Stress fractures of the base of the metatarsal bones in young trainee ballet dancers

Stress fractures of the foot - current evidence on management

Stress fractures are a consequence of repeated submaximal loads with inadequate time for recovery and biologic repair or remodelling. The foot and ankle complex (FAC) represents a common site for development of stress fractures. Whilst the overall incidence of stress fractures is low, they are prevalent in athletes and military personnel causing significant time away from sports or work. Within these populations, certain stress fractures directly correlate to specific activities. Factors that commonly influence these fractures include an acute increase in new repetitive physical activity combined with muscle fatigue, training errors or improper athletic techniques, which challenge the regenerative and remodelling capacity of bone. Depending on the site that is subject to repetitive loading, various biomechanical factors can result in abnormal concentration of forces to specific areas of the FAC resulting in stress fracture. Decreased bone marrow density (BMD) is a major biologic cause for developing stress fractures. The female athlete triad comprising eating disorder, amenorrhea and osteoporosis in competitive athletes also predisposes to stress fractures. Vitamin D deficiency is also postulated to be the cause of these fractures and may contribute to poor healing. Clinical presentation is usually with vague pain of insidious onset which worsens with activity and improves with rest. Diffuse tenderness over the affected bone is common with only a minority having any visible swelling. Plain radiographs are the first line of investigation but rarely reveal an obvious fracture. MRI scans aid in diagnosis and CT scans help in treatment and characterisation of the fracture and monitor healing. Management relates to the site of injury, which stratifies them into high or low-risk. Stress fractures of the calcaneus, cuboid and cuneiforms are classed as low-risk fractures as they usually heal with simple activity modification or short duration of non-weight bearing. Stress fractures of the navicular, talus and hallucal sesamoids are classed as high-risk fractures due to higher rates of non-union and prolonged recovery time. Metatarsal fractures can be considered high or low-risk depending on location. These warrant aggressive management, often requiring surgical intervention. Adjuncts such as vitamin D supplements, external shockwave therapy, low-intensity pulsed ultrasound therapy have been used with varying success but there remains little supportive evidence of superiority in the available literature.

Investigating pre-professional dancer health status and preventative health knowledge

Introduction

Dance is a highly demanding physical pursuit coupled with pressure to conform to aesthetic ideals. Assessment of health status and preventative health knowledge of pre-professional dancers may help inform educational strategies promoting dancers' health and career longevity. The aim of this research was to establish a baseline understanding of dance students at a single pre-professional institution based on metrics focused on current health, nutrition, lifestyle, and wellbeing while also gauging knowledge of longer-term health implications.

Methods

Adopting a cross-sectional study design, the Dance-Specific Energy Availability Questionnaire was tailored for Australian participants and administered online.

Results

The response rate was 59.5% (69/116 eligible students) and the survey was completed in full by 63 students. Mean BMI was 20 kg/m2, although among females, 47% had a BMI < 20 (range 16 to 25 kg/m2), and at their lowest reported weight BMI was 14 to 25 kg/m2. Over a third had either experienced (31%) or were currently experiencing (3.4%) secondary amenorrhea (period absence ≥ 3 consecutive months). Most dancers did not exclude food groups, however, 24% had been advised to exclude particular foods in the past, mostly by dance teachers. A large percentage used nutritional supplements (68%) with 60% supplementing with iron and more than half (53%) taking two or more supplements. Only 25% had ever utilised a qualified dietitian, although 16% reported a history of eating disorders and 25% reported vegetarian or vegan eating patterns. REDs risk scores ranged from -16 to +16 points with negative scores indicating LEA and higher risk of REDs. The mean score for males was 5.2 (SD = 3.9) and 2.1 (SD = 5.9) for females, with 33.3% producing a negative score.

Conclusion

Results provide insight to health knowledge and particular issues pertinent for dancers and highlights the need for specific education strategies to promote a preventative health focus for those entering a pre-professional programme. This study also highlights the need for improved awareness of LEA and REDs among all practitioners working with dancers along with cultural and structural changes within the broader dance community to help protect and promote the wellbeing of dancers.

Shockwave Treatment vs Surgery for Proximal Fifth Metatarsal Stress Fractures in Soccer Players: A Pilot Study

BACKGROUND

To compare the clinical, radiologic, and functional outcomes between shockwave and operative treatments for proximal fifth metatarsal stress fractures in soccer players in a pilot study.

