INTRODUCTION — Fractures of the proximal fifth metatarsal pose an important diagnostic challenge. A difference of millimeters in location can lead to a vastly different prognosis and treatment plan; a suboptimal treatment regimen can cause delayed union, reinjury, and chronic disability. Confusion surrounding fracture terminology often compounds the problem of appropriate diagnosis and management.
This topic review will discuss the diagnosis and management of the three major types of proximal fifth metatarsal fractures. Discussions of other metatarsal, foot, and ankle injuries are found elsewhere. (See "Stress fractures of the metatarsal shaft" and "Metatarsal shaft fractures".)
CLINICAL ANATOMY — The fifth metatarsal is located on the lateral side of the foot (figure 1A-C). Its proximal portion is divided into three parts: the tuberosity, metaphysis, and proximal diaphysis (figure 2). The base, or proximal portion, of the fifth metatarsal articulates medially with the fourth metatarsal, while the tuberosity articulates proximally with the cuboid. Strong ligaments attach the fifth metatarsal to these two bones. Thus, range of motion is minimal. The lateral band of the plantar fascia (PF) attaches to the plantar aspect of the tuberosity. The peroneus brevis tendon (PB) attaches to the lateral aspect of the tuberosity. Tuberosity avulsion fractures are thought to result from traction by these structures during inversion injuries. (See 'Tuberosity (styloid) avulsion fractures' below.)
Variations in the blood supply to the fifth metatarsal help explain the pathophysiology of fracture healing. The tuberosity receives blood from multiple metaphyseal vessels and branches of the nutrient artery; the proximal diaphysis receives its blood supply solely from the nutrient artery (figure 3). A fracture to the proximal diaphysis is therefore more likely to disrupt the blood supply, thereby inhibiting healing and increasing the risk of nonunion [1].
HOW TO CLASSIFY AND DISTINGUISH AMONG FRACTURE TYPES — In 1902, Sir Robert Jones described a series of acute fractures of the proximal fifth metatarsal diaphysis [2]. Confusion over terminology has clouded the management of these fractures ever since. Some clinicians use the eponym "Jones Fracture" to refer specifically to acute diaphyseal fractures. Others use it indiscriminately to describe all proximal fifth metatarsal fractures. To add to the confusion, some authors separate these fractures into two groups [3], while others refer to three groups [4-7].
This review will use more recent classification schemes that avoid the term Jones fracture and separate proximal fifth metatarsal fractures into three basic types: tuberosity avulsion fractures; acute proximal diaphyseal fractures; and, stress fractures of the proximal diaphysis (table 1 and figure 4).
The easiest way to distinguish among the three basic fracture types is to locate the medial tip of the fracture line and compare its location to the intermetatarsal joint, which lies between the bases of the fourth and fifth metatarsals (figure 2). Each fracture can then be distinguished in the following manner:
●Styloid fractures exit proximal to the intermetatarsal joint, as seen in the accompanying radiograph (image 1).
●Acute proximal diaphyseal fractures extend into or towards the intermetatarsal joint, as seen in the accompanying radiograph (image 2).
●Stress fractures typically exit or extend distal to the intermetatarsal joint (image 3).
Note that this scheme is not foolproof, and some fractures of the proximal fifth metatarsal occur in borderline locations, in which case it can be difficult to determine the fracture type. In such cases, appropriate follow-up and reassessment are important. In addition, as is true when interpreting any radiograph, clinicians must take into account the mechanism and history when determining the most likely fracture type.
TUBEROSITY (STYLOID) AVULSION FRACTURES — The tuberosity, or styloid, is the most proximal portion of the fifth metatarsal (figure 2). It protrudes in the lateral and plantar planes. Fractures of the tuberosity are among the most common lower extremity fractures. They generally heal without difficulty and are readily managed by primary care clinicians.
Mechanism of injury — Tuberosity avulsion fractures occur during forced inversion of the foot and ankle while they are in plantar flexion. This may occur when a basketball player lands awkwardly after a jump or a runner inverts his or her ankle while running on an uneven surface. The cause of the injury was once thought to be forceful contraction of the peroneus brevis during hindfoot inversion [8]. Further studies suggested the mechanism of injury to be contracture of the lateral band of the plantar fascia [9]. Subsequently, studies using magnetic resonance (MR) and computed tomography (CT) imaging concluded that both structures are likely involved [10].
