Stress Fracture is a topic covered in the 5-Minute Clinical Consult.

To view the entire topic, please or purchase a subscription.

Medicine Central™ is a quick-consult mobile and web resource that includes diagnosis, treatment, medications, and follow-up information on over 700 diseases and disorders, providing fast answers—anytime, anywhere. Explore these free sample topics:

Medicine Central

-- The first section of this topic is shown below --

Basics

Description

  • Overuse injuries caused by cumulative microdamage from repetitive bone loading
  • Stress fractures occur in different situations:
    • Fatigue fracture: abnormal stress applied to normal bone (e.g., young college athletes or new military recruits with increased physical activity demands and inadequate conditioning)
    • Insufficiency fracture: normal stress applied to structurally abnormal bone (e.g., femoral neck fracture in osteopenic bone)
    • Combination fracture: abnormal stress applied to abnormal bone (e.g., female long-distance runners with premature osteoporosis from female athletic triad)
  • Weight-bearing bones of the lower extremity are most commonly affected at the following sites:
    • Tibia/fibula
    • Metatarsal bones
    • Navicular
    • Femoral neck
    • Pars interarticularis
  • Less commonly affected sites:
    • Pelvis
    • Calcaneus
    • Ribs
    • Ulna
  • High-risk stress fractures occur in zones of tension or areas with poor blood supply and are more likely to result in fracture displacement and/or nonunion. High-risk sites include the following:
    • Tension side of femoral neck
    • Anterior tibial diaphysis
    • Sesamoids
    • Pars interarticularis of lumbar spine (L4, L5)
    • 5th metatarsal at metaphyseal–diaphyseal junction
    • Proximal 2nd metatarsal
    • Medial malleolus
    • Tarsal navicular
    • Patella
    • Talar neck
  • Synonym(s): march fracture; fatigue fracture

Epidemiology

Incidence
  • Greatest incidence in 15- to 27-year-olds
  • Females more commonly affected than males
  • Affects 9–21% of track and field athletes annually
  • Up to 95% of stress fractures occur in the lower extremities (1)[A].
  • Among runners, stress fractures account for 15–20% of all musculoskeletal related injuries (1)[A].
  • Across all sports, the most commonly injured body sites are the lower leg (40.3%), foot (34.9%), lower back/lumbar spine/pelvis (15.2%) (2)[C].
  • Occurs in <1% of general population

Prevalence
  • Affects 5% of military recruits
  • Affects 1–3% of college athletes

Etiology and Pathophysiology

  • Bone is dynamic and constantly remodeling in response to applied physiologic stress.
  • Repetitive loading or overuse causes microfractures that don’t heal due to imbalance between bone resorption and bone formation.
  • If microdamage accumulates in excess of reparation, bony fatigue leads to stress fracture.

Risk Factors

  • Intrinsic (1)[A]
    • Females are at 2.3 times higher risk than males.
    • Female athlete triad (low energy availability with or without disordered eating, menstrual dysfunction, and low bone mineral density)
    • History of previous stress fracture—increases risk of future stress fracture by 5 times
    • History of osteoporosis, osteomalacia, rheumatoid arthritis, prolonged corticosteroid therapy
    • Body composition—increased risk of stress fractures with BMI <19
    • Skeletal malalignment: pes cavus, pes planus, leg length discrepancies, excessive forefoot varus, tarsal coalitions, prominent posterior calcaneal process, tight heel cords
    • Biomechanical factors such as increased vertical loading rate (e.g., heel-to-toe running instead of forefoot striking)
    • Muscle fatigue and decreased lean muscle mass
    • Extremes of body size and composition
    • Previous inactivity or low aerobic fitness
  • Extrinsic (1)[A]
    • Type of exercise—both male and female athletes who participate in running, track and field, cross country, and gymnastics are at highest risk (2)[C].
    • Training regimen—running >32 km/week increases risk by 2 times in all athletes, by 3 times in female athletes.
    • Nutritional/dietary habits—history of a diagnosed eating disorder
    • Rapid increase in mileage, running pace, or training volume
    • Inappropriate footwear
    • Hard training surface
    • Inadequate recovery or rest and training with fatigued muscle
    • There is no evidence that use of oral contraceptives is related to stress fracture risk.

General Prevention

  • Avoid abrupt increases in physical activity (no more than 10% increase in load per week).
  • Reduce intensity and duration of activity if new-onset pain.
  • Proper footwear
  • Increasing dynamic physical activity (jumping; plyometric training) increases bone density and resistance to mechanical stress.
  • Decrease vertical loading rate either by switching to forefoot strike running or (if continuing with heel-to-toe strike) by using a heel pad insert.
  • Shock-absorbing foot inserts may help.
  • Increased calcium and vitamin D intake may reduce stress fractures in female runners and military recruits.

Commonly Associated Conditions

  • Osteoporosis/osteopenia
  • Female athlete triad
  • Metabolic bone disorders

-- To view the remaining sections of this topic, please or purchase a subscription --

Citation

* When formatting your citation, note that all book, journal, and database titles should be italicized* Article titles in AMA citation format should be in sentence-case
TY - ELEC T1 - Stress Fracture ID - 117075 ED - Baldor,Robert A, ED - Domino,Frank J, ED - Golding,Jeremy, ED - Stephens,Mark B, BT - 5-Minute Clinical Consult, Updating UR - https://im.unboundmedicine.com/medicine/view/5-Minute-Clinical-Consult/117075/all/Stress_Fracture PB - Wolters Kluwer ET - 27 DB - Medicine Central DP - Unbound Medicine ER -