The classification systems of stress fractures: a systematic review

Increase in paediatric bone stress injuries: a single-center study during the COVID-19 pandemic

BACKGROUND

Melbourne, Australia was considered the most locked-down city during the COVID19 Pandemic. School was conducted from home and all organized sport ceased. Our institution noted an increased presentation of bone stress injuries (BSI) ranging from periostitis to stress fractures. This study reviews the prevalence of these injuries to gain insights into BSI presentation, diagnosis and best management.

METHODS

A retrospective review of lower limb long bone stress injuries between April 1st 2020 and March 31st 2022, and from 2018 to 2020 for comparison, was conducted. A chart review of those meeting inclusion criteria for demographics, fracture characteristics, investigations, and treatment administered was conducted.

RESULTS

Thirteen patients (two female, 11 male) met inclusion criteria. Only four patients were identified in the comparison period. The average age was 11.6 years, and average symptom duration was 7 weeks. Distinct morphologies were noted, specifically three discrete patterns of tibial injury were identified. Patients underwent an average of three imaging studies prior to diagnosis. Nine of 13 patients were prescribed a period of non-weight bearing, averaging 3.5 weeks. Seven of 13 patients were prescribed a formal 'partial weight bearing' (50%) period averaging 6.4 weeks.

CONCLUSION

There was a significant increase in paediatric BSI presentation over the COVID-19 lockdowns. This may be linked to the effect of reduced physical activity. Knowledge of the three clear tibial morphologies identified in this study will inform future diagnosis and reduce investigation expenditure. These findings may inform public health measures during mandated lockdowns and raise a diagnostic framework for such injuries.

Tibial Stress Fracture and "Shin Splint" Syndrome in the Same Patient Diagnosed on 99mTC-Methylene Diphosphonate Bone Scintigraphy and Single-Photon Emission/Computed Tomography

We present a case of an 18-year-old male athlete who presented with complaints of right lower leg pain for 10 days following intense exercise. The most likely diagnosis was a possible tibial stress fracture or a ''shin splint'' syndrome. The radiograph did not reveal any significant abnormality in the form of any fracture or a cortical break. We performed planar bone scintigraphy including single-photon emission computed tomography (CT)/CT that revealed the presence of the two concomitant pathologies in the form of a hot spot which corresponded with a bone lesion in the tibial stress fracture and subtle remodeling activity without evidence of significant cortical lesion in the shin splints in bilateral lower limbs (R>L).

Does Magnetic Resonance Imaging Grading Correlate With Return to Sports After Bone Stress Injuries? A Systematic Review and Meta-analysis

BACKGROUND

While some studies have failed to reveal any significant relationship between magnetic resonance imaging (MRI) grading and return to sports after bone stress injuries, others have reported either a linear or nonlinear relationship.

PURPOSE

To evaluate the prognostic value of MRI grading for time to return to sports and rate of return to sports after bone stress injuries.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search was performed in PubMed, Web of Science, SPORTDiscus, and Google Scholar. Studies reporting return to sports data after bone stress injuries using MRI grading systems were included in this review. The risk of bias was evaluated using the Quality in Prognosis Studies tool. Meta-analyses were performed to summarize the mean time to return to sports. The Pearson correlation was used to determine the relationship between time to return to sports and MRI grade. A meta-analysis of proportions was conducted to determine the percentage of athletes who successfully returned to sports.

RESULTS

A total of 16 studies with 560 bone stress injuries met inclusion criteria. Higher MRI-based grading was associated with an increased time to return to sports (P < .00001). Pooled data revealed that higher MRI-based grading correlated with a longer time to return to sports (r = 0.554; P = .001). Combining all anatomic locations, the mean time to return to sports was 41.7 days (95% CI, 30.6-52.9), 70.1 days (95% CI, 46.9-93.3), 84.3 days (95% CI, 59.6-109.1), and 98.5 days (95% CI, 85.5-112.6) for grade 1, 2, 3, and 4 injuries, respectively. Trabecular-rich sites of injury (eg, pelvis, femoral neck, and calcaneus) took longer to heal than cortical-rich sites of injury (eg, tibia, metatarsal, and other long-bone sites of injury). Overall, more than 90% of all athletes successfully returned to sports.

CONCLUSION

The findings from this systematic review indicate that MRI grading may offer a prognostic value for time to return to sports after the nonsurgical treatment of bone stress injuries. Both MRI grade and location of injury suggest that individually adapted rehabilitation regimens and therapeutic decisions are required to optimize healing and a safe return to sports.

