the injury is unstable and is managed operatively.

Malleolar fractures — Isolated malleolar fractures tend to be stable if they are nondisplaced (ie, no significant contralateral injury of ligaments or bone and no syndesmotic injury). However, care must be taken with fractures of the medial malleolus. Disruption of lateral or posterior structures often occurs in association with these fractures, though they may initially appear to be isolated injuries.

Posterior malleolar fractures occur either from the impact of the talus on the posterior aspect of the tibia (often as part of a pilon fracture (image 2)) or from an external rotation or pronation (eversion) force. They occur in association with disruption of the posterior tibiofibular ligament. Posterior malleolar fractures rarely occur in isolation [13]. They are more commonly associated with fibular fractures and additional ligament damage, and they are generally unstable injuries.

Fractures of both the lateral and medial malleoli are called bimalleolar fractures and are generally unstable. A bimalleolar fracture with a fracture of the posterior malleolus is referred to as a trimalleolar fracture. Trimalleolar fractures are unstable and typically occur with injuries of greater force. They have a higher risk of complication than bimalleolar fractures and require surgical stabilization.

CLINICAL PRESENTATION AND EXAMINATION — Emergency conditions, such as an open fracture, neurovascular compromise, or fracture dislocation, must be treated immediately. (See 'Initial treatment' below.)

In addition to the mechanism of injury, the clinician’s history should ascertain the following:

●Site of the most significant pain

●Other injured areas (eg, lumbar spine, hip, knee)

●Length of time from injury to presentation

●Neurovascular symptoms

●Ability to bear weight

●History of any previous injury or surgery

●Related comorbidities (eg, diabetes)

An ankle fracture, particularly one sustained in a fall, may mask other injuries such as a lumbar compression fracture.

Clinicians should inspect the injured ankle for:

●Swelling

●Deformity

●Skin abnormalities, such as lacerations (possible open fracture), tenting, or blistering (caused by rapid stretching of the skin)

The amount of swelling is not a reliable guide to the presence of a fracture.

Clinicians should palpate the ankle looking for the point of maximal tenderness and other tender areas. The examiner should palpate the tibia and fibula, especially the fibular neck, to evaluate for possible associated fractures. Testing for ligamentous laxity can be deferred until after radiographs are obtained; it is often not tolerated in the setting of an acute fracture.

Pulses of the dorsalis pedis and posterior tibialis arteries and distal capillary refill should be checked. Sensation and motor function should be assessed. A detailed discussion of the physical examination of the ankle is found elsewhere. (See "Ankle sprain in adults: Evaluation and diagnosis".)

Once emergency conditions have been ruled out, the first priority in the evaluation of ankle fractures is to determine whether the fracture is stable, and can be managed nonoperatively, or unstable, and must be referred. Typically, an ankle fracture is stable if it meets the following criteria:

●It is isolated to the lateral, medial, or posterior malleolus

●It is nondisplaced and at or below the level of the mortise

●It is not associated with a ligamentous injury

An ankle fracture is unstable if two or more sites of significant injury are present, such as a lateral malleolar fracture with deltoid ligament disruption or a bimalleolar fracture. (See 'Indications for orthopedic consultation or referral' below.)

DIAGNOSTIC IMAGING — The Ottawa ankle rules have been shown to help the examiner in determining if radiographs of the ankle or foot are needed in the evaluation of an acute ankle injury (figure 10).

Patients who do not meet the Ottawa criteria are unlikely to have a fracture, and radiographs are typically not needed in the acute setting [14]. A full discussion of the Ottawa rules is found elsewhere. (See "Ankle sprain in adults: Evaluation and diagnosis", section on 'Ottawa ankle rules'.)

Ankle fractures are typically evaluated using plain radiographs. Anterior-posterior (AP), oblique, and lateral views are standard. The oblique radiograph, also called the mortise view, should be obtained as an AP projection with a 10 to 20 degree lateral angle to help visualize injuries of the syndesmosis and talus (image 3). On the mortise view, the relationship of the medial and lateral malleoli can be measured with respect to the talus. Normally, the distances between the talus and the lateral malleolus, the talus and the medial malleolus, and the talus and the tibial plafond are uniform throughout the mortise.

