eMedicine Specialties > Physical Medicine and Rehabilitation > Lower Limb Musculoskeletal Conditions
Stress Fracture
Updated: Aug 10, 2009
Introduction
Background
Stress fractures are overuse injuries of bone. These fractures, which may be nascent or complete, result from repetitive subthreshold loading that, over time, exceeds the bone's intrinsic ability to repair itself. Briefhaupt originally described stress fractures in military recruits in 1855. Our present understanding of the pathophysiology of stress fractures and of bone's response to loading has been advanced by numerous studies investigating the epidemiology of stress fractures in military recruits and in athletes.
Stress fractures most commonly occur in the lower limbs as a result of the ground-reaction forces (GRFs) that must be dissipated during running, walking, marching, or jumping. Stress fractures of the vertebral arch, upper limbs, ribs, and even the scapula have also been described and are not uncommon in some sports. (See images below and Images 1-3.)
This image is of a 17-year-old male wrestler with a 2-month history of left-sided low back pain, worse with extension. Total body scintigraphy findings were unremarkable. Courtesy of Michael Spieth, MD, and Nandita Bhattacharjee, MD, MHA; Marshfield Clinic Department of Radiology.
Same patient as in Images 1 and 3. Single-photon emission computed tomography (SPECT) images demonstrate abnormal delayed uptake in the posterior elements of L5. Courtesy of Michael Spieth, MD, and Nandita Bhattacharjee, MD, MHA; Marshfield Clinic Department of Radiology.
Same patient as in Images 1-2. Subsequent MRI revealed an area of bright signal in the left pars interarticularis of L5 on T2-weighted images, confirming the diagnosis of acute unilateral spondylolysis. The patient was treated successfully with activity restriction and bracing with a lumbar corset for 3 months, at which point he was asymptomatic. Plain film imaging at follow-up (not shown) was unremarkable, with no evidence of spondylolysis on oblique views. Courtesy of Michael Spieth, MD, and Nandita Bhattacharjee, MD, MHA; Marshfield Clinic Department of Radiology.
Pathophysiology
Bone, like muscle, is an adaptable tissue capable of repair, regeneration, and remodeling in response to environmental (particularly mechanical) signals. Bones are exposed to both stress (ie, load) and strain (ie, deformation) with weight-bearing exercise. One measure of load is GRF, which can approach 12 times body weight during jumping and landing. Factors influencing the local skeletal response to loading include bone geometry and bone density. For example, cortical (ie, long) bones are generally more resistant to compressive forces than trabecular bones, but long bones also experience more strain in response to torsion or bending forces. In addition, a bone's strength is roughly proportional to the square of its mineral density; thus, osteopenic bone is weaker than bone of normal density.
Wolff law states that bone develops the structure most suited to resist the forces acting upon it. The ability of bone to remodel has tremendous clinical consequences. For example, an individual on prolonged bed rest quickly begins to lose bone mineral density (BMD). Conversely, an athlete who engages in a sporting discipline that requires repetitive jumping and landing is likely to have a higher BMD than a sedentary person. Such adaptation is the result of a continuous process of bone resorption and subsequent repair mediated at the cellular level by osteoclasts and osteoblasts, respectively.
Advanced cross sectional imaging has demonstrated that bone responds to repetitive loading via a continuum of stress responses that precede the onset of clinical symptoms. In their study involving a cohort of military recruits, Kiuru et al reported that only 40% of the MRI findings suggestive of a low-grade bone stress injury correlated with clinical symptoms.1 The vast majority of the radiographically detected areas of bone stress reaction remained clinically silent despite uninterrupted training, and disappeared upon follow-up imaging at the conclusion of the 5-month training program. Therefore, under normal circumstances, bone appears able to keep up with necessary repairs without manifesting clinically significant injury as it remodels in accordance with Wolff law. However, when a bone's reparative and adaptive capacity is overwhelmed by chronic overload, damage can begin to accumulate. If allowed to progress, this multifactorial process may eventually result in a stress fracture.
