Calcaneus fractures

INTRODUCTION — Calcaneal fractures are relatively uncommon, comprising 1 to 2 percent of all fractures, but important because they can lead to long-term disability. Axial loading of the foot following a fall from a height is the most common mechanism for severe calcaneal fractures. There are two broad categories of calcaneal fractures: extraarticular and intraarticular. Extraarticular fractures are generally more straightforward to assess and manage. Patients with calcaneus fractures often have multiple concurrent injuries, and it is important to consider this possibility when evaluating patients.

The initial assessment of calcaneus fractures, differentiation of intraarticular from extraarticular fractures, and the nonoperative management of appropriate extraarticular fractures are reviewed here. A brief overview of the assessment and management of intraarticular fractures is also included. General fracture management and other foot fractures are discussed separately. (See "General principles of acute fracture management" and "General principles of definitive fracture management" and "General principles of fracture management: Bone healing and fracture description" and "General principles of fracture management: Early and late complications" and "Talus fractures".)

EPIDEMIOLOGY — The calcaneus is the most commonly fractured tarsal bone, representing 60 percent of all tarsal fractures in adults [1]. The peak incidence occurs in younger males [2]. Most calcaneal fractures are occupational, and are caused by axial loading from a fall [2]. The majority are displaced intraarticular fractures (60 to 75 percent) [2]. According to a retrospective review of 752 calcaneal fractures occurring over a 10-year period, the annual incidence of calcaneal fractures is 11.5 per 100,000, with a male to female ratio of 2.4:1 [3]. Seventy-two percent of these fractures resulted from falls.

CLINICAL ANATOMY — The foot has three divisions: the hindfoot (calcaneus and talus), midfoot (navicular, cuboid, and cuneiforms), and forefoot (metatarsals and phalanges) (figure 1A-C). The calcaneus is the largest tarsal bone and supports the axial load from the weight of the body (figure 2 and figure 3 and figure 4).

Superiorly, the calcaneus has three facets (anterior, middle and posterior), which articulate with the talus to form the subtalar joint (figure 5). The posterior facet is the largest of the three facets and the major weightbearing surface of the calcaneus. The middle and posterior facets are separated from one another by a sulcus. The middle facet is reinforced by the sustentaculum tali, a projection of the calcaneus that articulates with the medial portion of the talus. The flexor hallucis longus tendon passes under the sustentaculum.

The anterior surface of the calcaneus articulates with the cuboid. The posterior portion of the calcaneus is known as the tuberosity. The Achilles tendon inserts on its superior aspect, a possible site for avulsion fractures. The inferior portion of the tuberosity has medial and lateral processes, which are common sites of extra-articular fractures. A central peroneal tubercle along the lateral surface of the calcaneus serves as an attachment site for the calcaneofibular and talocalcaneal ligaments.

The tendons of the peroneus brevis and peroneus longus pass behind the lateral malleolus and then along the lateral surface of the calcaneus. These tendons can sometimes dislocate from a retinacular injury sustained concomitantly with a calcaneus fracture. Also, displaced fragments or exostoses that form during fracture healing may impinge upon these tendons. The extensor digitorum brevis originates from the dorsolateral distal calcaneus, and may avulse a fragment from the calcaneus (see 'Avulsion of extensor digitorum brevis origin' below). The bifurcate ligament anchors the anterior process of the calcaneus to the navicular and cuboid bones. With certain twisting injuries, this ligament may avulse the anterior process of the calcaneus. (See 'Anterior process fracture' below.)

Neurovascular bundles run along the medial and lateral surfaces of the calcaneus, making them especially prone to injury from trauma and surgical procedures [4,5]. Injuries to the two nerves in this area, the lateral and medial plantar nerves, typically cause numbness along the respective side of the sole, but may also cause heel pain or toe flexion weakness [6]. The medical calcaneal artery passes behind and then below the sustentaculum tali. The lateral calcaneal artery passes along the lateral aspect of the calcaneus from posterior to anterior.

Several accessory ossicles, including the os trigonum and the os peroneum, may be present in the area of the calcaneus (figure 1C and figure 1A). They are not seen in all patients but are common and can be mistaken for avulsion fractures (image 1).

MECHANISM AND CLINICAL PRESENTATION — Clinical presentation of a calcaneal fracture depends upon its location and the severity of the injury. Most calcaneus fractures result from significant trauma, typically an axial loading of the foot following a fall or jump from a height. Pain is usually quite severe and weightbearing is often impossible. Swelling and tenderness are typically evident, and may be severe. Deformity of the heel may be apparent. (See 'Medial or lateral process fracture' below and 'Body fractures not involving the subtalar joint' below and 'Intraarticular fracture types' below.)

Presentations of anterior process fractures and avulsion fractures of the extensor digitorum brevis may be subtle, with the only findings being moderate pain and tenderness just distal to the insertion of the anterior talofibular ligament. The mechanism of injury is often identical to that of lateral ankle sprains (ankle inversion), for which these fractures are often mistaken. (See 'Anterior process fracture' below and 'Avulsion of extensor digitorum brevis origin' below.)

Stress fractures of the calcaneus often present with heel pain during the first steps after rising from bed, mimicking plantar fasciitis. However, unlike plantar fasciitis, calcaneal stress fractures typically manifest tenderness along the sides of the calcaneus. Isolated fractures of the sustentaculum present with pain and tenderness over the upper middle part of the medial calcaneus. (See 'Sustentaculum tali fracture' below and 'Stress fractures' below.)

The typical presentation for each major type of calcaneus fracture is described in further detail below.

