Navicular Fracture 

Updated: May 18, 2017
Author: Michael J Ameres, MD; Chief Editor: Sherwin SW Ho, MD 

Overview

Background

The navicular plays an important role in maintaining the medial longitudinal arch of the foot. Commonly, fractures of the navicular are not evident on plain radiographs. This often leads to a delay in diagnosis, which may result in prolonged disabling foot pain in individuals, particularly young athletes. The 4 types of navicular fractures are (1) cortical avulsion, (2) tuberosity, (3) body, and (4) stress.[1, 2, 3, 4, 5]

Cortical and tuberosity avulsion fractures

Avulsion fracture, the most common fracture of the navicular, is often associated with ligamentous injuries and results from twisting forces on the mid foot. These fractures are commonly treated conservatively, except for avulsion of the posterior tibial tendon insertion (tuberosity fracture), which may be repaired operatively, especially if a proximal dislocation of 1 cm or more is present. An avulsion of the posterior tibial tendon insertion must be differentiated from an accessory navicular (see Other Problems to Be Considered).

Fractures of the navicular body

Fractures of the body are commonly associated with other injuries of the midtarsal joint. Sangeorzan et al categorized navicular body fractures into 3 types, as follows[6] :

  • Type 1 is a coronal fracture with no dislocation.

  • Type 2 is a dorsolateral to plantomedial fracture with medial forefoot displacement.

  • Type 3 is a comminuted fracture with lateral forefoot displacement and carries the worst prognosis.

All navicular body fractures with 1 mm or more of displacement require open reduction and internal fixation.

Stress fractures

The rest of this article primarily discusses the diagnosis and treatment of navicular stress fractures, which are usually sports-related injuries.

In 1855, Brehaulpt first described stress fractures in military recruits who were subjected to long marches. As more civilians took up physically demanding sports, the incidence of stress fractures has increased in the general population. Towne et al first described stress fracture of the tarsal navicular in 1970.[7]

In athletes, navicular stress fractures are of particular concern because they are underdiagnosed and can lead to significant disability if the diagnosis is delayed.[1, 2, 3, 4, 5, 8] In a study by Torg et al in 1982, the average time between the fracture and diagnosis was estimated to be 7 months.[9] Given the significant improvement in outcome with early diagnosis and proper treatment, navicular stress fractures should be considered in any athlete with midfoot pain. In a 2006 study by Saxena and Fullem, navicular stress fractures took up to 4 months to heal posttreatment.[10]

Fracture-dislocation of the navicular may occur in athletes.[11, 12, 13, 14, 15, 16, 17, 18] This uncommon injury generally requires reduction and examination for stability via fluoroscopy, with the patient under general anesthesia. If the postreduction examination findings confirm stability of the navicular, treatment with a non–weight-bearing cast may be sufficient; otherwise, internal fixation is required.

For excellent patient education resources, visit eMedicineHealth's First Aid and Injuries Center. Also, see eMedicineHealth's patient education articles Broken Foot and Cast Care.

Epidemiology

Frequency

United States

Navicular stress fractures may account for up to 35% of stress fractures in athletes. Because navicular stress fractures are not easily observed on plain radiographs, the reported incidence rates vary widely. The overall incidence may appear to be increasing due to advances in imaging.[19, 20, 21, 22, 23, 24, 25]

Among track-and-field athletes, up to 21% may experience a stress fracture in the course of a year.[26, 27] In these athletes, up to 15% of stress fractures are of the navicular.[26] Other studies have demonstrated similar findings.[28, 29, 30, 31] The highest incidence of stress fractures is in jumping and sprinting events.

Among military recruits, the incidence is approaching that of athletes, as the training of military recruits closely mirrors the training of athletes.[28, 32, 33, 34]

International

Worldwide, the incidence of navicular stress fracture is related to the sport of participation and to the training that is involved rather than to geographic location.

Functional Anatomy

The tarsal navicular is a disk-shaped bone that articulates distally with the 3 cuneiforms, proximally with the talar head, and, occasionally, laterally with the cuboid. The distal articulation with the 3 cuneiforms is by means of 3 facets that have a common synovial cavity. The plantar and dorsal cuneonavicular ligaments reinforce the distal articulation.

On the lateral side are the plantar, dorsal, and interosseous cuboideonavicular ligaments and, occasionally, a syndesmotic joint with the cuboid. Medially, the distal articulation serves as an attachment for the posterior tibial tendon and the spring, or plantar calcaneonavicular, ligament. On the proximal side, it envelops the talar head completely. The thickened talonavicular ligaments reinforce the talonavicular joint in a plantar and dorsal orientation. Medially, the anterior fibers of the deltoid ligament add support.