Animal studies have demonstrated that bone subjected to repetitive cyclical loading develops what has been termed microdamage. Furthermore, a physiological threshold appears to exist, below which such microdamage is not detectable. Increased osteoclastic activity at sites of bone stress or strain may cause transient weakening of the bone locally, predisposing the area to microdamage. Unless given appropriate time for healing and osteoblastic-mediated bone deposition, adjacent sites of microdamage are thought to coalesce, giving rise to an area of stress reaction or injury. At this stage, the individual may be minimally symptomatic and conventional radiographs are likely to appear normal. With progressive overload, the bone becomes increasingly vulnerable and the individual proceeds to develop symptoms that are thought to reflect the extent of underlying bone injury.
If uninterrupted, the process may culminate in a stress fracture. Some clinicians prefer to distinguish between stress fractures of normal bone that becomes fatigued through abnormal loading (ie, fatigue fractures) and stress fractures of pathologic bone that may fail even under comparatively normal loads (ie, insufficiency fractures). However, both processes are characterized by disrupted bone homeostasis and inadequate repair in the face of repetitive overload.
Frequency
United States
Estimates of the annual incidence of stress fractures among athletes and military recruits range from 5-30%. Stress fractures are among the 5 most common injuries suffered by runners and have been reported to account for up to half of the injuries sustained by military recruits. The interaction between genetic susceptibility and other internal and external risk factors determines an individual's likelihood of sustaining a bony stress injury.
Race
Stress fractures probably occur less frequently among African Americans than among whites by virtue of the generally higher BMD found in African Americans.
Sex
Most studies suggest that females are at increased risk of developing stress fractures compared with males. The incidence of stress fractures among female military recruits and athletes has been reported to be twice that of their male counterparts. Disordered eating places females at higher risk of developing stress fractures. The clinician should be mindful that a stress fracture may herald the existence of underlying amenorrhea, disordered eating, and osteoporosis (the "female athlete's triad"). Therefore, diagnosis of a stress fracture in a female should prompt the clinician to obtain a dietary history to ensure adequate intake of both energy (calories) and calcium. Finally, in the proper clinical context, a stress fracture should alert the clinician to the possibility of osteoporosis or other underlying skeletal pathology.
Age
Stress fractures typically affect individuals who are more active, and the incidence probably increases with age due to age-related reduction in BMD. By no means, however, should the diagnosis be dismissed in children, whose bones have not reached peak density and strength.
- Interestingly, some evidence suggests that the risk of stress fracture may be lower among adult runners who have a broad athletic background that includes childhood participation in "ball sports." This finding provides additional incentive for coaches and parents to avoid promoting early sport-specialization among young athletes.
Clinical
History
The most salient historical feature in the diagnosis of stress fracture is the insidious onset of activity-related pain.
- Early on, the pain typically is mild and occurs toward the end of the inciting activity.
- Subsequently, the pain may worsen and occur earlier, limiting participation in sports activities.
- While rest may provide transient relief of symptoms in the early stages, as the stress injury progresses, the athlete's pain may persist even after cessation of activity.
- Night pain is a frequent complaint.
- Pain resulting from long-bone fractures is thought to be localized, while pain associated with stress injury of trabecular bone is characteristically described as more diffuse.
- Stress fractures, like most overuse injuries, typically are multifactorial in etiology; thus, if the diagnosis has been made or is suspected, the clinician is in the position to try to determine what risk factors precipitated or contributed to the injury.
- Details of the athlete's training history should be noted, both in terms of volume and intensity.
- Intensive sustained muscular activity may result in bone strain and overload. This type of mechanism of injury is common in rowers, who are prone to stress fractures of the ribs.
- Muscle fatigue, perhaps because of poor conditioning or as the result of overtraining, can attenuate the shock-absorbing capacity of the muscular system, resulting in greater transmission of GRFs to the associated parts of the skeleton.
- Structural malalignments (eg, leg-length discrepancies) or biomechanical inefficiencies (eg, excessive subtalar pronation) can result in increased stress and strain on the tibiae.
