Stress fractures in athletes. A study of 320 cases

Proximal fibular stress fractures in children and adolescents, what should we rely on? Lessons learned from a case

Fibula fractures are the third most common stress fractures in children and adolescents. The triad of localised periosteal reaction, endosteal thickening and radiolucent cortical lines, localised in the distal third of the fibula along with a typical clinical history is in most cases sufficient to establish the diagnosis. Proximal fibula stress lesions are a very rare finding, with few reports in the literature. Stress fractures in this location demand careful investigation before a definitive diagnosis can be made. In the presence of non-specific MRI findings, stress fracture should be a diagnosis of exclusion. The authors report a case referred to their department by a sports medicine physician with a suspicion of stress fracture of the proximal fibula without characteristic imaging findings, which was ultimately confirmed as a stress lesion only by biopsy.

Epidemiology of stress fracture injuries among US high school athletes, 2005-2006 through 2012-2013

BACKGROUND

High school athletes in the United States sustain millions of injuries annually, approximately 10% of which are fractures. However, there is no clear estimate of the number of stress fractures sustained by high school athletes annually despite reports that stress fractures account for 0.7% to 20% of injuries seen in sports medicine clinics. This suggests a high utilization of resources for a potentially preventable injury. In addition, stress fractures have been associated with low energy availability and disordered eating in young athletes, highlighting the importance of early recognition and intervention.

PURPOSE

To investigate stress fracture rates and patterns in a large national sample of US high school athletes.

STUDY DESIGN

Descriptive epidemiologic study.

METHODS

Data from High School RIO (Reporting Information Online), a national sports injury surveillance study, were analyzed to describe rates and patterns of stress fracture injury sustained from 2005-2006 through 2012-2013, across sports and by sex.

RESULTS

From 2005-2006 through 2012-2013, a total of 51,773 injuries were sustained during 25,268,873 athlete-exposures, of which 389 (0.8%) were stress fractures, resulting in an overall stress fracture rate of 1.54 per 100,000 athlete-exposures. Rates per 100,000 athlete-exposures were highest in girls' cross country (10.62), girls' gymnastics (7.43), and boys' cross country (5.42). In sex-comparable sports, girls sustained more stress fractures (63.3%) than did boys (36.7%) and had higher rates of stress fracture (2.22 vs 1.27; rate ratio, 1.75; 95% CI, 1.38-2.23). The most commonly injured sites were the lower leg (40.3% of all stress fractures), foot (34.9%), and lower back/lumbar spine/pelvis (15.2%). Management was nonsurgical in 98.7% of the cases, and 65.3% of injuries resulted in ≥3 weeks of time loss, medical disqualification, or an end to the season before athletes could return to play.

CONCLUSION

Although a rare injury, stress fractures cause considerable morbidity for high school athletes of both sexes. Future research should evaluate risks of stress fractures to drive development of targeted prevention efforts.

Stress fracture of the pelvis and lower limbs including atypical femoral fractures-a review

Stress fractures, that is fatigue and insufficiency fractures, of the pelvis and lower limb come in many guises. Most doctors are familiar with typical sacral, tibial or metatarsal stress fractures. However, even common and typical presentations can pose diagnostic difficulties especially early after the onset of clinical symptoms. This article reviews the aetiology and pathophysiology of stress fractures and their reflection in the imaging appearances. The role of varying imaging modalities is laid out and typical findings are demonstrated. Emphasis is given to sometimes less well-appreciated fractures, which might be missed and can have devastating consequences for longer term patient outcomes. In particular, atypical femoral shaft fractures and their relationship to bisphosphonates are discussed. Migrating bone marrow oedema syndrome, transient osteoporosis and spontaneous osteonecrosis are reviewed as manifestations of stress fractures. Radiotherapy-related stress fractures are examined in more detail. An overview of typical sites of stress fractures in the pelvis and lower limbs and their particular clinical relevance concludes this review.

Teaching Points

• Stress fractures indicate bone fatigue or insufficiency or a combination of these.

• Radiographic visibility of stress fractures is delayed by 2 to 3 weeks.

• MRI is the most sensitive and specific modality for stress fractures.

• Stress fractures are often multiple; the underlying cause should be evaluated.

• Infratrochanteric lateral femoral fractures suggest an atypical femoral fracture (AFF); endocrinologist referral is advisable.