EXAMINATION — Calcaneus fractures are frequently caused by major trauma and associated with significant injury. Thus, the physical examination should include vital signs and a careful evaluation looking for signs of internal injury, particularly for patients involved in high energy trauma (eg, fall from height) or at high risk of injury (eg, elderly patient). Following major trauma, an obvious hindfoot or ankle injury, particularly if there is deformity, may distract the examiner from other more serious problems. If there is any doubt about the nature or extent of injury, it is best that the patient be evaluated in the emergency department. (See "Initial management of trauma in adults".)

Examination of the patient with a foot or ankle injury follows the standard approach, including inspection, palpation, and range of motion testing, if this is tolerated. Neurovascular assessment is required. Look carefully at the skin for abrasions, lacerations, blistering from rapid stretching of the skin, and tenting. Any break in the skin increases the risk of infection and may complicate the application of a splint or cast. Open fractures and fracture-dislocations are considered orthopedic emergencies since delays in treatment lead to worse outcomes, including avascular necrosis. Blister formation may suggest more forceful trauma. Swelling may be severe, making landmarks difficult to identify.

Typically, patients with a calcaneus fracture from high energy trauma manifest tenderness around the heel and hindfoot. Areas to palpate include the tuberosity, body, and anterior portions of the calcaneus (picture 1 and picture 2 and figure 2). Tenderness over the calcaneocuboid joint is associated with an anterior process fracture (tenderness directly over the lateral ankle ligaments suggests an ankle sprain).

Nerve integrity can be assessed by confirming sensation in each independently innervated area of the foot (figure 6), and by testing flexion and extension of the great toe, small toes, and ankle. The neurologic examination is described in detail separately. (See "The detailed neurologic examination in adults".)

Assessment of the dorsalis pedis and posterior tibialis pulses and distal capillary refill is required. If the pulses are not palpable due to swelling, a handheld Doppler device can be used to determine if they are present. Immediate surgical consultation is required for any vascular deficit [7].

DIAGNOSTIC IMAGING — Calcaneal fractures are diagnosed on the basis of imaging studies. Radiographic evaluation of a suspected calcaneus fracture begins with plain radiographs, including lateral and axial views (image 2 and image 3 and figure 7). Additional views and computed tomography (CT) are obtained when clinicians require greater detail about the extent of the fracture or when there is concern for an occult fracture despite nondefinitive initial radiographs. In addition, half of patients with a calcaneus fracture sustained during a fall or other high-energy trauma have concomitant injuries, including fracture of the contralateral calcaneus and compression fractures of the thoracolumbar spine (image 4 and image 5A), and areas of concern based upon the clinical evaluation should be imaged [2,8]. (See "Initial management of trauma in adults".)

Lateral and axial plain radiographs of the calcaneus are usually sufficient to detect the presence of a displaced fracture or dislocation, but high quality data describing their sensitivity and specificity are lacking. Overlying shadows on the axial view can make interpretation difficult, but an understanding of the anatomy simplifies this task. An anteroposterior (AP) plain radiograph of the foot is sometimes included in a calcaneus series. Although the AP view may demonstrate certain fractures, such as avulsions of the extensor digitorum brevis origin, it is seldom helpful and can usually be omitted from the initial series [2].

If a fracture is present or strongly suspected on the basis of plain radiographs, the next step is to use the lateral radiograph to assess two important angles: Bohler’s angle and the angle of Gissane. To measure Bohler’s angle, draw a line from the highest (ie, most cephalic) point of the posterior calcaneus (tuberosity) to the highest midpoint of the calcaneus (ie, highest point of the posterior articular facet). Then, draw a second line from this highest midpoint to the highest point of the anterior process of the calcaneus. The angle between these lines is Bohler’s angle, which normally measures between 20 and 40 degrees (image 6A-B) [2,9,10]. An angle of less than 20 degrees indicates a depressed fracture. The angle of Gissane is formed by the two strong cortical struts of the calcaneus that lie beneath the lateral process of the talus; the lines used to measure the angle run approximately along the superior aspect of the posterior facet and the superior aspect of the anterior process (image 7). This angle should measure between 100 and 130 degrees [8]. If there is doubt about whether an angle is normal, a radiograph of the patient’s contralateral calcaneus can be obtained for comparison. Note that it is possible, although uncommon, for these angles to fall within the normal range despite the presence of a calcaneal fracture.

Imaging in addition to lateral and axial views is sometimes required to diagnose a calcaneal fracture. In most such cases, CT is preferred, but additional plain views may be beneficial in certain circumstances. An oblique view may help if an avulsion fracture is suspected (image 1). Broden’s views enable assessment of the posterior facet and may demonstrate a fracture, particularly an intraarticular fracture, that is poorly seen on other views (image 8 and image 9) [2].

CT may be required to fully characterize certain fractures, particularly intraarticular fractures (image 5A-D). CT is also used to determine whether a fracture extends into the subtalar joint. Hence, CT is recommended for most fractures through the body of the calcaneus, since these may have intraarticular extension that is not apparent on plain radiographs. When more detailed imaging is needed but CT is not available, other views (eg, obliques, Broden’s) and an ankle series can be obtained, but these are vastly inferior to CT for the evaluation of intraarticular fractures [2].

MRI has a limited but potentially important role in select cases. If an occult nondisplaced calcaneus fracture is suspected (eg, persistent symptoms plus suggestive but non-definitive findings on CT), MRI may be used to confirm or rule out a fracture (image 10). MRI is also sensitive for detecting early stress fractures of the calcaneus. (See 'Stress fractures' below and "Overview of stress fractures", section on 'Imaging studies'.)

DIAGNOSIS — The patient with a calcaneal fracture typically presents with pain, swelling, and possibly deformity around the heel, ankle, and hindfoot following trauma usually involving landing on the foot after a fall from a height. Less commonly, calcaneal fractures are caused by ankle inversion and manifest only mild to moderate pain and swelling. In either case, the diagnosis of calcaneal fracture is made with radiographic studies. CT may be needed to fully characterize the fracture or to make a definitive diagnosis in some cases, and should be obtained if clinical suspicion for a fracture remains high in the face of negative plain radiographs.