- Concurrent injury may result in subclinical biomechanical adaptations along the kinetic chain, placing atypical loads on bone and precipitating a stress injury.
- Poor bone health, whether because of hormonal, dietary, or pathological causes (eg, osteoporosis, hyperparathyroidism, skeletal involvement from malignancy), can weaken bone and make it more susceptible to injury.
- These conditions and other intrinsic and extrinsic risk factors for the development of stress fractures are summarized in Causes below.
Physical
Upon physical examination, individuals with stress fractures typically report pain upon palpation or percussion of the affected area.
- Inspection of the site may reveal localized swelling and, possibly, erythema.
- Loading the affected bone using specific maneuvers (such as the "hop test" or the "fulcrum test") may reproduce the athlete's pain. Note that no single physical examination test is sufficiently sensitive and specific to permit the unequivocal diagnosis of a stress fracture. Rather, taking the individual's history and examination into consideration, the clinician must have sufficient clinical suspicion to include the diagnosis among the different possible causes of the presenting complaints.
- Some practitioners believe that application of a vibrating tuning fork over the affected bone can provoke the athlete's pain, but Brukner et al dispute the validity of this test.2
- As part of a thorough physical examination, the practitioner should assess the athlete's flexibility, lower limb alignment (including leg lengths), foot structure (eg, pes cavus vs pes planus), and motor function (eg, evaluating for strength imbalances).
Causes
Disrupted bone homoeostasis and inadequate repair in the face of repetitive overload cause stress fractures. A variety of risk factors are thought to predispose individuals to the development of stress fractures.- Intrinsic risk factors
- Low BMD (potentially modifiable)
- Lower limb malalignment (potentially modifiable)
- Foot structure (unmodifiable)
- Height - Tall stature (unmodifiable)
- Muscle fatigue/poor overall conditioning (modifiable)
- Weakness/strength imbalance (modifiable)
- Pathologic bone states (potentially unmodifiable)
- Menstrual/hormonal irregularities (potentially modifiable)
- Genetic predisposition (unmodifiable)
- Extrinsic risk factors
- Excessive volume or intensity of training (modifiable)
- Sporting discipline (modifiable) - For example, runners are prone to tibial shaft stress fractures, whereas tennis players appear to be most vulnerable to navicular injuries, and volleyball players may be at a relatively increased risk of pars interarticularis injuries.
- Change in training regimen - "New coach" phenomenon (potentially modifiable)
- Change in training surface - Density or topography (modifiable)
- Worn-out training shoes (modifiable)
- Cigarette smoking (modifiable)
- Inadequate nutrition - Energy (calories), calcium, vitamin D (modifiable)
- Medication usage - For example, chronic steroid use (potentially modifiable)
More on Stress Fracture |
Overview: Stress Fracture |
| Differential Diagnoses & Workup: Stress Fracture |
| Treatment & Medication: Stress Fracture |
| Follow-up: Stress Fracture |
| Multimedia: Stress Fracture |
| References |
| Further Reading |
| Next Page » |
References
Kiuru MJ, Niva M, Reponen A, Pihlajamaki HK. Bone stress injuries in asymptomatic elite recruits: a clinical and magnetic resonance imaging study. Am J Sports Med. Feb 2005;33(2):272-6.
Brukner P, Bennell K, Matheson G. Stress Fractures. 1st ed. Melbourne, Australia: Blackwell Science Asia; 1999.
Bui-Mansfield LT, Thomas WR. Magnetic resonance imaging of stress injury of the cuneiform bones in patients with plantar fasciitis. J Comput Assist Tomogr. Jul-Aug 2009;33(4):593-6. [Medline].
Arendt E, Agel J, Heikes C, Griffiths H. Stress injuries to bone in college athletes: a retrospective review of experience at a single institution. Am J Sports Med. Nov-Dec 2003;31(6):959-68. [Medline].