Along with the calcaneocuboid joint, the talonavicular joint forms the transverse tarsal joint, which allows motion of the forefoot on the hindfoot. The ligamentous structure is such that when the hind part of the foot is everted, the joint is mobile, and when the hind part of the foot is inverted, the joint is fixed.

The blood supply of the navicular comes from small branches of the posterior tibial and dorsalis pedis arteries. This supply leaves the medial and lateral areas of the navicular relatively well supplied compared with the central section of the navicular. This relative difference correlates with the common site of stress fractures.

Sport-Specific Biomechanics

The navicular is part of 2 important structures that are essential for normal gait: (1) the medial longitudinal arch and (2) the transverse tarsal joint (also called the midtarsal or Chopart joint).

The medial longitudinal arch is composed of the navicular, calcaneus, talus, 3 cuneiforms, and 3 medial metatarsals. This arch provides support for normal gait, in particular from mid stance until push-off.

The transverse tarsal joint is essential for normal gait and is composed of the talonavicular joint and the calcaneocuboid joint. At heel strike, this joint is flexible and plays an important role in absorbing ground impact and accommodating the foot to the ground. At push-off, the transverse tarsal joint is locked and is helpful in forward propulsion.

 

Presentation

History

Navicular stress fractures must be considered in any athlete with midfoot pain. Typically, the pain is of insidious onset and may have been present for months. In addition, the pain often worsens with activity and improves with rest. Pain may be present at the dorsum of the foot, or it may radiate along the medial longitudinal arch. Slight swelling may or may not be present.

Historically, persons participating in the following sports and activities have a relatively high risk of navicular fracture:

  • Track and field[26, 27, 28, 29, 30, 31] – Particularly sports involving jumping and sprinting

  • Ballet and other dancing activities[35]

  • Equestrian sports

  • Basketball

  • Soccer[36]

  • American football

  • Australian-rules football

  • Rugby

  • Gymnastics[37]

  • Military training[28, 32, 33, 34]

Physical

Possible findings from the physical examination in an individual who has a navicular fracture include the following:

  • Tenderness at the "N spot," which is defined as the proximal dorsal portion of the navicular (see the image below). This is the most important physical finding.

    Palpation of the N spot. Palpation of the N spot.
  • Tenderness at the midmedial arch over the navicular

  • Pain with passive eversion

  • Pain with active inversion

  • Pain that is often reproduced if the patient hops while in the equinus position

  • Possible mild dorsal midfoot swelling

Causes

The particular cause of stress fractures in athletes or military recruits is often elusive. Obviously, the repetitive stress of their chosen activity leads to the fracture, but identifying a defect in technique, equipment, or schedule of activity is often difficult.

  • Some factors that have been implicated as causes of stress fractures include the following:

    • Starting athletic activity at a high level without a gradual increase in activity over time

    • Starting a second sport and assuming that the body is conditioned to participate at that sport immediately and at a high level. The navicular is at particular risk when runners participate in sports that require jumping and do not take the time for proper conditioning in their new sport.

    • Ill-fitting and/or old, worn equipment

    • Change in running or field surfaces

    • Relative osteopenia

    • Biomechanical abnormality

  • Some risk factors for stress fracture include the following:

    • Female sex

    • Menstrual irregularities[38]

    • Unequal leg length

    • Any medical condition or behavior that may result in relative osteopenia, including smoking, hypothyroidism, steroid use, and rheumatoid arthritis

    • Sudden, significant weight loss

 

DDx

 

Workup

Imaging Studies

See the list below:

  • Radiograph

    • A plain radiograph of the foot rarely demonstrates the presence of a navicular stress fracture. For this reason, negative radiographic findings cannot be used to rule out the presence of a navicular fracture.[39, 40]

    • The tarsal navicular is frequently underpenetrated during routine standing anteroposterior (AP), lateral, and oblique views of foot; however, a coned-down AP radiograph that is centered on the tarsal navicular may help in visualization. The continuity of the cortical bone, especially on an AP radiograph, should be carefully examined because when a fracture is present, the lateral fragment may resemble a separate tarsal bone and can be easily overlooked. However, even with special techniques and a careful examination, a radiograph is not sufficient to rule out a stress fracture of the tarsal navicular.

  • Technetium (99m Tc) bone scanning

    • This study is useful for making the diagnosis of a navicular stress fracture.

    • Increased radionuclide uptake occurs at the navicular.

    • This modality is sensitive to, but not specific for, a fracture; therefore, a computed tomography (CT) scan is necessary for a definitive diagnosis.[40]

  • CT scanning

    • These studies are useful for making and confirming the diagnosis of navicular stress fractures.