Overuse-Related Injuries of the Musculoskeletal System: Systematic Review and Quantitative Synthesis of Injuries, Locations, Risk Factors and Assessment Techniques

Overuse-related musculoskeletal injuries mostly affect athletes, especially if involved in preseason conditioning, and military populations; they may also occur, however, when pathological or biological conditions render the musculoskeletal system inadequate to cope with a mechanical load, even if moderate. Within the MOVIDA (Motor function and Vitamin D: toolkit for risk Assessment and prediction) Project, funded by the Italian Ministry of Defence, a systematic review of the literature was conducted to support the development of a transportable toolkit (instrumentation, protocols and reference/risk thresholds) to help characterize the risk of overuse-related musculoskeletal injury. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) approach was used to analyze Review papers indexed in PubMed and published in the period 2010 to 2020. The search focused on stress (overuse) fracture or injuries, and muscle fatigue in the lower limbs in association with functional (biomechanical) or biological biomarkers. A total of 225 Review papers were retrieved: 115 were found eligible for full text analysis and led to another 141 research papers derived from a second-level search. A total of 183 papers were finally chosen for analysis: 74 were classified as introductory to the topics, 109 were analyzed in depth. Qualitative and, wherever possible, quantitative syntheses were carried out with respect to the literature review process and quality, injury epidemiology (type and location of injuries, and investigated populations), risk factors, assessment techniques and assessment protocols.

MRI of tibial stress fractures: relationship between Fredericson classification and time to recovery in pediatric athletes

BACKGROUND

Tibial stress fractures are not uncommon in pediatric athletes. The severity of injury may be graded using magnetic resonance imaging (MRI).

OBJECTIVE

To determine whether Fredericson MRI grading of tibial stress fractures can differentiate times to recovery across different grades in pediatric athletes.

MATERIALS AND METHODS

A medical record search identified all athletes younger than 19 years old who had tibial stress fractures confirmed by MRI and were treated by sports medicine specialists in our clinic system over a 5-year period. Two pediatric radiologists graded MRI exams using the Fredericson system. Time to recovery (in days) was defined in four ways: pain onset to full participation, pain onset to zero pain, first treatment to full sport participation and first treatment to zero pain. Recovery times were compared to tibial stress fracture Fredericson MRI grade and to the use of a recovery device.

RESULTS

Thirty-eight pediatric athletes (age range: 7-18 years, mean: 15.4±2.2 years) had 42 tibial stress fractures while participating in 12 different sports. About half (55%) were track and/or cross-country athletes. The mean time from diagnosis to report of no pain for all patients was 55.6±5.0 days. We found no significant difference in time to recovery across stress fracture grade or with the use of a recovery device.

CONCLUSION

No differences were noted between Fredericson stress fracture grades and different time periods to recovery or between differences in recovery time and the return to full participation in sports, regardless of the use of assistive devices.

Bone Stress Injuries Are Associated With Differences in Bone Microarchitecture in Male Professional Soldiers

Bone stress injuries are commonly due to repetitive loading, as often described in competitive athletes or military recruits. The underlying pathophysiology of bone stress injuries is multifactorial. The present cross-sectional study investigated (i) cortical and trabecular bone microstructure as well as volumetric bone mineral density in subjects with bone stress injuries at the tibial diaphysis, measured at the distal tibia and the distal radius by means of high-resolution peripheral quantitative computed tomography (CT), (ii) areal bone mineral density using dual-energy X-ray absorptiometry as well as calcaneal dual X-ray absorptiometry and laser, and (iii) the influence on bone turnover markers of formation and resorption at the early phase after injury. A total of 26 Caucasian male professional soldiers with post-training bone stress injury at the tibial diaphysis were included (case group). A total of 50 male, Caucasian professional soldiers from the same military institution served as controls (control group). High-resolution peripheral quantitative CT revealed a higher total area at the radius within the case group. Cortical bone mineral density was reduced at the radius and tibia within the case group. The trabecular number and trabecular thickness were reduced at the tibia in the case group. The trabecular network was more inhomogeneous at the radius and tibia within the case group. Calcaneal dual X-ray absorptiometry and laser was significantly reduced in the case group. This study quantified differences in bone microstructure among otherwise healthy individuals. Differences in bone microarchitecture may impair the biomechanical properties by increasing the susceptibility to sustain bone stress injuries. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2516-2523, 2019.