METHODS

Between 2017 and 2019, 18 soccer players with fifth metatarsal stress fractures attended at Mutualidad de Futbolistas Españoles-Delegación Catalana were included. Patients were randomly assigned into 2 groups receiving either surgery with an intramedullary screw (group 1) or high-energy focused extracorporeal shockwave treatment (group 2 performed once a week for 3 weeks using 2000 impulses at an energy flux density of 0.21 mJ/mm2 and 4 Hz frequency). Clinical (pain), radiologic (bone healing), and functional (Tegner Activity Scale and American Orthopaedic Foot & Ankle Society [AOFAS] ankle-hindfoot scales) outcomes before and after receiving the treatment were compared between both groups. In addition, ability and time to return to play was also compared between groups.

RESULTS

No patients were lost to follow-up. There were no statistically significant differences at last follow-up between surgery and extracorporeal shockwave treatment for bone healing, pain relief, AOFAS ankle-hindfoot score, Tegner score, and time return to play. No complications were reported in either of the 2 groups.

CONCLUSION

In this pilot study, extracorporeal shockwave treatment and operative treatment were found to be equally effective at reducing pain, achieving bone healing, and allowing the soccer players to return to play after proximal fifth metatarsal stress fractures. This study suggests that ESWT may be a good option for the management of proximal fifth metatarsal stress fractures in soccer players. If this approach proves successful in larger trials, the shockwave approach might help avoid known complications of the surgical treatment like wound problems, nerve injury, and hardware intolerance. Further investigations with larger sample size should be conducted in order to confirm the present conclusions.

LEVEL OF EVIDENCE

Level II, therapeutic, pilot randomized controlled trial.

Musculoskeletal Injury in an Australian Professional Ballet Company, 2018-2021: 953 Medical-Attention and 706 Time-Loss Injuries Over 4 Years

OBJECTIVES: To describe the incidence rate, frequency, severity, recurrence, and burden of musculoskeletal injury in professional ballet. STUDY DESIGN: Descriptive epidemiological (retrospective). METHODS: Professional dancers (n = 73, 40 females, 33 males) provided consent for retrospective review of musculoskeletal injury data. Medical-attention injuries were reported to and recorded by onsite physiotherapists between January 2018 and December 2021. Time-loss injuries were any injury that prevented a dancer from taking a full part in all dance-related activities for >1 day. Injuries were classified using the OSICS-10.1 system. Injury incidence rates (IIRs; injuries/1000 h), severity, recurrence, and burden were calculated. RESULTS: Nine hundred and fifty-three medical-attention injuries were recorded in 72 (98%) dancers at an IIR of 2.79/1000 h (95% confidence interval [CI], 2.62-2.98). 706 were time-loss injuries, which were reported in 70 dancers at an IIR of 2.07/1000 h (95% CI: 1.92, 2.23). Overuse injuries represented 53% of medical-attention injuries. The most frequently injured body area and tissue/pathology were thoracic facet joint (n = 63/953, 7%) and ankle synovitis/impingement (n = 62/953, 6%). Bone stress injuries (BSIs) were the most severe with the highest median time loss (135 days, interquartile range [IQR] 181) followed by fractures (72.5 days, IQR 132). The injuries with the highest burden were tibial BSIs (13 days lost/1000 h; 95% CI: 13, 14). Jumping and lifting were the most frequently reported injury mechanisms. CONCLUSION: Almost all dancers required medical attention for at least one injury during the surveillance period. Approximately 74% of injuries resulted in time loss. BSIs and ankle synovitis/impingement were of high burden, and a high proportion of BSIs were recurrent. J Orthop Sports Phys Ther 2023;53(11):712-722. Epub 14 September 2023. doi:10.2519/jospt.2023.11858.

Republication of "Stress Fractures of the Foot and Ankle in Athletes"

Stress fractures of the foot and ankle are common injuries in athletes. Management differs considerably based on fracture location and predisposing factors. Repetitive loading of the foot and ankle in athletes should result in physiologic bone remodeling in accordance with Wolff's law. However, when there is not sufficient time for complete healing to occur before additional loads are incurred, this process can instead lead to stress fracture. Assessment of the athlete's training regimen and overall bone health is paramount to both the discovery and treatment of these injuries, although diagnosis is often delayed in the setting of normal-appearing initial radiographs. While most stress fractures of the foot or ankle can usually be treated nonoperatively with a period of activity modification, fractures in certain locations are considered "high risk" due to poor intrinsic healing and may warrant more proactive operative management.

