High-Risk Stress Fractures: Diagnosis and Management. PM R. 2016;8:S113-S124. [PMID: 26972260 DOI: 10.1016/j.pmrj.2015.09.019]

From Tissue to System: What Constitutes an Appropriate Response to Loading?

Optimal loading involves the prescription of an exercise stimulus that promotes positive tissue adaptation, restoring function in patients undergoing rehabilitation and improving performance in healthy athletes. Implicit in optimal loading is the need to monitor the response to load, but what constitutes a normal response to loading? And does it differ among tissues (e.g., muscle, tendon, bone, cartilage) and systems? In this paper, we discuss the "normal" tissue response to loading schema and demonstrate the complex interaction among training intensity, volume, and frequency, as well as the impact of these training variables on the recovery of specific tissues and systems. Although the response to training stress follows a predictable time course, the recovery of individual tissues to training load (defined herein as the readiness to receive a similar training stimulus without deleterious local and/or systemic effects) varies markedly, with as little as 30 min (e.g., cartilage reformation after walking and running) or 72 h or longer (e.g., eccentric exercise-induced muscle damage) required between loading sessions of similar magnitude. Hyperhydrated and reactive tendons that have undergone high stretch-shorten cycle activity benefit from a 48-h refractory period before receiving a similar training dose. In contrast, bone cells desensitize quickly to repetitive loading, with almost all mechanosensitivity lost after as few as 20 loading cycles. To optimize loading, an additional dose (≤ 60 loading cycles) of bone-centric exercise (e.g., plyometrics) can be performed following a 4-8 h refractory period. Low-stress (i.e., predominantly aerobic) activity can be repeated following a short (≤ 24 h) refractory period, while greater recovery is needed (≥ 72 h) between repeated doses of high stress (i.e., predominantly anaerobic) activity. The response of specific tissues and systems to training load is complex; at any time, it is possible that practitioners may be optimally loading one tissue or system while suboptimally loading another. The consideration of recovery timeframes of different tissues and systems allows practitioners to determine the "normal" response to load. Importantly, we encourage practitioners to interpret training within an athlete monitoring framework that considers external and internal load, athlete-reported responses, and objective markers, to contextualize load-response data.

Recurrent Medial Malleolar Stress Fracture: A Case Report and Discussion of Risk Factors

Stress fractures of the medial malleolus are uncommon and considered high-risk due to potential complications such as progression to complete fracture, delayed union, nonunion, and chronic pain. Identified risk factors include varus alignment of the lower limb, chronic anteromedial impingement, excessive pronation/supination, broad talar neck, and ankle instability. To our knowledge, no reports of recurrence after surgical treatment have been reported. An 18-year-old male professional football player presented with medial right ankle pain. He was diagnosed with a medial malleolar stress fracture and underwent surgical treatment with cannulated screw fixation. After a full recovery, he experienced a recurrence of the fracture after discontinuing the use of custom-made foot insoles. A second surgery using a malleolar plate and bone graft was performed, and the patient resumed his sports career successfully with continued use of the foot soles. Surgical treatment is the best treatment for medial malleolar stress fractures in high-demanding athletes, without any known case of recurrence. Lower limb malalignment, particularly the cavovarus foot, may also play a role in recurrence, as observed in this case. Varus limb malalignment has been associated with this fracture type and could be a contributing factor to recurrence. Recurrent medial malleolar stress fractures are rare, and this case presents a unique scenario of treatment failure due to biomechanical alterations. The surgical treatment yielded successful outcomes when combined with custom-made foot soles for lower limb alignment support. However, further research and reports on recurrence are needed to fully comprehend the risk factors for these challenging fractures in high-demanding athletes.

Lateral femoral neck stress fractures: A case report

BACKGROUND

Sport-induced injuries particularly affect young, healthy, and active individuals. Running, a popular and accessible sport, can cause a wide range of injuries, including stress fractures. Stress fractures can occur during high-intensity training or competitions, especially among well-trained amateurs and professional athletes. Adequate diagnosis can be complicated by the typically young age, unremarkable medical history, and vital condition of the patient. Stress fractures present insidiously, and this is specifically the case with stress fractures of the femoral neck. Timely intervention is crucial to prevent progressive displacement, as this can damage the blood supply to the femoral head.

CASE SUMMARY

A 30-year-old male runner presented to our outpatient clinic with persistent pain 3 weeks after running a marathon. X-ray showed a complete lateral fracture of the left femoral neck, which was treated surgically with a dynamic hip screw.

CONCLUSION

It is essential for healthcare providers to be vigilant for the subtle symptoms of stress fractures to ensure timely treatment. Early recognition prevents complication and leads to a better prognosis.

Subchondral bone fatigue injury in the parasagittal condylar grooves of the third metacarpal bone in thoroughbred racehorses elevates site-specific strain concentration

Condylar stress fracture of the distal end of the third metacarpal/metatarsal (MC3/MT3) bones is a major cause of Thoroughbred racehorse injury and euthanasia worldwide. Functional adaptation to exercise and fatigue damage lead to structural changes in the subchondral bone that include increased modeling (resulting in sclerotic bone tissue) and targeted remodeling repair (resulting in focal resorption spaces in the parasagittal groove). Whether these focal structural changes, as detectable by standing computed tomography (sCT), lead to elevated strain at the common site of condylar stress fracture has not been demonstrated. Therefore, the goal of the present study was to compare full-field three-dimensional (3D) strain on the distopalmar aspect of MC3 bone specimens with and without focal subchondral bone injury (SBI). Thirteen forelimb specimens were collected from racing Thoroughbreds for mechanical testing ex vivo and underwent sCT. Subsequently, full-field displacement and strain at the joint surface were determined using stereo digital image correlation. Strain concentration was observed in the parasagittal groove (PSG) of the loaded condyles, and those with SBI in the PSG showed higher strain rates in this region than control bones. PSG strain rate in condyles with PSG SBI was more sensitive to CT density distribution in comparison with condyles with no sCT-detectable injury. Findings from this study help to interpret structural changes in the subchondral bone due to fatigue damage and to assess risk of incipient stress fracture in a patient-specific manner.