Validation of the Shin Pain Scoring System: A Novel Approach for Determining Tibial Bone Stress Injuries

Background

The incidence of adolescent overuse injuries, including bone stress injuries (BSIs), is on the rise. The identification of a BSI in the early stages is key to successful treatment. The Shin Pain Scoring System (SPSS) was developed to aid clinicians in identifying patients with a BSI.

Hypothesis

The SPSS will correlate with magnetic resonance imaging (MRI) grading of a BSI in an adolescent population.

Study Design

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

Methods

Enrolled in this study were 80 adolescent high school athletes between the ages of 13 and 18 years participating in a variety of sports with more than 1 week of atraumatic shin pain. The SPSS questionnaire was completed for each participant, and physical examination findings were recorded. Each question and physical examination item was allotted a point value, which totaled 29 points. Radiographs and MRI scans of both lower legs were obtained for each participant. The SPSS score was statistically analyzed using logistic regression, a classification matrix, and a 2 × 2 contingency table to evaluate validity and predictability.

Results

Logistic regression analysis of our data determined that 3 categories of SPSS scores provided the highest diagnostic value when compared with MRI grading based on the Fredericson classification (0-4). The SPSS correctly identified 43.5% of injuries for category 1 (MRI grades 0-1), 62.5% for category 2 (MRI grade 2), and 50.0% for category 3 (MRI grades 3-4). Overall, the SPSS correctly identified the degree of BSI in 54.4% of all tibias studied. Binary analysis for validity demonstrated a sensitivity of 96%, specificity of 26%, positive predictive value of 76%, and negative predictive value of 71% for the SPSS relative to the "gold standard" MRI results.

Conclusion

The SPSS is a potentially valid method to identify tibial BSIs, given the sensitivity and negative and positive predictive values. It also provides helpful categorization to alert clinicians to the presence of a BSI and direct further diagnostics and/or interventions. The SPSS should be considered as an additional tool to use when evaluating adolescents with atraumatic tibial BSIs.

Individual Differences in Women During Walking Affect Tibial Response to Load Carriage: The Importance of Individualized Musculoskeletal Finite-Element Models

Subject-specific features can contribute to the susceptibility of an individual to stress fracture. Here, we incorporated tibial morphology and material properties into a standard musculoskeletal finite-element (M/FE) model and investigated how load carriage influences joint kinetics and tibial mechanics in women. We obtained the morphology and material properties of the tibia from computed tomography images for women of three distinctly different heights, 1.51 m (short), 1.63 m (medium), and 1.75 m (tall), and developed individualized M/FE models for each. Then, we calculated joint and muscle forces, and subsequently, tibial stress/strain for each woman walking at 1.3 m/s under various load conditions (0, 11.3, or 22.7 kg). Among the subjects investigated, using individualized and standard M/FE models, the joint reaction forces (JRFs) differed by up to 4 (hip), 22 (knee), and 26% (ankle), and the 90th percentile von Mises stress by up to 30% (tall woman). Load carriage evoked distinct biomechanical responses, with a 22.7-kg load decreasing the peak hip JRF during late stance by ∼18% in the short woman, while increasing it by ∼39% in the other two women. It also increased peak knee and ankle JRFs by up to ∼48 (tall woman) and ∼36% (short woman). The same load increased the 90th percentile von Mises stress (and corresponding cumulative stress) by 31 (28), 22 (30), and 27% (32%) in the short, medium, and tall woman, respectively. Our findings highlight the critical role of individualized M/FE models to assess mechanical loading in different individuals performing the same physical activity.

Exercise-induced leg pain in athletes: diagnostic, assessment, and management strategies