Isolated lateral and medial malleolar fractures are best seen on the AP view (image 4 and image 5). Posterior malleolar fractures are best seen on the lateral view (image 6 and image 7). On the mortise view, discrepancies in the relationship between the talus and the medial and lateral malleoli can help identify an unstable fracture or soft tissue injury (image 8 and image 9).

The presence of medial injury determines the stability of lateral malleolar fractures. Stress radiographs are needed to determine the stability of the joint in cases of a lateral malleolar fracture with deltoid ligament tenderness but no widening of the joint on initial radiographs. Deltoid ligament injury is assumed if a distance greater than 4 mm is measured between the talus and the medial malleolus on either a standard mortise or stress radiograph (image 9) [12,15]. Adequate external rotation of the foot is necessary for obtaining accurate stress radiographs. Clinicians should avoid inflicting undue pain when obtaining such studies by providing adequate analgesia and limiting the force applied when this causes excessive discomfort. If adequate stress radiographs cannot be obtained, the patient should be referred for specialty consultation.

The gravity stress mortise radiograph has been shown to be as sensitive and specific as a manual stress mortise radiograph (picture 1) [15,16]. A decision about surgical intervention should not be based on stress radiographs alone. The integrity of the deltoid ligament can be further assessed with magnetic resonance imaging (MRI) or ultrasound [17] if necessary.

Isolated medial malleolar and isolated posterior malleolar fractures are considered stable if no associated injury or tibiotalar joint displacement is present, fracture displacement is equal to 2 mm or less, and joint surface involvement is less than 25 percent [9,12,13]. In the case of isolated posterior malleolar fractures, no displacement on a lateral radiograph is acceptable. If it is unclear whether displacement is present on plain radiograph, a CT scan should be obtained [18].

If a fracture of the talus is suspected, or if significant comminution is present, a CT scan will further delineate the extent of the injury and identify fracture displacement. If plain films are negative and clinical suspicion is high for specific soft tissue or cartilage injuries, MRI is more useful (image 10 and figure 3). Both MRI and triple-phase bone scintigraphy (bone scan) (image 11) are helpful in diagnosing a stress fracture in the ankle region, especially if plain radiographs are normal. (See "Overview of stress fractures".)

INDICATIONS FOR ORTHOPEDIC CONSULTATION OR REFERRAL — Open fractures and any injury with associated neurologic or vascular deficits require immediate surgical referral.

The two major indications for operative fixation of an ankle fracture are loss of joint congruency or loss of joint stability [3,9,12]. Loss of joint congruency, such as occurs with severe posterior malleolar fractures and pilon fractures, occurs in the setting of more severe trauma (pilon fractures occur when relatively strong axial forces drive the tibial plafond into the talar dome (image 2)). Fractures that create joint instability as a result of minor trauma are more common.

Typically, an ankle fracture is unstable if two sites of significant injury are present. All trimalleolar, bimalleolar, and isolated malleolar fractures with an opposing ligament rupture (eg, a lateral malleolar fracture with deltoid ligament disruption) are unstable and require orthopedic referral. If there is any uncertainty about the stability of the ankle, the patient should be referred. Unstable fractures are generally managed surgically although, in some instances at centers with appropriate expertise, may be treated with molded casting [19].

Injuries that lead to a distal fibular fracture above the tibiotalar joint line are almost always associated with a syndesmotic disruption and should be referred to an orthopedist (image 12 and image 13 and image 14). Posterior malleolar fractures that result in loss of joint congruency should also be referred.

Unstable fractures often require open reduction with internal fixation. Whether operative or nonoperative management is used, the goal of treatment is anatomic alignment to maximize function and minimize the risk of post-traumatic osteoarthritis.

TREATMENT

Initial treatment — Emergency conditions, such as an open fracture or neurovascular impairment, require immediate surgical consultation and treatment. Fracture dislocations must be reduced immediately to prevent severe complications, such as avascular necrosis.