Clinical presentation and examination — Because tuberosity fractures occur with ankle inversion and symptoms are often mild, patients frequently present to primary care settings complaining of a sprained ankle. The key to detecting this injury is to apply the Ottawa ankle rules systematically to all patients with lateral foot pain following an inversion injury. These rules have been shown to detect essentially all tuberosity fractures, while simultaneously reducing unnecessary foot radiographs (figure 5) [11]. A full discussion of the Ottawa rules is found elsewhere. (See "Ankle sprain in adults: Evaluation and diagnosis", section on 'Ottawa ankle rules'.)
Patient history should include the onset, quality, and duration of symptoms as well as the mechanism of injury. Physical examination should include inspection, palpation for the point of maximal tenderness, palpation of sites recommended in the Ottawa ankle rules, and neurovascular assessment. The clinician should briefly evaluate adjacent structures including the other metatarsals, tarsals, and ankle. With a tuberosity fracture, the clinician will elicit tenderness at the base of the metatarsal and may note swelling and ecchymosis at the site of maximal tenderness. Walking is usually possible but painful.
Radiographic findings — Standard radiographs of the foot should be obtained: anteroposterior, anteroposterior oblique, and lateral (image 4 and image 5 and image 6). However, one small study found a significant percentage of tuberosity avulsion fractures were not visible on standard foot radiographs, but they were seen on anteroposterior and oblique views of the ankle [12]. Hence, clinicians should obtain ankle radiographs if they strongly suspect a tuberosity fracture and initial foot radiographs are negative.
Radiographs typically reveal a radiolucency perpendicular to the long axis of the fifth metatarsal. The fracture may be intraarticular (ie, extend into the cuboid-metatarsal articulation) (image 1) or extra-articular (ie, proximal to the cubometatarsal joint). Tuberosity fractures DO NOT extend into the joint between the fourth and fifth metatarsal (figure 2 and figure 4). Fractures that extend into this joint have a substantially different prognosis and treatment, and they are described below. (See 'Acute fractures of the proximal diaphysis (Jones fracture)' below.)
Radiographs of the foot often reveal two normal structures that may be confused with tuberosity fractures: accessory bones and growth plates. Small accessory bones (or ossicles), such as the os peroneum, may lie near the base of the fifth metatarsal (figure 1A-C). These are typically rounded, smooth-surfaced, relatively far from the tuberosity (compared with a fracture fragment), and possess a uniform cortical appearance around the entire perimeter. Familiarity with accessory bone appearance and location will help prevent fracture misidentification (image 1). Chronically symptomatic ossicles occasionally require excision for definitive pain relief [13].
In adolescents, an apophysis (growth center associated with a tendon insertion) can often be seen in the tuberosity. It always lies parallel to the long axis of the fifth metatarsal and has smooth, corticated edges. Apophysitis, an inflammation of the apophysis, may develop in active adolescents. This self-limiting condition resolves with completion of growth and is treated with rest.
Indications for orthopedic consultation or referral
Emergency referral — Emergency referral is rarely required for tuberosity fractures. The rare fracture that is open or associated with a neurologic or vascular deficit requires immediate surgical referral.
General indications — Orthopedic referral is recommended when there is greater than 3 mm of displacement (image 7 and image 8), a step-off of more than 1 to 2 mm on the articular surface with the cuboid, other associated fractures, or symptomatic nonunion (image 9). All of these may require surgical intervention.
One author recommends surgical fixation if the fracture fragment includes more than 30 percent of the metatarsal-cuboid joint surface [8], but other authors do not list this criterion [4]. A case series of 95 patients reported that fractures with larger avulsion fragments (corresponding to more than about 60 percent of the metatarsal-cuboid joint surface) have a higher rate of displacement during treatment [14]. These authors proposed a new classification scheme for styloid fractures and recommended consideration of early surgical repair for patients with larger avulsion fragments. However, these findings have yet to be confirmed in other studies and the clinical significance of secondary displacement of smaller fracture fragments remains unclear. Nevertheless, consultation with an orthopedist or podiatrist is reasonable for nondisplaced styloid fractures if the fragment includes more than about 60 percent of the metatarsal-cuboid joint surface, especially for patients who are athletes or very active.
