AUTHOR AND EDITOR INFORMATION

Section 1 of 11  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

INTRODUCTION

Section 2 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

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 follows⁶:

• 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} In a study by Torg et al in 1982, the average time between the fracture and diagnosis was estimated to be 7 months.⁸ 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.⁹

Fracture-dislocation of the navicular may occur in athletes.^{10, 11, 12, 13, 14, 15, 16, 17} 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 eMedicine's Foot, Ankle, Knee, and Hip Center, Fractures and Broken Bones Center, Breaks, Fractures, and Dislocations Center, and Sports Injury Center. Also, see eMedicine's patient education articles Broken Foot and Cast Care.
 
Related eMedicine topics:
Dislocations, Foot
Fractures, Foot 
Stress Fracture [in the Radiology section]

Related Medscape topics:
Resource Center Exercise and Sports Medicine
Resource Center Trauma
CME/CE Medical Interventions Effectively Treat Overuse Injuries in Adult Endurance Athletes

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.^{18, 19, 20, 21, 22, 23, 24}

Among track-and-field athletes, up to 21% may experience a stress fracture in the course of a year.^{25, 26} In these athletes, up to 15% of stress fractures are of the navicular.²⁵ Other studies have demonstrated similar findings.^{27, 28, 29, 30} 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 more closely mirrors the training of athletes.^{27, 31, 32, 33}

Related eMedicine topics:
Metatarsals, Fractures [in the Radiology section]
Metatarsal Stress Fracture [in the Sports Medicine section]
Stress Fracture [in the Physical Medicine and Rehabilitation section]

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.

CLINICAL

Section 3 of 11  

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• Clinical
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• Follow-up
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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^{25, 26, 27, 28, 29, 30} – Particularly sports involving jumping and sprinting
• Ballet and other dancing activities³⁴
• Equestrian sports
• Basketball
• Soccer³⁵
• American football
• Australian-rules football
• Rugby
• Gymnastics³⁶
• Military training^{27, 31, 32, 33}

Related Medscape topics:
Resource Center Exercise and Sports Medicine
Resource Center Trauma
CME/CE Medical Interventions Effectively Treat Overuse Injuries in Adult Endurance Athletes

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 Image 1). This is the most important physical finding.
• 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 irregularities³⁷
  • 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

Related eMedicine topics:
Female Athlete Triad
Nutrition for the Female Athlete

Related Medscape topics:
Resource Center Exercise and Sports Medicine
Resource Center Osteoporosis

DIFFERENTIALS

Section 4 of 11  

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Other Problems to Be Considered

Accessory navicular: This condition manifests clinically as a painful bump of the medial navicular and is usually treated conservatively with nonsteroidal anti-inflammatory drugs (NSAIDs), activity modification, and/or orthotics. It may require excision for persistent pain.

Avascular necrosis of the navicular

Calcaneus bone injury

Köhler disease^{38, 39, 40}: Osteochondrosis of the navicular usually manifests in children younger than 6 years and is treated with short leg cast for up to 8 weeks.

Other midfoot fractures or dislocations

Planovalgus foot⁴¹

WORKUP

Section 5 of 11  

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• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• Multimedia
• References

Imaging Studies

• 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.
  • 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 (^99mTc) 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.
• 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 follows⁴²:
  • • 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.^{43, 44}
  • This study is relatively expensive.
• Ultrasound²⁰
• • 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.

TREATMENT

Section 6 of 11  

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• Follow-up
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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.

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.⁴⁵ In another study, bone healing took up to 4 months, for both operative and nonoperative treatment.⁹

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.

Other Treatment

Although no trials support the use of bone growth stimulators for navicular stress fractures, they may be a helpful adjunct.¹⁰ 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.^{46, 47, 48, 49} Whether these results are applicable to acute fractures and fractures of the navicular remains to be determined.

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).

Medical Issues/Complications

Delayed union and nonunion produce persistent pain at the navicular. 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.⁴⁵ 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.⁹

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.

MEDICATION

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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.

