> Table of Contents > Stress Fracture
Stress Fracture
Nandhini Veeraraghavan, MD, CAQSM
image 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
    • Metatarsal bones
    • Fibula
    • 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
  • Accounts for as many as 8% of visits to sports medicine and orthopedic clinics
  • Occurs in <1% of general population
Prevalence
  • Affects 5% of military recruits
  • Affects 1-3% of college athletes
ETIOLOGY AND PATHOPHYSIOLOGY
  • Bone is a dynamic tissue that is constantly remodeling in response to applied physiologic stress.
  • Repetitive loading or overuse causes microfractures that can'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
    • Female athlete triad (low energy availability with or without disordered eating, menstrual dysfunction, and low bone mineral density)
    • History of previous stress fracture
    • History of osteoporosis, osteomalacia, rheumatoid arthritis, corticosteroid therapy
    • Skeletal malalignment: pes cavus, pes planus, leg length discrepancies, excessive forefoot varus, tarsal coalitions, prominent posterior calcaneal process, tight heel cords
    • 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
    • Type of exercise—running, track and field, basketball, gymnastics, soccer, and dance are highest risk.
    • Rapid increase in mileage, running pace, or training volume
    • Inappropriate footwear
    • Hard training surface
    • Inadequate recovery or rest and training with fatigued muscle
  • Tobacco use
GENERAL PREVENTION
  • Avoid abrupt increases in physical activity (no more than 10% increase in load per week).
  • Reduce intensity and duration of activity if newonset 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 heelto-toe strike) by using a heel pad insert.
  • Shock-absorbing foot inserts may help.
  • Increasing calcium and vitamin D intake may reduce stress fracture rates in female runners and military recruits.
COMMONLY ASSOCIATED CONDITIONS
  • Osteoporosis/osteopenia
  • Female athlete triad
  • Metabolic bone disorders
image DIAGNOSIS
PHYSICAL EXAM
  • Height, weight, BMI, and any stigmata of disordered eating (cold extremities, hypercarotenemia, lanugo hair, calluses on back of fingers, poor oral hygiene, parotid gland hypertrophy, bradycardia, or orthostatic hypotension)
  • Antalgic gait
  • Point tenderness or percussion tenderness over injury site
  • Placing a vibrating tuning fork over the fracture site may intensify pain.
  • Swelling may be present.
  • Specific tests:
    • Hop test for tibial stress fracture: cannot hop on one leg 10 times; if able to perform test, consider shin splints (medial tibial stress syndrome).
    • Fulcrum test for femoral stress fracture: With patient seated, provoke pain by applying downward force on the distal femur while other hand uses the midthigh as fulcrum on femoral shaft (use with caution to avoid completing a femoral neck stress fracture if clinical suspicion is high).
    • Single-leg hyperextension (Stork) test for pars interarticularis fracture of lumbar spine: Stand on leg of symptomatic side and extend lumbar spine. Positive if painful.
  • Anatomic malalignment may be present (leg length discrepancy, pes planus/cavus).
DIFFERENTIAL DIAGNOSIS
  • Shin splints (medial tibial stress syndrome—pain resolves with rest; stress fracture pain does not)
  • Infection (osteomyelitis)
  • Soft tissue injury (sprain, tendonitis, and periostitis)
  • Compartment syndrome
  • Bony fracture
  • Neoplasm (osteoid osteoma)
  • Entrapment syndromes
  • Intermittent claudication
DIAGNOSTIC TESTS & INTERPRETATION
  • None unless clinically indicated for suspected disease (e.g., female athlete triad, hyperparathyroidism, and vitamin D deficiency)
  • Plain films:
    • First line in suspected stress fracture
    • Findings typically seen 2 to 8 weeks after onset of pain.
    • Sensitivity during early stages (1 to 2 weeks) may be as low as 10%.
    • May see periosteal callus, “gray cortex sign” (region of decreased cortical intensity), osteopenia, endosteal reaction, or ill-defined cortical margin
    • Severe cases may show discrete fracture.
Follow-Up Tests & Special Considerations
  • MRI:
    • Gold standard for imaging stress fractures
    • Very sensitive
    • Better evaluation of exact anatomic location and extent of injury
  • Bone scan:
    • Sensitive but nonspecific for stress fracture
    • Should not be used to assess healing process
  • P.991

  • CT scan:
    • Less sensitive than MRI or bone scan for early stress fractures but has an important role in evaluating occult fractures of foot, tibia, carpal scaphoid, and pars interarticularis
    • Can distinguish diseases (osteoid osteoma, malignancy, and osteomyelitis) that mimic stress fracture on bone scan
    • Bony detail provided by CT scan allows differentiation of complete versus incomplete fracture, especially when MRI is equivocal.
  • US:
    • Not routinely used but may be of particular help in the evaluation of metatarsal stress fracture to distinguish from other causes of metatarsalgia (e.g., Morton neuroma)
  • Classification by radiographic grading (1)
  • Grade I: normal x-ray, positive short time inversion recovery (STIR) MRI
  • Grade II: normal x-ray, positive STIR + positive T2-weighted MRI
  • Grade III: discrete line or discrete periosteal reaction on x-ray, positive T1/T2-weighted MRI but with no definite cortical break
  • Grade IV: fracture or periosteal reaction on x-ray, positive T1/T2-weighted fracture line.
image TREATMENT
  • Protection, rest, ice, compression, and elevation (PRICE) for acute pain and edema
  • Decrease activity to the level of pain-free functioning.
  • Pain at rest or with gentle range of motion (ROM) may require temporary immobilization.
  • Painful ambulation requires patients use crutches with periodic walking trial to assess readiness for nonaided ambulation.