Once emergency conditions are excluded, clinicians should evaluate the fracture more closely, focusing on any malalignment or instability, to determine proper management and follow-up (see 'Indications for orthopedic consultation or referral' above). The ankle should be splinted at 90 degrees (ie, neutral position) to provide support and control pain. Usually, a short-leg posterior splint is sufficient. A sugar-tong (ie, coaptation) splint can be added for additional mediolateral support. If significant swelling or deformity is present, adequate padding should be placed prior to application of the splint to allow for further swelling, while maintaining stability.

Clinicians should instruct the patient to call immediately for:

●Pain that is severe or increasing

●Numbness that is new or worsening

●Skin discoloration (eg, dusky toes) distal to the splint

These complaints may represent vascular compromise or some other serious complication and should be investigated immediately. Any patient complaint of skin irritation, a splint which has become excessively tight or loose, or a splint which has gotten wet should also be assessed. An examination and repeat radiographs to check for acceptable alignment are generally performed during the first follow-up visit at 7 to 10 days.

For stable, nondisplaced, isolated malleolar fractures, the patient should rest, elevate the involved ankle above the level of the heart, and apply ice, while keeping the splint dry. The importance of elevating the leg should be emphasized to patients, as complications with splint treatment often stem from allowing the foot to remain in a dependent position for too long.

Patients awaiting orthopedic consultation or surgery should remain nonweightbearing in a splint (as described above), apply ice while keeping the splint dry, and use pain medication as needed. If surgery is planned in the acute setting, excessive use of narcotic analgesics should be avoided, if possible, until the orthopedic surgeon is able to explain the procedure and obtain informed consent. Management of specific fracture types is discussed immediately below.

Management of specific malleolar fractures — There is little high quality evidence to determine the best treatment of ankle fractures [20]. Our recommendations below are based upon limited randomized trials, observational data, and clinical experience.  

Lateral malleolar fractures — Fracture stability determines treatment. The location of an isolated lateral malleolar fracture in relationship to the joint can help to determine if the fracture is stable. Lateral malleolar fractures below the level of the tibiotalar joint line (ie, mortise) (image 15) are typically stable and less likely to be associated with additional ligament injuries. When an ankle injury causes a fracture above the level of the mortise (image 12 and image 13 and image 14), it is typically unstable due to the associated syndesmosis injury and must be referred for surgical evaluation. (See 'Indications for orthopedic consultation or referral' above.)

The stability of fractures at the level of the mortise (image 4 and image 9 and image 16) depends upon the integrity of the medial structures (mainly the deep deltoid ligament and the medial malleolus) [14]. The presence of a lateral malleolar fracture together with a medial fracture or deltoid ligament injury significantly increases the risk of joint instability, even if alignment is well maintained (image 8) [12].

Instability is demonstrated by 2 mm or more of displacement of the fibular fracture, an associated medial fracture, or a medial ligament disruption, all of which should prompt orthopedic referral (image 9). Medial swelling, ecchymosis, and tenderness, suggests the possibility of medial ligament injury and requires orthopedic consultation. Uncertainty about the stability of medial structures indicates the need for stress radiographs, such as the gravity stress mortise view (picture 1), to determine the degree of instability [15]. If medial instability is demonstrated or suspected, orthopedic referral is obtained. If the medial structures are intact and there is minimal fibular displacement, non-surgical treatment has a high success rate [21,22]. Stress radiographs are described above. (See 'Diagnostic imaging' above.)

Two long-term follow-up studies of patients with isolated lateral malleolar fractures at or below the level of the ankle joint reported that greater than 90 percent of patients had good clinical results regardless of treatment, provided fibular displacement did not exceed 3 mm [21,22]. Other studies comparing operative with nonoperative treatment of isolated lateral malleolar fractures have shown no significant difference in outcomes [5-7,9,23]. Based upon such studies, treatment for isolated lateral malleolar fractures is primarily nonoperative.

If the fracture consists solely of a small, nondisplaced transverse avulsion fragment, the patient may be treated like a patient with a severe ankle sprain, ie, with early motion, bracing, and gradual rehabilitation (image 15). (See "Ankle sprain in adults: Evaluation and diagnosis".)