Distal Femoral Stress Fractures Has High Operation Rates in Adolescent and Young Adult Athletes

BACKGROUND

Although stress fractures of the distal femur are rare, symptoms can overlap with other peri-articular knee pathology, delaying diagnosis. Untreated stress fractures have the potential to progress into completed fractures with a higher likelihood for requiring surgery and longer recovery times in otherwise healthy adolescents and young adults. This case series represents the largest cohort of adolescent athletes with distal femoral stress fractures who presented with activity-related knee pain.

METHODS

Patients treated nonoperatively and operatively for metaphyseal distal femur stress fractures at a tertiary referral center over a four-year period were retrospectively identified from the medical record.

RESULTS

Eight patients (mean age 16.8 y; range 14 to 22 y; 87.5% male; mean body mass index [BMI] 20.9) with a total of 10 distal femur stress fractures were identified. All patients were involved in competitive sports or military training. There was an average of 3.8 encounters with a medical provider between presentation with activity-related knee pain and diagnosis with distal femur stress fracture. All except 1 patient (87.5%) were initially incorrectly diagnosed with another type of peri-articular knee pathology. Six stress fractures (60%) were treated conservatively with protected weight bearing, activity modification, and gradual return to activity. Four completed stress fractures (40%) required operative fixation-3 healed uneventfully, while 1 had an asymptomatic delayed union. Vitamin D insufficiency (<30 ng/mL) was identified in 7 of 8 patients (87.5%) and 3 patients (37.5%) had an underweight BMI (<18.5). The mean clinical follow-up was 13.1 weeks (range, 2.8 to 32.0 wk).

CONCLUSIONS

High clinical suspicion for distal femoral stress fractures is needed to avoid misdiagnosis or delayed diagnosis in young, active individuals with activity-related knee pain refractory to conservative management. In this patient population, activity-related knee pain recalcitrant to activity modification, rest, and physical therapy warrants further workup with magnetic resonance imaging and orthopaedic evaluation. Though rare, misdiagnosis can result in catastrophic fractures with prolonged rehabilitation needs. An open line of communication and streamlined access for referral between primary care providers and orthopaedic surgeons is critical in preventing misdiagnosis and delayed treatment. Furthermore, the treatment of concomitant metabolic disorders and nutritional deficiency should not be neglected when treating distal femoral stress fractures.

LEVEL OF EVIDENCE

Level-IV (case series).

An assessment of the diagnosis, treatment, and outcomes of lower extremity stress fractures in pediatric and adolescent populations

OBJECTIVES

To present one of the first descriptive case series of pediatric and adolescent lower extremity stress injuries, their management, and outcomes in athletes and non-athletes.

METHODS

The IRB-approved retrospective study included patients under 18 years at a tertiary children's hospital who were diagnosed with a lower extremity stress fracture/reaction. Demographic data, mechanism of injury, physical exam, radiographic findings, treatment, & outcomes were collected. Descriptive statistical analysis was conducted.

RESULTS

Ninety-seven patients with stress injuries on clinical exams and on radiographs or MRI were included. The average age when diagnosed was 11.7 years (range 1.1-18 years) and the most common injuries were to the tibia (n = 33, 28.4%) and the least common involved were the cuneiforms (n = 4, 3.4%). Patients under the age of 14 were more likely to experience cuboid and calcaneal stress injuries (mean age 5.5 and 8.3 years respectively). Nineteen patients (19.6%) had high-risk stress fractures, with the average age of 14.9 years versus 11.6 for those with low risk (p-value = 0.01) and return to activity time being 15 weeks compared to 10.5 (p-value = 0.027). The most common forms of treatment were controlled ankle motion (CAM), walker boots (58.6%), and physical therapy (PT) (38.1%). The mean Lower Extremity Function Score of the patient population was 73.8, indicating no clinically important difference from full functionality.

CONCLUSION

Lower extremity stress injuries in this cohort were most seen in the tibia, although patients younger than 14 had a high number of cuboid and calcaneal stress injuries. Those with high-risk stress fractures were older and took longer to recover from when compared to low-risk injuries. Treatment is commonly conservative, with CAM boots and PT being the most frequently utilized interventions and serving as a successful approach to treatment, with patients returning to activity at an average of 11.4 weeks, which is comparable to similar studies.

[Stress fractures in the military context]

BACKGROUND

Soldiers, especially as recruits, are exposed to significantly elevated stress patterns of the foot due to occupation-related marching and excessive running. This can lead to military-specific stress fractures of the metatarsals, i.e., marching fractures. The treatment and prevention of stress fractures are of particular importance in the military context due to the impact on operational capability and treatment costs. A uniform classification of these fractures does not yet exist.

OBJECTIVE

Review of stress fractures in the military setting with presentation of the incidence, risk factors, classification, treatment and prevention possibilities.

MATERIAL AND METHODS

A PubMed®-based review of the current literature on stress fractures in the military context was conducted and the results were discussed with a focus on specific military medical treatment options.

RESULTS

There are several possibilities to classify stress fractures, the most well-known being a 4-level magnetic resonance imaging (MRI)-based classification. Prevention and treatment possibilities are multifaceted but so far insufficiently validated.

CONCLUSION

Military-specific stress fractures should be grouped according to a 4-level and MRI-based classification. The treatment options include both conservative and surgical measures and should be implemented taking the patient's individual requirements into account. Preventive measures play a key role in the military context. They include the adaptation of screening tools, training and equipment and require continuous evaluation and development.