Initial treatment — Nondisplaced avulsion fractures require only symptomatic treatment [4]. Standard initial therapy for acute musculoskeletal injury may be used. Rest, ice, elevation of the foot above heart-level, and acetaminophen help reduce symptoms acutely. Unless the patient is unusually symptomatic, treatment with a soft compression bandage and a hard-soled post-operative shoe provides adequate support and protection, and some pain relief. In general, commercially available walking boots are more comfortable, and the authors prefer them to a post-operative shoe for this injury.
Clinicians should ensure that the walking boot or post-operative shoe fits well. With a post-operative shoe, the heel should not slip out the back and the foot should not plantar-flex easily. If the patient continues to have pain with weightbearing in a walking boot, a short period of crutch use for partial or non-weightbearing may be necessary. Gradual transition is then made to full weightbearing in the walking boot. Rarely is casting necessary. Regardless of treatment, weightbearing is allowed as tolerated.
The relatively benign nature of these fractures and the simple approach to management are supported by several studies [15-17]. In one trial, 60 patients were randomly assigned to either a soft dressing or short-leg cast. Decreased recuperation time (33 versus 46 days) was needed in the soft dressing group, but otherwise there were no significant differences in outcome [15]. In another trial involving 96 patients randomly assigned to treatment in a hard-soled shoe or a short-leg cast, no clinically or statistically significant differences were noted in pain or patient satisfaction, and there were no cases of nonunion [17]. The time to return to preinjury activity was shorter in the hard-soled shoe group (average 37 versus 43 days in the cast group).
Follow-up care — We recommend an initial follow-up visit one week after diagnosis and every two to three weeks thereafter until healing is achieved and full function returns. Most patients are asymptomatic within three weeks, with radiographic union in eight weeks [6]. Follow-up radiographs should be obtained approximately eight weeks after injury to document healing. Physical therapy may help patients who are slow to recover function. If a cast is used, it may be removed two to four weeks after injury. After removal, progressive range-of-motion exercises and stretching should be started. Physical therapy is much more likely to be needed if a cast was used.
Complications — Complications are unusual, although a prospective observational study that included 62 styloid fractures found that 25 percent of patients continued to experience some pain one year after injury [18]. Nonunion may occur. A minority of patients will have prolonged discomfort, especially if the fracture was displaced or there was a step-off on the articular surface. Delayed unions can occur, especially in older patients.
After three months of persistent nonunion without evidence of callus formation, some clinicians use external bone stimulators in hopes of promoting healing, but there are no controlled studies demonstrating the effectiveness of these devices.
Return to work or sports — Once healed, patients may gradually resume their usual activities as tolerated, using their symptoms as a guide. Because tuberosity fractures are not prone to refracture, the patient may increase activity less gradually than with other proximal fifth metatarsal fractures. Patients with physically demanding jobs should wait until the fracture is fully healed and strength regained before resuming work.
We occasionally insert a steel shank or an off the shelf orthotic (suitable brands include Powerstep or Superfeet) in the athletic or work shoe of patients trying to return to play or work soon after radiographic healing becomes apparent. These inserts provide additional support and reduce pain and swelling during the early phases of a patient’s return to activity, and can be particularly useful in patients with significant pes planus (flat foot) or whose gait demonstrates pronounced pronation.
ACUTE FRACTURES OF THE PROXIMAL DIAPHYSIS (JONES FRACTURE) — These fractures, first described by Jones in 1902, occur within 1.5 cm of the metatarsal tuberosity and extend towards or into the intermetatarsal joint (figure 2 and figure 4) [2]. The area where these fractures occur is referred to using different terms, including "proximal diaphysis" and "junction of the metaphysis and diaphysis." Fractures in this area generally result from an acute injury. It is important to distinguish acute traumatic fractures from stress fractures, which may also develop in this location, as treatment is often different.
Mechanism of injury — Inversion does not cause this fracture. Some researchers claim it is caused by vertical or mediolateral forces exerted on the base of the fifth metatarsal, while the heel is raised and the foot is plantar flexed [19]. Others ascribe the injury to a significant adduction force applied to the forefoot, while the ankle is in plantar flexion [4]. Practically speaking, athletes can sustain this injury through sudden change in direction with the heel off the ground during events such as football, basketball, or tennis matches.