Sairyo K, Katoh S, Takata Y. MRI signal changes of the pedicle as an indicator for early diagnosis of spondylolysis in children and adolescents: a clinical and biomechanical study. Spine. Jan 15 2006;31(2):206-11.
Kuhn KM, Riccio AI, Saldua NS, et al. Acetabular retroversion in military recruits with femoral neck stress fractures. Clin Orthop Relat Res. Jul 9 2009;[Medline].
Snyder RA, Deangelis JP, Koester MC, et al. Does shoe insole modification prevent stress fractures? A systematic review. HSS J. Jun 9 2009;[Medline].
Anderson K, Sarwark JF, Conway JJ, et al. Quantitative assessment with SPECT imaging of stress injuries of the pars interarticularis and response to bracing. J Pediatr Orthop. Jan-Feb 2000;20(1):28-33. [Medline].
Swenson EJ, DeHaven KE, Sebastianelli WJ, et al. The effect of a pneumatic leg brace on return to play in athletes with tibial stress fractures. Am J Sports Med. May-Jun 1997;25(3):322-8. [Medline].
Whitelaw GP, Wetzler MJ, Levy AS, et al. A pneumatic leg brace for the treatment of tibial stress fractures. Clin Orthop. Sep 1991;(270):301-5. [Medline].
Entwistle RC, Sammons SC, Bigley RF, et al. Material properties are related to stress fracture callus and porosity of cortical bone tissue at affected and unaffected sites. J Orthop Res. Apr 20 2009;[Medline].
Keeley A, Bloomfield P, Cairns P, et al. Iliotibial band release as an adjunct to surgical management of patellar stress fracture in the athlete: a case report and review of the literature. Sports Med Arthrosc Rehabil Ther Technol. Jul 30 2009;1(1):15. [Medline].
Arendt EA. Stress fractures and the female athlete. Clin Orthop. Mar 2000;(372):131-8. [Medline].
Bennell K, Brukner P. How Should You Treat a Stress Fracture?. Evidence-based Sports Medicine. 2002;491-517.
Bennell K, Matheson G, Meeuwisse W, Brukner P. Risk factors for stress fractures. Sports Med. Aug 1999;28(2):91-122. [Medline].
Buvanendran A, Reuben SS. COX-2 inhibitors in sports medicine: utility and controversy. Br J Sports Med. Nov 2006;40(11):895-6.
Callahan LR. Stress fractures in women. Clin Sports Med. Apr 2000;19(2):303-14. [Medline].
DiFiori JP. Stress fracture of the proximal fibula in a young soccer player: a case report and a review of the literature. Med Sci Sports Exerc. Jul 1999;31(7):925-8.
Donahue SW, Sharkey NA. Strains in the metatarsals during the stance phase of gait: implications for stress fractures. J Bone Joint Surg Am. Sep 1999;81(9):1236-44. [Medline].
Ellerin BE, Helfet D, Parikh S, et al. Current therapy in the management of heterotopic ossification of the elbow: a review with case studies. Am J Phys Med Rehabil. May-Jun 1999;78(3):259-71. [Medline].
Finestone A, Giladi M, Elad H, et al. Prevention of stress fractures using custom biomechanical shoe orthoses. Clin Orthop. Mar 1999;(360):182-90. [Medline].
Fredericson M, Ngo J, Cobb K. Effects of ball sports on future risk of stress fracture in runners. Clin J Sport Med. May 2005;15(3):136-41.
Green NE, Rogers RA, Lipscomb AB. Nonunions of stress fractures of the tibia. Am J Sports Med. May-Jun 1985;13(3):171-6. [Medline].
Ho ML, Chang JK, Chuang LY, et al. Effects of nonsteroidal anti-inflammatory drugs and prostaglandins on osteoblastic functions. Biochem Pharmacol. Sep 15 1999;58(6):983-90. [Medline].
Hofmann AA, Bloebaum RD, Koller KE. Does celecoxib have an adverse effect on bone remodeling and ingrowth in humans?. Clin Orthop Relat Res. Nov 2006;452:200-4.