INDICATIONS FOR SURGICAL REFERRAL — Emergent (ie, immediate) surgical referral is required for open fractures, fractures associated with neurovascular injury, fractures associated with dislocation (which must be reduced immediately), and suspicion or diagnosis of acute compartment syndrome.

Virtually all intraarticular calcaneus fractures should be assessed and managed by a surgeon, and urgent referral is indicated. In addition, calcaneal fractures that are comminuted or involve noticeable displacement warrant urgent referral. As a general rule, it is best to contact the surgeon at the time of diagnosis and arrange timely evaluation. The surgeon consulted to manage the fracture may be an orthopedist or a podiatrist depending upon the local practice environment. The indications for surgical referral for specific types of calcaneal fractures are discussed below. (See 'Extraarticular fracture types' below.)

CLASSIFICATION AND PROGNOSIS — When classifying calcaneus fractures, the most important step is to distinguish extraarticular from intraarticular injuries. Extraarticular calcaneus fractures have a good prognosis and rarely require surgery; intraarticular fractures have a poor prognosis and are difficult to evaluate and treat.

The following figure illustrates the major types of extraarticular calcaneus fractures (figure 8). Most are avulsion-type fractures, resulting from twisting/deforming forces [8]. These include fractures of the anterior process, sustentaculum tali, dorsal aspect of the tuberosity (Achilles tendon insertion), and the origin of the extensor digitorum brevis tendon. Extraarticular fractures caused by sheering or impact forces include transverse fractures of the tuberosity and fractures of the medial and lateral processes of the tuberosity. CT imaging may be required to exclude intraarticular extension of transverse tuberosity fractures. Radiographic examples of each type of extraarticular fracture are included under the discussion of each fracture below.

Intraarticular calcaneus fractures usually result from high energy trauma such as falling from a height onto the heel. Intraarticular fractures generally have a poor prognosis because they extend into an important weight bearing joint (subtalar) and are often displaced. Surgery is often required to repair these injuries and early referral is indicated. The following images demonstrate an intraarticular fracture on plain radiograph and CT (image 5A-D). Intraarticular fractures can be subclassified, but a wide variety of patterns are possible and their description is beyond the scope of this topic. A discussion of these patterns can be found elsewhere [2].

OVERVIEW OF COMPLICATIONS — Calcaneus fractures are prone to early and late complications. Thus, an important part of the initial patient evaluation is to identify and manage acute complications and associated injuries. Complications are less common with extraarticular fractures, but are particularly common with intraarticular fractures (especially if displaced). Skin tenting leading to skin necrosis is much more common with posterior displacement of fragments. Other dangerous complications such as compartment syndrome and neurovascular injury are much more common with displaced intraarticular fractures. Clinicians should maintain a high index of suspicion for complications with these fracture types, and consider admission for observation if swelling is extreme or pain difficult to manage.

Early complications

●Swelling is often severe. Treatment consists of prompt elevation of the heel above the level of the heart, ice, and application of a compression dressing and splint [11]. Hospital admission for pain control and monitoring for Acute compartment syndrome may be necessary [11].

●Severe pain – The soft tissues around the heel are normally quite tense and swelling into the area causes significant pressure, which can dramatically worsen pain. (See "General principles of acute fracture management", section on 'Pain management'.)

●Acute compartment syndrome (ACS) develops in up to 10 percent of calcaneus fractures [11-13]. ACS is most likely to develop in displaced fractures involving the body of the calcaneus. Displaced, comminuted, intraarticular fractures appear to be at highest risk [14]. Stress fractures and non-displaced extraarticular fractures are unlikely to develop ACS. If not recognized early and treated, ACS can result in severe, permanent disability. Disproportionately severe pain is a hallmark of ACS, but most calcaneus fractures are extremely painful and thus ACS can be difficult to recognize in this setting [2]. Thus, it is important to maintain a high index of suspicion for this complication and measure compartment pressures if it is suspected. Because the foot has multiple soft tissue compartments, multiple measurements are necessary and should be performed by a clinician with experience managing ACS in the foot [13,15]. If compartment pressures are elevated, emergent fasciotomy is needed to prevent ischemic injury. ACS is discussed in detail separately. (See "Acute compartment syndrome of the extremities".)

●Fracture blisters form when fluid from swelling seeps between skin layers, producing blisters with either clear or bloody fluid. Surgical incisions made through blisters have been associated with serious wound infections, and any necessary incisions should be modified to avoid blisters [2].

Other potential early complications include:

●Skin necrosis results from posterior displacement of fracture fragments against the skin at the heel. Skin necrosis can lead to prolonged healing and infection, and can convert a closed to an open fracture. In a retrospective study of 139 calcaneus fractures, skin necrosis occurred in 21 cases with posterior displacement [16]. However, none of the patients who underwent emergent reduction to relieve skin pressure experienced this complication.

●Open fractures have a much worse overall prognosis, including higher rates of deep infection, osteomyelitis, and amputation [2]. (See "Nonvertebral osteomyelitis in adults: Clinical manifestations and diagnosis".)

●Associated injuries – Up to 50 percent of patients have other concurrent injuries [2,8]. Fractures sustained from high energy trauma involving an axial load (eg, fall from height) are most likely to have concurrent injuries. These may include other lower extremity injuries as well as compression fractures of the thoracolumbar spine. (See "Thoracic and lumbar spinal column injury in adults: Evaluation".)

