Figure 1. Initial radiograph taken in the emergency room; the opaque spots on the first metatarsal are the sesamoid bones.
Figure 2. Radiograph taken 8 weeks after injury.
A 17-year-old adolescent presents with left foot pain that has persisted for the last 8 weeks. She is an avid runner and 3 weeks ago had a radiograph showing a subtle periosteal reaction around the distal third metatarsal (Figure 1). She was placed in a walking boot and has avoided running since. A second radiograph taken in the office (Figure 2) shows significant callus formation around the distal third metatarsal. On physical examination, the patient has mild tenderness to palpation over the distal third metatarsal. The patient is concerned about how the stress fracture occurred.
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The incidence of lower extremity stress fractures is much more common in girl and women athletes compared with boys and men.1 Metatarsal stress fractures are particularly common among girl/women runners and dancers. Stress fractures are more common in the second and third metatarsal due to their length and relative immobility.1
Early radiographic findings for a stress fracture may include a subtle radiolucency of the shaft and/or cortex. Subtle periosteal bone formation may be seen as early as 2 weeks from injury and thicker callus formation is usually seen 4 to 6 weeks after the injury. Risk factors for stress fractures include inadequate dietary intake (which is associated with athletic amenorrhea), lack of rest to allow for proper bone turnover and healing, and a 25 hydroxy vitamin D level <40 ng/mL.2
Treatment involves resting the foot with an immobilizer; weight-bearing as tolerated. With a hard-soled shoe taking pressure off the metatarsals, nonweight-bearing restrictions are unnecessary.1
Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor in chief of the Journal of Orthopaedics for Physician Assistants.
1. Frank RM, Romeo AA, Bush-Joseph CA, Bach BR Jr. Injuries to the female athlete in 2017. Part I: general considerations, concussions, stress fractures, and the female athlete triad. JBJS Rev. 2017;5(10):e4. doi:10.2106/JBJS.RVW.17.00017
2. Miller JR, Dunn KW, Ciliberti LJ Jr, Patel RD, Swanson BA. Association of vitamin D with stress fractures: a retrospective cohort study. J Foot Ankle Surg. 2016;55(1):117-120. doi:10.1053/j.jfas.2015.08.002