Stress fractures in the lower extremity: The importance of increasing awareness amongst radiologists
Introduction
Using the term stress fracture may be confusing, as it has different meanings in contemporary literature. Most authors use it to indicate fatigue fractures, where others use it in its proper meaning, indicating a group of fractures made up of fatigue fractures and insufficiency fractures (including pathologic fractures). In this article it is used as a substitute for fatigue fractures.
Stress fractures belong to the wide spectrum of overuse injuries. Due to their strenuous training activities, military recruits and competitive athletes are primarily affected and have been subject of most articles written about stress fractures. However, the increase in participation of recreational athletes in major sports events (i.e. marathon running), often pushing their limits, have led to an increase of stress fractures in this population as well. Increased incidence has subsequently increased understanding of stress fracture mechanism and behavior, resulting in recognition of low and high risk sub categories.
In 1855, the Prussian military physician Breithaupt was the first to describe the stress fractures in the metatarsals of soldiers, now commonly referred to as a march fracture, depicting clinical setting and symptoms [1]. Forty years later, only 2 years after the discovery of roentgen and its clinical application, Stechow reported on radiographic identification of metatarsal stress fractures [2]. The diagnosis remained a solely military one until Pirker reported on the first stress fracture diagnosed in an athlete, a transverse femoral shaft fracture, in 1934 [3]. Devas was the first to report a large series of stress fractures in athletes in 1956 [4]. Since then, stress fractures have been increasingly reported upon in medical literature in both clinical and research settings.
This paper intends to increase radiologists’ awareness of stress fractures and to give a compact overview of background on stress fractures. The clinical picture and symptoms of stress fractures will be described and special attention will be given to the imaging options available for early diagnosis of the condition, as this has significant implications for treatment and outcome, which are also briefly discussed. Although stress fractures can occur in almost any bone, 95% of stress fractures occur in the lower extremity. Therefore, stress fractures of the lower extremity are the focus of this paper.
Section snippets
Etiology
The risk of stress fractures is influenced by many factors, being divided into intrinsic (gender, age, race, fitness and muscle strength) and extrinsic factors (training regimen, footwear, training surface and type of sport), biomechanical factors (bone mineral density and bone geometry), anatomic factors (foot morphology, leg length discrepancy and knee alignment), hormonal factors (delayed menarche, menstrual disturbance and contraception) and nutritional factors (low calcium and vitamin D
Imaging
Radiologists play a central role in detecting stress fractures and ruling out differentials by using state of the art imaging techniques. Radiographs are notoriously unreliable at an early stage, but are mandatory to rule out differentials like tumor, infection or frank fracture. However, if radiographs are negative more advanced techniques should be applied, timely diagnosis being essential for treatment and prognosis. Accurate estimates of return to competition time is another benefit of
Treatment and prevention
Relative rest, meaning cessation of the offending activity, will be adequate therapy in lower grade low risk stress fractures, while immobilization by bed rest or use of crutches may be necessary in higher grades. However, high risk stress fractures at certain anatomic locations will not heal without surgery or are likely to evolve to delayed union, non-union or displaced complete fractures. Important examples of these high risk stress fractures are tension sided femoral neck, patella, anterior
Femur/femoral neck (tension side = high risk, compression side = low risk)
Stress fractures of the femur can occur throughout the bone, but most commonly affect the femoral neck, one of the contributing factors being fatigue of the gluteus medius muscle resulting in diminished shock absorbance [37]. In addition to the general risk factors mentioned earlier, coxa vara seem to predispose for femoral neck fractures [38]. The complications of femoral neck fractures make this entity more important than its incidence, possible devastating results for the athlete ensue if
Conclusion
Raised awareness of medical staff and increased athletic activity have increased the incidence of stress fractures, now making up about 15% of the general sports medicine practice. These fractures can affect essentially every bone in the body, but are most frequent in the lower extremity. Timely diagnosis is essential to prevent dramatic consequences for the athlete, yet this is not easy. Thorough knowledge of typical sport mechanics and a high index of suspicion is needed to accurately image a
References (48)
- et al.
The pathophysiology of stress fractures
Clin Sports Med
(2006) - et al.