Related eMedicine topics:
Opioid Abuse
Toxicity, Acetaminophen
Toxicity, Narcotics
Toxicity, Nonsteroidal Anti-inflammatory Agents

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Resource Center Pain Management: Advanced Approaches to Chronic Pain Management 
Resource Center Pain Management: Pharmacologic Approaches
CME Integrating Ongoing Research and Knowledge into the Clinical Management of Chronic Pain
CME Overcoming Barriers to Pain Relief: An Interactive Patient Case Symposium
CME/CE Use of Multiple NSAIDs Reduces Arthritis Pain but May Increase Complications

Drug Category: Analgesics

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.

Drug Name	Ibuprofen (Motrin, Ibuprin)
Description	DOC for mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.
Adult Dose	400-600 mg PO q4-6h while symptoms persist; not to exceed 3.2 g/d
Pediatric Dose	<6 months: Not established 6 months to 12 years: 4-10 mg/kg/dose PO tid/qid >12 years: Administer as in adults
Contraindications	Documented hypersensitivity; in the presence of peptic ulcer disease, recent GI bleeding or perforation, renal insufficiency, or high risk of bleeding
Interactions	Coadministration with aspirin increases the risk of inducing serious NSAID-related adverse effects; probenecid may increase the concentrations and, possibly, the toxicity of NSAIDs; may decrease the effect of hydralazine, captopril, and beta-blockers; may decrease the diuretic effects of furosemide and thiazides; may increase PT duration when taking anticoagulants (instruct patients to watch for signs of bleeding); may increase the risk of methotrexate toxicity; phenytoin levels may be increased when administered concurrently
Pregnancy	B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus
Precautions	Caution in patients with congestive heart failure, hypertension, and decreased renal and hepatic function; caution in the presence of anticoagulation abnormalities or during anticoagulant therapy

Drug Name	Oxycodone (OxyContin, OxyIR, Roxicodone)
Description	Indicated for moderate to severe pain.
Adult Dose	5-30 mg PO q4h prn
Pediatric Dose	0.05-0.15 mg/kg/dose PO; not to exceed 5 mg/dose PO q4-6h prn
Contraindications	Documented hypersensitivity
Interactions	Phenothiazines may decrease the analgesic effects; toxicity increases with coadministration of either CNS depressants or TCAs
Pregnancy	C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions	Duration of action may increase in elderly persons; be aware of total daily dose of acetaminophen, and do not exceed 4 g/d, because higher doses may cause liver toxicity.

FOLLOW-UP

Section 8 of 11  

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• Clinical
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• Follow-up
• Miscellaneous
• Multimedia
• References

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.^{10, 11, 12, 13, 14, 15, 16, 17} 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.^{27, 50}

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.

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.

Related Medscape topics:
Resource Center Exercise and Sports Medicine
Resource Center Trauma
CME/CE Medical Interventions Effectively Treat Overuse Injuries in Adult Endurance Athletes

MISCELLANEOUS

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• Follow-up
• Miscellaneous
• Multimedia
• References

Medical/Legal Pitfalls

• The primary medicolegal pitfall with regard to navicular fractures in athletes is a delay in diagnosis. Because findings from plain radiographs are commonly normal in the presence of a navicular stress fracture, a high index of suspicion and a characteristic history should lead the physician toward further investigation.

Related Medscape topic:
Resource Center Medical Malpractice and Legal Issues

MULTIMEDIA

Section 10 of 11  

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• Follow-up
• Miscellaneous
• Multimedia
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Media file 1:  Palpation of the N spot.
	View Full Size Image
Media type:  Photo