Exercise behavior of ultramarathon runners: baseline findings from the ULTRA study

Little is known about exercise habits of those who compete in foot races longer than the standard 42-km marathon distance. The purpose of this work was to describe the past-year and lifetime exercise patterns of a large cohort of ultramarathon runners. Information on exercise history was collected on 1,345 current and former ultramarathon runners as baseline data for participation in a longitudinal observational study. Median age at the first ultramarathon was 36 years, and the median number of years of regular running before the first ultramarathon was 7 (interquartile range, 3-15). Age at first ultramarathon did not change across the past several decades, but there was evidence of an inverse relationship (r = -0.13, p < 0.0001) between number of years of regular running before the first ultramarathon and calendar year. The active ultramarathon runners (n = 1,212) had a previous year median running distance of 3,347 km, which was minimally related to age (r = -0.068, p = 0.018), but mostly related to their longest ultramarathon competition of the year (p < 0.0001). Running injuries represented the most common reason for discontinuation of regular running, whereas work and family commitments were reported as the main reasons for not running an ultramarathon in the previous year among those who were regularly running and intending to run ultramarathons again. We conclude that runners tend to be well into adulthood and with several years of running experience before running their first ultramarathon, but 25% have only been regularly running for 3 years or less at the time of their first ultramarathon.

Stress fractures of the foot and ankle in athletes

Context:

Stress fractures of the foot and ankle are a common problem encountered by athletes of all levels and ages. These injuries can be difficult to diagnose and may be initially evaluated by all levels of medical personnel. Clinical suspicion should be raised with certain history and physical examination findings.

Evidence Acquisition:

Scientific and review articles were searched through PubMed (1930-2012) with search terms including stress fractures and 1 of the following: foot ankle, medial malleolus, lateral malleolus, calcaneus, talus, metatarsal, cuboid, cuneiform, sesamoid, or athlete.

Study Design:

Clinical review.

Level of Evidence:

Level 5.

Results:

Stress fractures of the foot and ankle can be divided into low and high risk based upon their propensity to heal without complication. A wide variety of nonoperative strategies are employed based on the duration of symptoms, type of fracture, and patient factors, such as activity type, desire to return to sport, and compliance. Operative management has proven superior in several high-risk types of stress fractures. Evidence on pharmacotherapy and physiologic therapy such as bone stimulators is evolving.

Conclusion:

A high index of suspicion for stress fractures is appropriate in many high-risk groups of athletes with lower extremity pain. Proper and timely work-up and treatment is successful in returning these athletes to sport in many cases. Low-risk stress fracture generally requires only activity modification while high-risk stress fracture necessitates more aggressive intervention. The specific treatment of these injuries varies with the location of the stress fracture and the goals of the patient.

Low-intensity pulsed ultrasound in lower limb bone stress injuries: a randomized controlled trial

OBJECTIVE

To evaluate the effectiveness of low-intensity pulsed ultrasound (LIPUS) for the improvement of lower limb bone stress injuries in a civilian population.

DESIGN

A prospective, randomized, double-blinded, placebo-controlled trial to compare LIPUS with placebo.

SETTING

Civilian private practice population in Sydney, Australia.

PARTICIPANTS

Subjects were recruited if a grade II-IV bone stress injury was diagnosed on magnetic resonance imaging (MRI) of either the postero-medial tibia, fibula or second, third, or fourth metatarsal. Subjects of all levels of sporting activity were included. Thirty subjects were initially recruited, and 23 subjects were included in the final analysis.

INTERVENTIONS

Subjects were randomized into either the treatment or placebo arm and matched to the site of injury (tibia, fibula, or metatarsal). Subjects in both arms used either treatment or placebo devices for 20 minutes daily for 4 weeks.

MAIN OUTCOME MEASURES

Six clinical parameters (night pain, pain at rest, pain on walking, pain with running, tenderness, and pain with single leg hop) were compared before and after intervention. The changes in MRI grade and bone marrow edema size were also compared.

RESULTS

There were no significant differences between the treatment and placebo conditions for changes in MRI grading (2.2 vs 2.4, P = 0.776) or bone marrow edema size (3 vs 4.1, P = 0.271). There were no significant differences between the treatment and placebo conditions for the 6 clinical parameters.

CONCLUSIONS

Low-intensity pulsed ultrasound was found not to be an effective treatment for the healing of lower limb bone stress injuries in this study. However, this was measured over a relatively short duration of 4 weeks in a small, mostly female population.

CLINICAL RELEVANCE

This double-blinded, randomized, placebo-controlled trial has shown that LIPUS is not an effective treatment for lower limb bone stress injuries.