Bone Stress Injuries at the Ankle and Foot

Bone stress injuries (BSIs) are a frequent finding in athletes, particularly of the foot and ankle. A BSI is caused by recurring microtrauma to the cortical or trabecular bone exceeding the repair capacity of normal bone. The most frequent fractures at the ankle are low risk, characterized by a low risk for nonunion. These include the posteromedial tibia, the calcaneus, and the metatarsal diaphysis. High-risk stress fractures have a higher risk for nonunion and need more aggressive treatment. Examples are the medial malleolus, navicular bone, and the base of the second and fifth metatarsal bone.Imaging features depend on the primary involvement of cortical versus trabecular bone. Conventional radiographs may remain normal up to 2 to 3 weeks. For cortical bone, early signs of BSIs are a periosteal reaction or the "gray cortex sign," followed by cortical thickening and fracture line depiction. In trabecular bone, a sclerotic dense line may be seen. Magnetic resonance imaging enables early detection of BSIs and can differentiate between a stress reaction and a fracture. We review typical anamnestic/clinical findings, epidemiology and risk factors, imaging characteristics, and findings at typical locations of BSIs at the foot and ankle that may help guide treatment strategy and patient recovery.

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.

Case study: Treating infraspinatus and supraspinatus trigger points and supraspinatus tendinopathy utilizing piezoelectric shockwave

Two individual case studies demonstrate piezoelectric shockwave treatment for the resolution of a supraspinatus tendinopathy and supraspinatus and infraspinatus myofascial trigger points (MTPs) via musculoskeletal ultrasound. This is the first documentation of improvement of both tendon and muscle fiber patterns in canine patients treated with piezoelectric shockwave. These cases validate the use of piezoelectric shockwave during the rehabilitation of common canine shoulder injuries.

Comparison of Dance-Related Foot and Ankle Injuries Among Pre-Professional Ballet, Contemporary, and Chinese Dancers

BACKGROUND

Foot and ankle injuries have been noted as the most common in dancers. However, the variability of injury epidemiology across different dance genres has not been clearly evaluated. Herein, this study aimed to evaluate the prevalence and incidence of foot and ankle problems in pre-professional ballet, contemporary, and Chinese dancers.<br/> Methods: Participants (N = 54) were recruited from a local dance institution that offered a formal undergraduate dance program. Demographic characteristics and specifics of foot and ankle pain during dancing were collected through an online self-reporting survey from September 2018 to June 2019. Descriptive statistical analyses, including injury incidence and risk rates, were conducted.<br/> Results: The overall response rate was 69.3%, with a total of 88 subjects eligible for analysis of which the results from 54 subjects were ultimately analyzed. The incidence of foot and ankle pain during the academic year of 2018 to 2019 was highest in contemporary dancers (0.38 per 1,000 dance hours) when compared to that of ballet (0.32 per 1,000 dance hours) and Chinese dancers (0.22 per 1,000 dance hours). Prevalence of foot and ankle pain within the same year was 84% in ballet dancers, 79% in Chinese dancers, and 70% in contemporary dancers. Ballet dancers were six times more likely to suffer from pain in the Achilles region than Chinese and contemporary dancers (p < 0.01). Chinese dancers were found to experience more forefoot and midfoot problems compared to ballet and contemporary dancers (p < 0.05).<br/> Conclusion: This study illustrated that foot and ankle pain is highly prevalent among pre-profes- sional dancers. Ballet was associated with the highest prevalence of foot-ankle pain while contemporary dance was associated with the highest incidence. There were significant differences of foot and ankle pain among dance genres and anatomical subregions, which suggests a need for targeted genre-specific injury prevention programs in hopes of preventing potentially career-ending injuries in dancers.

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.

Fractures of the Base of the Fifth Metatarsal Bone: A Critical Analysis Review

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Fractures of the proximal fifth metatarsal (PFMT) are one of the most common foot injuries, accounting for 61% to 78% of all foot fractures, but full consensus on their classification, diagnosis, and treatment has not yet been reached.

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The most commonly accepted classification is that of Lawrence and Botte, who divided the location of PFMT fractures into 3 zones with respect to their healing potential.

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Avulsion fractures of the tuberosity of the base (zone 1) generally heal well, and nonoperative treatment is commonly recommended.

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Internal fixation may be considered for displaced fractures that extend into the fourth-fifth intermetatarsal joint (zone 2) as well as for nondisplaced fractures in athletes or high-demand patients, with the aims of reducing the healing time and expediting return to sport or work.