[Stress injuries of bone in children and adolescents]

Stress injuries of bone in childhood and adolescence are the result of an imbalance between physical stress on the growing musculoskeletal system and its intrinsic resilience. Children who are very active in sports are particularly affected. The classical stress injuries mainly occur in the area of the lower leg, the metatarsus and the lower lumbar spine due to the disproportionate load on healthy bone; however, overuse syndromes can also occur in the area of the growth plates and possibly lead to growth plate disorders. The anamnesis usually shows stress-related pain that has existed for a long time without trauma. As part of the differential diagnosis, a stress injury must first be included in the considerations due to it being a rare entity. An X‑ray examination can show the first signs of a stress reaction. In the event of a conspicuous periosteal reaction, a malignant event must also be considered. As a rule, the MRI examination is then groundbreaking and in some rare cases biopsies have to be considered. The treatment of stress injuries is usually conservative. Recurrences should be counteracted by exercise control.

[High-risk stress fractures in competitive athletes]

Bone stress injuries are chronic overload reactions of the bone, which are characterized by the load-dependent occurrence of locally perceived pain and tenderness on palpation at the site of the injury. Structurally normal bone becomes fatigued as a result of repetitive submaximal loading and/or inadequate regeneration. Certain stress fractures of the femoral neck (tension side), patella, anterior tibial cortex, medial malleolus, talus, tarsal navicular bone, proximal fifth metatarsal, and sesamoid bones of the great toe tend to develop complications (complete fractures, delayed union, pseudarthrosis, dislocation, arthrosis). These injuries are classified as high-risk stress fractures. Aggressive diagnostics and treatment are recommended when a high-risk stress fracture is suspected. Treatment is frequently different from low-risk stress fractures, including prolonged non-weight-bearing immobilization. In rare cases, surgery is indicated when conservative treatment fails, when a complete or non-healing fracture develops, or in cases of dislocation. The outcomes of both conservative and operative treatment are described as less successful compared with low-risk stress injuries.

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.

Current risks factors and emerging biomarkers for bone stress injuries in military personnel

INTRODUCTION

Bone stress injuries (BSIs) have plagued the military for over 150 years; they afflict around 5 to 10% of military recruits, more so in women, and continue to place a medical and financial burden on defence. While the tibia generally adapts to the rigours of basic military training, the putative mechanisms for bone maladaptation are still unclear.

METHODS

This paper provides a review of the published literature on current risk factors and emerging biomarkers for BSIs in military personnel; the potential for biochemical markers of bone metabolism to monitor the response to military training; and, the association of novel biochemical 'exerkines' with bone health.

RESULTS

The primary risk factor for BSI in military (and athletic) populations is too much training, too soon. Appropriate physical preparation before training will likely be most protective, but routine biomarkers will not yet identify those at risk. Nutritional interventions will support a bone anabolic response to training, but exposure to stress, sleep loss, and medication is likely harmful to bone. Monitoring physiology using wearables-ovulation, sleep and stress-offer potential to inform prevention strategies.

CONCLUSIONS

The risk factors for BSIs are well described, but their aetiology is very complex particularly in the multi-stressor military environment. Our understanding of the skeletal responses to military training is improving as technology advances, and potential biomarkers are constantly emerging, but sophisticated and integrated approaches to prevention of BSI are warranted.

Os supranaviculare and navicular osteochondral lesion contributing to the development of a navicular stress fracture in an adolescent male athlete: Case report

Stress fractures of the tarsal navicular bone can be problematic in the athlete. This case details the injury and outcome of an adolescent male athlete who experienced one year of intermittent foot pain without acute trauma. Radiographs and computed tomography demonstrated a triad of a navicular stress fracture, an os supranaviculare, and an osteochondral defect of the navicular bone. The patient underwent successful operative fixation and returned to painless full function with imaging demonstrating healing at six months. Diagnosis of a navicular stress fracture in the setting of both an os supranaviculare and osteochondral lesion of the navicular bone have not been reported elsewhere in the literature. While repetitive loading on the navicular bone can independently produce a stress fracture, the patient had an increased risk for this injury; the presumably pre-existing navicular osteochondral lesion and os supranaviculare may have resulted in decreased effective articular surface area, thereby increasing force on the navicular bone and producing a stress fracture. Understanding navicular stress fractures and concomitant bony pathology contributing to injury is crucial to successful diagnosis, management, and prevention of recurrence.

Lower Extremity Stress Fractures in the National Basketball Association, 2013-2014 Through 2018-2019

BACKGROUND

Players in the National Basketball Association (NBA) are at risk for lower extremity stress fractures, partly because of the sport's high-intensity demand on the lower body.

PURPOSE

To provide insight on the identification and management of potential risk factors associated with lower extremity stress fractures in NBA athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective study was conducted using the NBA electronic medical record database for all players who were on an NBA roster for ≥1 game from the 2013-2014 through 2018-2019 seasons. Player characteristics, games missed, and treatment methodology were independently analyzed. Results were presented as incidence per 1000 player-games.

RESULTS

There were 22 stress fractures identified in 20 NBA players over the course of 6 years, with an average of 3.67 stress fractures per year and an incidence of 0.12 stress fractures per 1000 player-games. Most stress fractures occurred in the foot (17/22), and 45% (10/22) of stress fractures were treated surgically, with the most common site of operation being the navicular. On average, approximately 37 games and 243 days were missed per stress fracture injury. There was no significant difference in time to return to play between high-risk stress fractures treated operatively versus nonoperatively (269.2 vs 243.8 days; P = .82).

CONCLUSION

The overall incidence of stress fractures in NBA players was 0.12 per 1000 player-games, and a high percentage of players returned to NBA activity after the injury. There was a relatively even distribution between high-risk stress fractures treated operatively and nonoperatively. When comparing high-risk stress fractures treated operatively to ones treated nonoperatively, no significant difference in average time to return to play in the NBA was found.