Clinical presentation and examination — Patients describe pain on the lateral side of the foot anterior to the ankle and have difficulty bearing weight. Edema and ecchymosis are usually present. Abrupt onset of pain following a distinct injury suggests an acute fracture. Occasionally, the symptoms of a stress fracture will suddenly worsen after an acute stress (eg, dramatic increase in training intensity) or trauma. In such cases, the clinician may be misled into suspecting an acute fracture rather than a stress fracture. The clinician may be able to differentiate by inquiring about persistent pain prior to the acute event.
Patient history should include the onset, quality, and duration of symptoms as well as the mechanism of injury. Physical examination should include inspection, palpation for the point of maximal tenderness, palpation of sites recommended in the Ottawa ankle rules, and neurovascular assessment. The clinician should briefly evaluate adjacent structures including the other metatarsals, tarsals, and ankle. With all foot and ankle injuries, clinicians should systematically apply the Ottawa rules to avoid missed fractures and unnecessary radiographs (figure 5).
Radiographic findings — It can be difficult to distinguish between acute and stress fractures, and these injuries are often treated differently. Therefore, all radiographs should be carefully examined.
Standard radiographs of the foot (anteroposterior, oblique, and lateral) should be obtained. The fracture line of acute fifth metatarsal diaphyseal fractures typically extends into or towards the articulation between the bases of the fourth and fifth metatarsal (image 2). With acute fractures, the fracture line is sharp and the surrounding bone appears normal. With stress fractures, surrounding bone will appear abnormal. An early stress fracture will demonstrate cortical thickening of the surrounding bone (image 3). An older stress fracture will demonstrate a widened fracture line and partial or complete obliteration of the medullary canal (image 10). (See 'Radiographic findings' below.)
Indications for orthopedic consultation or referral
Emergency referral — As with tuberosity fractures, emergency referral is rarely required. The rare fracture that is open or associated with a neurologic or vascular deficit requires immediate surgical referral.
General indications — Displaced fractures of the proximal diaphysis generally require internal fixation, and any patient with greater than 2 mm of displacement should be referred to an orthopedist or podiatrist [4].
Initial treatment — Once conditions requiring emergency referral have been excluded, initial treatment consists of immobilization in a posterior splint, strict nonweightbearing (crutches are required), and a follow-up visit in three to five days. Icing (while keeping the splint dry) and elevation of the injured foot above the level of the heart are recommended to minimize swelling. Appropriate analgesics should be provided.
Surgery versus conservative therapy — For nondisplaced, acute fractures, most authors recommend conservative treatment [4,6-8]. However, unlike tuberosity fractures, fractures of the diaphysis are difficult to classify properly, and conservative treatment is more likely to fail. Before initiating long-term conservative treatment of such a fracture, the primary care clinician should discuss with the patient both the difficulties inherent in nonoperative management and alternative treatment options, including early referral to an orthopedist or podiatrist for possible operative repair.
Acute diaphyseal fractures pose several challenges. First, it can be difficult to distinguish between acute and stress fractures. (See 'Stress fractures of the proximal diaphysis' below.) Thus, it is important to ask about symptoms preceding any acute injury and carefully examine all radiographs to detect findings suggesting a stress fracture. Second, treatment includes casting and strict nonweightbearing for up to several months, and even motivated patients will find compliance difficult. Finally, up to 50 percent of acute diaphyseal fractures treated conservatively may result in nonunion or refracture [4].
The incidence of nonunion and refracture may be overestimated, as some studies have likely misclassified stress fractures among the acute fractures [4]. However, even in studies where fractures are carefully differentiated, delayed union is surprisingly common following acute injury. One study that appears to have carefully separated acute and stress fractures found that four of eight basketball players with acute fractures treated nonoperatively had not healed by 12 weeks [20]. The relatively poor vascular supply to this area (figure 3) and stress at the fracture site from premature return to weightbearing exercise are two major reasons for poor healing [6].
Only one randomized trial has compared surgical and conservative treatment of these fractures [21]. In this study, 19 patients were treated with intramedullary screw fixation followed by two weeks of immobilization, while 18 patients were immobilized in a nonweightbearing, short-leg cast for eight weeks, followed by a walking cast or hard-sole shoe, until there was both clinical and radiographic evidence of fracture union. Treatment failure, defined as a symptomatic fracture present on radiograph at 26 weeks after the initial injury, occurred in eight patients treated conservatively but in only one treated operatively. The median time required for patients to return to running and jumping sports also differed significantly: conservatively-treated patients required 15 weeks (95% CI 13-18), while surgically-treated patients needed only eight weeks (95% CI 6.8-9).