Later complications

●Complex regional pain syndrome (see "Complex regional pain syndrome in adults: Treatment, prognosis, and prevention")

●Osteomyelitis, which occurs primarily after open fractures. (See "Nonvertebral osteomyelitis in adults: Clinical manifestations and diagnosis".)

●Surgery-related ‒ While the complications described here can happen with nonoperative management or surgical repair, certain complications occur primarily or only after surgery. These include cutaneous nerve injury, wound dehiscence (occurs in up to 25 percent of surgeries), and scarring, subluxation, and adhesions affecting the peroneal tendons [2].

●Malunion (common with conservative treatment of intraarticular fractures) – Malunion may result in heel widening, which can make it difficult to wear shoes. It may also lead to impingement against adjacent structures such as the fibula and peroneal tendons or nerves. (See 'Intraarticular fracture types' below.)

●Peroneal tendon injury – This may include tendon dislocation, tendinitis, or stenosis from lateral displacement and impingement of the wall of the calcaneus.

●Nerve entrapment usually occurs after nonoperative treatment due to impingement on the nerve from soft tissue, malunion, or exostosis [2]. The posterior tibial nerve is most commonly involved, leading to pain and paresthesia in the medial heal and the underside of the forefoot and toes. The pain is often worse at night and with activity. (See "Overview of lower extremity peripheral nerve syndromes", section on 'Tibial nerve'.)

●Chronic pain (common) – Many patients with intraarticular fractures experience persistent pain after healing. Lateral heel pain is most common and may be related to degenerative joint disease, impingement against other structures, abnormal biomechanics, or plicae that develop during healing [2,15]. Heel pad pain is next most common and may be caused by exostoses or the disruption of normal heel pad septae. (See "Approach to the management of chronic non-cancer pain in adults".)

●Secondary osteoarthritis (common) – This long-term complication usually involves either the subtalar or calcaneocuboid joint. (See "Clinical manifestations and diagnosis of osteoarthritis".)

DIFFERENTIAL DIAGNOSIS

High energy trauma — Calcaneal fractures are usually the result of high energy trauma (generally a fall from a height) and the patient typically has an obvious ankle or rear-foot injury. Other significant bony and soft tissue (eg, tendon) injuries of the lower leg, ankle, hindfoot, and midfoot can present with symptoms and signs similar to a calcaneal fracture but are readily distinguished with diagnostic imaging in the large majority of cases.

Low energy trauma — Calcaneal fractures caused by low energy trauma, namely anterior process fractures and avulsion fractures of the extensor digitorum brevis, often involve a mechanism (ankle inversion) and present in a manner that make them difficult to distinguish from a lateral ankle sprain. These fractures may manifest only mild to moderate pain and swelling. The key to correct diagnosis lies in identifying the location of tenderness: tenderness associated with the fracture overlies the calcaneocuboid joint; tenderness from an ankle sprain is located more proximally, directly over the lateral ankle ligaments.

The differential diagnosis of calcaneal stress fractures is discussed separately. (See 'Mechanism and clinical presentation' below.)

EXTRAARTICULAR FRACTURE TYPES — The following figure illustrates the major types of extraarticular calcaneus fractures (figure 8). Most are avulsion-type fractures, resulting from twisting/deforming forces [8].

Anterior process fracture — These fractures are often misdiagnosed as an ankle sprain [2,17,18]. Careful attention to examination and radiograph findings allows one to distinguish these fractures from sprains.

Mechanism and clinical presentation — Two mechanisms account for anterior process fractures, each producing a different type of injury [17]:

●Avulsion fractures are produced by adduction and plantar flexion of the foot (similar to the mechanism for lateral ankle sprains) (image 11A-C and image 12). The anterior process fragment is avulsed by the pull of the bifurcate ligament as it is stretched during injury. As seen in the attached examples, these fractures typically extend into the calcaneocuboid joint (the same mechanism may cause small avulsions at the origin of the extensor digitorum brevis tendon on the anterior portion of the calcaneus; these relatively benign injuries are discussed below). (See 'Avulsion of extensor digitorum brevis origin' below.)

●Compression fractures are produced by forceful abduction of the forefoot, which causes compression of the calcaneocuboid joint (image 13).

Patients with anterior process fractures have pain and swelling anterior to the tip of the lateral malleolus. With tenderness in this area and an inversion mechanism, it is not surprising that these fractures are often misdiagnosed as lateral ankle sprains. The key to correct diagnosis lies in recognizing that the tenderness of an anterior process fracture overlies the calcaneocuboid joint, while tenderness from an ankle sprain is located more proximally, directly over the lateral ankle ligaments.

To locate the calcaneocuboid joint, place the tip of your thumb on the lateral malleolus and the tip of your middle finger on the proximal fifth metatarsal (picture 3). The tip of your index finger now points to the location of this joint. Tenderness in this area suggests an anterior process fracture.

Imaging — If the history and examination suggest an anterior process avulsion fracture, oblique views of the foot should be obtained. This fracture is typically best seen on the internal oblique view, but often not well demonstrated on other views (image 11A-C). Avulsions of the anterior process are usually small and non-displaced or minimally displaced.

Compression fractures are best seen on the lateral view (image 13). These fractures are typically larger than avulsion fractures and often displaced. CT may be helpful in evaluating larger compression fractures to determine whether more than 25 percent of the joint surface is involved. MR imaging is also sensitive for detecting subtle or nondisplaced anterior process fractures (image 10).

Indications for orthopedic or podiatric referral — Compression fractures of the anterior process often require more aggressive treatment, even when not displaced, and surgical referral is generally required. Patients with avulsion fractures that are either displaced or involve more than 25 percent of the calcaneocuboid joint typically require surgery and should be referred [2]. If conservative treatment is unsuccessful (ie, persistent pain not steadily improving), referral is indicated.