The purpose of this review is to describe and critically evaluate current knowledge regarding diagnosis, assessment, and management of chronic overload leg injuries which are often non-specific and misleadingly referred to as 'shin splints'. We aimed to review clinical entities that come under the umbrella term 'Exercise-induced leg pain' (EILP) based on current literature and systematically searched the literature. Specifically, systematic reviews were included. Our analyses demonstrated that current knowledge on EILP is based on a low level of evidence. EILP has to be subdivided into those with pain from bone stress injuries, pain of osteo-fascial origin, pain of muscular origin, pain due to nerve compression and pain due to a temporary vascular compromise. The history is most important. Questions include the onset of symptoms, whether worse with activity, at rest or at night? What exacerbates it and what relieves it? Is the sleep disturbed? Investigations merely confirm the clinical diagnosis and/or differential diagnosis; they should not be solely relied upon. The mainstay of diagnosing bone stress injury is MRI scan. Treatment is based on unloading strategies. A standard for confirming chronic exertional compartment syndrome (CECS) is the dynamic intra-compartmental pressure study performed with specific exercises that provoke the symptoms. Surgery provides the best outcome. Medial tibial stress syndrome (MTSS) presents a challenge in both diagnosis and treatment especially where there is a substantial overlap of symptoms with deep posterior CECS. Conservative therapy should initially aim to correct functional, gait, and biomechanical overload factors. Surgery should be considered in recalcitrant cases. MRI and MR angiography are the primary investigative tools for functional popliteal artery entrapment syndrome and when confirmed, surgery provides the most satisfactory outcome. Nerve compression is induced by various factors, e.g., localized fascial entrapment, unstable proximal tibiofibular joint (intrinsic) or secondary by external compromise of the nerve, e.g., tight hosiery (extrinsic). Conservative is the treatment of choice. The localized fasciotomy is reserved for recalcitrant cases.

Injury Surveillance and Reporting for Trainees with Bone Stress Injury: Current Practices and Recommendations

Background

Musculoskeletal injuries, including lower extremity bone stress injuries (BSI) significantly impact initial entry training (IET) in the U.S. Army due to limited duty days, trainee attrition, early medical discharge, and related financial costs. Factors complicating trainee BSI surveillance include inconsistent BSI coding practices, attrition documentation as both administrative separations and medical discharges and the inability to code for BSI grade or severity when using International Statistical Classification of Diseases and Related Health Problems 10th revision (ICD-10) codes.

Methods

A multidisciplinary expert panel developed policy guidance to enhance clinical and administrative management of BSI, following extensive analysis of current, peer-reviewed literature. Policy guidance incorporates leading practices concerning clinical BSI management, including imaging procedures, recommended notifications, early intervention, and ICD-10 diagnostic coding procedures. Policy guidance also standardizes BSI grading criteria for magnetic resonance imaging and skeletal scintigraphy (bone scan).

Findings

Multidisciplinary expert opinion indicates inconsistent BSI diagnosis and management across IET due to variability in trainee BSI grading, documentation, and coding practices. Injury surveillance conducted by the United States Army Medical Command (USAMEDCOM) will benefit from routine, standardized musculoskeletal injury data base searches by BSI severity/grade and anatomical location upon implementation of BSI policy guidance.

Discussion

Effective injury surveillance is critical for determining trainee BSI incidence and attrition, developing anticipated return to duty (RTD) timelines, and assessing long-term outcomes. BSI RTD timelines should account for gender, BSI grade/severity, anatomical location, and type of intervention. Well-defined RTD timelines would benefit administrative decision-making purposes, including whether to grant convalescent leave or enroll in the Warrior Training and Rehabilitation Program during BSI recovery. Enhanced management procedures may improve initial enlistment completion rates for trainees sustaining at least one BSI who eventually complete IET.

Expected Time to Return to Athletic Participation After Stress Fracture in Division I Collegiate Athletes

BACKGROUND

Few studies have documented expected time to return to athletic participation after stress fractures in elite athletes.

HYPOTHESIS

Time to return to athletic participation after stress fractures would vary by site and severity of stress fracture.

STUDY DESIGN

Retrospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

All stress fractures diagnosed in a single Division I collegiate men's and women's track and field/cross-country team were recorded over a 3-year period. Site and severity of injury were graded based on Kaeding-Miller classification system for stress fractures. Time to return to full unrestricted athletic participation was recorded for each athlete and correlated with patient sex and site and severity grade of injury.

RESULTS

Fifty-seven stress fractures were diagnosed in 38 athletes (mean age, 20.48 years; range, 18-23 years). Ten athletes sustained recurrent or multiple stress fractures. Thirty-seven injuries occurred in women and 20 in men. Thirty-three stress fractures occurred in the tibia, 10 occurred in the second through fourth metatarsals, 3 occurred in the fifth metatarsal, 6 in the tarsal bones (2 navicular), 2 in the femur, and 5 in the pelvis. There were 31 grade II stress fractures, 11 grade III stress fractures, and 2 grade V stress fractures (in the same patient). Mean time to return to unrestricted sport participation was 12.9 ± 5.2 weeks (range, 6-27 weeks). No significant differences in time to return were noted based on injury location or whether stress fracture was grade II or III.