The results of this lone randomized trial are consistent with the conclusions of two systematic reviews, one of 26 studies and another of 6, which also found that surgery reduces the risk of non-union [22,23]. However, given the small number of events in the trial and the generally weak quality of the studies included in the reviews, some may question the validity of these findings.
In light of the difficulties in treating acute diaphyseal fractures, early surgical fixation [5,8] and prolonged use of a customized weightbearing orthosis [6,24] are reasonable options in select cases. Regardless of the ultimate choice, treatment decisions must be made after thorough discussion with the patient.
Follow-up care — If the clinician and patient opt for conservative management, this may be performed as described below. Before undertaking this approach, however, the patient must understand the fragility of this injury, the relatively high risk of nonunion despite painstaking adherence to treatment guidelines (including strict nonweightbearing status for two months or longer), and the possibility of subsequent need for surgery if nonoperative treatment fails. (See 'General indications' above.)
Nonoperative management — Three to five days postinjury, after swelling has begun to subside, the patient should be seen in follow-up. A well-molded, short-leg, nonweightbearing cast should be applied. If there is concern about displacement (eg, trauma since initial radiographs were obtained, or noncompliance with splint or nonweightbearing status), radiographs may be repeated to assure the fracture remains nondisplaced. While the patient may rest the cast lightly on the ground, the patient should be carefully admonished not to bear weight. He or she should also receive standard cast instructions (eg, to seek evaluation immediately for symptoms suggestive of a compartment syndrome, how to care for the cast, to be seen promptly should the cast become uncomfortable, etc).
Approximately two weeks after casting, the patient should return for follow-up and a cast check. The integrity and fit of the cast should be assessed. Resolution of swelling may have caused the cast to become loose and may necessitate replacement. Significant wear or weakening of the sole and heel suggest the patient has been bearing weight. If so, the patient should be warned of the potential consequences (ie, nonunion) and re-admonished not to bear weight. The cast should be reinforced if necessary. The patient need not return for four to six weeks, unless a new symptom or cast problem necessitates an earlier visit.
After six to eight weeks of nonweightbearing, the patient should have the cast removed and radiographs repeated. If healing is noted (ie, resolution of point tenderness, callus on radiograph at fracture site), the cast may be discontinued and rehabilitation begun. If the fracture shows no evidence of healing, several options exist: continued casting (nonweightbearing), a foot orthosis, or medullary screw fixation [4]. Continuing conservative management for an additional four to six weeks is reasonable, but consultation should be strongly considered to help the patient assess the available options. Referral is recommended if follow-up radiographs suggest a developing stress fracture. (See 'Stress fractures of the proximal diaphysis' below.)
Postcast rehabilitation — Once healing is evident and the cast is removed, the patient should begin progressive weightbearing and exercises to restore normal foot and ankle function. Formal physical therapy is often helpful. It is strongly recommended for patients who required casting longer than eight weeks or who are over the age of 40.
Because of the risk of refracture, the patient should resume weightbearing very gradually. The patient begins with partial weightbearing (ie, placing most of his or her weight on crutches and only a small portion on the affected foot). Each day the patient gradually shifts more weight onto the foot. This lets the foot progressively adjust to weightbearing and helps the ankle gradually regain a normal range of motion. When the patient can walk comfortably with full weight on the foot (roughly three to seven days after cast removal), crutches may be discontinued.
From this point, the total time spent standing and walking can be gradually increased by approximately 5 to 10 percent each day. Throughout the recovery period, the patient should stretch the calf muscles and perform ankle range-of-motion exercises several times daily. If pain recurs at the fracture site, activity should be decreased. The patient should return for re-evaluation, if pain becomes severe or persists despite decreased activity. The clinician may discharge the patient from care once foot and ankle function are approaching baseline and pain is resolved. The patient should be instructed to return for any problems, especially recurrent pain, which may indicate refracture.
Complications — Primary complications include delayed union and nonunion.
Intramedullary screw fixation is the standard treatment for nonunion of these fractures, but complications and persistent nonunions still occur. Shock wave therapy may provide an alternative approach, but evidence is scant and further study is needed. In one small, retrospective study of patients with metaphyseal-diaphyseal fractures of the proximal fifth metatarsal, comparable healing rates were achieved using shock wave therapy and intramedullary screw [25].