Prevalence of Female and Male Athlete Triad Risk Factors in Ultramarathon Runners

OBJECTIVE

To identify the prevalence of male and female athlete triad risk factors in ultramarathon runners and explore associations between sex hormones and bone mineral density (BMD).

DESIGN

Multiyear cross-sectional study.

SETTING

One hundred-mile ultramarathon.

PARTICIPANTS

Competing runners were recruited in 2018 and 2019.

ASSESSMENT OF RISK FACTORS

Participants completed a survey assessing eating behaviors, menstrual history, and injury history; dual-energy x-ray absorptiometry for BMD; and laboratory evaluation of sex hormones, vitamin D, and ferritin (2019 cohort only).

MAIN OUTCOME MEASURE

A Triad Cumulative Risk Assessment Score was calculated for each participant.

RESULTS

One hundred twenty-three runners participated (83 males and 40 females, mean age 46.2 and 41.8 years, respectively). 44.5% of men and 62.5% of women had elevated risk for disordered eating. 37.5% of women reported a history of bone stress injury (BSI) and 16.7% had BMD Z scores <-1.0. 20.5% of men had a history of BSI and 30.1% had Z-scores <-1.0. Low body mass index (BMI) (<18.5 kg/m 2 ) was seen in 15% of women and no men. The Triad Cumulative Risk Assessment classified 61.1% of women and 29.2% of men as moderate risk and 5.6% of both men and women as high risk.

CONCLUSIONS

Our study is the first to measure BMD in both male and female ultramarathon runners. Our male population had a higher prevalence of low BMD than the general population; females were more likely to report history of BSI. Risk of disordered eating was elevated among our participants but was not associated with either low BMD or low BMI.

Low energy availability surrogates associated with lower bone mineral density and bone stress injury site

BACKGROUND

Exercise is an osteogenic stimulus that should increase bone mineral density (BMD) and protect against injury. However, some female athletes have lower BMD and increased bone stress injury (BSI) risk. Impaired bone health seen in athletes may be explained by low energy availability as described by concepts of Relative Energy Deficiency in Sport (RED-S) and Female Athlete Triad (Triad).

OBJECTIVE

To elucidate the relationship between RED-S/Triad risk factors and BSI to high-risk (femoral neck, sacrum) and low-risk (other) bones.

DESIGN

Cross-sectional survey and retrospective chart review.

SETTING

Tertiary care academic center.

PATIENTS

Female athletes aged 15-30 years participating in ≥4 h/week of exercise presenting to sports medicine/orthopedics clinic who had a self-reported BSI and available dual-energy x-ray absorptiometry (DXA) measurement of BMD.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASUREMENTS

Location of BSI.

RESULTS

In 127 athletes, high-risk BSI was associated with surrogates of low energy availability (p = .032) and having a DXA Z-score < -1 (p = .035) but not a current/past history of menstrual dysfunction (p = .348). Accumulating RED-S/Triad risk factors increase the odds of incurring a high-risk BSI (p = .048).

CONCLUSIONS

Adolescent/young female athletes who sustain BSI at high-risk sites (femoral neck, sacrum) may have underlying risk factors (eg, low energy availability, poor overall bone health) that should prompt further workup and referral to optimize health in these athletes.

Generalized Uncoupled Bone Remodeling Associated With Delayed Healing of Fatigue Fractures

Fatigue fractures in bones are common injuries with load‐bearing activities, during which the remodeling aimed at removing microdamage has been suggested to play a role in increasing related fracture risk. Much attention has been given to the uncoupling between osteoclastic bone resorption and osteoblastic osteogenesis in fatigue fracture cases; however, the underlying pathophysiologic mechanisms of impaired fracture healing are yet unknown. Here we report multiple fatigue fractures in a physically active woman receiving contraceptive pills for years. Her fracture healing was remarkably slow, although she has been otherwise healthy. The patient underwent bone biopsy of the iliac crest that showed remarkable peritrabecular fibrosis with increased osteoclastic bone resorption combined with relatively low bone formation. Analysis of bone biochemical composition revealed a more complex picture: First, notable declines in bone mineral content–based parameters indicating abnormal mineralization were evident in both cancellous and cortical bone. Second, there was elevation in mineral crystal size, perfection, and collagen maturity in her bone tissues from different anatomical sites. To our knowledge, this is the first report showing generalized uncoupling in bone remodeling, increased peritrabecular fibrosis, and bone compositional changes associated with delayed healing of fatigue fractures. These results may explain delayed healing of fatigue and stress fractures. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Injury Prevention, Safe Training Techniques, Rehabilitation, and Return to Sport in Trail Runners

This current concept, narrative review provides the latest integrated evidence of the musculoskeletal injuries involved with trail running and therapeutic strategies to prevent injury and promote safe participation. Running activities that comprise any form of off-road running (trail running, orienteering, short-long distance, different terrain, and climate) are relevant to this review. Literature searches were conducted to 1) identify types and mechanisms of acute and chronic/overuse musculoskeletal injuries in trail runners, 2) injury prevention techniques most relevant to running trails, 3) safe methods of participation and rehabilitation timelines in the sport. The majority of acute and chronic trail running-related musculoskeletal injuries in trail running occur in the lower leg, primarily in the knee and ankle. More than 70% are due to overuse, and ankle sprains are the most common acute injury. Key mechanisms underlying injury and injury progression include inadequate neuromotor control-balance-coordination, running through fatigue, and abnormal kinematics on variable terrain. Complete kinetic chain prehabilitation programs consisting of dynamic flexibility, neuromotor strength and balance, and plyometrics exercise can foster stable, controlled movement on trails. Patient education about early musculoskeletal pain symptoms and training adjustment can help prevent injury from progressing to serious overuse injuries. Real-time adjustments to cadence, step length, and knee flexion on the trail may also mitigate impact-related risk for injury. After injury occurs, rehabilitation will involve similar exercise components, but it will also incorporate rest and active rest based on the type of injury. Multicomponent prehabilitation can help prevent musculoskeletal injuries in trail runners through movement control and fatigue resistance.

