Lower extremity and pelvic stress fractures in athletes

Male Runners With Lower Energy Availability Have Impaired Skeletal Integrity Compared to Nonathletes

CONTEXT

Female athletes, particularly runners, with insufficient caloric intake for their energy expenditure [low energy availability (EA) or relative energy deficiency] are at risk for impaired skeletal integrity. Data are lacking in male runners.

OBJECTIVE

To determine whether male runners at risk for energy deficit have impaired bone mineral density (BMD), microarchitecture, and estimated strength.

DESIGN

Cross-sectional.

SETTING

Clinical research center.

PARTICIPANTS

39 men (20 runners, 19 controls), ages 16-30 years.

MAIN OUTCOME MEASURES

Areal BMD (dual-energy x-ray absorptiometry); tibia and radius volumetric BMD and microarchitecture (high-resolution peripheral quantitative computed tomography); failure load (microfinite element analysis); serum testosterone, estradiol, leptin; energy availability.

RESULTS

Mean age (24.5 ± 3.8 y), lean mass, testosterone, and estradiol levels were similar; body mass index, percent fat mass, leptin, and lumbar spine BMD Z-score (-1.4 ± 0.8 vs -0.8 ± 0.8) lower (P < .05); and calcium intake and running mileage higher (P ≤ .01) in runners vs controls. Runners with EA

CONCLUSIONS

Despite weight-bearing activity, skeletal integrity is impaired in male runners with lower caloric intake relative to exercise energy expenditure, which may increase bone stress injury risk. Lower estradiol and lean mass are associated with lower tibial strength in runners.

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Key Words

• HR-pQCT
• athletes
• bone density
• energy availability

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MESH Headings

• Humans
• Male
• Female
• Leptin
• Cross-Sectional Studies
• Calcium
• Bone Density
• Absorptiometry, Photon
• Lumbar Vertebrae
• Testosterone
• Estradiol

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Grants

• K23 DK115903 NIDDK NIH HHS
• K24 HD071843 NICHD NIH HHS
• 1UL1TR002541-01 NIH HHS
• K24 HL092902 NHLBI NIH HHS
• Massachusetts General Hospital Executive Committee on Research
• National Institutes of Health
• Department of Defense Research Participation Program
• U.S. Army Research Institute of Environmental Medicine
• Oak Ridge Institute for Science and Education

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Affiliation(s)

Melanie S Haines Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Harvard Medical School, Boston, MA 02115, USA
Snimarjot Kaur Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Harvard Medical School, Boston, MA 02115, USA
Geetanjali Scarff Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
Meghan Lauze Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
Anu Gerweck Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
Meghan Slattery Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA
Nicolas M Oreskovic Harvard Medical School, Boston, MA 02115, USA Department of Internal Medicine and Pediatrics, Massachusetts General Hospital, Boston, MA 02114, USA
Kathryn E Ackerman Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Harvard Medical School, Boston, MA 02115, USA Female Athlete Program, Division of Sports Medicine, Boston Children's Hospital, Boston, MA 02115, USA
Adam S Tenforde Harvard Medical School, Boston, MA 02115, USA Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, Cambridge, MA 02129, USA
Kristin L Popp Harvard Medical School, Boston, MA 02115, USA Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Military Performance Division, United States Army Research Institute of Environmental Medicine, Natick, MA 01760, USA Department of Energy, Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
Mary L Bouxsein Harvard Medical School, Boston, MA 02115, USA Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Center for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA
Karen K Miller Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Harvard Medical School, Boston, MA 02115, USA
Madhusmita Misra Neuroendocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA Harvard Medical School, Boston, MA 02115, USA Division of Pediatric Endocrinology, Massachusetts General Hospital, Boston, MA 02114, USA

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Healthy Eating Index and Dietary Inflammatory Index are not correlated with body composition in female collegiate athletes

OBJECTIVE

This cross-sectional study investigated associations among the Healthy Eating Index (HEI)-2015, Dietary Inflammatory Index (DII), and body composition in female collegiate athletes.

PARTICIPANTS

Female NCAA Division I student-athletes (n = 41, 18-21 years old) were included from various sports and did not report any diagnosed chronic diseases.