CONCLUSION

The expected time to return to full unrestricted athletic participation after diagnosis of a stress fracture is 12 to 13 weeks for all injury sites.

CLINICAL RELEVANCE

Athletes with grade V (nonunion) stress fractures may require more time to return to sport.

Taking a holistic approach to managing difficult stress fractures

Stress fractures and other bony stress injuries occur along a spectrum of severity which can impact treatment and prognosis. When treating these injuries, it should be borne in mind that no two stress fractures behave exactly alike. Given that they are not a consistent injury, standardized treatment protocols can be challenging to develop. Treatment should be individualized to the patient or athlete, the causative activity, the anatomical site, and the severity of the injury. A holistic approach to the treatment of the most difficult stress fractures should be taken by orthopedists and sports medicine specialists. This approach is necessary to obtain optimal outcomes, minimize loss of fitness and time away from sports participation, and decrease the risk of recurrence.

Diagnosis, treatment, and rehabilitation of stress fractures in the lower extremity in runners

Stress fractures account for between 1% and 20% of athletic injuries, with 80% of stress fractures in the lower extremity. Stress fractures of the lower extremity are common injuries among individuals who participate in endurance, high load-bearing activities such as running, military and aerobic exercise and therefore require practitioner expertise in diagnosis and management. Accurate diagnosis for stress fractures is dependent on the anatomical area. Anatomical regions such as the pelvis, sacrum, and metatarsals offer challenges due to difficulty differentiating pathologies with common symptoms. Special tests and treatment regimes, however, are similar among most stress fractures with resolution between 4 weeks to a year. The most difficult aspect of stress fracture treatment entails mitigating internal and external risk factors. Practitioners should address ongoing risk factors to minimize recurrence.

The treatment and outcomes of medial malleolar stress fractures: a systematic review of the literature

Context:

The medial malleolus is considered a high-risk stress fracture and can be debilitating to the highly active or athletic populations. A range of treatment methods have been described with varying outcomes. Currently, there is no gold standard treatment option with optimal results described.

Objective:

A systematic search of the literature to determine treatment options and outcomes in medial malleolus stress fractures.

Data Sources:

OVID/Medline, EMBASE, and the Cochrane Library from 1950 to September 2013.

Study Selection:

Included studies mentioned treatment and outcomes of medial malleolus stress fractures.

Study Design:

Systematic review.

Level of Evidence:

Level 4.

Data Extraction:

The searches used combinations of the terms stress fracture, medial malleolus, management, and treatment. Two authors independently reviewed the selected articles and created individual tables, which were later compiled into a master table for final analysis.

Results:

Six retrospective case series were identified (n = 31 patients). Eighty percent (25/31) of patients were men, with an average age of 24.5 years. Ninety percent (28/31) of patients were at least involved in recreational athletics. All patients were able to return to sport. Complications were seen in both groups ranging from minor stiffness to nonunion requiring open reduction internal fixation.

Conclusion:

Nonoperative and operative interventions have proven to be successful with regard to healing and return to play for medial malleolar stress fractures in the recreational and competitive athlete. However, early operative intervention can possibly create a higher likelihood of early healing, decrease in symptoms, and return to play.

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.

Stress fractures of the ribs and upper extremities: causation, evaluation, and management

Stress fractures are common troublesome injuries in athletes and non-athletes. Historically, stress fractures have been thought to predominate in the lower extremities secondary to the repetitive stresses of impact loading. Stress injuries of the ribs and upper extremities are much less common and often unrecognized. Consequently, these injuries are often omitted from the differential diagnosis of rib or upper extremity pain. Given the infrequency of this diagnosis, few case reports or case series have reported on their precipitating activities and common locations. Appropriate evaluation for these injuries requires a thorough history and physical examination. Radiographs may be negative early, requiring bone scintigraphy or MRI to confirm the diagnosis. Nonoperative and operative treatment recommendations are made based on location, injury classification, and causative activity. An understanding of the most common locations of upper extremity stress fractures and their associated causative activities is essential for prompt diagnosis and optimal treatment.

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.