  • Pneumatic leg brace is effective in decreasing the return-to-play time for tibial shaft stress fracture (2)[C].
  • For low-risk stress fracture, slowly increase impact loading once ambulation and daily activities are pain free. Progression of activity depends on the individual and should be modified according to symptoms (3,4).
  • High-risk fractures often require immediate immobilization and a period of non-weight-bearing. Many patients will require early surgical intervention to avoid nonunion and facilitate earlier return to sport (5,6).
  • In bisphosphonate-associated femoral stress fracture, prophylactic nail fixation may avoid fracture completion, shorten hospital stay, and decrease subsequent morbidity (7)[C].
MEDICATION
First Line
  • Calcium and vitamin D supplementation should be initiated when dietary intake is inadequate or deficiencies are found.
  • Acetaminophen
  • NSAIDs are beneficial for pain and inflammation but may adversely affect fracture healing and should, therefore, be used only sparingly.
  • Bisphosphonates theoretically could treat stress fractures by suppressing bone remodeling. There is no conclusive evidence to prove that this improves fracture healing in humans. Currently, only case reports have shown benefit (8)[A].
ISSUES FOR REFERRAL
Orthopedic consultation for high-risk fractures, failure to improve with standard treatment, evidence of nonunion within 3 to 4 weeks, or inability to tolerate rehabilitation
ADDITIONAL THERAPIES
  • Electrical stimulation may be an adjunct for delayed union and nonunion.
  • Extracorporeal shock wave therapy (ESWT) and pulsed US may have some potential benefits but require additional study (9)[A].
  • Physical therapy:
    • Correct training errors and inappropriate mechanics predisposing to stress fracture.
    • Strengthen muscles around the site of stress fracture.
    • Encourage cross-training to maintain fitness.
    • Correct anatomic variations.
    • Antigravity treadmills
image ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
  • Once the patient is pain free, low-impact training can start and be advanced gently as tolerated.
  • Once running has resumed, increase mileage slowly.
Patient Monitoring
Radiographs every 4 to 6 weeks to document healing progress
PATIENT EDUCATION
  • Gradually increase activity as long as pain free
  • Rest and reevaluate if there is a recurrence of pain.
  • Correct mechanical and training errors.
  • Strengthen core muscles.
PROGNOSIS
  • Stress fractures in young people have a good prognosis.
  • Older patients or those with metabolic bone disease often develop insufficiency fractures in other bones.
  • Time to return to full activity:
    • Grade I: 3+ weeks
    • Grade II: 5+ weeks
    • Grade III: 11+ weeks
    • Grade IV: 14+ weeks
REFERENCES
1. Beck BR, Bergman AG, Miner M, et al. Tibial stress injury: relationship of radiographic, nuclear medicine bone scanning, MR imaging, and CT severity grades to clinical severity and time to healing. Radiology. 2012;263(3):811-818.
2. Matheson GO, Brukner P. Pneumatic leg brace after tibial stress fracture for faster return to play. Clin J Sport Med. 1998;8(1):66.
3. Mayer SW, Joyner PW, Almekinders LC, et al. Stress fractures of the foot and ankle in athletes. Sports Health. 2014;6(6):481-491. doi:10.1177/1941738113486588.
4. Pegrum J, Crisp T, Padhiar N. Diagnosis and management of bone stress injuries of the lower limb in athletes. BMJ. 2012;344:e2511. doi:10.1136/bmj.e2511.
5. Shindle MK, Endo Y, Warren RF, et al. Stress fractures about the tibia, foot, and ankle. J Am Acad Orthop Surg. 2012;20(3):167-176.
6. Behrens SB, Deren ME, Matson A, et al. Stress fractures of the pelvis and legs in athletes: a review. Sports Health. 2013;5(2):165-174.
7. Ward WG Sr, Carter CJ, Wilson SC, et al. Femoral stress fractures associated with long-term bisphosphonate treatment. Clin Orthop Relat Res. 2012;470(3):759-765.
8. Shima Y, Engebretsen L, Iwasa J, et al. Use of bisphosphonates for the treatment of stress fractures in athletes. Knee Surg Sports Traumatol Arthrosc. 2009;17(5):542-550.
9. Griffin XL, Smith N, Parsons N, et al. Ultrasound and shockwave therapy for acute fractures in adults. Cochrane Database Syst Rev. 2012;(2):CD008579. doi:10.1002/14651858.CD008579.pub2.
Additional Reading
&NA;
  • Chen YT, Tenforde AS, Fredericson M. Update on stress fractures in female athletes: epidemiology, treatment, and prevention. Curr Rev Musculoskelet Med. 2013;6(2):173-181. doi:10.1007/s12178-013-9167-x.
  • Ross AC, Manson JE, Abrams SA, et al. The 2011 report on dietary reference intakes for calcium and vitamin D from the Institute of Medicine: what clinicians need to know. J Clin Endocrinol Metab. 2011;96(1):53-58.
See Also
&NA;
Algorithm: Foot Pain
Codes
&NA;
ICD10
  • M84.38XA Stress fracture, other site, initial encounter for fracture
  • M84.369A Stress fracture, unsp tibia and fibula, init for fx
  • M84.376A Stress fracture, unspecified foot, init encntr for fracture
Clinical Pearls
&NA;
  • The diagnosis of stress fractures requires a high index of suspicion. X-rays are often negative initially.
  • Identify and treat female athletic triad to prevent stress fractures.
  • Progress activity levels gradually and avoid sudden increases in activity or running mileage to help prevent stress fractures.
  • High-risk fractures often require immobilization and surgery.