Classification and return-to-play considerations for stress fractures

Stress fractures are common injuries, particularly in endurance athletes. Stress fracture management should take into consideration the injury site (low risk versus high risk), the grade (extent of microdamage accumulation), and the individual's competitive situation. The authors briefly discuss the pathophysiology and diagnostic process of stress fractures and expand on the classification of stress fractures and its impact on return-to-play decision making based on the relative risk of the fracture.     

Stress fracture of the ulna occurring in military recruits after rifle drill training

Stress fractures are a common injury in military recruits in the lower extremities, but are rare in the upper limbs. The locations of reported stress fractures occurring in the upper extremities are mainly in the ulna and olecranon. We report on two cases of mid-ulnar stress fractures in a team of honor guards following rifle drill training from excessive weight lifting, repetitive pronation of the forearm, and a sudden increase in the training load. According to the report, some readjustment must be made in the training protocol for military recruits. Stress fractures are also being recognized as a prevalent problem in the upper body.     

Aetiology of rib stress fractures in rowers

Rib stress fractures are a common and significant problem in the rowing population. They occur in approximately 6.1 to 12% of rowers and account for the most time lost from on-water training and competition. This review discusses possible causative factors for rib stress fractures in rowers. Central to the establishment of causative factors is the identification that each rib forms part of a closed ring of bone that is completed anteriorly by the sternum and posteriorly by the thoracic vertebrae. Because of the shared sternum anteriorly each ring of bone is mechanically connected. Subsequently, during rowing individual ribs are not loaded in isolation, rather the rib cage is loaded as a complete unit. Incorporating this functioning as a complete unit a possible mechanism by which different factors contribute to rib stress fracture can be developed. In rowing, muscle factors generate loading of the rib cage. The characteristics of this loading stimulus are influenced by equipment, technique and joint factors. Rib-cage loading generates bone strain in individual ribs with the response of each rib depending upon site-specific skeletal factors. Depending on the characteristics of the bone strain in terms of the magnitude and rate of strain, microdamage may develop. The bone response to this microdamage is reparative remodelling. Whether this response is capable of repairing the damage to prevent progression to a stress fracture is dependent upon training and gender factors. Identification of these factors will generate a better understanding of the aetiology of this injury, which is required for improved prevention and treatment strategies.     

Pelvic stress fracture in female runners

Stress fractures are a common injury in long-distance runners, and typically involve the lower extremities. Although relatively rare, pubic ramus stress fractures also occur, primarily in female runners. Bone imaging visualized a pubic stress fracture and a tibial stress fracture in a female long-distance runner with groin pain. Pubic stress fractures should be considered in female runners who present with groin pain. Radionuclide bone imaging is useful in diagnosing these lesions.     

Stress fractures in elite male football players

The objective was to investigate the incidence, type and distribution of stress fractures in professional male football players. Fifty‐four football teams, comprising 2379 players, were followed prospectively for 189 team seasons during the years 2001–2009. Team medical staff recorded individual player exposure and time‐loss injuries. The first team squads of 24 clubs selected by UEFA as belonging to the 50 best European teams, 15 teams of the Swedish Super League and 15 teams playing their home matches on artificial turf pitches were included. In total, 51 stress fractures occurred during 1 180 000 h of exposure, giving an injury incidence of 0.04 injuries/1000 h. A team of 25 players can therefore expect one stress fracture every third season. All fractures affected the lower extremities and 78% the fifth metatarsal bone. Stress fractures to the fifth metatarsal bone, tibia or pelvis caused absences of 3–5 months. Twenty‐nine percent of the stress fractures were re‐injuries. Players that sustained stress fractures were significantly younger than those that did not. Stress fractures are rare in men's professional football but cause long absences. Younger age and intensive pre‐season training appear to be risk factors.     

Stress fractures in the female athlete

Stress fractures are common among female athletes, especially runners. Although both intrinsic and extrinsic factors can contribute to stress injury etiology, the female athlete triad—negative energy balance leading to menstrual irregularity, and reduced bone mineral mass—is a significant contributor to the incidence of stress fractures in the female athlete. When combined with impact weight-bearing activity, this triad puts these women at increased risk for stress fractures. Treatment must focus on reversing identified risk factors, in addition to relative rest, and maintenance of fitness. Most stress fractures heal without complication. High-risk stress fractures should be evaluated and treated by a practitioner with expertise in the care of these injuries.     

Epidemiology of stress fractures

Stress fractures are a frequent cause of injury in competitive and recreational athletes. Although a number of epidemiologic studies have been conducted, the populations studied and data collection methods have varied. This article presents an overview of injury epidemiology and reviews the current body of literature regarding the occurrence of stress fractures in athletes. Given the heterogeneity of the populations studied and the variations in data collection, few broad conclusions can be drawn. There is a pressing need for large prospective studies to better establish the risks of stress fracture by sport, age, and gender.     