    • In addition, a CT scan helps to more precisely define the location and extent of the fracture. Saxena et al proposed a classification system based on CT scan findings as follows[41] :

      • Type 1 involves a dorsal cortical break.

      • Type 2 involves fracture propagation into the navicular body.

      • Type 3 consists of fracture propagation into another cortex.

      • Types 2 and 3 may benefit from early surgical intervention.

  • Magnetic resonance imaging (MRI)

    • MRI is the imaging modality of choice for diagnosing navicular stress fractures.

    • MRI is useful in grading the stress fracture, and thereby, this modality may help the clinician to adjust therapy based on the fracture severity.[42, 43]

    • This study is relatively expensive.

  • Ultrasound[21]

    • Currently, ultrasound is not sensitive enough to be useful in the diagnosis of stress fractures. However, experience with this imaging technique for stress fractures is very limited.

    • The standard caveats for ultrasound apply. The technique is noninvasive but operator dependent. The role of ultrasound in diagnosing navicular stress fractures remains to be determined.

Laboratory Studies

Vitamin D levels   It is unclear if low vitamin D levels after stress fractures are due to previously undiagnosed deficiency or increased utilization in the setting of an acute fracture. [44, 45]

 

Treatment

Acute Phase

Rehabilitation Program

Physical Therapy

Most patients are placed in a non–weight-bearing cast for 6 weeks. The importance of following a strict non–weight-bearing protocol must be emphasized to the patient. After 3 weeks, the state of the cast and the patient's adherence to the non–weight-bearing protocol must be assessed.[40] A study by Torg et al confirms the superiority of non–weight-bearing as the preferred initial treatment for navicular stress fractures.[46]

An exception to non–weight-bearing treatment is in patients who have pain only after significant exertion (eg, pain after running 2 miles). In these individuals, avoidance of running for 6-8 weeks may be sufficient to heal the fracture. The patient can then gradually return to his or her normal routine. If pain returns, then a non–weight-bearing cast may be indicated.

Surgical Intervention

Most physicians do not recommend immediate open surgical procedures when treating uncomplicated navicular stress fractures. In a comparison study by Potter et al, surgery had similar long-term return-to-activity rates relative to conservative therapy.[47] In another study, bone healing took up to 4 months, for both operative and nonoperative treatment.[10]

Fractures that are complicated by dislocation are assessed for stability following reduction. If the navicular is stable, then treatment may continue as outlined for uncomplicated navicular fractures. If the navicular is unstable, then internal fixation is required.

A complete fracture with wide separation may benefit from early surgical intervention. In addition, if the patient is not expected to tolerate the rehabilitation program, surgical correction may be considered.

Return to sport, particularly in elite athletes, may be quicker with surgical vs non-surgical treatment.[44]

A retrospective analysis by Coulibaly et al that compared operative and non-operative treatment of navicular fractures reported that the operative treatment group had considerably more complications of secondary osteoarthritis.[48]

Other Treatment

Although no trials support the use of bone growth stimulators for navicular stress fractures, they may be a helpful adjunct.[11] In particular, bone growth stimulators that use pulsed electromagnetic fields (PEMFs) have been shown to have similar success rates when compared with open repair in tibial fracture nonunions.[49, 50, 51, 52] Whether these results are applicable to acute fractures and fractures of the navicular remains to be determined.

Platelet-rich plasma (PRP) may help bone healing. Whole blood taken from the patient is processed to be used at the injury site. Although evidence suggests that PRP is safe and can promote bone formation, no clear evidence of benefit in fracture healing has been reported.[53, 54] No controlled trials of PROP use in healing of navicular fractures are underway.[55]

Recovery Phase

Rehabilitation Program

Physical Therapy

After the affected foot has been placed in a non–weight-bearing cast for 6 weeks, the cast is removed and tenderness at the N spot is assessed. If tenderness persists, then an additional 2 weeks of non–weight-bearing cast immobilization is recommended. However, if tenderness is not present at the N spot, then weight-bearing activity may begin. This activity is limited to a gradual return to normal activity under the care of a sports physician or physical therapist. The therapy may include muscle strengthening, range-of-motion exercises, and soft-tissue massage.

A stepwise regimen for the course of activity is as follows:

  1. The patient participates in his or her normal activities of daily life (ADLs), which may include swimming, for 2 weeks (Weeks 1 and 2).

  2. If the athlete remains free of pain after 2 weeks, a gradual return to jogging may be prescribed.

  3. After 2 weeks of a gradually progressive jogging regimen (Weeks 3 and 4), the patient is again assessed for pain.

  4. If the patient remains free from pain after 2 weeks after gradually progressing in the jogging regimen, then the athlete may gradually return to full activity over the final 2 weeks of the rehabilitation program (Weeks 5 and 6).