Management and prevention of bone stress injuries in long-distance runners

SYNOPSIS

Bone stress injury (BSI) represents the inability of bone to withstand repetitive loading, which results in structural fatigue and localized bone pain and tenderness. A BSI occurs along a pathology continuum that begins with a stress reaction, which can progress to a stress fracture and, ultimately, a complete bone fracture. Bone stress injuries are a source of concern in long-distance runners, not only because of their frequency and the morbidity they cause but also because of their tendency to recur. While most BSIs readily heal following a period of modified loading and a progressive return to running activities, the high recurrence rate of BSIs signals a need to address their underlying causative factors. A BSI results from disruption of the homeostasis between microdamage formation and its removal. Microdamage accumulation and subsequent risk for development of a BSI are related both to the load applied to a bone and to the ability of the bone to resist load. The former is more amenable to intervention and may be modified by interventions aimed at training-program design, reducing impact-related forces (eg, instructing an athlete to run "softer" or with a higher stride rate), and increasing the strength and/or endurance of local musculature (eg, strengthening the calf for tibial BSIs and the foot intrinsics for BSIs of the metatarsals). Similarly, malalignments and abnormal movement patterns should be explored and addressed. The current commentary discusses management and prevention of BSIs in runners. In doing so, information is provided on the pathophysiology, epidemiology, risk factors, clinical diagnosis, and classification of BSIs.

LEVEL OF EVIDENCE

Therapy, level 5.

Reproducibility of a peripheral quantitative computed tomography scan protocol to measure the material properties of the second metatarsal

Background

Peripheral quantitative computed tomography (pQCT) is an established technology that allows for the measurement of the material properties of bone. Alterations to bone architecture are associated with an increased risk of fracture. Further pQCT research is necessary to identify regions of interest that are prone to fracture risk in people with chronic diseases. The second metatarsal is a common site for the development of insufficiency fractures, and as such the aim of this study was to assess the reproducibility of a novel scanning protocol of the second metatarsal using pQCT.

Methods

Eleven embalmed cadaveric leg specimens were scanned six times; three times with and without repositioning. Each foot was positioned on a custom-designed acrylic foot plate to permit unimpeded scans of the region of interest. Sixty-six scans were obtained at 15% (distal) and 50% (mid shaft) of the second metatarsal. Voxel size and scan speed were reduced to 0.40 mm and 25 mm.sec^-1. The reference line was positioned at the most distal portion of the 2^nd metatarsal. Repeated measurements of six key variables related to bone properties were subject to reproducibility testing. Data were log transformed and reproducibility of scans were assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV%).

Results

Reproducibility of the measurements without repositioning were estimated as: trabecular area (ICC 0.95; CV% 2.4), trabecular density (ICC 0.98; CV% 3.0), Strength Strain Index (SSI) - distal (ICC 0.99; CV% 5.6), cortical area (ICC 1.0; CV% 1.5), cortical density (ICC 0.99; CV% 0.1), SSI – mid shaft (ICC 1.0; CV% 2.4). Reproducibility of the measurements after repositioning were estimated as: trabecular area (ICC 0.96; CV% 2.4), trabecular density (ICC 0.98; CV% 2.8), SSI - distal (ICC 1.0; CV% 3.5), cortical area (ICC 0.99; CV%2.4), cortical density (ICC 0.98; CV% 0.8), SSI – mid shaft (ICC 0.99; CV% 3.2).

Conclusions

The scanning protocol generated excellent reproducibility for key bone properties measured at the distal and mid-shaft regions of the 2^nd metatarsal. This protocol extends the capabilities of pQCT to evaluate bone quality in people who may be at an increased risk of metatarsal insufficiency fractures.

Identification of Differentially Expressed Gene after Femoral Fracture via Microarray Profiling

We aimed to investigate differentially expressed genes (DEGs) in different stages after femoral fracture based on rat models, providing the basis for the treatment of sport-related fractures. Gene expression data GSE3298 was downloaded from Gene Expression Omnibus (GEO), including 16 chips. All femoral fracture samples were classified into earlier fracture stage and later fracture stage. Total 87 DEGs simultaneously occurred in two stages, of which 4 genes showed opposite expression tendency. Out of the 4 genes, Rest and Cst8 were hub nodes in protein-protein interaction (PPI) network. The GO (Gene Ontology) function enrichment analysis verified that nutrition supply related genes were enriched in the earlier stage and neuron growth related genes were enriched in the later stage. Calcium signaling pathway was the most significant pathway in earlier stage; in later stage, DEGs were enriched into 2 neurodevelopment-related pathways. Analysis of Pearson's correlation coefficient showed that a total of 3,300 genes were significantly associated with fracture time, none of which was overlapped with identified DEGs. This study suggested that Rest and Cst8 might act as potential indicators for fracture healing. Calcium signaling pathway and neurodevelopment-related pathways might be deeply involved in bone healing after femoral fracture.

An unusual stress fracture: Bilateral posterior longitudinal stress fracture of tibia

INTRODUCTION

Stress fractures (SF) occur when healthy bone is subjected to cyclic loading, which the normal carrying range capacity is exceeded. Usually, stress fractures occur at the metatarsal bones, calcaneus, proximal or distal tibia and tends to be unilateral.