Acetabular stress fractures in military endurance athletes and recruits: incidence and MRI and scintigraphic findings

OBJECTIVE: To evaluate the incidence and the MRI and scintigraphic appearance of acetabular stress (fatigue) fractures in military endurance athletes and recruits. DESIGN AND PATIENTS: One hundred and seventy-eight active duty military endurance trainees with a history of activity-related hip pain were evaluated by both MRI and bone scan over a 2-year period. Patients in the study ranged in age from 17 to 45 years. They had hip pain related to activity and had plain radiographs of the hip and pelvis that were interpreted as normal or equivocal. The study was originally designed to evaluate the MRI and scintigraphic appearance of femoral neck stress fractures. Patients had scintigraphy and a limited MRI examination (coronal imaging only) within 48 h of the bone scan. Twelve patients demonstrated imaging findings compatible with acetabular stress fractures. RESULTS: Stress fractures are common in endurance athletes and in military populations; however, stress fracture of the acetabulum is uncommon. Twelve of 178 patients (6.7%) in our study had imaging findings consistent with acetabular stress fractures. Two patterns were identified. Seven of the 12 (58%) patients had acetabular roof stress fractures. In this group, two cases of bilateral acetabular roof stress fractures were identified, one with a synchronous tensile sided femoral neck stress fracture. The remaining five of 12 (42%) patients had anterior column stress fractures, rarely occurring in isolation, and almost always occurring with inferior pubic ramus stress fracture (4 of 5, or 80%). One case of bilateral anterior column stress fractures was identified without additional sites of injury. CONCLUSIONS: Stress fractures are commonplace in military populations, especially endurance trainees. Acetabular stress fractures are rare and therefore unrecognized, but do occur and may be a cause for activity-related hip pain in a small percentage of military endurance athletes and recruits.     

Multiple Rib Stress Fractures

Stress fracture of the ribs, an uncommon overuse injury, may mimic recalcitrant intercostal or back muscle strain. This report describes a 36-year-old man who sustained multiple rib stress fractures after he took up golf. Fatigue of the serratus anterior muscle appeared to be the mechanism for his injury. Relative rest followed by strengthening exercises helped the patient return to pain-free activity.     

Stress fractures: current concepts.

Stress fractures are extremely common lesions that occur in specific areas and are related to specific activities. They are caused by increased muscular activity on bones that are not yet ready to take the increased pull of the involved muscles. The insufficiency type of stress fractures found in patients with bone of diminished mineral content is being recognized more often as increasing numbers of middle-aged and elderly persons are becoming more physically active. A variety of imaging studies can be used to diagnose stress fractures. Radionuclide bone scanning and MR imaging often show abnormalities early in the course of the injury. However, when radiographs appear normal, findings on scintigrams may be more suggestive of the proper diagnosis. In patients with suspected stress injury, radiographs should be obtained a second time, 1-2 weeks after the initial study. Biopsy should be avoided until evidence is clear-cut that the lesion has not changed over a short time.     

Outcomes of stress fractures of the talus

BACKGROUND: Stress fractures of the talus are rare, and only a few small studies have been published. In the absence of follow-up studies, the outcomes of these injuries are unknown. HYPOTHESIS: Traumatic fractures of the talus frequently heal poorly, and stress fracture healing might remain inadequate. The purpose of this study was to determine the outcome of stress fractures of the talus treated in the authors' institution with reduced exercise and nonweightbearing. STUDY DESIGN: Case series (prognosis); Level of evidence, 4. METHODS: Patients with a diagnosed stress fracture in the talus by magnetic resonance imaging between April 1997 and March 2005 were recalled for a follow-up inspection by an orthopaedic surgeon, magnetic resonance imaging, and plain radiographs to determine the outcome of the injury. RESULTS: One of the 9 patients in our sample declined the invitation, leaving 8 patients with 9 stress fractures in the talus who participated in the follow-up examination. Five patients displayed subchondral degeneration and edema near the original injury area in the follow-up magnetic resonance imaging. In 2 patients, the degeneration was also visible on the plain radiographs. Three patients had mild and 2 moderate symptoms after the mean follow-up time of 45 months (range, 12-74 months). No serious complications in the healing process were seen. CONCLUSION: Stress fractures of the talus do not seem to seriously damage the foot. In a middle-term follow-up, however, minor to moderate symptoms and radiological degeneration of the injured area prevailed in roughly half of the patients.     

Stress fracture of the ulna in a professional tennis player using a double-handed backhand stroke

Stress fractures of the ulna are uncommon injuries, but they have been reported in athletes from various sports. In tennis players stress fractures of the ulna are described exclusively in the nondominant forearm of athletes using a two-handed backhand stroke. We report such a case in a 24-year-old tennis player, with special emphasis on diagnostic imaging, accurate grading of the injury, and specific treatment recommendations.     