If the isolated fracture is oblique through the lateral malleolus at or below the mortise, and there is no sign of instability, the patient may be treated in a short-leg walking cast or removable cast boot, in neutral position, for three to six weeks, weight-bearing as tolerated (image 16). Treatment in a removable cast boot causes less discomfort and loss of mobility, and no change in long-term outcomes, according to a small number of clinical trials [24,25]. The results of another randomized trial suggest that immobilization for three weeks in a short-leg walking cast or properly fitting rigid ankle orthosis further reduces the short-term loss of ankle mobility and the risk for deep vein thrombosis compared with treatment in a short-leg walking cast for six weeks, without compromising healing [26]. While further study is needed to confirm the effectiveness of limiting immobilization to three weeks, evidence in support of shorter periods of immobilization is growing.

Radiographs should be repeated 7 to 10 days after the injury for oblique fractures to ensure that alignment remains acceptable and again at four to six weeks to assess healing [12]. An examination of the ankle, including palpation for medial tenderness, should also be performed at these time intervals. In most cases, healing can be assessed clinically. Once healing is evident (ie, nontender over the fracture site with radiographic evidence of adequate callus around the fracture), the patient may begin unsupported weight-bearing and gradual rehabilitation. If healing is insufficient, the ankle should be immobilized or braced for an additional two weeks and then reassessed. Persistent pain and a lack of callus formation should prompt orthopedic referral.

Treatment of fractures of the proximal fibula and fibular shaft are discussed elsewhere. (See "Fibula fractures".)

Isolated medial or posterior malleolar fractures — Care must be taken with these fractures to confirm the absence of associated injuries. Fractures with associated injuries, such as a proximal fibular fracture, are referred. If there is concern for ligament injury in addition to the fracture, the patient should also be referred for orthopedic consultation. If the fractures are truly nondisplaced, isolated injuries, they can be treated initially in a splint (image 5). Patients should not bear weight until their initial follow-up visit.

Seven to ten days following the injury, patients are re-evaluated, including repeat radiographs to confirm alignment. If the isolated nature of the injury is confirmed by examination and radiograph, the patient can be placed in a walking cast or walking boot. The cast or boot should hold the ankle at 90 degrees to prevent a flexion contracture.

Patients remain in the cast or boot, weight-bearing as tolerated, for four to six weeks. Radiographs are repeated four weeks after the injury and subsequently every two weeks until the fracture is clinically healed (ie, nontender over the fracture site with radiographic evidence of adequate callus around the fracture). Once clinically healed, patients should begin a gentle rehabilitation program.

Lateral malleolar fractures with deltoid ligament injury — A lateral malleolar fracture with disruption of the deltoid ligament is unstable and is managed no differently than a bimalleolar fracture (image 9). The instability associated with these injuries has been confirmed in outcome studies and cadaveric research models [12]. Anatomic reduction of the ankle with surgical stabilization leads to better clinical results [12]. Patients with this injury should be splinted with the ankle joint at 90 degrees, remain nonweightbearing, and be referred to an orthopedist within a few days.

Bimalleolar and trimalleolar fractures — These fractures are unstable and require operative fixation. Patients should be splinted with the ankle joint at 90 degrees, remain nonweightbearing, and be referred to an orthopedist within a few days (image 8 and image 17).

REHABILITATION AFTER ANKLE FRACTURE — The goal of rehabilitation after an ankle fracture is to restore any loss of motion, strength, or proprioception that may have occurred as a result of the injury or the subsequent immobilization and disuse related to treatment. There is little evidence that any specific rehabilitation program improves clinical outcome [9]. It is possible that individuals may return to their preinjury level of activity more quickly with aggressive rehabilitation. Research about early weight-bearing and physical therapy is on-going. For most ankle fractures, rehabilitation can be carried out with a basic home exercise program of stretching, range of motion, strengthening, and balance exercises [27].

A systematic review of 38 controlled trials related to the rehabilitation of ankle fractures found the evidence to be of limited quality and noted the following [28]:

●Early performance of ankle exercises following surgical fixation improved ankle function and mobility, while decreasing pain, but was associated with higher rates of adverse events (eg, surgical wound complications), although most problems were minor. Use of a removable immobilization device was necessary for this approach. For protocols involving early exercise, the authors emphasized the importance of the patient’s ability to comply with the regimen safely and precisely.