METHODS

Demographics, dietary intake, anthropometrics, and body composition, including bone mineral density, were collected utilizing a questionnaire, three interview-based multiple-pass 24-h dietary recalls, and dual-energy X-ray absorptiometry.

RESULTS

Mean HEI-2015 and DII scores (using 39 of 45 components) were 56.2 ± 13.5 and -0.1 ± 1.9, respectively. Athletes did not meet recommended intake levels for servings of fruit, vegetables, fiber, calcium, vitamin D, omega-3, and omega-6. Saturated fat and added sugar intake exceeded the recommended intakes. Diet quality indices and body composition measures were not correlated.

CONCLUSIONS

Although female collegiate athletes consumed poor-quality diets, this was not associated with body composition or bone health.

Return to sport following low-risk and high-risk bone stress injuries: a systematic review and meta-analysis

OBJECTIVE

Bone stress injuries (BSIs) are classified in clinical practice as being at low- or high-risk for complication based on the injury location. However, this dichotomous approach has not been sufficiently validated. The purpose of this systematic review was to examine the prognostic role of injury location on return-to-sport (RTS) and treatment complications after BSI of the lower extremity and pelvis.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Web of Science, Cochrane CENTRAL and Google Scholar databases were searched from database inception to December 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Peer-reviewed studies that reported site-specific RTS of BSIs in athletes.

RESULTS

Seventy-six studies reporting on 2974 BSIs were included. Sixteen studies compared multiple injury sites, and most of these studies (n=11) described the anatomical site of injury as being prognostic for RTS or the rate of treatment complication. Pooled data revealed the longest time to RTS for BSIs of the tarsal navicular (127 days; 95% CI 102 to 151 days) and femoral neck (107 days; 95% CI 79 to 135 days) and shortest duration of time for BSIs of the posteromedial tibial shaft (44 days, 95% CI 27 to 61 days) and fibula (56 days; 95% CI 13 to 100 days). Overall, more than 90% of athletes successfully returned to sport. Treatment complication rate was highest in BSIs of the femoral neck, tarsal navicular, anterior tibial shaft and fifth metatarsal; and lowest in the fibula, pubic bone and posteromedial tibial shaft.

CONCLUSION

This systematic review supports that the anatomical site of BSIs influences RTS timelines and the risk of complication. BSIs of the femoral neck, anterior tibial shaft and tarsal navicular are associated with increased rates of complications and more challenging RTS.

PROSPERO REGISTRATION NUMBER

CRD42021232351.

Bilateral Ischial Tuberosity Stress Fractures in an Adolescent Football Player: A Case Report

ABSTRACT

Pelvic stress fractures are rare, making up an estimated 1% to 7% of all stress fractures with the primary locations being the pubic rami, pubic symphysis, and sacrum. Two cases of stress fractures of the ischium have been previously described in the literature, with both occurring in the ischial body. In this case, a 17-year-old high school American football player presented with nonspecific pelvic pain and bilateral point tenderness on deep palpation of the ischial tuberosities. Advanced imaging identified bilateral ischial tuberosity stress fractures. This report outlines the diagnosis and management of the first reported case of bilateral ischial tuberosity stress fractures. We report how ischial tuberosity stress fractures present clinically, potential management strategies, and highlight the use of computed tomography imaging for pelvic stress fractures. Knowledge of unusual stress fracture locations may improve early diagnosis, limit complications, reduce healthcare costs, and promote an accelerated recovery time.

Bone Marrow Lesions in Athletic Stress Injuries: An Overview

This article discusses the presumed pathophysiology of osseous sport-related stress changes, the optimal imaging strategy for detecting the lesions, and the progression of the lesions as seen on magnetic resonance imaging. It also describes some of the most common stress-related injuries in athletes by anatomical location and introduces some new concepts in the field.

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.

Health Outcomes after Pregnancy in Elite Athletes: A Systematic Review and Meta-analysis

PURPOSE

This study aimed to evaluate postpartum maternal health and training outcomes of females who were competing or training as elite athletes before or during pregnancy.