Management — Initially, a bulky compression dressing should be applied and the patient instructed to rest, elevate the foot above the level of the heart, and apply ice for the first 48 to 72 hours. No weightbearing should be allowed until casting or evaluation by the surgeon. Basic initial fracture care is discussed in greater detail separately. (See "General principles of acute fracture management".)

For patients with an avulsion fracture that is nondisplaced and does not involve more than 25 percent of the calcaneocuboid joint, a short-leg non-weightbearing cast is applied once swelling has subsided, generally three to seven days after the injury. Most non-displaced anterior process fractures heal well with four to six weeks of casting [1,17,18]. After cast removal, the patient begins range of motion exercises and progressive weight bearing, as activity is gradually increased. If the patient does not make steady progress on their own, supervised physical therapy is recommended. Slow progress or a long period without progress should prompt the clinician to obtain surgical referral or repeat radiographs to assess for possible non-union or other complications. (See 'Overview of complications' above.)

Activities that pose a risk of reinjury should be avoided for the first three to four weeks after the cast is removed. Such activities include activities on uneven ground and sports that involve quick changes of direction or substantial lateral movement. Careful attention to rehabilitation can speed return to full activity. In a minority of patients, recovery to pre-injury activity levels may take up to a year [17,18].

Avulsion of extensor digitorum brevis origin — Although this injury receives little attention, it appears to be fairly common. As an example, in one series of 100 consecutive patients with “clinically suspected ankle fractures,” 10 percent demonstrated radiographic evidence of avulsion of the extensor digitorum brevis origin [19].

Mechanism and clinical presentation — These fractures typically result from forced inversion of the foot. Pain, swelling, ecchymosis, and tenderness are present in the same location as described above for an anterior process fracture, although symptoms may be less severe than with anterior process fractures. (See 'Mechanism and clinical presentation' above.)

Imaging — These fractures are often best seen on AP views of the ankle (image 14). The bony avulsion may be seen on internal oblique views of the calcaneus (image 1), but typically cannot be seen on other views.

Indications for orthopedic or podiatric referral — Patients with large fragments (>1 cm), severe displacement (>3 to 4 mm) or persistent symptoms after conservative treatment should be referred.

Management — There is little published about the management of these fractures. Initial management is the same as that for anterior process fractures. According to some experts good results can be achieved with a conservative approach involving symptomatic treatment and physical therapy [19]. Minimally symptomatic patients may be managed with an elastic bandage, early weightbearing, and gradual progression of activities. Weightbearing may have to be delayed for approximately one week in more symptomatic patients. Range of motion exercises or physical therapy should be started as early as tolerated. The course of recovery is similar to that for a severe ankle sprain. Pain with inversion stress of the foot may persist for several months.

Medial or lateral process fracture

Mechanism and clinical presentation — Medial and lateral process fractures typically result from a fall onto the heel with the foot in either an inverted or everted position. The resulting forces sheer off a medial or lateral fragment from the posterior calcaneus. Pain, swelling, ecchymosis, and tenderness are present over the posterolateral or posteromedial heel. Tenderness is often exquisite.

Imaging — These fractures are usually best seen on an axial view of the calcaneus using plain radiographs (image 15). Subtle disruption in the cortex may be seen on the lateral view (image 16). A medial process fracture may best be seen with Broden’s view (image 9). Displacement of isolated medial and lateral process fractures rarely occurs. Comminuted fractures of the calcaneus often involve a medial process fragment [20], which may catch the eye more than other fracture fragments. Therefore, when assessing process fractures it is important to look for an additional fracture line that may extend into the subtalar joint.

Fracture reduction and indications for referral — Displaced fractures should be referred to an appropriate surgeon or a clinician skilled in fracture reduction. Displacement can often be corrected with closed reduction [1]. Uncorrected displacement may result in a heel deformity, which can cause difficulty wearing shoes and other long term complications. Failure of closed reduction to achieve proper alignment or displacement greater than 1.5 cm generally requires open reduction [2]. Persistent tenderness after conservative therapy warrants surgical referral.

Management — Initial management is the same as that for anterior process fractures. Compartment syndrome may occur acutely following medial or lateral process fractures and close monitoring is needed. (See 'Management' above.)

After swelling subsides, two treatment approaches may be used. One approach consists of wearing a fracture boot with no weight bearing permitted until healing is documented radiographically (8 to 10 weeks) [2]. Alternatively, the patient can be placed in a well-molded short-leg walking cast [2]. However, increased displacement and a painful heel lump after healing have been described in small case series [20], suggesting that weight bearing is best avoided until healing is complete if any displacement is present on initial imaging studies. Appropriate molding is especially important if closed reduction was required. The cast is kept in place for 8 to 10 weeks, until there is radiographic evidence of healing [1,2]. Tenderness may last several weeks beyond cast removal. If tenderness persists, partial weight bearing and heel padding can be implemented until symptoms subside.

Residual tenderness and pain with weightbearing may delay the patient’s return to full activity. The use of heal padding or orthotics may speed return to weight bearing activities. We recommend a gradual increase in the level of activity. Activities that pose a risk of reinjury should be avoided for the first three to four weeks after the cast is removed. Such activities include sports that involve quick changes of direction or substantial lateral movement.

Extraarticular tuberosity avulsion fracture

Mechanism and clinical presentation — Isolated tuberosity avulsion fractures are typically caused by the pull of the gastrocnemius and soleus muscles when the patient lands forcefully on their forefoot. These patients are often older with osteopenia or osteoporosis. After a fall onto the heel, avulsion tuberosity fractures can occur in combination with medial process fractures [20].

Patients with a tuberosity avulsion fracture typically manifest pain, swelling, ecchymosis, and tenderness over the posterior heel. Plantar flexion is typically weak, due to pain as well as partial disruption and lengthening of the gastrocnemius/soleus/Achilles tendon complex. Displaced fractures may produce tenting of the skin, which requires prompt intervention.