●Early ambulation following surgical repair may improve ankle motion, but studies supporting this approach are small and contradictory.

●Neither stretching nor manual therapy (passive motion exercises performed by a trained professional) appeared to improve function following the immobilization period regardless of whether management was surgical or conservative.

●Treatment with electrical or thermal stimulation devices or with ultrasound was not supported by high quality evidence.

COMPLICATIONS — Ankle fractures have a relatively low complication rate when managed appropriately in patients without comorbidities. Complication rates in patients with significant comorbidities (eg, diabetes or peripheral vascular disease) or behaviors known to impair fracture healing (eg, smoking) are higher [29,30]. (See 'Indications for orthopedic consultation or referral' above and 'Treatment' above and "General principles of fracture management: Early and late complications".)

Acute complications of ankle fractures, such as injuries to peripheral nerves or vascular structures, open fractures, and compartment syndrome, are readily identified in most cases and require immediate surgical consultation. Nerve injury can occur at the time of injury from lacerations caused by fracture fragments, direct contusion, or traction, but may also occur during subsequent treatment from casting or splinting materials that compress the nerve. Injuries to the lateral ankle or pressure on the proximal fibula from a cast or splint may lead to peroneal nerve injury causing weak foot dorsiflexion; injuries to the medial ankle may lead to tibial nerve injury. (See "Overview of lower extremity peripheral nerve syndromes", section on 'Fibular (peroneal) nerve' and "Overview of lower extremity peripheral nerve syndromes", section on 'Tibial nerve'.)  

Lower extremity compartment syndrome is less likely to occur from ankle fractures than from fractures of the diaphysis of the tibia or fibula. Nevertheless, any patient complaining of increasing pain or new numbness and tingling or other symptoms concerning for compartment syndrome during treatment for an ankle injury should be examined without delay. (See "Acute compartment syndrome of the extremities", section on 'Clinical features'.)

Venous thromboembolism (VTE) is an infrequent complication, particularly of fractures managed nonoperatively, but occurs more often in older adults and patients with a history of VTE [31]. In an observational study of over 86,000 patients with ankle fractures requiring immobilization, VTE occurred in 1.3 percent of patients within 90 days. While low, this rate was approximately sixfold greater than among matched patients with hand wounds and wrist fractures.

Occasionally, skin damage can occur from stretching or abrasions incurred at the time of injury or from subsequent splinting and casting. Blisters and abrasions should be followed closely until they heal because of the risk of cellulitis.

Potential chronic complications of ankle fractures include instability, osteoarthritis, and pain. Failure to recognize a syndesmotic injury that accompanies a fibular fracture above the ankle joint may lead to instability and premature osteoarthritis (image 18). In addition, a missed medial ligament injury in the setting of a lateral malleolar fracture can lead to instability, which can progress to joint pain and degeneration of the articular surface. While less than five percent of patients with unimalleolar fractures develop degenerative changes, detectable several years later by radiograph, as many as 20 percent of patients with bimalleolar fractures develop such radiographic findings [9].

Nonunion or malunion of ankle fractures is uncommon in healthy patients. Nevertheless, orthopedic referral is generally needed if a fracture does not appear to be healing as expected by eight weeks following the injury. Inadequate healing is suggested by persistent or worsening pain or tenderness at the fracture site, or by signs of inadequate healing on plain radiographs. Orthopedic referral is necessary if the fracture displaces during the course of treatment.

If functional deficits (eg, restricted motion) persist despite appropriate management and rehabilitation, reevaluation for associated injuries, such as ligament or tendon disruption, or osteochondral injury, should be performed. Orthopedic consultation or imaging with MRI may be needed in such cases.

Complex regional pain syndrome (CRPS) may develop in the days or weeks following an ankle fracture. Pain from CRPS is more severe than that expected from the inciting injury and is often associated with such findings as abnormal skin color, temperature change, diminished motor function, and edema (picture 2 and picture 3). Early identification and treatment of CRPS is important. (See "Complex regional pain syndrome in adults: Pathogenesis, clinical manifestations, and diagnosis", section on 'Clinical manifestations'.)