Do microcracks decrease or increase fatigue resistance in cortical bone?
J Biomech
(2004) - et al.
Imaging of stress fractures in the athlete
Radiol Clin North Am
(2002) Imaging of stress fractures
Clin Sports Med
(2006)- et al.
Stress injuries of bone: analysis of MR imaging staging criteria
Acad Radiol
(1998) - et al.
Femoral diaphyseal stress fractures: results of a systematic bone scan and magnetic resonance imaging evaluation in 25 runners
Phys Ther Sport
(2004) - et al.
The use of MR imaging in the assessment and clinical management of stress reactions of bone in high-performance athletes
Clin Sports Med
(1997) - et al.
16-Detector multislice CT in the detection of stress fractures: a comparison with skeletal scintigraphy
Clin Radiol
(2005) - et al.
The effect of prophylactic treatment with risedronate on stress fracture incidence among infantry recruits
Bone
(2004) - et al.
MR imaging of stress reactions, muscle injuries, and other overuse injuries in runners
Magn Reson Imaging Clin N Am
(1999)
Bone stress injuries of the talus in military recruits
Bone
Zur Pathologie des Menschlichen Fusses
Med Z
Fussoedem und Roentgenstrahlen
Dtsch Mil -Aerztl Z
Bruch der Oberschenkeldiaphyse durch Muskelzug
Arch Klin Chir
Stress fractures of the fibula; a review of fifty cases in athletes
J Bone Joint Surg Br
Stress Fractures
Presence of microscopic cracks in vivo bone
Henry Ford Hosp Bull
Mechanisms and management of stress fractures in physically active persons
J Athl Train
Modeling and remodeling responses to normal loading in the human lower limb
Am J Phys Anthropol
The behaviour of microcracks in compact bone
Eur J Morphol
Bone stress injuries in asymptomatic elite recruits: a clinical and magnetic resonance imaging study
Am J Sports Med
Bone stress injuries of the lower extremity: a review
Acta Orthop Scand
MR imaging, bone scintigraphy, and radiography in bone stress injuries of the pelvis and the lower extremity
Acta Radiol
Stress fractures
Radiology
Cited by (79)
Nonoperative Management of Tibial Stress Fractures Result in Higher Return to Sport Rates Despite Increased Failure Versus Operative Management: A Systematic Review
2023, Arthroscopy, Sports Medicine, and RehabilitationStress fracture of proximal tibia after proximal fibula osteotomy: A case report
2021, International Journal of Surgery Case ReportsCitation Excerpt :Stress fractures that occur in normal bone are often called fatigue fractures, whereas those that occur in abnormal bone (such as osteoporotic bone) are called deficiency fractures [15]. Most stress fractures occur in the lower limb bones, including the tibia (23.6%), navicular bone and metatarsals (17.6%), fibula (approximately 16%), and femur (6.6%), and the pelvic bones (1.6%) and spine (0.6%) may also develop stress fractures [16]. Stress fractures were first described by Breithaupt [17] in soldiers in the 19th century.
Stress Imaging of Bone
2021, Clinics in Sports MedicineAtypical femoral fracture as the cause of greater trochanteric pain syndrome – a case report
2021, Radiology Case ReportsCitation Excerpt :In our case, the patient showed no signs of healing or callus on repeat X-ray and MRI, and as no medical or conservative treatment helped the pain, internal fixation was performed with good pain relief. MRI is the gold standard in early recognition of stress fractures [7]. We have identified a similar case [13] in which GTPS was believed to be caused by pain generated by a femoral osteoid osteoma, but were only identified after a hip fracture had occurred.
Extreme Sports Injuries to the Pelvis and Lower Extremity
2018, Radiologic Clinics of North AmericaCitation Excerpt :At follow-up, this increases up to 30% to 70% because of the more extensive bone reaction.2 Findings in cortical bone include endosteal/periosteal callus formation, circumferential periosteal reaction with fracture line through one cortex, or frank fracture.2 In cancellous bone, findings include flakelike patches of new bone formation, cloudlike mineralized bone, or focal linear sclerosis perpendicular to the trabeculae.2
Fatigue evaluation of long cortical bone using ultrasonic guided waves
2018, Journal of Biomechanics