Female Athlete Hip Injuries: A Narrative Review

OBJECTIVE

In this narrative review, we highlight sex-specific anatomic and biomechanical features of the hip region in female athletes, as well as the potential impact of these characteristics on observed disparities in both intra-articular and extra-articular injury patterns between female and male athletes. It is our goal to broaden the scope of knowledge related to hip pathology in active female athletes among sports medicine providers with the hope of better optimizing sport participation and performance in female athletes.

DATA SOURCES

A literature review was conducted using PubMed database and Google Scholar search engine. Search terms included sport, female, athlete, sex differences, injury, hip, and all diagnoses discussed in this review. Cross-reference of these articles identified additional resources.

MAIN RESULTS

Sex-specific differences in both static design and dynamic function contribute to disparities in hip injury patterns between female and male athletes. Intra-articular injuries, including labral and ligamentum teres pathology, as well as extra-articular injuries, including iliopsoas tendon dysfunction, gluteal and proximal hamstring tendinopathy, ischiofemoral impingement, bone stress injuries, and certain nerve entrapment syndromes, seem to affect female athletes more commonly than male counterparts.

CONCLUSIONS

Given unique anatomic and functional considerations, the growing population of female athletes worldwide warrants specialized care and consideration. Potential predisposition to specific hip injuries should be taken into consideration during diagnostic evaluation of hip pain in the female athlete.

Treatment of Navicular Stress Fracture Accompanied by Os Supranaviculare: A Case Report

Navicular stress fractures (NSFs) are relatively uncommon, and predominantly affect athletes. Patients complain of vague pain, bruising, and swelling in the dorsal aspect of the midfoot. Os supranaviculare (OSSN) is an accessory ossicle located above the dorsal aspect of the talonavicular joint. There have been few previous reports of NSFs accompanied by OSSN. Herein we report the case of a patient with OSSN who was successfully treated for an NSF. A 34-year-old Asian man presented with a 6-month history of insidious-onset dorsal foot pain that occasionally radiated medially toward the arch. The pain worsened while sprinting and kicking a soccer ball with the instep, whereas it was temporarily relieved by rest for a week and analgesics. Plain radiographs of the weight-bearing foot and ankle joints revealed a bilateral, well-corticated OSSN. Computed tomography (CT) revealed a sagittally oriented incomplete fracture that extended from the dorsoproximal cortex to the center of the body of the navicular. The OSSN was excised and the joint was immobilized with a non-weight-bearing cast for 6 weeks, followed by gradual weight bearing using a boot. The 5-month follow-up CT scan demonstrated definite fracture healing. At the 1-year follow-up, the patient’s symptoms had resolved, the American Orthopedic Foot and Ankle Society midfoot score had improved from 61 to 95 points, and the visual analog scale pain score had improved from 6 to 0. We describe a rare case of NSF accompanied by OSSN. Because of the fracture gap and biomechanical properties of OSSN, OSSN was excised and the joint was immobilized, leading to a successful outcome. Further research is required to evaluate the relationship between NSFs and OSSN, and determine the optimal management of NSFs in patients with OSSN.

Triathlete with Multiple Stress Fractures in the Lower Limbs: Case Report and Literature Review

Recurrent stress fractures rarely affect the same athlete. We present the case of a female triathlete who suffered multiple stress fractures in both tibias, the right fibula, and the left femoral neck. Conservative treatment was instituted in all episodes, with rest, reduced training load, and physical therapy rehabilitation. The relative energy deficiency in sport syndrome, along with an eating disorder, training overload, and osteopenia, was identified as a risk factor. Although rare, multiple stress fractures can occur in female triathletes. These patients must be screened for risk factors associated with biomechanics, nutrition, and training to develop an effective prevention and treatment program.

The Effectiveness of Intramedullary Screw Fixation Using the Herbert Screw for Fifth Metatarsal Stress Fractures in High-Level Athletes

BACKGROUND

Intramedullary screw fixation is the most common operative procedure used for treatment of fifth metatarsal stress fractures in athletes. However, the optimal implant in intramedullary screw fixation is still being investigated.

PURPOSE

To review experiences with intramedullary screw fixation using the Herbert screw for fifth metatarsal stress fractures in high-level athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The authors retrospectively analyzed 37 high-level athletes (Tegner activity score ≥7) who underwent intramedullary screw fixation using the Herbert screw for fifth metatarsal stress fractures between August 2005 and August 2017. The minimum follow-up period of the patients was 2 years. In assessing the surgical results, time to obtain bone union, time to return to original level of sport participation, and treatment failures/complications were reviewed. Additionally, the effect of intraoperative plantar gap widening caused by the screw insertion was analyzed. The surgical results of the 2 groups, the no-gap group (intraoperative plantar gap widening, <1 mm) and the gap group (intraoperative plantar gap widening, ≥1 mm), were compared, while correlations between intraoperative plantar gap widening and the surgical results were statistically analyzed.

RESULTS

Bone union and return to the original sport were attained in all patients without treatment failures/complications such as delayed union, nonunion, or refracture. The mean time to obtain bone union was 10.1 weeks, and the mean time to return to sport was 10.9 weeks. In comparing the no-gap group (n = 16) and the gap group (n = 21), no significant differences in the time to obtain bone union (P = .392) or to return to sport (P = .399) were noted. Additionally, there was no correlation between intraoperative plantar gap widening and the time to obtain bone union (r = 0.131; P = .428) or to return to sport (r = 0.160; P = .331).