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Stress fractures of the proximal diaphysis (zone 3) are preferably treated operatively, particularly in the presence of signs of delayed union. With nonoperative treatment, supportive measures such as ultrasonography or external/extracorporeal shockwave therapy have been demonstrated to have limited potential for the enhancement of fracture-healing.

Effectiveness of physiotherapy interventions for injury in ballet dancers: A systematic review

Background

The unique repetitive nature of ballet dancing, which often involves transgressing endurance limits of anatomical structures, makes dancers prone to injury. The following systematic review aims to assess the effectiveness of physiotherapy interventions in the treatment of injuries in ballet dancers.

Methods

The review was performed in line with the PRISMA statement on preferred reporting items for systematic reviews and meta-analyses. Six electronic databases (PubMed, Ovid Embase, Cochrane, Medline, PEDro, Google Scholar) were queried. The study populations comprised active ballet dancers and/or ballet school attendees with acute and chronic injuries and those with persistent pain. There were no restrictions regarding age, sex, ethnicity or nationality. The Modified McMaster Critical Review Form for quantitative studies was used to assess the methodological quality of the studies reviewed in accordance with the relevant guidelines.

Results

Out of the total of 687 articles subjected to the review, 10 met the inclusion criteria. Diverse physiotherapeutic interventions were described and effectiveness was assessed using different parameters and measurements. Overall, the results indicate that physiotherapy interventions in ballet dancers exert a positive effect on a number of indices, including pain, ROM and functional status.

Conclusions

Due to the small amount of evidence confirming the effectiveness of physiotherapeutic interventions in ballet dancers after injuries and methodological uncertainties, it is recommended to improve the quality of prospective studies.

The physical features suitable for classical ballet training

OBJECTIVE

The aim of this study was to determine the prerequisite physical features of classical ballet education.

METHODS

Students who enrolled and were rejected for the applications of State Conservatory Ballet Main Art Branch in the academic year 2013-2014 and 2014-2015 were compared with their exam results. This study involves defining the physical ability and determining physical fitness by using Eurofit tests including the Flamingo Balance test (FB), Plate Tapping (PT), Sit and Reach (SITR), Standing Broad Jump (SBJ), Handgrip test (HG), Sit Up in 30 Seconds (SU) and Shuttle Run 10 × 5 meter (SR), Heath-Carter somatotyping method and anthropometric measurements which determine ballet students' body type and physical abilities. Sixty-nine girls between 8-11 years old who applied for ballet education at the State Conservatory Ballet Main Art Branch were included in the study. While the average of age, height and weight measurements of enrolled students were 9.40 ± 0.74 year, 1.38 ± 0.08 m and 30.03 ± 4.73 kg respectively, the same dimensions were found in rejected students, i.e. 9.79 ± 0.94 year, 1.40 ± 0.10 m and 35.59 ± 7.31 kg respectively.

RESULTS

Measurements of diameter, circumference and subcutaneous fat were lower (p< 0.05) for enrolled students. The major body type of enrolled students was identified as mesomorphy, whereas the major body type of rejected students was identified as endomorphy. All dimensions of the Eurofit tests, except the strength test, were significantly different in enrolled students (p< 0.05).

CONCLUSIONS

The parameters used in this study can be convenient in objectively evaluating classical ballet education.

Tc-99m HDP Single Photon Emission Computed Tomography/Computed Tomography in Stress Fracture of Base of Metatarsal Bone

Proximal metatarsal stress fractures are common at base of the second metatarsal, typically seen in repetitive impact athletes, dancers, and those with cavus feet. It is caused by increased bone resorption rather than formation in a state of abrupt increased physical activity or intensity, leading to repetitive microfractures and eventually stress fracture. It is characterized by swelling and tenderness of a prolonged duration. We report a case of a 40-year-old female having left foot pain diagnosed with stress fracture on Tc-99m HDP single-photon emission computed tomography (SPECT)-CT. We emphasize the use of SPECT/CT in allocating active source of pain in the feet.

Stress Fractures of the Foot and Ankle in Athletes

Stress fractures of the foot and ankle are common injuries in athletes. Management differs considerably based on fracture location and predisposing factors. Repetitive loading of the foot and ankle in athletes should result in physiologic bone remodeling in accordance with Wolff’s law. However, when there is not sufficient time for complete healing to occur before additional loads are incurred, this process can instead lead to stress fracture. Assessment of the athlete’s training regimen and overall bone health is paramount to both the discovery and treatment of these injuries, although diagnosis is often delayed in the setting of normal-appearing initial radiographs. While most stress fractures of the foot or ankle can usually be treated nonoperatively with a period of activity modification, fractures in certain locations are considered “high risk” due to poor intrinsic healing and may warrant more proactive operative management.

