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Navicular Stress Fractures in Identical Twin Runners

High-Risk Fractures Require Structured Treatment

Steven R. Murray, DA; Michael Reeder, DO; Troy Ward; Brian E. Udermann, PhD, ATC


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In Brief: Tarsal navicular fractures require an accurate and timely diagnosis to prevent costly and disabling complications. Diagnosis requires a thorough clinical evaluation that focuses on the patient's history, particularly his or her training regimen, and diet—as was the case with these 17-year-old girls. Plain radiography, ultrasound, bone scintigraphy, MRI, and CT help make a definitive diagnosis. Treatment of low-risk fractures involves relative rest and cessation of the precipitating activity. High-risk fractures often require non-weight-bearing immobilization, coupled with therapy, and may require surgery.

Stress fractures are common overuse injuries seen in athletic and military populations. The condition was first described in 1855 by Breithaupt.1 These injuries have been observed in numerous areas of the skeletal system2 but occur primarily in the bones of the lower extremities, particularly the tibia.3 Less than 1% of the general athletic population reports a stress fracture. Nonetheless, specific stress fractures are often associated with different sports (eg, the spine in gymnastics, the ribs in golf), and most stress fractures occur in the lower extremities of runners, who have an incidence rate as high as 20%.4

Stress fractures account for about 10% of all athletic injuries3 and are commonly seen by clinicians. Most stress fractures are rather straightforward, are characterized by insidious onset of localized pain that worsens with repetitive activity, and are classified as low risk.5 However, some stress fractures are accompanied by vague pain, may be difficult to diagnose quickly, can lead to complications and a prolonged recovery, and are described as high risk.4 In general, stress fractures are classified as low risk or high risk depending on their location and potential for serious sequelae.

We describe a case of high-risk stress fractures in the tarsal navicular bones of identical twin girls participating in high school distance running. This case demonstrates the insidious nature of these fractures, which often are overlooked by clinicians.

Case Report

History. Seventeen-year-old identical twin, female distance runners presented to our clinic 3 weeks apart with recurring foot pain of several weeks' duration. Both patients described insidious onset of foot pain after they added speed work to their normal training schedule of 50 miles of distance running per week during the spring track season.

Neither patient had a history of swelling, bruising, neurologic symptoms, or night pain. Most symptoms occurred only during running, but they could be elicited through palpation. Both patients had a history of menstrual irregularities consistent with oligomenorrhea (one had been taking oral contraceptives but had recently stopped using them), and one reported a prior posteromedial tibial stress fracture that healed without sequelae. The patients' self-reported diet histories revealed no specific abnormalities, except that both patients disliked dairy products and did not consistently consume calcium supplements.

Examination findings. Physical exams on both patients revealed minimal bilateral pronation. Gait analysis was otherwise unremarkable. The patients were 5 ft 3 in. tall and weighed 115 lb (body mass index [BMI] of 20.4 kg/m2) and 117 lb (BMI of 20.7), respectively. Both patients had diffuse tenderness to palpation in the proximal, medial, anterior aspect of the foot and reported pain directly over the navicular ("N" spot). There was no evidence of swelling, ecchymosis, skin changes, or instability of the foot or ankle. Range of motion was symmetric, with no increase in pain with resisted dorsiflexion of the foot.

Diagnostic tests. Initial plain radiographs were normal in both patients (figure 1). The initial bone scan in the first patient showed diffuse uptake in the talonavicular area (figure 2). Magnetic resonance imaging (MRI) of the first patient revealed a nondisplaced stress fracture of the navicular bone of the left foot and a stress reaction in the navicular bone of the right foot. An MRI of the second patient indicated a nondisplaced navicular stress fracture (figure 3). Neither patient's MRI revealed a complete fracture through both the dorsal and plantar cortices.

Treatment. Both patients' injured feet were immobilized in non-weight-bearing casts for 6 weeks. After the casts were removed, the patients were fitted with semirigid, molded orthoses and were allowed to gradually return to training over 8 weeks. The patients initially used crutches and graduated to minimal weight-bearing activities that were followed by aquatic therapy, ankle rehabilitation, cycling, and then jogging.