In uncomplicated cases, some patients have persistent pain after healing. Shoe modification or surgical referral may be required if this occurs.
Return to work or sports — The patient should gradually resume usual activities as tolerated, using symptoms as a guide. The progression to more demanding activities must be very gradual to avoid reinjury. Light running may begin once walking is painless and fluid. As with stress fractures, the patient should refrain from higher impact activities until fairly late in the recovery process. Patients with physically demanding jobs should wait until the fracture is fully healed and strength regained before resuming work.
STRESS FRACTURES OF THE PROXIMAL DIAPHYSIS — Stress fractures of the fifth metatarsal result from chronic and repetitive microtrauma, predominantly in younger athletes. They occur much less often than the acute fractures and tuberosity fractures described above (figure 2 and figure 4) [4]. Despite their infrequency, they deserve special attention because of their marked propensity for delayed union and nonunion, compared with other proximal fifth metatarsal fractures and stress fractures of other metatarsals [4].
Clinical presentation and examination — Patients usually experience a prodrome of pain up to several months prior to presentation, which is characteristically more intense during exercise or other weightbearing activity. Tenderness is present over the fracture site. Edema and ecchymosis may be present, but absence of these symptoms should not deter the clinician from considering this diagnosis.
Patient history should include the onset, quality, and duration of symptoms as well as the mechanism of injury. Physical examination should include inspection, palpation for the point of maximal tenderness, palpation of sites recommended in the Ottawa ankle rules, and neurovascular assessment. The clinician should briefly evaluate adjacent structures including the other metatarsals, tarsals, and ankle. With all foot and ankle injuries, clinicians should systematically apply the Ottawa rules to avoid missed fractures and unnecessary radiographs (figure 5).
Radiographic findings — Standard radiographs of the foot (anteroposterior, oblique, and lateral) should be obtained. Stress fractures are most commonly seen just distal to the intermetatarsal articulation (between the bases of the fourth and fifth metatarsal) (figure 2 and figure 4). However, stress fractures may also occur more proximally, where they can be confused with an acute (Jones) fracture.
Radiographic findings vary depending on the stage of the stress fracture. A classification system for predicting outcome and planning treatment has been developed (table 1 and table 2) [26]. Misclassification can lead to inappropriate treatment, potentially causing delayed healing.
In contrast to acute fractures, where the fracture line is sharp and the surrounding bone appears normal (image 2), the bone surrounding stress fractures appears abnormal. An early stress fracture will demonstrate cortical thickening (Torg type I) (image 3). An older stress fracture will demonstrate a widened fracture line and partial (Torg type II) or complete (Torg type III) obliteration of the medullary canal (image 10).
Indications for orthopedic consultation or referral
Emergency referral — Because of the chronic nature of these injuries, emergency referral is rarely if ever needed.
General indications — Referral is necessary for all Torg Type II and Type III fractures (table 2 and image 10), as the vast majority will require surgical fixation. An occasional patient with a Type II fracture may be a candidate for conservative management, but this determination should be made with the input of an orthopedist [4].
Referral is suggested for all Torg Type I fractures. Though conservative treatment is preferred for most, early operative fixation is a viable option, especially for athletes or extremely active patients [4,6-8,27]. In athletes, early surgical fixation is generally preferred because it allows the patient to avoid prolonged nonweightbearing immobilization (up to 20 weeks), thereby minimizing deconditioning and enabling a quicker return to competition.
Should the patient select a conservative approach, referral is indicated if treatment results in nonunion.
Initial treatment — The ideal candidate for conservative management is a patient with a Type I fracture who wants to avoid surgery and can tolerate prolonged nonweightbearing immobilization. The patient must be made aware that treatment may last up to 20 weeks and that nonunion may still occur. Rest, ice, elevation, and acetaminophen help reduce symptoms acutely.
Unlike acute fractures, stress fractures are unlikely to develop significant swelling after casting. Therefore, unless acute trauma occurred just before presentation, the risk of compartment syndrome is minimal, and the patient can usually be placed in a nonweightbearing short-leg cast at the initial visit. Crutches and strict nonweightbearing should be prescribed. The patient may rest the cast lightly on the ground, but should not bear weight. Standard cast instructions should be provided (eg, to seek evaluation immediately if symptoms suggestive of a compartment syndrome develop, how to care for the cast, to be evaluated promptly should the cast become uncomfortable, etc).