Imaging — A tuberosity avulsion fracture is usually well seen on a lateral plain radiograph (image 17). Displacement is common and extension into the subtalar joint may occur. CT should be performed if it is unclear from plain radiographs whether the fracture extends into the subtalar joint.

Indications for orthopedic or podiatric referral — If the overlying skin is in jeopardy due to tenting, immediate consultation is indicated. Displacement typically requires operative repair. Displacement <1 cm can be managed non-operatively [2], but consultation is advisable if displacement exceeds 2 to 3 mm. Avulsion fractures that extend into the subtalar joint should also be referred.

Complications — Tuberosity avulsion fractures are susceptible to the potential complications described above. In addition, uncorrected superior displacement of the avulsion fragment can result in a poorly functioning gastrocnemius-soleus unit, and delayed correction of skin tenting can lead to sloughing of the skin, possibly resulting in a prominent, uncomfortable lump developing over the heel. (See 'Overview of complications' above.)

Management of nondisplaced avulsion fracture — Initially, a bulky compression dressing should be applied and the patient instructed to rest, elevate the foot above the level of the heart, and apply ice for the first two to five days. Basic initial fracture care is discussed in greater detail separately. (See "General principles of acute fracture management".)

Displaced fractures may produce tenting of the skin, which requires prompt intervention to prevent skin necrosis. The risk of necrosis is particularly high in this region due to the thinness of the overlying soft tissues [2].

Once swelling has subsided, if the fragment is non-displaced, a short-leg non-weightbearing cast is applied with the foot in 5 to 10 degrees of plantar flexion (to minimize the pull of the Achilles tendon on the fracture fragment) [1]. This cast remains in place for six weeks. Radiographs should be repeated in the cast 7 to 10 days after injury to make sure the fragments remain non-displaced.

Because the ankle is casted in plantar flexion (rather than the neutral position used for most casts), return to normal function after cast removal takes more time and requires more effort than with many fractures. It is not unusual for patients to need three to six months to return to a reasonable activity level. After cast removal, it is important that the patient work to regain calf muscle flexibility and strength and ankle joint motion. Supervised physical therapy may speed recovery of function. Particularly for older patients, this approach may be superior to rehabilitation at home. During rehabilitation, activities that pose a risk of reinjury should be avoided until healing is more complete and ankle function has improved (at least three to four weeks).

Sustentaculum tali fracture

Mechanism and clinical presentation — Sustentaculum tali fractures occur infrequently and are caused by high energy trauma, such as a fall from a height onto an inverted ankle. Isolated fractures of the sustentaculum are rare; patients often sustain associated foot and ankle injuries [21]. Extension into the subtalar joint is common.

Isolated fractures of the sustentaculum present with pain, swelling, and tenderness of the medial heel. Pain increases with maneuvers that increase pressure against the sustentaculum, such as dorsiflexing the big toe (which stretches the flexor hallucis tendon that runs beneath the sustentaculum) or inverting the ankle.

Imaging — The sustentaculum is best seen on the axial view of the calcaneus (image 3). CT may be needed to exclude extension into the subtalar joint (image 18A-C). Associated injuries are common (especially of the foot and ankle of the involved extremity), and thus, it is important to obtain radiographs of any area in which an injury is suspected based upon clinical findings.

Indications for orthopedic or podiatric referral — Except for isolated, nondisplaced fractures (rare), sustentaculum fractures generally require surgical referral.

Management — Initially, a bulky compression dressing should be applied and the patient instructed to rest, elevate the foot above the level of the heart, and apply ice for the first two to five days. Basic initial fracture care is discussed in greater detail separately. (See "General principles of acute fracture management".)

An isolated nondisplaced fracture can be treated with a non-weight bearing short leg cast for six to eight weeks until there is radiographic evidence of healing [1]. Unless the patient has a sedentary job, the need to remain non-weight bearing precludes returning to work for six or more weeks. Following cast removal, patients should participate in a physical therapy program to regain motion and strength. Activities that pose a risk of reinjury should be avoided until healing is nearly complete and ankle function approaches preinjury levels (typically at least three to four weeks).

Body fractures not involving the subtalar joint

Mechanism and clinical presentation — Approximately 20 percent of calcaneus fractures involve the body without extending into the subtalar joint [2]. These are usually caused by falling onto the heel from a height. Patients typically present with severe pain and swelling that is more dramatic than with other extraarticular calcaneus fractures. Weightbearing is usually impossible. Swelling is often severe enough to produce fracture blisters.

Imaging — Extraarticular fractures of the body of the calcaneus often occur just posterior to the subtalar joint, but may occur anterior to the posterior facet of this joint. Even though fracture lines are often well seen on both axial and lateral plain radiographs, it can be difficult to exclude intraarticular extension using plain radiographs alone (image 19). Therefore, CT is generally required to characterize these fractures. The value of CT in evaluating extraarticular body fractures is demonstrated in the following examples (image 20). In this example, only one injury is apparent on the plain radiograph (image 21A-B). Displacement of fragments is common and can be missed if one does not measure Bohler’s angle (image 22). Detecting this is important, as displacement is an indication for surgical repair, even if all fracture lines are extraarticular.

Indications for orthopedic or podiatric referral — Extraarticular body fractures involving uncorrected displacement of more than 1 cm can lead to a number of problems and these injuries warrant surgical referral.

Management — Fractures of the calcaneal body that are non-displaced and do not extend into the subtalar joint usually heal well with conservative management [2]. Initial treatment consists of a bulky dressing, strict elevation of the foot above the level of the heart, and application of ice. This helps to reduce pain and minimizes swelling, which reduces the risk of fracture blisters. Elevation and icing should continue for three to four days [22]. Basic initial fracture care is discussed in greater detail separately. (See "General principles of acute fracture management".)