PRESENTATION OF CASE

This article presents a 58-year-old male patient with bilateral posterior longitudinal tibial stress fractures. A 58 years old male suffering for persistent left calf pain and decreased walking distance for last one month and after imaging studies posterior longitudinal tibial stress fracture was detected on his left tibia. After six months the patient was admitted to our clinic with the same type of complaints in his right leg. All imaging modalities and blood counts were performed and as a result longitudinal posterior tibial stress fractures were detected on his right tibia.

DISCUSSION

Treatment of tibial stress fracture includes rest and modified activity, followed by a graded return to activity commensurate with bony healing. We have applied the same treatment protocol and our results were acceptable but our follow up time short for this reason our study is restricted for separate stress fractures of the posterior tibia.

CONCLUSION

Although the main localization of tibial stress fractures were unilateral, anterior and transverse pattern, rarely, like in our case, the unusual bilateral posterior localization and longitudinal pattern can be seen.

The thrower's elbow

Overhead throwing activities expose the elbow to tremendous valgus stress, making athletes vulnerable to a specific constellation of injuries. Although baseball players, in particular pitchers, are the athletes affected most commonly, overhead throwing athletes in football, volleyball, tennis, and javelin tossing also are affected. The purpose of this review is to review the anatomy, biomechanics, pathophysiology, and treatment of elbow disorders related to overhead throwing athletes. Although focus is on management of ulnar collateral ligament injuries, all common pathologies are discussed.

The injured runner

Running is often recommended by physicians to maintain a healthy lifestyle. As more individuals participate in running-related activities, clinicians must be increasingly aware of common injuries. Training errors leading to overuse are the most common underlying factors in most running-related injuries. Clinicians need to keep in mind that the presenting injury is frequently the result of an inability to compensate for a primary dysfunction at another site. Although imaging may be helpful in differentiating among diagnoses with similar clinical presentations, a detailed history and physical examination are essential in making a correct diagnosis.

Stress fractures of the ankle malleoli diagnosed by ultrasound: a report of 6 cases

OBJECTIVE

To present the ultrasound appearance of stress fractures (SF) of the ankle malleoli.

MATERIAL AND METHODS

We present a retrospective review of 6 patients (4 women and 2 men, with an age range of 24-52 years, mean age of 39 years) in which ultrasound diagnosed, together with the clinical findings, an SF of the ankle malleoli. For all of these patients ultrasound was the first imaging technique applied because of a clinical suspicion of soft tissue injuries following excessive exertion. Patients were subsequently examined using standard radiographs and/or MRI.

RESULTS

At ultrasound patients showed thickening of the periosteum in all patients, calcified bone callus was evident in 3 out of 6 patients. Cortical irregularities and subcutaneous oedema were found in all but one patient. Colour Doppler showed local hypervascular changes in all patients. Local compression with the transducers during real-time scanning increased pain in all cases.

CONCLUSION

Ultrasound, together with the clinical findings, can diagnose an SF of the ankle malleoli. We suggest that sonologists should include malleolar SF in their differential diagnosis, particularly in the case of perimalleolar pain from over-solicitation. They must also include, as part of every ultrasound examination of the ankle, the evaluation of both malleoli and should be aware of the ultrasound appearance of malleolar SF. If the diagnosis remains uncertain, an MRI should be prescribed.

Stress fracture of the lateral cuneiform bone: a case report

Stress fractures are common overuse injuries of the bone that are most often seen in athletes and military personnel. These types of injuries seem to be commonly missed or delayed in diagnosis. Physicians should consider the possibility of such an injury while determining the diagnosis of a long-lasting foot pain. The aim of this paper was to report an isolated stress fracture of the lateral cuneiform bone. A review of the literature failed to find a similar case.

Higher incidence of bone stress injuries with increasing female athlete triad-related risk factors: a prospective multisite study of exercising girls and women

BACKGROUND

Identifying the risk factors associated with a bone stress injury (BSI), including stress reactions and stress fractures, may aid in targeting those at increased risk and in formulating prevention guidelines for exercising girls and women.

PURPOSE

To evaluate the effect of single or combined risk factors as defined by the female athlete triad-a syndrome involving 3 interrelated spectrums consisting of energy availability, menstrual function, and bone mass-with the incidence of BSIs in a multicenter prospective sample of 4 cohorts of physically active girls and women.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

At baseline, participants' (N = 259; mean age, 18.1 ± 0.3 years) anthropometric characteristics, eating attitudes and behaviors, menstrual function, sports participation or exercise activity, and pathological weight control behaviors were assessed. Dual-energy x-ray absorptiometry (DXA) measured the bone mass of the whole body, total hip, femoral neck, lumbar spine, and body composition. Participants were followed prospectively for the occurrence of injuries; those injuries confirmed by a physician were recorded.

