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Incidence of 14 to 35% of all stress fractures.
May account for up to 35% of stress fractures in athletes.
Incidence may be increasing due to advances in imaging.
Highest incidence of stress fractures occurs in field and track atheletes in jumping and sprinting events.
Military recruits have an incidence of navicular fractures approaching that of athletes, as the training of military recruits.
Incidence of navicular stress fracture is related participation in sports.
Commonly not evident on plain radiographs leadsing to a delay in diagnosis.
Delay in diagnosis may result in prolonged disabling foot pain in individuals.
4 types of navicular fractures are (1) cortical avulsion, (2) tuberosity, (3) body, and (4) stress.
Avulsion fractures are the most common types of fracture of the navicular.
Avulsion fracture is often associated with ligamentous injuries and results from twisting forces on the mid foot.
Avulsion fractures are commonly treated conservatively, except for avulsion of the posterior tibial tendon insertion, a tuberosity fracture, which is usually repaired surgically.
Fractures of the navicular body are commonly associated with other injuries of the midtarsal joint.
Navicular body fracturescan be divided into 3 types: Type 1 is a coronal fracture with no dislocation, Type 2 is a dorsolateral to plantomedial fracture with medial forefoot displacement and Type 3 is a comminuted fracture with lateral forefoot displacement and carries the worst prognosis.
Navicular body fractures with 1 mm or more of displacement require open reduction and internal fixation.
Stress fractures are usually sports-related injuries.
Navicular stress fractures are underdiagnosed and can lead to significant disability if the diagnosis is delayed.
Average time between stress fracture and diagnosis was estimated to be 7 months. (Torg et al).
Navicular stress fractures should be considered in any athlete with midfoot pain.
Navicular stress fractures take up to 4 months to heal posttreatment.
Uncommonly, fracture-dislocation of the navicular may occur in athletes and requires reduction and confirmation of stability, otherwise internal fixation is required.
Pain is of insidious onset and may have been present for months.
Pain often worsens with activity and improves with rest and may be present at the dorsum of the foot, or it may radiate along the medial longitudinal arch.
Swelling is variable.
Physical examination demonstrates tenderness at the proximal dorsal portion of the navicular bone.
Negative radiographic findings does not rule out the presence of a navicular fracture.
Bone scan is useful for making the diagnosis with ncreased radionuclide uptake occurs at the navicular.
Computed tomography scan can provide definitive diagnosis, and helps to define the location and extent of the fracture.
MRI is the imaging technique of choice for diagnosing navicular stress fractures.
Most patients are can be treated with a non–weight-bearing cast for 6 weeks.
In patients who have pain only after significant exertion avoidance of running for 6-8 weeks may be sufficient treatment.
Complete fractures with wide separation may benefit from surgery.
Delayed union and nonunion may be associated with persistent pain.
86% of patients who receive standard treatment return to normal activity.