Diabetic patients have an increased risk of complications after ankle fracture [12,29]. Skin injury, postoperative infection, and malunion occur more frequently in diabetics. We suggest more frequent clinic visits (every two to three weeks), including careful skin examination and radiographs, for these patients.

According to retrospective reviews, elderly patients generally have more complex fracture patterns when compared to those under age 65 and are more prone to postoperative complications [32,33]. However, overall functional outcomes among patients above and below 65 years are similar when baseline function and the complexity of the fracture are taken into account.  

ADDITIONAL INFORMATION — Several UpToDate topics provide additional information about fractures, including the physiology of fracture healing, how to describe radiographs of fractures to consultants, acute and definitive fracture care (including how to make a cast), and the complications associated with fractures. These topics can be accessed using the links below:

●(See "General principles of fracture management: Bone healing and fracture description".)

●(See "General principles of fracture management: Fracture patterns and description in children".)

●(See "General principles of acute fracture management".)

●(See "General principles of definitive fracture management".)

●(See "General principles of fracture management: Early and late complications".)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Lower extremity (excluding hip) fractures in adults" and "Society guideline links: Acute pain management".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, “The Basics” and “Beyond the Basics.” The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on “patient info” and the keyword(s) of interest.)

●Basics topics (see "Patient education: Ankle fracture (The Basics)" and "Patient education: Fractures (The Basics)" and "Patient education: How to care for your cast (The Basics)" and "Patient education: How to use crutches (The Basics)")

●Beyond the Basics topic (see "Patient education: Cast and splint care (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

●Epidemiology and mechanism – The great majority of ankle fractures are malleolar fractures; 60 to 70 percent are unimalleolar. Supination (inversion) injuries typically cause distraction (stretching) of the lateral ankle structures and compression of the medial structures. Pronation (eversion) injuries cause medial distraction and lateral compression. Structures being distracted generally fracture or tear before structures being compressed. (See 'Epidemiology and risk factors' above and 'Clinical anatomy' above and 'Mechanism of injury' above.)

●Indications for referral – Open fractures and any injury with associated neurologic or vascular deficits require immediate orthopedic referral. Fracture dislocations require rapid reduction and referral. Unstable injuries should be referred within a few days. (See 'Indications for orthopedic consultation or referral' above.)

●Physical examination – Ankle fractures, particularly ones sustained in a fall, may mask other injuries. Especially with cases involving older adults or significant trauma, be sure to palpate the lumbar spine, hip, tibia, fibula (especially the fibular neck), and foot to check for associated injuries. (See 'Clinical presentation and examination' above.)

●Stable versus unstable injury – Once emergency conditions have been ruled out, the first priority is to determine whether the fracture is stable, and can be managed nonoperatively, or unstable, and must be referred. Typically, an ankle fracture is stable if it meets the following criteria:

•It is isolated to the lateral, medial, or posterior malleolus

•It is nondisplaced and at or below the level of the mortise

•It is not associated with a ligamentous injury

An ankle fracture is unstable if two or more sites of significant injury are present, such as a lateral malleolar fracture with deltoid ligament disruption or a bimalleolar fracture. (See 'Clinical presentation and examination' above and 'Indications for orthopedic consultation or referral' above.)

●Diagnostic imaging – The Ottawa ankle rules help to determine whether radiographs of the ankle or foot are needed in the evaluation of an acute ankle injury (figure 10). Anterior-posterior (AP), oblique, and lateral radiographs are the standard views obtained if imaging is necessary. (See 'Diagnostic imaging' above.)

●Initial care – Initial management of ankle fractures consists of splinting, ice, elevation above the level of the heart, and analgesics. The ankle should be splinted at 90 degrees. Usually, a short-leg posterior splint is sufficient. (See 'Initial treatment' above.)

●Management – Unstable ankle fractures often require surgical repair. Management of the major types of ankle fractures is discussed in the text. The goal of rehabilitation is to restore any loss of motion, strength, or proprioception that may have occurred. (See 'Management of specific malleolar fractures' above and 'Rehabilitation after ankle fracture' above.)