Spatiotemporal characterization of microdamage accumulation in rat ulnae in response to uniaxial compressive fatigue loading

Repetitive fatigue loading can induce microdamage accumulation in bone matrix, which results in impaired mechanical properties and increased fracture susceptibility. However, the spatial distribution and time-variant process of microdamage accumulation in fatigue-loaded skeleton, especially for linear microcracks which are known to initiate bone remodeling, remain not fully understood. In this study, the time-varying process of the morphology and distribution of microcracks in rat ulnae subjected to uniaxial compressive fatigue loading was investigated. Right forelimbs of thirty four-month-old male Sprague-Dawley rats were subjected to one bout of cyclic ramp loading with 0.67 Hz at a normalized peak force of 0.055 N/g body weight for 6000 cycles, and the contralateral left ulnae were not loaded as the control samples. Ten rats were randomly euthanized on Days 3, 5, and 7 post fatigue loading. Our findings via two-dimensional histomorphometric measurements based on basic fuchsin staining and three-dimensional quantifications using contrast-enhanced micro-computed tomography (MicroCT) with precipitated BaSO₄ staining demonstrated that the accumulation of linear microcracks (increase in the amount of linear microcracks) on Day 5 was significantly higher than that on Day 3 and Day 7 post fatigue loading. Our histological and histomorphometric results revealed that linear microcrack density (Cr.Dn) in the tensile cortex at Days 3, 5 and 7 post fatigue loading was significantly higher than that in the compressive side, whereas linear microcrack length (Cr.Le) in the tensile cortex at Day 3 was significantly lower than that in the compressive cortex. Our findings revealed that microcrack accumulation exhibited a non-linear time-varying process at 3, 5 and 7 days post axial compressive fatigue loading (with observable peak Cr.Dn at Day 5). Our findings also revealed distinct distribution of microcrack density and morphology in rat ulnae with tensile and compressive strains, as characterized by more microcracks accumulated in tensile cortices, and longer cracks shown in compressive cortices.

Stress fractures of the foot and ankle, part 2: site-specific etiology, imaging, and treatment, and differential diagnosis

Stress fractures of the foot and ankle are a commonly encountered problem among athletes and individuals participating in a wide range of activities. This illustrated review, the second of two parts, discusses site-specific etiological factors, imaging appearances, treatment options, and differential considerations of stress fractures of the foot and ankle. The imaging and clinical management of stress fractures of the foot and ankle are highly dependent on the specific location of the fracture, mechanical forces acting upon the injured site, vascular supply of the injured bone, and the proportion of trabecular to cortical bone at the site of injury. The most common stress fractures of the foot and ankle are low risk and include the posteromedial tibia, the calcaneus, and the second and third metatarsals. The distal fibula is a less common location, and stress fractures of the cuboid and cuneiforms are very rare, but are also considered low risk. In contrast, high-risk stress fractures are more prone to delayed union or nonunion and include the anterior tibial cortex, medial malleolus, navicular, base of the second metatarsal, proximal fifth metatarsal, hallux sesamoids, and the talus. Of these high-risk types, stress fractures of the anterior tibial cortex, the navicular, and the proximal tibial cortex may be predisposed to poor healing because of the watershed blood supply in these locations. The radiographic differential diagnosis of stress fracture includes osteoid osteoma, malignancy, and chronic osteomyelitis.

Stress fractures of the foot and ankle

Stress fractures occur as a result of microscopic injuries sustained when bone is subjected to repeated submaximal stresses. Overtime, with repeated cycles of loading, accumulation of such injuries can lead to macro-structural failure and frank fracture. There are numerous stress fractures about the foot and ankle of which a trauma and orthopaedic surgeon should be aware. These include: metatarsal, tibia, calcaneus, navicular, fibula, talus, medial malleolus, sesamoid, cuneiform and cuboid. Awareness of these fractures is important as the diagnosis is frequently missed and appropriate treatment delayed. Late identification can be associated with protracted pain and disability, and may predispose to non-union and therefore necessitate operative intervention. This article outlines the epidemiology and risk factors, aetiology, presentation and management of the range of stress fractures in the foot and ankle.

Overuse Injuries in Professional Ballet: Influence of Age and Years of Professional Practice

Background:

In spite of the high rate of overuse injuries in ballet dancers, no studies have investigated the prevalence of overuse injuries in professional dancers by providing specific diagnoses and details on the differences in the injuries sustained as a function of age and/or years of professional practice.