METHODS

Online databases were searched up to August 26, 2020. Studies of any design and language were eligible if they contained information on the relevant population (postpartum athletes [any period after pregnancy]), exposure (engaged in the highest level of sport immediately before or during pregnancy), comparators (sedentary/active controls), and outcomes: maternal (breastfeeding initiation and duration, postpartum weight retention or loss, bone mineral density, low back or pelvic girdle pain, incontinence [prevalence or severity of stress, urge or mixed urinary incontinence, fecal incontinence], injury, anemia, diastasis recti, breast pain, depression, anxiety) and training (<6 wk time to resume activity, training volume or intensity, performance level).

RESULTS

Eleven studies (n = 482 females, including 372 elite athletes) were included. We identified "very low" certainty evidence demonstrating a higher rate of return to sport before 6 wk postpartum among elite athletes compared with nonelite athletes (n = 145, odds ratio = 6.93, 95% confidence interval = 2.73-17.63, I2 = 11). "Very low" certainty evidence from three studies (n = 179) indicated 14 elite athletes obtained injuries postpartum (7 stress fractures, 9 "running injuries"). "Very low" certainty evidence from five studies (n = 262) reported that 101 (40.5%) elite athletes experienced improved performance postpartum.

CONCLUSION

Compared with controls, "very low" quality evidence suggests that elite athletes return to physical activity early in the postpartum period and may have an increased risk of injury. Additional high-quality evidence is needed to safely guide return to sport of elite athletes in the postpartum period.

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.

Part II: presentation, diagnosis, classification, treatment, and prevention of stress fractures in female athletes

Objectives: Stress fractures (SFx) occur as the result of repetitive loads over short periods of time, which leads to micro-damage of the bone through cortical resorption, ultimately leading to fracture. They are a common injury in female athletes and often cause significant morbidity. The goal of this study is to review the presentation, diagnosis, classification, treatment, and prevention of SFx in female athletes.Results: A thorough history, physical exam, and appropriate imaging can facilitate early diagnosis of stress fracture (SFx) and faster resolution of symptoms with more conservative management. The female athlete triad is an especially important factor that contributes to the increased risk of SFx in females. The continuum of stress injuries ranges from mild microfailure to complete fracture, which has resulted in the development of newer grading schemas through MRI and radiographic findings. Stress fractures are also classified as low- or high-risk according to anatomic location, as blood supply and applied forces at different locations affect the likelihood of fracture propagation, displacement, delayed union, or non-union.Conclusions: The ability to screen for at-risk athletes is paramount in preventing SFx. Recognition and prompt treatment of the female athlete triad requires a multidisciplinary approach in order to restore energy balance, correct menstrual irregularities, and improve bone health. This review provides a basis for understanding how to identify and treat stress fractures, which may allow treating physicians to diagnose this condition earlier and minimize any associated morbidity.

Part I: epidemiology and risk factors for stress fractures in female athletes

Objectives: Stress fractures (SFx) are a common athletic injury, occurring in up to 40% of athletes at some point in their career. These injuries can cause pain, permanent disability, financial burden, and loss of playing time. This review presents updated epidemiology and comprehensive analysis of risk factors for stress fractures, especially as it pertains to female athletes.Results: Stress fractures (SFx) account for up to 10% of all orthopedic injuries and up to 20% of injuries seen in sports medicine clinics, with an incidence among female athletes as high as 13%. Lower extremity SFx represent 80-95% of SFx, and the increased popularity of endurance running has contributed to the tibia (49% prevalence) replacing the metatarsals (9%) as the most common location for lower extremity SFx. Studies have demonstrated that 50% of peak bone mass is acquired during adolescence, a 'peak time' for eating disorder and female athlete triad development; furthermore, catch-up growth cannot be expected in athletes with diminished bone growth in this critical period. The female athlete triad (low energy availability with or without disordered eating, menstrual dysfunction, and low bone mineral density) are well-known risk factors for SFx; the risk of SFx for female athletes presenting with a single aspect of the triad is 15-20%, and this risk increases to 30-50% for female athletes presenting with multiple aspects of the triad.Conclusion: This review provides a basis for how to identify populations at greatest risk for SFx. Prompt recognition of the intrinsic and extrinsic risk factors for SFx in female athletes is imperative to early diagnosis and to develop targeted strategies to prevent SFx occurrence or recurrence.