REFERENCES

Section 11 of 11

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2. Dunjey M. Stress fractures in athletes. Department of Podiatry Encyclopedia. Perth, Australia: Curtln Health Science, Curtin University. 1999;1-14.
3. Ho K, Abu-Laban RB. Ankle and foot. In: Rosen P, Barkin RM, eds. Emergency Medicine: Concepts and Clinical Practice. 4^th ed. St Louis, Mo: Mosby-Year Book; 1998:836-56.
4. Marder RA, Lian GJ, eds. Midfoot: tarsal navicular stress fracture. Sports Injuries of the Ankle and Foot. New York, NY: Springer-Verlag; 1997:64-8.
5. Heckman JD. Fractures and dislocations of the foot. In: Rockwood CA, Green DP, eds. Rockwood and Green's Fractures in Adults. 4^th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 1996:2355-62.
6. Sangeorzan BJ, Benirschke SK, Mosca V, Mayo KA, Hansen ST Jr. Displaced intra-articular fractures of the tarsal navicular. J Bone Joint Surg Am. Dec 1989;71(10):1504-10. [Medline]. [Full Text].
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9. Saxena A, Fullem B. Navicular stress fractures: a prospective study on athletes. Foot Ankle Int. Nov 2006;27(11):917-21. [Medline].
10. Cohen M, Roman A, Lovins JE. Totally implanted direct current stimulator as treatment for a nonunion in the foot. J Foot Ankle Surg. Jul-Aug 1993;32(4):375-81. [Medline].
11. Samoladas E, Fotiades H, Christoforides J, Pournaras J. Talonavicular dislocation and nondisplaced fracture of the navicular. Arch Orthop Trauma Surg. Feb 2005;125(1):59-61. [Medline].
12. Pinney SJ, Sangeorzan BJ. Fractures of the tarsal bones. Orthop Clin North Am. Jan 2001;32(1):21-33. [Medline].
13. Garland DE, Moses B, Salyer W. Long-term follow-up of fracture nonunions treated with PEMFs. Contemp Orthop. Mar 1991;22(3):295-302. [Medline].
14. Fitch KD, Blackwell JB, Gilmour WN. Operation for non-union of stress fracture of the tarsal navicular. J Bone Joint Surg Br. Jan 1989;71(1):105-10. [Medline]. [Full Text].
15. Orava S, Hulkko A. Delayed unions and nonunions of stress fractures in athletes. Am J Sports Med. Jul-Aug 1988;16(4):378-82. [Medline].
16. Rymaszewski LA, Robb JE. Mechanism of fracture-dislocation of the navicular: brief report. J Bone Joint Surg Br. May 1988;70(3):492. [Medline]. [Full Text].
17. Coughlin L, Kwok D, Oliver J. Fracture dislocation of the tarsal navicular. A case report. Am J Sports Med. Nov-Dec 1987;15(6):614-5. [Medline].
18. Wall J, Feller JF. Imaging of stress fractures in runners. Clin Sports Med. Oct 2006;25(4):781-802. [Medline].
19. Lee S, Anderson RB. Stress fractures of the tarsal navicular. Foot Ankle Clin. Mar 2004;9(1):85-104. [Medline].
20. Craig JG, Jacobson JA, Moed BR. Ultrasound of fracture and bone healing. Radiol Clin North Am. Jul 1999;37(4):737-51, ix. [Medline].
21. Knapp TP, Garrett WE Jr. Stress fractures: general concepts. Clin Sports Med. Apr 1997;16(2):339-56. [Medline].
22. Arendt EA, Griffiths HJ. The use of MR imaging in the assessment and clinical management of stress reactions of bone in high-performance athletes. Clin Sports Med. Apr 1997;16(2):291-306. [Medline].
23. Alfred RH, Belhobek G, Bergfeld JA. Stress fractures of the tarsal navicular. A case report. Am J Sports Med. Nov-Dec 1992;20(6):766-8. [Medline].
24. Kiss ZS, Khan KM, Fuller PJ. Stress fractures of the tarsal navicular bone: CT findings in 55 cases. AJR Am J Roentgenol. Jan 1993;160(1):111-5. [Medline]. [Full Text].
25. Bennell KL, Malcolm SA, Thomas SA, Wark JD, Brukner PD. The incidence and distribution of stress fractures in competitive track and field athletes. A twelve-month prospective study. Am J Sports Med. Mar-Apr 1996;24(2):211-7. [Medline].
26. Bennell KL, Malcolm SA, Thomas SA, et al. Risk factors for stress fractures in track and field athletes. A twelve-month prospective study. Am J Sports Med. Nov-Dec 1996;24(6):810-8. [Medline].
27. Rome K, Handoll HH, Ashford R. Interventions for preventing and treating stress fractures and stress reactions of bone of the lower limbs in young adults. Cochrane Database Syst Rev. 2005;2:CD000450. [Medline].
28. Brukner P, Bradshaw C, Khan KM, White S, Crossley K. Stress fractures: a review of 180 cases. Clin J Sport Med. Apr 1996;6(2):85-9. [Medline].
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Article Last Updated: Feb 11, 2008