CONCLUSION

The use of the Herbert screw for intramedullary screw fixation to treat fifth metatarsal stress fractures in high-level athletes provided satisfactory results enabling all the athletes to return to the original sport without treatment failures/complications. Additionally, intraoperative plantar gap widening does not affect the surgical results using this technique.

Association between common stressful life events and coping strategies in adults

BACKGROUND

As shown in previous persons that used the effective coping strategies are more aware to recent stressful life events in their live, this study conducted to investigate the main stressful life events and common coping styles in adult's population.

MATERIALS AND METHODS

This cross-sectional study was conducted in 2018. In overall, 345 persons aged 18 years and more by stratified cluster sampling were enrolled in the study. The valid questionnaires including the coping inventory for stressful situations-21, the Holmes-Rahe Stress Inventory, and 28-item General Health Questionnaire (GHQ-28) were used to interview. The analysis of variance and t-student (t-test) was used to determine the association between the two variables. The statistical significance level was considered <0.05.

RESULTS

The top three importance events among 43 stressful items in our study were change in financial state, gain of a new family member, and death of close family member. We found that task-oriented coping (P < 0.001) and avoidance-oriented coping (P = 0.021) significantly more used in males compered to females. According to Holmes-Rahe life stress inventory instructions only 4.7% of participants are prone to getting ill in next 2 years.

CONCLUSION

The results of this study showed a positive relationship between coping styles and lower risk of mental health problems and stressful life events. Hence, activities and training programs aiming to enhance personal approach coping skills is important to reduce of side effects of stressful life events especially those recently exposed to negative life events and stresses.

The Epidemiology, Risk Factors, and Nonsurgical Treatment of Injuries Related to Endurance Running

ABSTRACT

Running is a popular form of exercise that is easily accessible to various populations; endurance running, defined as distances beyond 5 km, continues to grow within the sport. Endurance running-related injuries are common in the lower extremities and are primarily overuse related. A multitude of risk factors for injury exist, including extrinsic factors, such as running distance and frequency, and intrinsic factors, such as biomechanics and nutrition status. Training and rehabilitation techniques vary with a general focus on strengthening and gradual increase in activity, but evidence is mixed, and it is difficult to generalize programs across different running populations. Management of specific running groups, including youth runners, is an area in which additional research is needed. New treatments, such as orthobiologics and wearable technology, have promising potential to optimize performance and recovery and minimize injury. However, they need to be further evaluated with high-quality studies.

Risk Factors, Diagnosis and Management of Bone Stress Injuries in Adolescent Athletes: A Narrative Review

Physical activity is known to be beneficial for bone; however, some athletes who train intensely are at risk of bone stress injury (BSI). Incidence in adolescent athlete populations is between 3.9 and 19% with recurrence rates as high as 21%. Participation in physical training can be highly skeletally demanding, particularly during periods of rapid growth in adolescence, and when competition and training demands are heaviest. Sports involving running and jumping are associated with a higher incidence of BSI and some athletes appear to be more susceptible than others. Maintaining a very lean physique in aesthetic sports (gymnastics, figure skating and ballet) or a prolonged negative energy balance in extreme endurance events (long distance running and triathlon) may compound the risk of BSI with repetitive mechanical loading of bone, due to the additional negative effects of hormonal disturbances. The following review presents a summary of the epidemiology of BSI in the adolescent athlete, risk factors for BSI (physical and behavioural characteristics, energy balance and hormone disruption, growth velocity, sport-specific risk, training load, etc.), prevention and management strategies.

High Cortico-Trabecular Transitional Zone Porosity and Reduced Trabecular Density in Men and Women with Stress Fractures

To determine whether stress fractures are associated with bone microstructural deterioration we quantified distal radial and the unfractured distal tibia using high resolution peripheral quantitative computed tomography in 26 cases with lower limb stress fractures (15 males, 11 females; mean age 37.1 ± 3.1 years) and 62 age-matched healthy controls (24 males, 38 females; mean age 35.0 ± 1.6 years). Relative to controls, in men, at the distal radius, cases had smaller cortical cross sectional area (CSA) (p = 0.012), higher porosity of the outer transitional zone (OTZ) (p = 0.006), inner transitional zone (ITZ) (p = 0.043) and the compact-appearing cortex (CC) (p = 0.023) while trabecular vBMD was lower (p = 0.002). At the distal tibia, cases also had a smaller cortical CSA (p = 0.008). Cortical porosity was not higher, but trabecular vBMD was lower (p = 0.001). Relative to controls, in women, cases had higher distal radial porosity of the OTZ (p = 0.028), ITZ (p = 0.030) not CC (p = 0.054). Trabecular vBMD was lower (p = 0.041). Distal tibial porosity was higher in the OTZ (p = 0.035), ITZ (p = 0.009), not CC. Stress fractures are associated with compromised cortical and trabecular microstructure.

Stress Fractures of the Hip and Pelvis

Stress fractures refer to overuse injuries of bone resulting from repetitive mechanical stress. Stress fractures of the hip and pelvic region, while relatively uncommon, have become increasingly recognized in certain populations, particularly long-distance runners and military recruits. The diagnosis of such injuries can be challenging, often hampered by a nonspecific physical examination and limited sensitivity of plain radiography. Early recognition is important to direct appropriate management, lessen time lost from sport, and avoid potential complications. The present article reviews the epidemiology, diagnosis, and management of bone stress injuries of the hip and pelvis, specifically the sacrum, pubic ramus, and femoral neck.

Femoral neck shaft angle in relation to the location of femoral stress fracture in young military recruits: femoral head versus femoral neck stress fracture

OBJECTIVE

To evaluate the influences of the femoral neck shaft angle (FNSA) on the location of the femoral stress fracture and to assess the potential differences in FNSA between fractured and normal femurs.