If fracture blisters develop, they should be monitored for subsequent ulceration or infection. An initial follow-up visit three to five days after the injury is recommended, at which time the skin can be reassessed.

Displaced fractures can lead to a number of problems, including shortening of the Achilles tendon, impingement of the peroneal tendons, and widening of the heel that makes normal shoes uncomfortable, and surgical correction is often performed. If widening of the heel is the only deformity, treatment with closed reduction may be adequate.

Casting is not recommended for non-displaced body fractures that spare the subtalar joint. Instead, early range of motion is preferred [2,22]. Some authors recommend that the patient not bear weight for 10 to 12 weeks until healing occurs [2]. Others recommend initial non-weightbearing, which progresses to toe-touch walking when tolerated, and then partial weightbearing for 6 to 12 weeks [22]. By delaying weightbearing until healing is demonstrated on radiographs, the risk of fracture displacement is reduced.

Follow-up radiographs are recommended 10 to 12 weeks after injury to confirm healing. They are also recommended if symptoms persist longer than 16 to 20 weeks or if non-union or malunion are suspected (persistent pain, swelling, and/or development of deformity).

Patients with non-displaced calcaneal body fractures generally return to their preinjury activity level faster than those with other calcaneus fractures. This is due to the relative stability of these fractures, which allows for early range of motion exercises and progressive weight bearing over the course of treatment.

INTRAARTICULAR FRACTURE TYPES

Mechanism and clinical presentation — The large majority of intraarticular fractures are caused by falling from a height and landing on the heel. The clinical presentation is similar to that of calcaneal body fractures that do not extend into the joint, except that deformity of the heel is more likely to be apparent and swelling can be much more severe. Severe swelling carries with it a high risk of compartment syndrome (up to 10 percent) [11-13] as well as a high risk of skin problems from sloughing and fracture blisters. Bruising that appears on the arch of the foot one to two days after the injury suggests the presence of this fracture. Associated injuries are common, often involving the ipsilateral leg, contralateral leg, or thoracolumbar spine.

Imaging — Plain radiographs of intraarticular fractures can show comminution, displacement, and flattening of Bohler’s angle (image 6A). However, extension of the fracture into the subtalar joint may or may not be apparent on plain radiographs. CT imaging often reveals intraarticular extension or fracture fragments not apparent on plain radiographs and therefore is essential for appropriate classification and optimal management of intraarticular fractures (image 3 and image 18A-C). Three dimensional CT reconstructions allow better visualization of the spatial relationships of fragments (image 5D).

Many classification schemes have been proposed for intraarticular calcaneus fractures [2], but these are beyond the scope of this chapter. Because of the very high forces typically involved with these fractures, associated injuries are common and other symptomatic areas should be imaged as indicated, particularly the thoracolumbar spine (image 4).

Indications for orthopedic or podiatric referral — Virtually all intraarticular calcaneus fractures should be assessed and managed by an orthopedist. Correct classification is difficult and operative management is often needed.

Management — The best treatment for intraarticular calcaneal fractures remains unclear. Initial treatment consists of a bulky dressing, strict elevation above heart level, and regular icing. Severe pain, tense tissues, or severe swelling suggests the possibility of compartment syndrome and the need to obtain immediate surgical consultation for compartment pressure measurement and possible fasciotomy [13,15]. Hospitalization is often necessary for pain control and close observation for compartment syndrome. (See "Acute compartment syndrome of the extremities".)

Despite advancements in imaging that enable more detailed characterization of intraarticular calcaneus fractures, significant controversy remains regarding surgical versus non-operative management, and there is little controlled data to inform management decisions [23-26]. Systematic reviews have failed to clarify which treatment approach is best [23,24,27]. Earlier meta-analyses found that while surgery results in better anatomical restoration and a higher probability of returning to prior employment, pain is no better and any benefits come at the cost of higher complication rates [28,29]. A subsequent meta-analysis suggests that surgery may offer some short-term benefits (improved foot function over the first 6 to 24 months and fewer patients with chronic pain at 24 months) [30]. The authors note the limited quality of available evidence, in part due to small sample sizes and the impracticality of blinding when comparing nonoperative to operative treatment. They highlight the need for better studies, focusing in particular on newly developed, minimally invasive procedures.

STRESS FRACTURES

Mechanism and clinical presentation — Repetitive overload can lead to a stress fracture of the calcaneus. Typically, a substantial increase in activity level or a shift to running or training on harder surfaces precedes the development of symptoms [31]. A case of a stress fracture developing in an experienced runner shortly after switching to minimalist shoes has been reported [32]. Stress fractures and running injuries are discussed in detail separately. (See "Overview of stress fractures" and "Running injuries of the lower extremities: Risk factors and prevention".)

Patients with a calcaneal stress fracture present with heel pain that is often worst during the first steps taken in the morning or after sitting still for a time [33]. As a result, this injury is easily confused with plantar fasciitis or Achilles tendinopathy. If activity is not curtailed, pain eventually persists throughout the day. Swelling may be present but often is not [1]. Patients with calcaneal stress fractures typically have tenderness along the medial and lateral walls of the posterior calcaneus, while patients with plantar fasciitis and Achilles tendinopathy usually do not. Hence, pain elicited by squeezing the sides of the posterior calcaneus between the fingers will usually distinguish a stress fracture from other common causes of heel pain. (See "Plantar fasciitis" and "Achilles tendinopathy and tendon rupture".)