For patients in whom clinical suspicion for a stress fracture is high, but radiographs are negative, we suggest the patient substantially limit activity and that plain radiographs be repeated in two weeks. We reserve MRI for highly competitive athletes who are unwilling to reduce activity levels and patients in whom clinical suspicion remains high but follow-up radiographs at two weeks again fail to reveal any evidence of fracture.
Follow-up care — The patient should be seen monthly to assess the integrity and fit of the cast. Monthly radiographs should be obtained, beginning two months after casting, to assess healing. If the cast needs replacement due to looseness or weakening, radiographs should be obtained out of the cast. If the cast does not require changing, radiographs can be taken through the cast. This will make it more difficult to detect signs of healing, and it may be necessary to remove a sound cast in order to obtain better radiographs. This is especially true as the duration of casting approaches 16 to 20 weeks.
After healing is clearly present (eg, tenderness resolved, well-established callus present across fracture site) the cast may be discontinued and the patient may begin gradual, progressive weightbearing and range-of-motion exercises. Physical therapy referral is often helpful, especially if immobilization exceeds two to three months. It is important to caution the patient that advancing activities too rapidly may cause a recurrence of the fracture. If the patient experiences pain reminiscent of the stress fracture, activities should be curtailed immediately and the foot reevaluated.
Complications — Nonunion and delayed union are the most common complications. Chronic discomfort following treatment and prolonged recovery after cast removal may also occur.
Return to work or sports — As range of motion improves and walking becomes fluid and painless, the patient may begin gentle running for short distances. The distance and intensity may be increased very gradually each week. Cross training through cycling and swimming can help the patient regain cardiovascular fitness while minimizing impact on the foot. High-impact and high-stress activities, such as jumping, pivoting, etc, should be reserved for the final stages of rehabilitation, after bones and supporting structures have regained strength. Throughout the rehabilitation process, the patient should remain vigilant for symptoms suggesting a recurrence of the stress fracture and seek immediate re-evaluation should they develop.
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
●Overview of fracture types and key distinctions – Three different fracture types occur in the proximal fifth metatarsal: tuberosity avulsion, acute diaphyseal, and stress diaphyseal. The prognosis and treatment differ substantially among them. The most difficult distinction to be made is between acute fractures and stress fractures of the proximal diaphysis. Acute fractures lack a prodrome of chronic symptoms, occur abruptly, and demonstrate a sharp fracture line with normal surrounding bone on initial radiographs. Stress fractures generally present after a prodrome of chronic pain and have a characteristic radiographic appearance based on their age. A summary of important diagnosis and management points are listed below by fracture.
●Tuberosity avulsion fractures
•Mechanism – Avulsion fractures occur in the tuberosity (styloid), proximal to the intermetatarsal joint (figure 4). These fractures typically do well. They occur with forced inversion of the foot and ankle, while they are in plantar flexion (eg, when a basketball player lands awkwardly or a runner inverts their ankle on an uneven surface). (See 'Mechanism of injury' above.)
•Clinical presentation – Because tuberosity fractures occur with ankle inversion and symptoms are often mild, patients frequently present to primary care settings complaining of a sprained ankle. The key to detecting this injury is to apply the Ottawa ankle rules systematically to all patients with lateral foot pain following an inversion injury (figure 5). (See 'Clinical presentation and examination' above.)
•Diagnostic imaging – Standard foot radiographs should be obtained; ankle radiographs sometimes reveal fractures not seen on foot films. Radiographs typically reveal a radiolucency perpendicular to the long axis of the fifth metatarsal. The fracture may extend into the cuboid-metatarsal articulation or lie proximal to this joint. Tuberosity fractures do not extend into the joint between the fourth and fifth metatarsal; if this occurs, an acute diaphyseal fracture is present. (See 'Radiographic findings' above.)
•Indications for surgical referral – Orthopedic referral is recommended when there is displacement, a step-off of more that 1 to 2 mm on the articular surface with the cuboid, other associated fractures, or symptomatic nonunion. (See 'Indications for orthopedic consultation or referral' above.)
•Nonoperative treatment – For nondisplaced avulsion fractures, we suggest symptomatic therapy alone (Grade 2B). In most cases, this can be achieved with a hard-soled shoe, but occasionally more definitive immobilization (eg, casting) is required for pain control. (See 'Initial treatment' above.)