RESULTS

Twenty-eight participants (10.8%) incurred a BSI. Forty-six percent of those who had ≥12 h/wk of purposeful exercise, a bone mineral density (BMD) Z score <-1.0, and who exhibited 3 to 4 of the following: BMI <21.0 kg/m2, oligo- or amenorrhea, elevated dietary restraint, and/or participation in a leanness sport exercise/activity at baseline, incurred a BSI during the prospective study period. Single factors significantly (P < .05) associated with the development of a BSI included ≥12 h/wk of purposeful exercise (14.7%), BMI <21.0 kg/m2 (15.3%), and low bone mass (BMD Z score <-1.0; 21.0%). The strongest 2- and 3-variable combined risk factors were low BMD (Z score <-1.0) + ≥12 h/wk of exercise, with 29.7% incurring a BSI (odds ratio [OR], 5.1; 95% CI, 2.2-12.1), and ≥12 h/wk of exercise + leanness sport/activity + dietary restraint, with 46.2% incurring a BSI (OR, 8.7; 95% CI, 2.7-28.3).

CONCLUSION

In the sample, which included female adolescents and young adults participating in competitive or recreational exercise activities, the risk of BSIs increased from approximately 15% to 20% for significant single risk factors to 30% to 50% for significant combined female athlete triad-related risk factor variables. These data support the notion that the cumulative risk for BSIs increases as the number of Triad-related risk factors accumulates.

Stress fractures in runners

Stress fractures, were first described in military recruits but in recent years have increasingly been described in runners. In most surveys they comprise between 10 and 20% of all running injuries. The tibia is the most common site of all stress fractures although recent studies involving track and field athletes show an increased incidence of navicular stress fractures. The diagnosis is based on the clinical findings of a history of exercise-related bone pain with local bony tenderness on examination. The diagnosis is often confirmed by a typical appearance on an isotope bone scan or plain radiograph. In general, treatment consists of relative rest from the aggravating activity until symptom-free and then graduated resumption of activity. Attention also needs to be paid to correction of possible causative factors. These include excessive training, low bone density, low calcium intake, menstrual abnormalities in females and biomechanical features such as excessive sub-talar pronation. Certain stress fractures, such as those in the navicular, require specific management, e.g. six weeks non-weight bearing cast immobilization.

Incidence and Time to Return to Training for Stress Fractures during Military Basic Training

Currently, little is known about the length of time required to rehabilitate patients from stress fractures and their return to preinjury level of physical activity. Previous studies have looked at the return to sport in athletes, in a general population, where rehabilitation is not as controlled as within a captive military population. In this study, a longitudinal prospective epidemiological database was assessed to determine the incidence of stress fractures and the time taken to rehabilitate recruits to preinjury stage of training. Findings demonstrated a background prevalence of 5% stress fractures in Royal Marine training; femoral and tibial stress fractures take 21.1 weeks to return to training with metatarsal stress fractures being the most common injury taking 12.2 weeks. Rehabilitation from stress fractures accounts for 814 weeks of recruit rehabilitation time per annum. Stress fracture incidence is still common in military training; despite this stress fracture recovery times remain constant and represent a significant interruption in training. It takes on average 5 weeks after exercise specific training has restarted to reenter training at a preinjury level, regardless of which bone has a stress fracture. Further research into their prevention, treatment, and rehabilitation is required to help reduce these burdens.

Health and exercise-related medical issues among 1,212 ultramarathon runners: baseline findings from the Ultrarunners Longitudinal TRAcking (ULTRA) Study

Regular exercise is associated with substantial health benefits; however, little is known about the health impact of extreme levels of exercise. This study examined the prevalence of chronic diseases, health-care utilization, and risk factors for exercise-related injuries among ultramarathon runners. Retrospective, self-reported enrollment data from an ongoing longitudinal observational study of 1,212 active ultramarathon runners were analyzed. The most prevalent chronic medical conditions were allergies/hay fever (25.1%) and exercise-induced asthma (13.0%), but there was a low prevalence of serious medical issues including cancers (4.5%), coronary artery disease (0.7%), seizure disorders (0.7%), diabetes (0.7%), and human immunodeficiency virus (HIV) infection (0.2%). In the year preceding enrollment, most (64.6%) reported an exercise-related injury that resulted in lost training days (median of 14 days), but little nonattendance of work or school due to illness, injury, or exercise-related medical conditions (medians of 0 days for each). The knee was the most common area of exercise-related injury. Prior year incidence of stress fractures was 5.5% with most (44.5%) involving the foot. Ultramarathon runners who sustained exercise-related injuries were younger (p<0.001) and less experienced (p<0.01) than those without injury. Stress fractures were more common (p<0.01) among women than men. We conclude that, compared with the general population, ultramarathon runners appear healthier and report fewer missed work or school days due to illness or injury. Ultramarathon runners have a higher prevalence of asthma and allergies than the general population, and the prevalence of serious medical issues was nontrivial and should be recognized by those providing medical care to these individuals. Ultramarathon runners, compared with shorter distance runners, have a similar annual incidence of exercise-related injuries but higher proportion of stress fractures involving the foot, and it is the younger and less experienced ultramarathoners who appear most at risk for injury.