Hypothesis:

Overuse injuries are the most prevalent injuries in ballet dancers. Professional ballet dancers suffer different types of injuries depending on their age and years of professional practice.

Study Design:

Descriptive epidemiology study.

Methods:

This descriptive epidemiological study was carried out between January 1, 2005, and October 10, 2010, regarding injuries sustained by professional dancers belonging to the major Spanish ballet companies practicing classical, neoclassical, contemporary, and Spanish dance. The sample was distributed into 3 different groups according to age and years of professional practice. Data were obtained from the specialized medical care the dancers received from the Trauma and Orthopaedic Surgery Service at Fremap in Madrid. The dependent variable was the study of the injury.

Results:

A total of 486 injuries were identified over the study period, with overuse injuries being the most common etiology (P < .0001); these injuries were especially prevalent in junior professional dancers practicing classical ballet and veteran dancers practicing contemporary ballet (P = .01). Specifically, among other findings, stress fractures of the base of the second metatarsal (P = .03), patellofemoral syndrome, and os trigonum syndrome were more prevalent among junior professionals (P = .04); chondral injury of the knee in senior professionals (P = .04); and cervical disc disease in dancers of intermediate age and level of experience.

Conclusion:

Overall, overuse injuries were more prevalent in younger professionals, especially in women. This finding was especially true for the more technical ballet disciplines. On the other hand, in the athletic ballet disciplines, overuse lesions occurred mainly in the more senior professionals.

Clinical Relevance:

This study provides specific clinical diagnoses obtained through physical examination as well as details on the different injury types sustained as a function of age and/or years of professional practice, an important aspect for ballet and sports practice in general.

Management of sports injuries of the foot and ankle: An update

Injuries to the foot in athletes are often subtle and can lead to a substantial loss of function if not diagnosed and treated appropriately. For these injuries in general, even after a diagnosis is made, treatment options are controversial and become even more so in high level athletes where limiting the time away from training and competition is a significant consideration. In this review, we cover some of the common and important sporting injuries affecting the foot including updates on their management and outcomes. Cite this article: Bone Joint J 2016;98-B:1299-1311.

Overuse Injuries in Professional Ballet: Injury-Based Differences Among Ballet Disciplines

Background

Despite overuse injuries being previously described as the most frequent in ballet, there are no studies on professional dancers providing the specific clinical diagnoses or type of injury based on the discipline.

Hypothesis

Overuse injuries are the most frequent injuries in ballet, with differences in the type and frequency of injuries based on discipline.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

This was a descriptive cross-sectional study performed between January 1, 2005, and October 10, 2010, on injuries occurring in professional dancers from leading Spanish dance companies who practiced disciplines such as classical, neoclassical, contemporary, and Spanish ballet. Data, including type of injury, were obtained from specialized medical services at the Trauma Service, Fremap, Madrid, Spain.

Results

A total of 486 injuries were evaluated, a significant number of which were overuse disorders (P < .0001), especially in the most technically demanding discipline of classical ballet (82.60%). Injuries were more frequent among female dancers (75.90%) and classical ballet (83.60%). A statistically significant prevalence of patellofemoral pain syndrome was found in the classical discipline (P = .007). Injuries of the adductor muscles of the thigh (P = .001) and of the low back facet (P = .02) in the Spanish ballet discipline and lateral snapping hip (P = .02) in classical and Spanish ballet disciplines were significant.

Conclusion

Overuse injuries were the most frequent injuries among the professional dancers included in this study. The prevalence of injuries was greater for the most technically demanding discipline (classical ballet) as well as for women. Patellofemoral pain syndrome was the most prevalent overuse injury, followed by Achilles tendinopathy, patellar tendinopathy, and mechanical low back pain.

Clinical Relevance

Specific clinical diagnoses and injury-based differences between the disciplines are a key factor in ballet.