The comprehensive description of stress fractures: a new classification system

BACKGROUND

Stress fractures represent a fatigue failure of bone, occurring with a spectrum of severity of structural injury, and healing potential varies by location. There is no comprehensive classification system for stress fractures incorporating both clinical and radiographic characteristics of the injury that is applicable to all bones. We introduce a system that is reproducible, generalizable, easy to use, and clinically relevant, with three descriptors: fracture grade, fracture location, and imaging modality.

METHODS

After a review of current classification systems, a five-tier system was proposed to determine fracture grade: Grade I indicated asymptomatic stress reaction on imaging, Grade II indicated pain with no fracture line, Grade III indicated non-displaced fracture, Grade IV indicated displaced fracture, and Grade V indicated nonunion. Example cases of each grade with clinical vignettes and images were prepared to test the interobserver and intraobserver reliability of the system by the test and retest evaluation among fifteen clinicians. A questionnaire and recall test assessed the ease of use, clinical applicability, and recall accuracy.

RESULTS

Test and retest analysis showed that the system had almost perfect agreement in intraobserver reliability with a kappa value of 0.81. The overall intraobserver reliability showed almost perfect agreement with a kappa value of 0.81. Almost perfect agreement with a kappa value of 0.83 was also produced when these responses were compared with our assessment. The overall interobserver reliability had substantial agreement with a kappa value of 0.78. The reliability of the group compared with that of the answer key was almost perfect with a kappa value of 0.83. The recall test showed an overall accuracy of 97.3%. Of the fifteen evaluators who completed questionnaires, fourteen (93.3%) said that the system would be easily remembered, would facilitate communication among colleagues, and would be useful in clinical practice.

CONCLUSIONS

The proposed stress fracture classification system is clinically relevant, easily applied, and generalizable, and has excellent interobserver and intraobserver reliability.

Update on stress fractures in female athletes: epidemiology, treatment, and prevention

Stress fractures are a common type of overuse injury in athletes. Females have unique risk factors such as the female athlete triad that contribute to stress fracture injuries. We review the current literature on risk factors for stress fractures, including the role of sports participation and nutrition factors. Discussion of the management of stress fractures is focused on radiographic criteria and anatomic location and how these contribute to return to play guidelines. We outline the current recommendations for evaluating and treatment of female athlete triad. Technologies that may aid in recovery from a stress fracture including use of anti-gravity treadmills are discussed. Prevention strategies may include early screening of female athlete triad, promoting early participation in activities that improve bone health, nutritional strategies, gait modification, and orthotics.

Ultrasound as a primary evaluation tool of bone stress injuries in elite track and field athletes

BACKGROUND

Little is known about therapeutic ultrasound (TUS) to diagnose bone stress injuries.

HYPOTHESIS

Therapeutic ultrasound is an accurate, cost-efficient alternative to other imaging methods for primary assessment of bone stress injuries.

STUDY DESIGN

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

METHODS

One hundred thirteen elite track and field athletes (mean age, 20.1 years; range, 17-28 years) underwent TUS and magnetic resonance imaging (MRI) for clinical suspicion of a bone stress injury. A 5-stage MRI grading system was used to classify bone stress injuries. Sensitivity, specificity, accuracy, and positive and negative predictive values of TUS were calculated using MRI as the standard for diagnosis.

RESULTS

At MRI, of 113 assessed patients, 3 (2.7%) had grade 0 injuries, 12 (10.6%) had grade 1, 15 (13.3%) had grade 2, 77 (68.2%) had grade 3, and 6 (5.3%) had grade 4. At TUS, no injury was detected in 22 of 113 patients: 2 with grade 0 injury, 8 with grade 1, 8 with grade 2, and 4 with grade 3. Using MRI as the gold standard, TUS showed 81.8% sensitivity, 66.6% specificity, 99.0% positive predictive value, 13.4% negative predictive value, and 81.4% accuracy.

CONCLUSION

Therapeutic ultrasound is a reproducible procedure that is reliable to diagnose bone stress injuries.

An iliac bone stress fracture in a basketball player

The authors describe the case of an athlete from the Brazilian national men's basketball team (sub-16) who reported pain in the right iliac region at the end of the season. Clinical and imaging exams revealed an iliac bone stress fracture. A conservative treatment of removing the load from the fracture in combination with physical therapy was chosen. The athlete improved satisfactorily and returned to the sport at the same level as prior to the injury after 14 weeks of treatment.