Medial supracondylar stress fracture in an adolescent pitcher/

We report the occurrence of a medial supracondylar stress fracture in an adolescent pitcher. To our knowledge, this fracture has not been described in the literature, and awareness of this entity allows initiation of therapy and precludes further unnecessary work-up. The radiographic, computed tomography, and magnetic resonance imaging appearances are reviewed and the mechanism of injury is discussed.

Evaluation and treatment of biking and running injuries

Exercise is universally recognized as a key feature for maintaining good health. Likewise, lack of physical activity is a major risk factor for chronic disease and disability, an especially important fact considering our rapidly aging population. Biking and running are frequently recommended as forms of exercise. As more individuals participate in running-related and cycling-related activities, physicians must be increasingly aware of the common injuries encountered in these pursuits. This review focuses on the evaluation and management of common running-related and cycling-related injuries.

Stress fractures in the elderly: different pathogenetic features compared with young patients

Stress fractures mainly occur in the lower limb as a result of cyclic submaximal stresses. Most commonly affected by this specific type of fractures are young athletes, military or elderly subjects with metabolic bone diseases like osteoporosis. In consideration of the heterogeneity of affected patients is presumable that there are different pathogenic mechanisms. In young person bone tissue, although metabolically intact, is not able to withstand the stresses to which it is chronically subjected, also because of muscle fatigue. This leads to a macrostructural failure and to the development of "fatigue" fractures. Instead, in elderly patients, there are numerous physiological conditions that determine a bone metabolism alteration. This is the main reason for the structural changes in trabecular and cortical bone, which is reflected in reduced biomechanical strength. In addition, muscular situation, such as muscle fiber atrophy, is unable to correctly support bone tissue, leading to the development of insufficiency fractures.

Tibial hyperostosis: a diagnostic approach

Tibial hyperostosis may be encountered in musculoskeletal imaging, incidentally or during the investigation of a leg pain. Hyperostosis involves the exuberant production of osseous tissue and results in cortical, periosteal and/or endosteal thickening of the bone. As a long bone with thick cortices, the tibia has a significant probability of being affected by ubiquitous bone diseases. As a tubular long bone, the tibia is likely to be involved in extensive infectious conditions such as osteomyelitis. As a bone of the lower limb, the tibia undergoes high stresses and may be affected by decrease in bone strength or repetitive submaximal stress. The tibia is also particularly involved in some bone sclerosing dysplasias and Paget's disease. In this work, we aim at highlighting the main conditions leading to tibial hyperostosis and try to provide key elements to narrow down the several diagnostic possibilities. Osteoid osteomas, fatigue or insufficiency fractures, infectious conditions, vascular lesions, sclerosing bone dysplasias and Paget's disease represent the main challenging diagnoses to discuss.

Modified valgus osteotomy of the femoral neck for late presenting femoral neck stress fractures in military recruits

Neglected or late presenting femoral neck stress fractures are often associated with varus deformity, with potential risks of nonunion and osteonecrosis. We proposed a surgical technique whereby a wedge osteotomy was performed at the basal part of the neck, on the tensile surface, keeping the inferomedial femoral neck as a hinge. The femoral shaft was abducted to close the osteotomy site and it was fixed with three cannulated cancellous screws. Three military recruits who presented with neglected femoral neck stress fracture with varus deformity were operated on with the proposed modified femoral neck valgus osteotomy. All the fractures united without any complications and the patients resumed their professional activity.

Stress fractures

Stress fractures are common injuries in military recruits and athletes, particularly long-distance runners. A high index of suspicion coupled with a thorough history and correct imaging are vital in the diagnosis. A delay in their diagnosis or undertreatment can result in extended recovery times that are particularly damaging to sportspeople where these injuries can be career-ending. In most cases, treatment includes reducing the causative activity to a pain-free level. “High-risk” fractures which typically include the femoral neck, anterior tibia, proximal fifth metatarsal and tarsal navicular may however require surgical fixation. Stress fractures carry a high risk of recurrence and prevention involves reducing modifiable risk factors through training and diet adjustments. All members involved in an athlete or military recruit’s training should therefore be aware of the presence of eating disorders, the effects of overtraining and the importance of rest in order to reduce the incidence of these injuries.