Therapeutic Ultrasound may have a role in determining return to play decisions as pain with therapeutic ultrasound has corelated with MRI finding in navicular stress injuries.[56]

Medical Issues/Complications

Delayed union and nonunion produce persistent pain at the navicular.[57] Plain radiographs and/or a CT scan may show the persistent fracture. In such cases, referral to a surgeon is required for open reduction and fixation. In addition, fracture of the tarsal navicular may be complicated by avascular necrosis.

Surgical Intervention

A comparison study of surgery relative to conservative treatment by Potter showed no difference in an athlete's long-term return to activity.[47] However, tenderness was more common in the surgical group. Some athletes who successfully returned to activity for 2 years or more had persistent tenderness at the N-spot.

In a study by Saxena and Fullem that compared nonoperative treatment with operative treatment, navicular stress fractures took up to 4 months to heal, regardless of the therapy.[10]

Delayed union and nonunion of the navicular may require surgical intervention. A variety of techniques have been used for repair. These include (1) curettage and bone grafting, (2) internal fixation, (3) excision of the symptomatic ossicles, or (4) a combination of these techniques.

Other Treatment (Injection, manipulation, etc.)

A custom-molded orthotic with longitudinal and transverse arch support may be prescribed to help relieve stress on the navicular during this transition phase.

Maintenance Phase

Rehabilitation Program

Physical Therapy

In the maintenance phase, the athlete must adhere to the general guidelines that are indicated for preventing stress fractures. A constant level of daily activity should be maintained, and the athlete should increase or decrease this level only gradually. The athlete should initiate new activities and sports in the same gradual manner.

Medical Issues/Complications

As outlined in the Clinical, Causes section, an attempt should be made to identify a precipitating event or defect in training that contributed to the stress fracture.

Diet

Assess diet for deficiencies in Calcium and Vitamin D as well as an overall Nutritional assessment. 

Prevention

There is some evidence that Calcium and Vitamin D supplements decrease the incidence of stress fractures, particularly in females. Smoking, low physical activity and poor nutritional status are also known risk factors for stress fractures.

 

Medication

Medication Summary

As with all fractures, pain management should be a primary concern. Often, acetaminophen or an NSAID (eg, ibuprofen) suffices for the acute pain of a navicular stress fracture because immobilization and rest should considerably improve the pain. Moreover, the persistence of pain, especially in the recovery phase, is an important sign that healing has not occurred and the fracture is still present. However, additional pain relief should not be withheld if the patient does not have relief with acetaminophen or NSAIDs alone. In this case, an opiate (eg, oxycodone) may be required, particularly for breakthrough pain. Adjustment of pain medications may be necessary, especially in the acute phase.

Analgesics

Class Summary

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients who have sustained trauma.

Acetaminophen (Tylenol, Feverall, Tempera, Aspirin-Free Anacin)

Indicated for mild to moderate pain. DOC for pain in patients with documented hypersensitivity to aspirin or NSAIDs, with upper GI disease, or who are taking oral anticoagulants.

Ibuprofen (Motrin, Ibuprin)

DOC for mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Oxycodone (OxyContin, OxyIR, Roxicodone)

Indicated for moderate to severe pain.

 

Follow-up

Return to Play

After 6 weeks of not bearing weight on the injured foot, the patient is assessed for pain at the N spot. If the patient is free from pain, a gradual return to normal activity is begun. This gradual return should be in a stepwise fashion over 6 weeks. The specifics of this regimen are discussed under Physical therapy in the Recovery Phase, Rehabilitation Program section, above.

Complications

The complications of a navicular stress fracture can include delayed union, nonunion, and progression to overt fracture-dislocation.[11, 12, 13, 14, 15, 16, 17, 18] Any of these complications can lead to prolonged disability and/or arthritis of the talonavicular joint. Up to 14% of patients treated correctly do not return to previous activities. Often, these complications require surgical intervention.

Prevention

In general, proper and well-fitting equipment, a gradual increase in activities, and a gradual approach to new activities limit the risk of stress fractures. Shock-absorbing inserts in footwear may reduce the incidence of lower-extremity stress fractures in military recruits.[28, 58]

Prognosis

Using the aforementioned stepwise regimen of 6 weeks of not bearing weight on the injured foot, followed by a gradual return to normal activity (see Physical therapy in the Recovery Phase, Rehabilitation Program section, above), one can expect 86% of patients who receive such treatment to return to normal activity.

Patient Education

Importantly, recognize that navicular stress fractures can occur in a wide range of athletes in many different sports, and that the diagnosis is made based on clinical considerations, positive bone scan findings, and confirmatory CT scan findings. However, once the diagnosis is made, non–weight-bearing treatment often results in full recovery.