Hoy G, Wood T, Phillips N. When physiology becomes pathology: the role of magnetic resonance imaging in evaluating bone marrow oedema in the humerus in elite tennis players with an upper limb pain syndrome. Br J Sports Med. Aug 2006;40(8):710-3; discussion 713.
Ivkovic A, Bojanic I, Pecina M. Stress fractures of the femoral shaft in athletes: a new treatment algorithm. Br J Sports Med. Jun 2006;40(6):518-20; discussion 520.
Johnson BA, Neylon T, Laroche R. Lesser metatarsal stress fractures. Clin Podiatr Med Surg. Oct 1999;16(4):631-42. [Medline].
Jones BH, Knapik JJ. Physical training and exercise-related injuries. Surveillance, research and injury prevention in military populations. Sports Med. Feb 1999;27(2):111-25. [Medline].
Jones BH, Thacker SB, Gilchrist J, et al. Prevention of lower extremity stress fractures in athletes and soldiers: a systematic review. Epidemiol Rev. 2002;24(2):228-47. [Medline].
Kaufman KR, Brodine SK, Shaffer RA, et al. The effect of foot structure and range of motion on musculoskeletal overuse injuries. Am J Sports Med. Sep-Oct 1999;27(5):585-93. [Medline].
Kibler WB. ACSM's Handbook for the Team Physician. Baltimore, Md: Williams & Wilkins; 1996.
Kibler WB, Herring SA, Press JM. Functional Rehabilitation of Sports and Musculoskeletal Injuries. Aspen Publishers: Gaithersburg, Md; 1998.
Komatsubara S, Sairyo K, Katoh S. High-grade slippage of the lumbar spine in a rat model of spondylolisthesis: effects of cyclooxygenase-2 inhibitor on its deformity. Spine. Jul 15 2006;31(16):E528-34.
Lauder TD, Dixit S, Pezzin LE, et al. The relation between stress fractures and bone mineral density: evidence from active-duty Army women. Arch Phys Med Rehabil. Jan 2000;81(1):73-9. [Medline].
Lippi G, Franchini M, Guidi GC. Non-steroidal anti-inflammatory drugs in athletes. Br J Sports Med. Aug 2006;40(8):661-2; discussion 662-3.
Maquirriain J, Ghisi JP. The incidence and distribution of stress fractures in elite tennis players. Br J Sports Med. May 2006;40(5):454-9; discussion 459.
Milgrom C, Simkin A, Eldad A, et al. Using bone''s adaptation ability to lower the incidence of stress fractures. Am J Sports Med. Mar-Apr 2000;28(2):245-51. [Medline].
Miller SF, Congeni J, Swanson K. Long-term functional and anatomical follow-up of early detected spondylolysis in young athletes. Am J Sports Med. Jun 2004;32(4):928-33.
Milner CE, Ferber R, Pollard CD. Biomechanical factors associated with tibial stress fracture in female runners. Med Sci Sports Exerc. Feb 2006;38(2):323-8.
Murnaghan M, Li G, Marsh DR. Nonsteroidal anti-inflammatory drug-induced fracture nonunion: an inhibition of angiogenesis?. J Bone Joint Surg Am. Nov 2006;88 Suppl 3:140-7.
Neal BC, Rodgers A, Clark T, et al. A systematic survey of 13 randomized trials of non-steroidal anti- inflammatory drugs for the prevention of heterotopic bone formation after major hip surgery. Acta Orthop Scand. Apr 2000;71(2):122-8. [Medline].
Orava S, Karpakka J, Hulkko A, et al. Diagnosis and treatment of stress fractures located at the mid-tibial shaft in athletes. Int J Sports Med. Aug 1991;12(4):419-22. [Medline].
Rauh MJ, Macera CA, Trone DW. Epidemiology of stress fracture and lower-extremity overuse injury in female recruits. Med Sci Sports Exerc. Sep 2006;38(9):1571-7.
Rome K, Handoll HH, Ashford R. Interventions for preventing and treating stress fractures and stress reactions of bone of the lower limbs in young adults. Cochrane Database Syst Rev. 2005;CD000450.