Medial iliac stress fractures in athletes: report of two rare cases: review of literature and clinical recommendations

Stress fractures are a common diagnosis in sports medicine and can result in significant loss of function, athlete playing time, and potentially lead to chronic symptoms. However, unusual locations of stress fractures may present with vague symptoms and a relatively benign physical exam, leading to difficulty in arriving at the correct diagnosis. Pelvic stress fractures are less common than lower-extremity stress fractures in athletes, occurring in only 1-5% of all stress fractures and typically occur in pubic rami. Furthermore, iliac bone stress fractures are even rarer, with only a few case reports in the literature. Their presentation can easily be missed on routine workup and imaging. We present two cases of the very rare superomedial iliac bone stress fracture in athletes, an unusual location for this uncommon stress fracture. We review the available literature on this condition and provide clinical commentary on workup and treatment recommendations.

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.

Forefoot transverse arch height asymmetry is associated with foot injuries in athletes participating in college track events

[Purpose] The association between foot injuries and foot alignment, including the transverse arch height (TAH) and asymmetry, was examined in athletes participating in college track events. [Participants and Methods] This study included 55 male athletes participating in a college track and field club. Data including demographic information and the incidence of foot injuries within a year prior to participation in this study were obtained via questionnaires. TAH and the medial longitudinal arch height during 10 and 90% loading, leg-heel alignment, and the heel angle were measured before calculating the asymmetry of each alignment parameter measured. Participants were categorized into an injury or a normal group. Unpaired t-tests were used to perform between-group comparisons for each alignment parameter measured and asymmetry. Additionally, logistic regression analysis was performed to identify factors associated with foot injuries after adjustment for demographic data. [Results] TAH asymmetry during 10 and 90% loading was significantly greater in the injury group. Further logistic regression analysis performed showed that only TAH asymmetry during 90% loading was significantly associated with foot injuries after adjustment for demographic data. [Conclusion] With regard to track events, a greater asymmetry of forefoot TAH in a weight-bearing position was observed to be associated with foot injuries.

ACR Appropriateness Criteria® Stress (Fatigue/Insufficiency) Fracture, Including Sacrum, Excluding Other Vertebrae

Stress fractures, including both fatigue and insufficiency types, are frequently encountered in clinical practice as a source of pain in both athletes and patients with predisposing conditions. Radiography is the imaging modality of choice for baseline diagnosis. MRI has greatly improved our ability to diagnose radiographically occult stress fractures. Tc-99m bone scan and CT may also be useful as diagnostic tools. Although fatigue and insufficiency fractures can be self-limited and go onto healing even without diagnosis, there is usually value in initiating prompt therapeutic measures as incomplete stress fractures have the potential of progressing to completion and requiring more invasive treatment or delay in return to activity. This is particularly important in the setting of stress fractures of the femoral neck. Accuracy in the identification of these injuries is also relevant because the differential diagnosis includes entities that would otherwise be treated significantly different (ie, osteoid osteoma, osteomyelitis, and metastasis). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Magnetic Resonance Imaging of Sports Injuries Involving the Ankle

Understanding of ankle injuries has evolved for the past few decades, influenced by capability to visualize ligaments, tendons, and bone marrow on magnetic resonance imaging (MRI). Natural history of injury progression, complications, and healing has also been characterized using MRI. Stress injury is particularly common at the ankle in athletes and "weekend warriors" alike. This article will discuss manifestations of ankle injury on MRI as well as associated findings that should be addressed.

Diagnostic Accuracy of Various Imaging Modalities for Suspected Lower Extremity Stress Fractures: A Systematic Review With Evidence-Based Recommendations for Clinical Practice

BACKGROUND

The literature is filled with conflicting findings regarding diagnostic accuracy and protocols for imaging suspected lower extremity stress fractures. The absence of systematic reviews on this topic has limited the development of evidence-based recommendations for appropriate imaging protocols in cases of suspected lower extremity stress fractures.

PURPOSE

To determine the diagnostic accuracy statistics of imaging modalities used to diagnose lower extremity stress fractures and to synthesize evidence-based recommendations for clinical practice.

STUDY DESIGN

Systematic review.