Imaging — With early stress fractures, plain radiographs are usually normal [34]. When visible, an early stress fracture typically appears as a subtle sclerotic band (image 23). Magnetic resonance imaging (MRI) is much more sensitive for demonstrating calcaneal stress fractures, particularly early in their course (image 24) [34]. As the injury heals, sclerosis becomes more prominent and is easier to detect on plain radiographs (image 25). Preliminary studies suggest that ultrasound may be useful in the early diagnosis of calcaneus stress fractures, but further research is needed [35]. Most stress fractures occur at the posterior margin of the calcaneus, but they can develop at the middle and anterior portions [34].

Indications for orthopedic referral or podiatric — Calcaneal stress fractures typically heal well and referral is usually not needed. Uncertainty about the diagnosis, persistent symptoms despite appropriate treatment, and progression to frank fracture are indications for surgical referral.

Management — The treatment of stress fractures varies based upon the patient’s severity of symptoms, activity level, and comorbidities. For patients with mild symptoms, activity restriction coupled with heel inserts may suffice. For patients with severe symptoms (eg, pain with any walking), crutches and non-weight bearing are recommended until symptoms subside [1]. Generally a short course of acetaminophen or nonsteroidal antiinflammatory medication provides adequate analgesia. Concerns about the effects of NSAIDs on fracture healing are discussed separately. (See "Nonselective NSAIDs: Overview of adverse effects", section on 'Possible effect on fracture healing'.)

For patients who want to maintain cardiovascular fitness during the healing process, we suggest non-weight bearing exercise such as swimming and pool running. With appropriate treatment, symptoms usually subside over one to two weeks. When pain and tenderness resolve, the patient can gradually resume activities with the goal of attaining their preinjury level of performance over four to six weeks. Symptoms that persist despite appropriate activity restriction may require more aggressive treatment or referral [33]. (See "Overview of stress fractures", section on 'Treatment concepts' and "Overview of stress fractures", section on 'Return to activity'.)

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".)

SUMMARY AND RECOMMENDATIONS

●Epidemiology and mechanisms of injury – Calcaneus fractures are relatively uncommon, but they are associated with high rates of acute and long term complications. Most result from significant trauma, typically an axial loading of the foot following a fall or jump from a height. Pain is usually severe and weightbearing is often impossible. Swelling and tenderness are typically evident; deformity of the heel may be apparent. However, presentations of anterior process fractures and avulsion fractures of the extensor digitorum brevis may be subtle, with the only findings being moderate pain and tenderness just distal to the insertion of the anterior talofibular ligament. The mechanism of injury for these two fracture types is often identical to that of lateral ankle sprains. (See 'Epidemiology' above and 'Mechanism and clinical presentation' above.)

●Physical examination and concomitant injury – Calcaneus fractures caused by major trauma are often associated with significant concomitant injury, particularly fractures involving the lower extremities and thoracolumbar spine. Therefore, a careful trauma evaluation is important. When examining a suspected calcaneus fracture, look carefully for abrasions, lacerations, blistering from rapid stretching of the skin, skin tenting, and bony deformity, and palpate the tuberosity, body, and anterior portions of the calcaneus. (See "Initial management of trauma in adults" and 'Examination' above.)

●Diagnosis and imaging – Calcaneal fractures are diagnosed by imaging studies. Radiographic evaluation begins with plain radiographs, including lateral and axial views. Additional views and computed tomography (CT) are obtained when clinicians require greater detail about the extent of the fracture or when there is concern for an occult fracture despite nondefinitive initial radiographs. (See 'Diagnostic imaging' above and 'Diagnosis' above.)

Radiographic evaluation includes the following:

•If a fracture is present or suspected, Bohler’s angle (image 6A) should be measured to detect displacement.

•Radiographs should be carefully examined for extension of the fracture into the subtalar joint.

•If plain radiographs do not exclude extension of the fracture into the subtalar joint, CT should be performed to assess for intraarticular extension.

•CT is recommended for all intraarticular calcaneus fractures to fully characterize the fracture.

●Indications for surgical referral – Emergency (ie, immediate) surgical referral is required for open fractures, fractures associated with neurovascular injury, fractures associated with dislocation (which must be reduced immediately), and suspicion or diagnosis of acute compartment syndrome. (See "Acute compartment syndrome of the extremities".)

Virtually all intraarticular calcaneus fractures should be assessed and managed by a surgeon, and urgent referral is indicated. In addition, calcaneal fractures that are comminuted or involve noticeable displacement warrant urgent referral. As a general rule, it is best to contact the surgeon at the time of diagnosis. (See 'Indications for surgical referral' above.)

●Initial management – Initial management includes:

•Elevating the affected foot above heart level and applying ice.

•Providing adequate analgesia.

•Assessing the skin and swelling.

•Evaluating for other associated injuries of the feet, ankles, legs, and thoracolumbar spine.

•Possible admission for observation and pain control depending upon the severity of the fracture, and consequent risk of major complications (eg, compartment syndrome), and the presence of concomitant injury.

●Distinguishing extra- and intra-articular fracture – When classifying calcaneus fractures, the most important step is to distinguish extraarticular from intraarticular injuries.

•Extraarticular fractures generally have a good prognosis, and if nondisplaced may not require referral. The major types of extraarticular fractures are reviewed in the text. (See 'Classification and prognosis' above and 'Extraarticular fracture types' above.)

•Intraarticular fractures virtually always require referral. Their management is controversial and surgery may be performed. (See 'Intraarticular fracture types' above.)

●Complications – Calcaneus fractures, particularly those that are intraarticular or involve posterior displacement, are prone to early and late complications. Important early complications include acute compartment syndrome, skin necrosis, concomitant injury of the thoracolumbar spine, and severe pain. (See 'Overview of complications' above.)

ACKNOWLEDGMENT — The authors acknowledge Joan Street, RT, of the University of Florida for providing several of the images for this topic.