Correlation of MRI grading of bone stress injuries with clinical risk factors and return to play: a 5-year prospective study in collegiate track and field athletes

BACKGROUND

Bone stress injuries are common in track and field athletes. Knowledge of risk factors and correlation of these to magnetic resonance imaging (MRI) grading could be helpful in determining recovery time.

PURPOSE

To examine the relationships between MRI grading of bone stress injuries with clinical risk factors and time to return to sport in collegiate track and field athletes.

STUDY DESIGN

Cohort study (prognosis); Level of evidence, 2.

METHODS

A total of 211 male and female collegiate track and field and cross-country athletes were followed prospectively through their competitive seasons. All athletes had preparticipation history, physical examination, and anthropometric measurements obtained annually. An additional questionnaire was completed regarding nutritional behaviors, menstrual patterns, and prior injuries, as well as a 3-day diet record. Dual-energy X-ray absorptiometry was performed at baseline and each year of participation in the study. Athletes with clinical evidence of bone stress injuries had plain radiographs. If radiograph findings were negative, MRI was performed. Bone stress injuries were evaluated by 2 independent radiologists utilizing an MRI grading system. The MRI grading and risk factors were evaluated to identify predictors of time to return to sport.

RESULTS

Thirty-four of the athletes (12 men, 22 women) sustained 61 bone stress injuries during the 5-year study period. The mean prospective assessment for participants was 2.7 years. In the multiple regression model, MRI grade and total-body bone mineral density (BMD) emerged as significant and independent predictors of time to return to sport. Specifically, the higher the MRI grade (P = .004) and lower the BMD (P = .030), the longer the recovery time. Location of the bone injury at predominantly trabecular sites of the femoral neck, pubic bone, and sacrum was also associated with a prolonged time to return to sport. Female athletes with oligomenorrhea and amenorrhea had bone stress injuries of higher MRI grades compared with eumenorrheic athletes (P = .009).

CONCLUSION

Higher MRI grade, lower BMD, and skeletal sites of predominant trabecular bone structures were associated with a delayed recovery of bone stress injuries in track and field athletes. Knowledge of these risk factors, as well as nutritional and menstrual factors, can be clinically useful in determining injury severity and time to return to sport.

Tension band plating of a nonunion anterior tibial stress fracture in an athlete

The authors present a rare technique of tension band plating of the anterior tibia in the setting of a nonunion stress fracture. Surgical management with an intramedullary nail is a viable and proven option for treating such injuries. However, in treating elite athletes, legitimate concerns exist regarding the surgical disruption of the extensor mechanism and the risk of anterior knee pain associated with intramedullary nail use. The described surgical technique demonstrates the use of tension band plating as an effective treatment of delayed union and nonunion anterior tibial stress fractures in athletes without the potential risks of intramedullary nail insertion.

Bone stress injuries of the leg in athletes

Bone stress injuries, whose incidence is increasing among competitive and recreational athletes, represent a pathophysiological continuum along which a bone responds to a changing mechanical environment. Frank stress fracture is the endpoint of this process, resulting from the accumulation of microinjuries due to repeated abnormal stresses. The legs are largely the most frequently affected bone district. The aim of this paper is to review the imaging findings of the whole spectrum of stress-induced bone lesions of the leg in athletes. We emphasise the role of computed tomography and magnetic resonance imaging, which allow recognition of early alterations.

Anterior tibial stress fractures treated with anterior tension band plating in high-performance athletes

PURPOSE

The non-surgical treatment of anterior tibial cortex stress fractures requires long periods of abstention from sports activities and often results in non-union. Many different surgical techniques have already been previously described to treat these fractures, but there is no consensus on the best treatment. We describe the outcome of treatment using anterior tibial tension band plating in three high-performance athletes (4 legs) with anterior tibial cortex stress fractures.

METHODS

Tibial osteosynthesis with a 3.5-mm locking compression plate in the anterolateral aspect of the tibia was performed in all patients diagnosed with anterior tibial stress fracture after September 2010 at Santa Casa Hospital.

RESULTS

All of the fractures were consolidated within a period of 3 months after surgery, allowing for an early return to pre-injury levels of competitive sports activity. There were no infection, non-union, malunion or anterior knee pain complications.

CONCLUSIONS

Anterior tibial tension band plating leads to prompt fracture consolidation and is a good alternative for the treatment of anterior tibial cortex stress fractures. Bone grafts were shown to be unnecessary.

Stress fractures of the tibia and medial malleolus

Tibial diaphyseal stress fractures are rare in the general population, but are more frequently seen in the athletic and military communities. The diagnosis of this problem may be problematic and needs to be considered in all athletes and military recruits who present with shin or ankle pain. The female triad in athletes (low-energy availability/disordered eating, amenorrhea, and osteoporosis/osteopenia) should be considered in those women who sustain this injury. Management is usually conservative with a variety of rehabilitation programs suggested, but a pragmatic approach is to manage the patient symptomatically.