The importance of periodized training, especially gradual increases in speed training and the incorporation of recovery and rest days, was emphasized to both patients. They also received nutritional counseling from a registered dietitian, who emphasized proper caloric intake and calcium supplementation. Both patients went on to compete successfully during the fall cross-country season with no recurring injuries.


Our patients are textbook examples of runners who experience stress fractures. They presented with localized pain after having aggressively increased their running speed in their workouts. Initial plain radiographs were negative, which is typical for runners who develop sudden, localized bone pain because of stress fractures.6 In fact, it generally takes up to 3 weeks for stress fractures to be visible on x-rays.7 The definitive diagnosis for most stress fractures is ascertained through the response to simple rest.6

Stress fractures typically heal completely within 2 months of complete rest from the aggravating activity. However, most athletes, especially distance runners, are unwilling to accept a 2-month layoff from training without visible evidence of injury, as was the case with our patients. Furthermore, indications for more specific treatment may result from the use of advanced imaging. Thus, we obtained MRIs, which showed tarsal navicular stress fractures. Bone scans, while quite sensitive, do not show as much anatomic detail as an MRI. Nonetheless, one is not a precursor to the other.

Because our patients were female and oligomenorrheic, they were at higher risk for stress fractures. Girls and women are up to 12 times more likely to suffer stress fractures than boys and men are,8 and those who have menstrual irregularities are at an even higher risk.9

Another factor that likely contributed to the patients' conditions was their diet. Athletes who consume calcium-deficient diets are also more susceptible to stress fractures.10

Immobilization with strict non-weight-bearing casts was warranted. Treatment consisting of only rest, followed by a gradual return to activity, often results in delayed union and nonunion of the bone in high-risk fractures.11 Complete immobilization in a non-weight-bearing cast for 6 weeks is recommended to treat an incomplete fracture and is the approach we successfully employed.

Because our patients experienced the same fracture, albeit in different feet, the problem was multifactorial and could best be addressed by educating them about periodized training, having them optimize their diet and take a calcium supplement, and by fitting them with orthoses to correct possible faulty biomechanics. The management plan was successful, as the patients' fractures healed, and they were able to train throughout the summer and compete during the fall cross-country season with no further injuries.

Review of Stress Fractures

Most stress fractures seen in athletes are rather straightforward, with the patient reporting insidious, localized pain after a marked increase in the duration or intensity of exercise, typically running. The pathogenesis of stress fractures is cyclic, repetitive loading of the bone that causes incremental damage that ultimately exceeds the skeletal system's reparative ability. Bone is a dynamic tissue that adapts to the stresses put upon it; however, when bone resorption outpaces bone formation, the bone becomes more fragile and highly susceptible to stress fractures.12

Multiple factors contribute to the development of stress fractures, such as bone composition, vascular supply, hormonal imbalances, nutritional status, and physical activity. Biomechanical factors also play a major role, with three mechanical events leading to stress fractures: (1) the applied load is increased; (2) the number of repetitions is increased; or (3) the load is applied to a smaller surface area.2

Identifying the contributing factors and modifying or eliminating them to prevent recurrence is paramount to proper diagnosis and treatment of stress fractures. This necessitates evaluating the patient's training history—specifically, any recent, abrupt changes in intensity and duration—in addition to running terrain, shoes, biomechanical abnormalities, diet, bone density, and, in women, menstrual history. Training errors are the predominant cause of stress fractures, but in female patients, diagnosis could be more complex, especially with respect to the female athlete triad (ie, osteoporosis, amenorrhea, and disordered eating),12 and these factors should be assessed as well.

Most stress fractures—those considered to be low risk—are relatively easy to recognize through patient history and palpation, because the athlete will feel sharp pain directly over the fracture. Low-risk fractures generally heal in 6 to 8 weeks with rest from the aggravating activity.5 Patients should be encouraged to maintain fitness through cross-training. Causes of the stress fracture must be eliminated (eg, through training adaptations, diet and supplement modifications, and the use of orthoses) before the athlete resumes the precipitating activity.