Novel candidate genes putatively involved in stress fracture predisposition detected by whole-exome sequencing

While genetic factors in all likelihood contribute to stress fracture (SF) pathogenesis, a few studies focusing on candidate genes have previously been reported. The objective of this study is to gain better understanding on the genetic basis of SF in a gene-naive manner. Exome sequence capture followed by massive parallel sequencing of two pooled DNA samples from Israeli combat soldiers was employed: cases with high grade SF and ethnically matched healthy controls. The resulting sequence variants were individually verified using the Sequenom™ platform and the contribution of the genetic alterations was validated in a second cohort of cases and controls. In the discovery set that included DNA pool of cases (n = 34) and controls (n = 60), a total of 1174 variants with >600 reads/variant/DNA pool were identified, and 146 (in 127 genes) of these exhibited statistically significant (P < 0·05) different rates between SF cases and controls after multiple comparisons correction. Subsequent validation of these 146 sequence variants individually in a total of 136 SF cases and 127 controls using the Sequenom™ platform validated 20/146 variants. Of these, three missense mutations (rs7426114, rs4073918, rs3752135 in the NEB, SLC6A18 and SIGLEC12 genes, respectively) and three synonymous mutations (rs2071856, rs2515941, rs716745 in the ELFN2, GRK4, LRRC55 genes) displayed significant different rates in SF cases compared with controls. Exome sequencing seemingly unravelled novel candidate genes as involved in SF pathogenesis and predisposition.

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.

MRI of isolated cuboid stress fractures in adults

OBJECTIVE

Isolated cuboid stress fractures are rare. The purpose of this study was to evaluate the MRI appearance of this condition.

MATERIALS AND METHODS

A retrospective search for patients with the diagnosis of a cuboid stress fracture was performed for a 19-year period. All patients underwent an initial three-view radiographic foot series for pain. MRI was performed because symptoms persisted beyond 4 weeks.

RESULTS

Ten patients, nine of whom were women, were diagnosed with isolated cuboid stress fractures. These patients were divided into an athletic group (mean age, 36.3 years) and nonathletic group (mean age, 55.0 years). In the athletic group, there were five runners, one ballet dancer, and one gymnast, and in the nonathletic group, there was one with osteoporosis, one with a plantar fascia rupture, and one who recently underwent a fasciotomy. Eight stress fractures were linear and two were stellate and all were surrounded by marrow edema. Six fractures were located inferolaterally, one superolaterally, one laterally, one medially, and one was subchondral in location. All but one involved the peroneal sulcus and cuboid crest region. Nine of 10 feet showed pathology in the plantar fascia, seven in the peroneal tendons, and four in the posterior tibial tendon.

CONCLUSION

An isolated stress fracture of the cuboid is most likely to occur in the lateral aspect of the cuboid. The cause is likely multifactorial and may include compressive and tensile forces, but plantar fascia dysfunction and age-related bone loss, which are more prevalent in women, may be additional contributing factors.

Proximal base stress fracture of the second metatarsal in a Highland dancer

A 15-year-old female Highland dancer presented to the accident and emergency department with an ankle inversion injury on a background of several weeks of pain in the right foot. A radiograph of the right foot demonstrated a stress fracture at the base of the second metatarsal. She was treated conservatively with a below knee removable supportive walking boot with a rocker bottom sole. She re-presented to the accident and emergency department 3 weeks later with pins and needles in the right foot; she was given crutches to use along side the supportive walking boot. Radiographs 12 weeks after the first presentation showed healing of the stress fracture. The patient was now asymptomatic of the injury. She was unable to fully train for 12 weeks due to the injury. Conservative management was successful in this patient.

Fifth metatarsal fractures in the athlete: evidence for management

Shortest time to union, and to return to sporting activity, are the goals of management of fifth metatarsal fractures in the athlete. Whereas zone 1 injuries are largely treated conservatively, zone 2 and 3 injuries are best treated with surgical fixation in athletes, most commonly with intramedullary screw fixation. Fixation with the addition of bone graft has also yielded good results. In the chronic setting, good results have been shown with intramedullary screw fixation, surgical debridement and bone grafting alone, and tension band wiring. Shock wave therapy and pulsed electromagnetic fields may have a place in chronic and acute injury.

Stress fractures in elderly patients

PURPOSE

The purpose of this study was to investigate specific risk factors, common fracture locations and possible sex-specific differences in elderly patients with stress fractures.

METHODS

This analysis enrolled 105 patients (83 women, 22 men) with stress fractures. For the analysis of possible risk factors related to increasing age, data from 82 patients (67 women, 15 men) aged 40 years and older (mean age of 57.4 ± 11.0 years) were compared with that from a younger control group [23 patients (16 women, seven men), mean age 28.4 ± 6.7 years]. Bone mineral density (BMD) was determined using dual-energy X-ray absorptiometry bone densitometry (DXA) and blood samples were taken.