Diaphyseal tibiofibular synostosis in a runner

Diaphyseal tibiofibular synostosis is a very rare cause of shin and ankle pain. A 35-year-old male presented with complaints of left shin and ankle pain of 3 years duration that was sometimes worse after running a few miles. One year before presenting to our hospital, the actual cause for his pain was missed when only lumbar radiographs were taken at another institution. A full-length tibia film revealed a diaphyseal tibiofibular synostosis at our hospital. The presence of a synostosis should alert the surgeon to search for the various abnormalities usually associated with this condition. Magnetic resonance imaging and enhanced 3-dimensional computed tomography are essential to rule out the possibility of a neoplastic process and to determine its relation to the neurovascular structures. Simple excision of the synostosis can provide excellent symptomatic relief with a minimal risk of complications.

[Stress reactions in bones of the foot in sport: diagnosis, assessment and therapy]

Stress reactions and stress fractures are defined as structural damage to bone caused by repetitive stress or stereotypical loading. The balance between loading and unloading of bone is disrupted in stress reactions and stress fractures through the sport-specific demands and by the exogenous or endogenous risk factors present. In sports orthopedics the localization of stress reactions and stress fractures are subdivided into high risk fractures and low risk fractures. Conventional diagnostic radiology can initially be inconclusive. With symptoms persisting over 2 weeks further diagnostics using magnetic resonance imaging (MRI) should be performed. In the area of the foot stress reactions and stress fractures can often occur bilaterally or multifocally and most commonly affect the second metatarsals followed by the third metatarsals. Fractures of the fifth metatarsal, second metatarsal base, medial malleolus as well as navicular and sesamoid fractures are high risk fractures requiring special clinical and radiological monitoring. Basically, conservative treatment using the 2-phase model is the treatment of choice. In delayed union or severe pain surgical treatment is indicated.

Incidence and risk factors for medial tibial stress syndrome and tibial stress fracture in high school runners

PURPOSE

Medial tibial stress syndrome (MTSS) and tibial stress fracture (SF) are common lower leg disorders in runners. A prospective study was done to identify the incidence of MTSS and SF in high school runners and to determine risk factors.

METHODS

A total of 230 runners participating in high school running teams were evaluated. All runners aged 15 years as first grade of high school were involved in the study. They were followed up for 3 years. The measured items included height, weight, body mass index (BMI), range of hip and ankle motion, straight leg raising (SLR), intercondylar and intermalleolar interval, Q-angle, navicular drop test, hip abductor strength and physical conditioning. Each runner was followed for 3 years to report occurrence of MTSS and SF.

RESULTS

A total number of 102 MTSS (0.29 athlete exposures) and 21 SF (0.06 athlete exposures) were identified. In females, BMI significantly increased the risk of MTSS after adjustment for the other variables in this study (adjusted odds ratio, 0.51; 95 % confidence interval, 0.31-0.86). Increased internal rotation of the hip significantly increased the risk of MTSS (adjusted odds ratio, 0.91; 95 % confidence interval, 0.85-0.99). In males, limited SLR also significantly increased the risk of SF with adjustment for the other variables in this study (adjusted odds ratio, 1.38; 95 % confidence interval, 1.04-1.83).

CONCLUSION

A significant relationship was found between BMI, internal hip rotation angle and MTSS in females, and between limited SLR and SF in males.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

Stress fractures of the pelvis and legs in athletes: a review

CONTEXT

Stress fractures are common injuries in athletes, often difficult to diagnose. A stress fracture is a fatigue-induced fracture of bone caused by repeated applications of stress over time.

EVIDENCE ACQUISITION

PubMed articles published from 1974 to January 2012.

RESULTS

Intrinsic and extrinsic factors may predict the risk of stress fractures in athletes, including bone health, training, nutrition, and biomechanical factors. Based on their location, stress fractures may be categorized as low- or high-risk, depending on the likelihood of the injury developing into a complete fracture. Treatment for these injuries varies substantially and must account for the risk level of the fractured bone, the stage of fracture development, and the needs of the patient. High-risk fractures include the anterior tibia, lateral femoral neck, patella, medial malleolus, and femoral head. Low-risk fractures include the posteromedial tibia, fibula, medial femoral shaft, and pelvis. Magnetic resonance is the imaging test of choice for diagnosis.

CONCLUSIONS

These injuries can lead to substantial lost time from participation. Treatment will vary by fracture location, but most stress fractures will heal with rest and modified weightbearing. Some may require more aggressive intervention, such as prolonged nonweightbearing movement or surgery. Contributing factors should also be addressed prior to return to sports.