Several specific stress fractures have been described as especially challenging, troublesome, or high risk because of the potential for delayed union, nonunion, or complete fracture.4 These stress fractures, which may require surgical treatment, occur in the femoral neck, patella, anterior cortex of the tibia, medial malleolus, talus, tarsal navicular bones (as seen in this case), fifth metatarsal, and great toe sesamoid bones.

In regard to diagnosis of navicular fractures, two recent papers13,14 recommend the use of computed tomography (CT) in the initial evaluation. The authors suggest that CT can help physicians determine whether surgical or nonsurgical treatment is warranted. Additionally, Kaeding et al13 proposed that all complete fractures that are visible on CT, regardless of the presence or absence of sclerotic margins, be treated with open reduction internal fixation and 6 to 8 weeks of postoperative immobilization. Several authors have proposed using CT to confirm healing before proceeding with aggressive rehabilitation and allowing the patient to return to activity.14 Table 1 lists the typical sites of high-risk stress fractures, their signs and symptoms, suggested examination procedures, and proposed treatments.

TABLE 1. Presentation, Evaluation, and Treatment of High-Risk Stress Fractures
SiteSigns and SymptomsDiagnostic EvaluationTreatment*
Femoral neckUsually insidious pain in
the groin, buttock, or knee
Usually requires bone
scan or MRI
ORIF for distraction-type
PatellaInsidious pain; may
relate to ACL surgery
Requires MRIORIF for chronic or
displaced fractures
Tibia (anterior)Anterior tibial pain'Dreaded black line'
on lateral plain films
Consider intermedullary
nailing in elite athletes
Medial malleolusMedial ankle painMay be seen on plain films;
may require MRI or bone scan
Possible ORIF in complete
TalusInsidious ankle painUsually requires MRI
or CT
immobilization unless
fracture is displaced
Tarsal navicularInsidious midfoot painUsually requires MRI or CTORIF in complete fractures
Fifth metatarsalPain in mid- to proximal
fifth metatarsal
Often seen on plain filmsConsider ORIF in elite
Great toe sesamoidsTenderness directly over
the plantar aspect of the
first MTP joint
May be seen on plain films;
MRI may help differentiate
acute from chronic stress
Conservative treatment
initially; surgical evaluation
may be needed if
treatment fails
*Some controversy exists in the literature regarding proper treatment of high-risk stress fractures.4,11-14 We have listed treatments for the most serious spectrum of fractures. Initial conservative treatment requires a minimum of 6 to 8 weeks of non-weight-bearing immobilization. Surgery is often needed.

MRI = magnetic resonance imaging; ORIF = open reduction and internal fixation; ACL = anterior cruciate ligament; CT = computed tomography; MTP = metatarsophalangeal

Back on Track

Many stress fractures are easily recognized and can be treated successfully with relative rest and cessation of the precipitating activity. However, some stress fractures are considered high risk on the basis of their potential morbidity and require non-weight-bearing immobilization, therapy, and possibly surgery. This discussion of stress fractures should provide clinicians with a better understanding of the presentation, evaluation, and treatment of high-risk stress fractures. In light of our example, further considerations on genetic predispositions and family nutrition should be studied.


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Dr Murray is head of the department of human performance and wellness at Mesa State College in Grand Junction, Colorado. Dr Reeder is a physician at Western Orthopedics and Sports Medicine, Grand Junction, and a team physician for Mesa State College. Mr Ward is an athletic training student in the department of human performance and wellness at Mesa State College. Dr Udermann is an assistant professor at the department of exercise and sport science at the University of Wisconsin, La Crosse. Address correspondence to Steven R. Murray, DA, Dept of Human Performance and Wellness, Mesa State College, 1100 North Ave, Grand Junction, CO 81501; e-mail to [email protected].

Disclosure information: Drs Murray, Reeder, and Udermann and Mr Ward disclose no significant relationship with any manufacturer of any commercial product mentioned in this article. No drug is mentioned in this article for an unlabeled use.