Shaffer RA, Rauh MJ, Brodine SK. Predictors of stress fracture susceptibility in young female recruits. Am J Sports Med. Jan 2006;34(1):108-15.
Shikare S, Samsi AB, Tilve GH. Bone imaging in sports medicine. J Postgrad Med. Jul-Sep 1997;43(3):71-2. [Medline].
Simkin A, Leichter I, Giladi M, et al. Combined effect of foot arch structure and an orthotic device on stress fractures. Foot Ankle. Aug 1989;10(1):25-9. [Medline].
Sinha AK, Kaeding CC, Wadley GM. Upper extremity stress fractures in athletes: clinical features of 44 cases. Clin J Sport Med. Oct 1999;9(4):199-202. [Medline].
Soler T, Calderon C. The prevalence of spondylolysis in the Spanish elite athlete. Am J Sports Med. Jan-Feb 2000;28(1):57-62. [Medline].
Standaert CJ, Herring SA. How Should You Treat Spondylolysis in the Athlete?. Evidence-based Sports Medicine. 2002;239-265.
Stasinopoulos D. Treatment of spondylolysis with external electrical stimulation in young athletes: a critical literature review. Br J Sports Med. Jun 2004;38(3):352-4.
Stewart GW, Brunet ME, Manning MR, Davis FA. Treatment of stress fractures in athletes with intravenous pamidronate. Clin J Sport Med. Mar 2005;15(2):92-4.
Stovitz SD, Arendt EA. NSAIDs should not be used in treatment of stress fractures. Am Fam Physician. Oct 15 2004;70(8):1452, 1454. [Medline].
Torstveit MK, Sundgot-Borgen J. The female athlete triad: are elite athletes at increased risk?. Med Sci Sports Exerc. Feb 2005;37(2):184-93.
Välimäki VV, Alfthan H, Lehmuskallio E, et al. Risk factors for clinical stress fractures in male military recruits: a prospective cohort study. Bone. Aug 2005;37(2):267-73.
Van der Wall H, McLaughlin A, Bruce W, et al. Scintigraphic patterns of injury in amateur weight lifters. Clin Nucl Med. Dec 1999;24(12):915-20. [Medline].
Varner KE, Younas SA, Lintner DM, Marymont JV. Chronic anterior midtibial stress fractures in athletes treated with reamed intramedullary nailing. Am J Sports Med. Jul 2005;33(7):1071-6.
Wheeler P, Batt ME. Do non-steroidal anti-inflammatory drugs adversely affect stress fracture healing? A short review. Br J Sports Med. Feb 2005;39(2):65-9.
Further Reading
Related eMedicine articles:
Femoral Neck Stress and Insufficiency Fractures
Femoral Neck Fracture
Femur Injuries and Fractures
General Principles of Fracture Care
Metatarsals, Fractures
Pars Interarticularis Injury
Pelvis, Insufficiency Fractures
Stress Fracture [Radiology]
Stress Fractures
Clinical guidelines:
ACR Appropriateness Criteria® stress/insufficiency fracture, including sacrum, excluding other vertebrae. American College of Radiology - Medical Specialty Society. 1995 (revised 2008). 8 pages. NGC:007002
Clinical trials:
Bone Geometry, Strength, and Biomechanical Changes in Runners With a History of Stress Fractures
Keywords
stress fracture, stress fractures, metatarsal fracture, stress fracture foot, stress fracture treatment, stress fracture symptoms, stress fracture tibia, tibial stress fracture, stress fracture femur, fatigue fracture, insufficiency fracture, stress fracture of the lower limbs, lower limb stress fracture, overuse injury, overuse injuries, bone mineral density, disrupted bone homeostasis, inadequate bone repair, bone strain, pars interarticularis stress fracture, spondylolysis, neck of the femur stress fracture, femur neck stress fracture, stress fracture of the tibia, second metatarsal stress fracture






Overview: Stress Fracture