MATERIALS AND METHODS

Thirty-seven patients with femoral stress fractures who underwent both plain hip radiographs and MRI, from January 2016 to September 2019, were retrospectively included. Patients were classified as having either femoral head stress fracture (group A, n = 26) or femoral neck stress fracture (group B, n = 11). The FNSA was measured in anteroposterior (AP) hip radiograph. The Mann-Whitney U testing was used to compare the continuous values between the two groups. A receiver operating characteristic (ROC) analysis was used to evaluate the value of FNSA for predicting the risk of femoral stress fracture.

RESULTS

The FNSA was significantly higher in group A (median 135.9°, range 129.5-138.6°) than group B (median 124.3°, range 119.5-129.0°) (p < 0.001), but there were no significant differences in other clinical factors. Furthermore, the FNSA was significantly higher at the fractured femurs (median 135.9°, range 129.9-138.6°) than contralateral normal femurs (median 127.9°, range 123.8-132.1°) in the patients with unilateral femoral head stress fracture (n = 22) (p < 0.001). The ROC analysis revealed that the area under curve (AUC), sensitivity, and specificity for predicting the risk of femoral head stress fracture were 0.807, 72.7%, and 68.2%, respectively, at a FNSA cutoff of 131.0°.

CONCLUSION

FNSA was associated with the location of the femoral stress fracture. In addition, FNSA could serve as a predictive factor for the risk of femoral head stress fractures.

Stress fractures in uncommon location: Six case reports and review of the literature

BACKGROUND

Individuals' interest in sports activities has been increasing, contributing to more stress fracture occurrences in uncommon locations on the skeleton. In this study, several cases of stress fractures in atypical locations are presented, and the possibility of combining diagnostic methods to make accurate and quick diagnoses is explored. Additionally, different causes of stress fractures, as well as various modalities of treatment, are highlighted. Other potential factors of stress fractures were identified by a literature review.

CASE SUMMARY

Six cases of stress fractures in the calcaneus, intermediate cuneiform bone, sacrum, tibia (bilateral), navicular bone and femoral neck are presented, with different types of diagnostic imaging and treatments. All of the cases were associated with an aspect of mobility because all of the patients were physically active in various sport disciplines.

CONCLUSION

The type of therapeutic procedure selected should depend on the specific clinical case, i.e., the patient's condition and level of physical activity.

[Factors associated with stress fracture: A case-control study in a Peruvian navy medical center]

Introduction

Stress fractures are injuries produced by the overuse of certain extremities, generating repetitive fatigue in the bone with insufficient rest periods and hormonal disorders, among others. High osteoclastic activity and lower activity of the osteoblasts at the cortical level occurs.

Objective

To determine the factors associated with a stress fracture in a single medical center of the Peruvian navy.

Methods

We conducted an observational, analytical case-control study. The dependent variable was stress fracture confirmed by magnetic resonance imaging of the patients; the independent variables were age, sex, calcemia, socioeconomic status, and time of daily physical activity. All data were extracted from the medical records. Crude and adjusted odds ratios were calculated with 95% confidence intervals.

Results

The sample was comprised of 238 patients (119 cases and 119 controls), of which 79.8% were male, and 20.2% were female; the average age was 20.25. In the bivariate analysis, stress fractures were associated with male sex (odds ratio 3.00; 95% confidence interval 1.51 to 5.95), hypocalcemia (2.83; 2.32 to 3.44), more than two hours of daily physical activity (24.7; 12.51 to 48.95) and socioeconomic level C (6.66; 2.82 to 15.74). Time dedicated to physical activity (adjusted odds ratio 44.46; 95% confidence interval 17.93 to 110.22) and socioeconomic level C (adjusted odds ratio 22.57; 95% confidence interval 7.03 to 72.74) were associated in the multivariate analysis.

Conclusion

We found that stress fractures were associated with physical activity time and a lower socioeconomic level. Further studies are needed to evaluate the relationship with other factors in the military population of Peru.

Time-Dependent Magnetic Resonance Imaging Changes in Occult Femoral Neck Fracture During Conservative Treatment: A Case Report

CASE

A 53-year-old woman presented to the emergency department with persistent left hip pain after a fall while riding a bicycle. Although x-ray imaging revealed no evidence of fracture, an abnormal intensity vertical line along the left femoral neck was observed in the magnetic resonance imaging (MRI). Furthermore, 2 weeks after injury, MRI revealed a newly developed abnormal intensity oblique band at the femoral neck. After discussing several treatment options with the patients, she chose the conservative treatment.

CONCLUSION

Careful follow-ups and MRI were undertaken 6 times within 32 weeks. Bone union was observed 32 weeks after the injury, and no bone displacement was observed.

A Case Report of Mixed Osteomalacia and Low Bone Density from Vitamin D Deficiency as a Cause of Bilateral Tibial Stress Fractures in a Young Male Military Recruit from Singapore

Despite being a tropical country, vitamin D deficiency is common in Singapore. All young Singaporean males between the age of 18 and 21 years have to undergo mandatory military service. Stress fractures occur in military recruits, and risk factors include a sudden increase in physical activity and vitamin D deficiency. We report the bone histomorphometry findings from a case of bilateral tibial stress fractures in an 18-year-old military recruit who had vitamin D deficiency. The histomorphometry showed a mixed osteomalacia and osteoporosis pattern. This case is unique as it shows that stress fractures from a marching exercise can occur in apparently healthy well young man with vitamin D deficiency despite living in a tropical country.