METHODS

A generic search strategy for published studies was performed using multiple databases. A study was eligible for inclusion if it met all of the following criteria: (1) at least 1 diagnostic imaging modality was studied, (2) at least 1 radiological reference standard was used, (3) the study reported or allowed computation of diagnostic accuracy statistics (sensitivity, specificity, positive likelihood ratio, negative likelihood ratio), (4) a full-text version was available, (5) the article was written in English, and (6) the study included lower extremity stress fractures. Studies that examined asymptomatic individuals or patients with fractures due to disease or pharmacologic intervention were excluded.

RESULTS

Reported sensitivity and specificity (95% CI) were as follows: For conventional radiography, sensitivity ranged from 12% (0%-29%) to 56% (39%-72%) and specificity ranged from 88% (55%-100%) to 96% (87%-100%). For nuclear scintigraphy (NS), sensitivity ranged from 50% (23%-77%) to 97% (90%-100%) and specificity from 33% (12%-53%) to 98% (93%-100%). For magnetic resonance imaging (MRI), sensitivity ranged from 68% (45%-90%) to 99% (95%-100%) and specificity from 4% (0%-11%) to 97% (88%-100%). For computed tomography, sensitivity ranged from 32% (8%-57%) to 38% (16%-59%) and specificity from 88% (55%-100%) to 98% (91%-100%). For ultrasound, sensitivity ranged from 43% (26%-61%) to 99% (95%-100%) and specificity from 13% (0%-45%) to 79% (61%-96%).

CONCLUSION

MRI was identified as the most sensitive and specific imaging test for diagnosing stress fractures of the lower extremity. When MRI is available, NS is not recommended because of its low specificity, high dosage of ionizing radiation, and other limitations. Conventional radiographs are likely to result in false negatives upon initial presentation, particularly in the early stages of stress fracture, and in some cases may not reveal an existing stress fracture at any time. A diagnostic imaging algorithm was developed with specific recommendations for cost-efficient imaging of low-risk and high-risk suspected stress fractures.

Visualization of stress fractures of the foot using PET-MRI: a feasibility study

BACKGROUND

Diagnosis and treatment of stress fractures still remains to be a clinical and radiological challenge. Therapeutic options vary from conservative treatment to surgical treatment without a clear treatment concept. Recently the combination of PET and MRI has been introduced, aiming a superior diagnostic accuracy in clinical practice. Therefore the aim of our study was to analyse whether PET-MRI would be a feasible technique to recognize stress fractures of the foot and to analyse if our conservative treatment plan leads to a good clinical outcome.

METHODS

Therefore, 20 patients with suspected stress fractures of the foot and ankle underwent plain radiography and (18)F-Fluoride PET-MRI. Two blinded readers assessed in consensus both imaging techniques for the presence of stress fracture, stress reaction or osteoarthritis. Patients with stress fractures or stress reactions in the foot and ankle area underwent our conservative treatment plan, with immobilization in a VACO®ped cast for 6 weeks under partial weight bearing on forearm crutches. The benefit of our conservative therapeutic concept was evaluated by the patients on the basis of VAS and FAOS scoring systems before and after treatment.

RESULTS

8 out of 20 patients underwent conservative treatment after diagnosis of either a stress fracture or a stress reaction of the foot and ankle area. PET-MRI identified four stress fractures and seven stress reactions. In all cases, no pathological findings were present on plain X-ray. FAOS and VAS significantly improved according to the patients' records.

CONCLUSIONS

PET-MRI seems to be a useful modality to diagnose stress fractures and stress reactions of the foot and ankle area, especially when conventional modalities, such as plain radiographs fail. Conservative management is a promising therapeutic option for the treatment of stress fractures. To rule out the benefits compared to a surgical treatment plan, further studies are needed.

The effect of concentrated bone marrow aspirate in operative treatment of fifth metatarsal stress fractures; a double-blind randomized controlled trial

BACKGROUND

Fifth metatarsal (MT-V) stress fractures often exhibit delayed union and are high-risk fractures for non-union. Surgical treatment, currently considered as the gold standard, does not give optimal results, with a mean time to fracture union of 12-18 weeks. In recent studies, the use of bone marrow cells has been introduced to accelerate healing of fractures with union problems. The aim of this randomized trial is to determine if operative treatment of MT-V stress fractures with use of concentrated blood and bone marrow aspirate (cB + cBMA) is more effective than surgery alone. We hypothesize that using cB + cBMA in the operative treatment of MT-V stress fractures will lead to an earlier fracture union.