Follow-up is performed initially one week after diagnosis and every two to three weeks thereafter until healing is achieved and full function returns. Most patients are asymptomatic, or nearly so, within three weeks, with radiographic union in eight weeks. Follow-up radiographs should be obtained approximately eight weeks after injury to document healing. (See 'Follow-up care' above.)
●Acute fractures of the proximal diaphysis
•Clinical presentation – Acute fractures of the proximal diaphysis occur at the level of the inter-metatarsal joint (figure 4). Patients describe pain on the lateral side of the foot anterior to the ankle, have difficulty bearing weight, and may have surrounding edema and ecchymosis. Abrupt onset of pain following a distinct injury suggests an acute fracture. Occasionally a stress fracture will suddenly worsen after an acute stress, which may mislead a clinician into diagnosing an acute fracture. Inquiring about persistent pain prior to the acute event can help avoid this pitfall. (See 'Clinical presentation and examination' above.)
•Diagnostic imaging – The fracture line of acute fifth metatarsal diaphyseal fractures typically extends into or towards the articulation between the bases of the fourth and fifth metatarsal. (See 'Radiographic findings' above.)
•Indications for surgical referral – Fractures displaced more than 2 mm require internal fixation, and the patient should be referred. For nondisplaced fractures, most authors recommend nonoperative treatment, although surgery may yield lower rates of nonunion. Athletes and active patients wishing to avoid six to eight weeks in a nonweightbearing cast may elect to have a surgical repair. (See 'Indications for orthopedic consultation or referral' above.)
•Management – Acute fractures of the proximal fifth metatarsal heal poorly compared with similar fractures of other metatarsals. Many authorities recommend conservative treatment, but studies involving athletes suggest surgery yields superior outcomes. Referral for possible early surgical fixation should be considered for all athletes. Before initiating conservative treatment, the clinician should thoroughly discuss the treatment options with the patient, including early referral for possible operative repair. For those patients selecting nonoperative management, we suggest treatment with a short-leg, nonweightbearing cast for six to eight weeks (Grade 2B). Delayed union and nonunion may occur even with expert conservative treatment and excellent patient compliance. A suggested treatment and rehabilitation schedule is described in the text. (See 'Surgery versus conservative therapy' above and 'Nonoperative management' above.)
●Stress fractures of the proximal diaphysis
•Mechanism – Stress fractures of the fifth metatarsal result from chronic and repetitive microtrauma, predominantly in younger athletes. They occur much less often than the acute diaphyseal and tuberosity avulsion fractures, but they have a much greater propensity for delayed union and nonunion.
•Clinical presentation – Patients usually experience a prodrome of pain up to several months prior to presentation, which is characteristically more intense during exercise or other weightbearing activity. Tenderness is present over the fracture site. Edema and ecchymosis may be present, but absence of these signs should not deter the clinician from considering the diagnosis. (See 'Clinical presentation and examination' above.)
•Diagnostic imaging – Stress fractures are most commonly seen just distal to the intermetatarsal articulation between the bases of the fourth and fifth metatarsal (figure 4). They may also occur more proximally and be confused with an acute fracture. Radiographic findings vary depending on the stage of the stress fracture (table 2). Misclassification can lead to inappropriate treatment and poor outcomes. (See 'Radiographic findings' above.)
•Management and indications for surgical referral – We recommend surgical referral for all Torg grade II and III stress fractures (Grade 1B). We suggest surgical referral for all Torg grade I stress fractures (Grade 2C). However, for patients with grade I stress fractures who are eager to avoid surgery and able to tolerate 20 weeks of nonweightbearing immobilization, nonoperative treatment is reasonable. (See 'Indications for orthopedic consultation or referral' above.)
A nonoperative treatment schedule for grade I fractures is described in the text. (See 'Initial treatment' above.)
Once the injury is well healed, the patient may begin a gentle rehabilitation program. Activity may be increased very gradually with careful monitoring. High-impact and high-stress activities should be reserved for the final stages of rehabilitation, after bones and supporting structures have regained full strength. Throughout rehabilitation, the patient should remain vigilant for symptoms suggesting a recurrence of the stress fracture and seek immediate re-evaluation. (See 'Follow-up care' above.)