Low-risk stress fractures

Stress fractures can occur in almost any bone in the body, with the lower extremity weightbearing bones, especially the tibia, tarsals, and metatarsals, being affected most frequently. Although the cause of these fractures is multifactoral, repetitive physical forces without adequate rest are the primary culprits. Stress fractures may be broadly classified as low-risk or high-risk injuries. Low-risk stress fractures, the topic of this review article, can be diagnosed through a thorough history, physical examination, and radiographs. Nuclear scintigraphy is occasionally necessary for confirmation, especially for fractures of the spine and pelvis. When diagnosed early and treated with restriction of activity, low-risk stress fractures have a favorable prognosis.     

Stress fractures of the anklein the athlete

Stress fractures of the ankle in the athlete are related to one of several proposed theories. Athletes sustaining these injuries usually participate in impact loading activities. The most common locations for stress fractures involving the ankle joint are the supramalleolar region of the fibula and the medial malleolus. Stress fractures of the distal fibula are usually treated conservatively with rest, activity modifications, and a short period of immobilization. Healing times and return to activity may take up to 12 weeks. Stress fractures of the medial malleolus have a higher rate of delayed unions and nonunions and require a higher degree of monitoring. Operative management has become an accepted method of treating stress fractures of the medial malleolus.     

Bone stress lesions in ballet dancers: scintigraphic assessment

Ballet dancers are athletes susceptible to ligamentous and bony injury. We reviewed retrospectively the bone scans (technetium-99m methylene diphosphonate) of 23 ballet dancers with pain in the back and/or lower extremities to determine the usefulness of scintigraphy in the detection of stress lesions of bone. The scintigraphic studies in 19 dancers identified multiple areas of stress injury in both symptomatic and asymptomatic locations. Thirteen dancers had 22 stress fractures (microfractures of trabeculae with associated bone repair) manifested by an intense focus of increased uptake of radiopharmaceutical, and 19 dancers had stress reactions (areas of accelerated remodeling and resorption of bone) demonstrated by diffusely increased uptake of radiotracer. Ten of the 13 dancers with stress fractures were symptomatic and six of the 19 dancers with stress reactions were symptomatic. The radiographs of 10 dancers with positive bone scans were normal or showed no distinction between acute and chronic injuries. Stress fractures were most prevalent in the feet, and stress reactions were most prevalent in the tibiae. The study confirmed that ballet dancers sustain significant bone stress in their legs and feet. Our results show that scintigraphy can be used to detect stress fractures and stress reactions at both symptomatic and asymptomatic sites in this population.     

Stress fractures in women

Stress fractures are common overuse injuries, reported more frequently in female athletes than in male athletes. The clinician should have a high index of suspicion for this injury whether an athlete presents with complaints of acute pain and disability or insidious onset of pain that is aggravated by activity and relieved by rest. Radiographs, bone scans, CT scans, and MR imaging may all be useful in confirming the diagnosis. Conservative treatment is usually successful, although one must be especially vigilant in treating a stress fracture prone to complications. Identifying risk factors for susceptibility to stress fracture development may help to avoid recurrence of the injury. More research is needed to determine cause versus association of these various risk factors in relationship to stress injury to bone.     

Painful stress fractures of the fabella in patients with total knee arthroplasty

OBJECTIVE: The purpose of this study was to document a distinct pattern of stress fractures in the fabella of patients with total knee replacement and to call attention to this unusual complication that causes knee pain in postoperative patients. CONCLUSION: Stress fractures involving the fabella can be a clinically important entity in the patient with persistent or new knee pain after total knee arthroplasty. Scrutiny of radiographs, when coupled with clinical information, allows correct diagnosis of this potentially debilitating injury in symptomatic postoperative patients.     

Stress fracture at the junction of the middle and distal third of the ulnar diaphysis in a spinner bowler: a case report and a review of the literature

Stress fractures of the ulnar shaft are uncommon injuries, which have been documented in a variety of sports. The location of the fracture is influenced by the activity and mechanism of injury with which it is associated. The combined traditional approach of clinical history, physical examination, plain radiographs and nuclear scintigraphy for unusual stress fracture may be troublesome. This report is the first to describe a stress fracture at the junction of the middle and distal third of the ulnar diaphysis in a bowler due to chronic torsional stress. We discuss the possible mechanism of injury and describe the diagnostic imaging. A review of the literature is also given and compared with the findings and data of this case.     

An unusual stress fracture in a multiple sport athlete

Most overuse injuries are a direct result of repetitive stresses which may create a condition of maltraining. Young athletes are no exception to this rule. Swimming and baseball both create stresses to the humerus which may result in injuries to the shoulder and upper extremity. Stress fractures (fatigue fractures) are usually limited to the lower extremity (i.e., tibia or metatarsal). Upper extremity stress fractures, especially of the humerus, are very uncommon. Precipitating factors include repetitive stresses, low grade external forces, rapid application of muscular force to the bone, or an underlying disease or pathologic weakness of the bone. The majority of these fractures are primarily due to abnormal and repetitive stresses to bones. This case study examines the mechanism of injury, clinical presentation, and treatment of a clinically apparent stress fracture which ultimately converted to an overt humerus fracture in a 14-yr-old cross-trained athlete.