METHODS/DESIGN

A prospective, double-blind, randomized controlled trial (RCT) will be conducted in an academic medical center in the Netherlands. Ethics approval is received. 50 patients will be randomized to either operative treatment with cB + cBMA, harvested from the iliac crest, or operative treatment without cB + cBMA but with a sham-treatment of the iliac crest. The fracture fixation is the same in both groups, as is the post-operative care.. Follow up will be one year. The primary outcome measure is time to union in weeks on X-ray. Secondary outcome measures are time to resumption of work and sports, functional outcomes (SF-36, FAOS, FAAM), complication rate, composition of osteoprogenitors in cB + cBMA and cost-effectiveness. Furthermore, a bone biopsy is taken from every stress fracture and analysed histologically to determine the stage of the stress fracture. The difference in primary endpoint between the two groups is analysed using student's t-test or equivalent.

DISCUSSION

This trial will likely provide level-I evidence on the effectiveness of cB + cBMA in the operative treatment of MT-V stress fractures.

TRIAL REGISTRATION

Netherlands Trial Register (reg.nr NTR4377 ).

Clinician approach to diagnosis of stress fractures including bisphosphonate-associated fractures

Stress fractures are repetitive strain injuries that occur in normal bones and in abnormal bones. Stress fractures share many features in common but differences depend on the status of the underlying bone. This review article for clinicians addresses aspects about stress fractures with particular respect to fatigue fractures, Looser zones of osteomalacia, atypical Looser zones, atypical femoral fractures associated with bisphosphonate therapy and stress fractures in Paget's disease of bone.

Hip structural analysis in adolescent and young adult oligoamenorrheic and eumenorrheic athletes and nonathletes

CONTEXT

Stress fractures are common in endurance athletes. Whereas studies have described distal tibia bone structure in athletes, there are few data regarding hip geometric parameters. Hip structural analysis (HSA) using dual-energy x-ray absorptiometry is a validated technique to assess hip bone structure.

OBJECTIVES

The purpose of this study was to compare hip geometry in young oligoamenorrheic athletes (AAs), eumenorrheic athletes (EAs), and nonathletes using HSA. We hypothesized that AAs would have impaired bone structure compared with that of EAs.

DESIGN

This was a cross-sectional study.

SETTING

The setting was a clinical research center.

SUBJECTS

We enrolled 55 AAs, 24 EAs, and 23 nonathletes of normal weight who were 14 to 22 years old. Athletes ran ≥20 miles/wk or were engaged in weight-bearing sports for ≥4 hours/wk.

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry was used for HSA and hip areal bone mineral density (aBMD).

RESULTS

Hip aBMD Z-scores were lower in AAs and in nonathletes than in EAs (P = .002). A larger proportion of AAs than EAs and nonathletes had hip Z-scores <-1 (30.9, 4.2, 17.4%, P = .01). At the narrow neck, trochanteric region, and femoral shaft, subperiosteal width, cross-sectional moment of inertia, and section modulus were higher in EAs than in nonathletes; values in AAs did not differ from those of nonathletes. Cross-sectional area was lower in AAs and in nonathletes than in EAs. Groups did not differ for cortical thickness or buckling ratio. Group differences were lost after adjustment for lean mass but not aBMD.

CONCLUSIONS

In an eugonadal state, athletic activity confers benefits for hip structure independent of aBMD. This advantage is lost in AAs, who do not differ from nonathletes for most parameters and fare worse than EAs for cross-sectional area.

Radiographically occult and subtle fractures: a pictorial review

Radiographically occult and subtle fractures are a diagnostic challenge. They may be divided into (1) “high energy trauma fracture,” (2) “fatigue fracture” from cyclical and sustained mechanical stress, and (3) “insufficiency fracture” occurring in weakened bone (e.g., in osteoporosis and postradiotherapy). Independently of the cause, the initial radiographic examination can be negative either because the findings seem normal or are too subtle. Early detection of these fractures is crucial to explain the patient's symptoms and prevent further complications. Advanced imaging tools such as computed tomography, magnetic resonance imaging, and scintigraphy are highly valuable in this context. Our aim is to raise the awareness of radiologists and clinicians in these cases by presenting illustrative cases and a discussion of the relevant literature.