RESULTS

A total of 211 stress fractures were found. Of these, 177 were found in the study group, of which 90.4 % were located in the lower limb. Lumbar and femoral BMD was significantly lower in elderly patients; however, the BMD of most patients was within the osteopenic or normal range. Within the study group, a total of 83.8 % had a vitamin D insufficiency (<30 μg/l); 75.5 % were not engaged in regular physical activity more than once a week. Overweight patients within the study group had significantly more stress fractures compared to normal weight patients (2.6 ± 1.7 vs. 1.9 ± 1.1, p<0.05).

CONCLUSIONS

A similar contribution of risk factors has been found for stress fractures in elderly patients and younger controls of the general population. Stress fracture incidence seems to be rather multifactorial and not based on osteoporotic changes alone. A balanced calcium and vitamin D metabolism seems to be of paramount importance for stress fracture prevention in elderly patients.

Candidate gene analysis in israeli soldiers with stress fractures

To investigate the association of polymorphisms within candidate genes which we hypothesized may contribute to stress fracture predisposition, a case-control, cross- sectional study design was employed. Genotyping 268 Single Nucleotide Polymorphisms- SNPs within 17 genes in 385 Israeli young male and female recruits (182 with and 203 without stress fractures). Twenty-five polymorphisms within 9 genes (NR3C1, ANKH, VDR, ROR2, CALCR, IL6, COL1A2, CBG, and LRP4) showed statistically significant differences (p < 0.05) in the distribution between stress fracture cases and non stress fracture controls. Seventeen genetic variants were associated with an increased stress fracture risk, and eight variants with a decreased stress fracture risk. None of the SNP associations remained significant after correcting for multiple comparisons (false discovery rate- FDR). Our findings suggest that genes may be involved in stress fracture pathogenesis. Specifically, the CALCR and the VDR genes are intriguing candidates. The putative involvement of these genes in stress fracture predisposition requires analysis of more cases and controls and sequencing the relevant genomic regions, in order to define the specific gene mutations. Key pointsUnderstanding the possible contribution of genetic variants to stress fracture pathogenesis.There is a paucity of data on the involvement of polymorphisms in specific genes in active military personnel/athletes which may contribute to stress fractures development.The results from the current study should facilitate a more comprehensive look at the genetic component of stress fractures.

Bilateral stress fracture of the tibia diagnosed by ultrasound. A case report

We report the case of a 35 years old patient presenting with bilateral pain in the medial aspect of both knees. Ultrasound examination revealed hyperechoic appearance of the subcutaneous tissue and periarticular soft tissue bilateral. Color Doppler studies showed significant vascular signals at the surface of the tibial plateaux. US appearance, together with clinical findings, suggested a diagnosis of simultaneous bilateral fatigue fracture. An MRI confirmed the diagnosis and the patient's symptoms resolved with rest. US may be a useful imaging tool in the diagnosis of stress fracture.

Bilateral stress fracture of the tibia diagnosed by ultrasound. A case report

We report the case of a 35 years old patient presenting with bilateral pain in the medial aspect of both knees. Ultrasound examination revealed hyperechoic appearance of the subcutaneous tissue and periarticular soft tissue bilateral. Color Doppler studies showed significant vascular signals at the surface of the tibial plateaux. US appearance, together with clinical findings, suggested a diagnosis of simultaneous bilateral fatigue fracture. An MRI confirmed the diagnosis and the patient's symptoms resolved with rest. US may be a useful imaging tool in the diagnosis of stress fracture.

Musculoskeletal injuries in young ballet dancers

PURPOSE

The aim of this study was to examine the incidence of musculoskeletal injuries, site and type of injury, and the most common injury diagnoses in young ballet dancers at the Royal Swedish Ballet School, a public school in Stockholm.

METHODS

This retrospective study of 476 students (297 girls and 179 boys) aged 10-21 years was based on medical records for the period August 1988 to June 1995. Data on diagnosis, site of injury and type of injury were collected, and the injuries were classified as traumatic or due to overuse.

RESULTS

In total, 438 injuries were recorded. The injury incidence rate was 0.8 per 1,000 dance hours in both female and male dancers and tended to increase with increasing age. Most injuries occurred as the result of overuse. Seventy-six per cent of all injuries occurred in the lower extremities. Ankle sprain was the most common traumatic diagnosis, while the most common overuse-related diagnosis was tendinosis pedis. A few gender differences were noted.

CONCLUSIONS

The findings of this study suggest that there is a need to apply primary injury prevention in young ballet dancers. Future studies could aim to identify (1) injury risk factors and (2) injury prevention programmes that are effective at reducing injury rates in young dancers.