Emerging Options for Biologic Enhancement of Stress Fracture Healing in Athletes

In an era of continual single-sport specialization and year-round training, overuse injuries, including stress injuries of bone, are increasingly common. These injuries can be season- or even career-ending. For many elite and professional athletes, the traditional treatment strategy of immobilization and extended rest from sports participation is often not practical or acceptable. An understanding of modern strategies for evaluating and treating stress fractures is paramount for maintaining athletic participation and optimal athletic performance. This begins with the ability to categorize and stratify bony stress injuries by both severity and risk of fracture progression. Surgical procedures such as open reduction and internal fixation or intramedullary fixation with possible bone grafting remain the standard of care for chronic or severe stress fractures. However, emerging techniques to augment the biologic environment are a minimally invasive adjunct for stimulating and supporting bone healing in elite-level athletes to optimize bone health, expedite recovery, and decrease the risk of nonunion or catastrophic fracture.

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.

Effectiveness of whey protein supplements on the serum levels of amino acid, creatinine kinase and myoglobin of athletes: a systematic review and meta-analysis

BACKGROUND

Consuming whey protein supplements, along with physiotherapy and psychotherapy, have been recognised in sports performance. Whey protein supplements (WPS) is one of the commonly used supplements as ergogenic aids for athletes to enhance their muscle performance and recovery during sport-related injuries. The purpose of this systematic review is to investigate the effectiveness of WPS over the blood biochemistry mainly amino acids, creatinine kinase and myoglobin which influence performance and recovery among athletes.

METHOD

A comprehensive literature search was conducted to identify randomised control trials (RCTs) and non-RCTs that investigated the effectiveness of WPS on amino acids, creatinine kinase and myoglobin among athletes. Risk of Bias in Non-Randomised Studies of Interventions tool (ROBINS-I) and Cochrane Risk of Bias Assessment tool were used to rule out the quality of studies. Meta-analysis was performed using a random effect model with STATA version 14.2. The weighted mean difference was used to estimate the effectiveness of WPS against other supplements.

RESULTS

A total of 333,257 research articles were identified; of these, 15 records were included to proceed with the analysis. Meta-analysis has shown that WPS has significantly overall increased the level of essential amino acids level by 624.03 nmol/L (CI = 169.27, 1078.8; I² = 100%; p = 0.00) and branched-chain amino acids level by 458.57 nmol/L (CI = 179.96, 737.18; I² = 100%; p = 0.00) compared to the control group (without WPS). Moreover, was observed to decrease myoglobin level by 11.74 ng/ml (CI = - 30.24, 6.76; I² = 79.6%; p = 0.007) and creatine kinase level by 47.05 U/L (CI = - 129.47, 35.37; I² = 98.4%; p = 0.000) compared to the control group.

CONCLUSION

The findings revealed that the clinical evidence supports the effectiveness of WPS as a positive ergogenic aid on athletes' amino acids, creatinine kinase and myoglobin.

Association of catastrophic condylar fracture with bony changes of the third metacarpal bone identified by use of standing magnetic resonance imaging in forelimbs from cadavers of Thoroughbred racehorses in the United States

OBJECTIVE To compare bony changes of the third metacarpal bone (MC3) of Thoroughbred racehorse cadavers with (cases) or without (controls) catastrophic condylar fracture by use of standing MRI. SAMPLE 140 forelimbs from 26 case horses (both forelimbs) and 88 control horses (single forelimb). PROCEDURES Bone marrow lesions (BMLs), identified as a decrease in T1-weighted (T1W) signal and increases in T2*-weighted (T2*W) and short tau inversion recovery (STIR) signals, and dense bone volume percentage (DBVP), identified as decreases in T1W, T2*W, and STIR signals, in the distopalmar aspect of MC3 were recorded. Logistic regression was used to compare fractured and nonfractured limbs of cases and fractured limbs of cases with randomly selected limbs of controls. RESULTS Among cases, fractured limbs were significantly more likely to have BMLs (26/26 [100%]) than were nonfractured limbs (7/26 [27%]). Fractured limbs of cases were significantly more likely to have BMLs (26/26 [100%]) than were limbs of controls (6/88 [7%]). Among cases, there was no significant difference in DBVP between fractured and nonfractured limbs in lateral (26% vs 21%, respectively) or medial (25% vs 20%, respectively) condyles. However, DBVP was significantly greater in fractured limbs of cases than in limbs of controls for lateral (26% vs 16%, respectively) and medial (25% vs 18%, respectively) condyles. CONCLUSIONS AND CLINICAL RELEVANCE Standing MRI revealed a significantly greater degree of bone change in racehorses with condylar fracture when comparing fractured and nonfractured limbs of case horses and fractured limbs of case horses with randomly selected limbs of control horses.

Sport Nutrigenomics: Personalized Nutrition for Athletic Performance

An individual's dietary and supplement strategies can influence markedly their physical performance. Personalized nutrition in athletic populations aims to optimize health, body composition, and exercise performance by targeting dietary recommendations to an individual's genetic profile. Sport dietitians and nutritionists have long been adept at placing additional scrutiny on the one-size-fits-all general population dietary guidelines to accommodate various sporting populations. However, generic "one-size-fits-all" recommendations still remain. Genetic differences are known to impact absorption, metabolism, uptake, utilization and excretion of nutrients and food bioactives, which ultimately affects a number of metabolic pathways. Nutrigenomics and nutrigenetics are experimental approaches that use genomic information and genetic testing technologies to examine the role of individual genetic differences in modifying an athlete's response to nutrients and other food components. Although there have been few randomized, controlled trials examining the effects of genetic variation on performance in response to an ergogenic aid, there is a growing foundation of research linking gene-diet interactions on biomarkers of nutritional status, which impact exercise and sport performance. This foundation forms the basis from which the field of sport nutrigenomics continues to develop. We review the science of genetic modifiers of various dietary factors that impact an athlete's nutritional status, body composition and, ultimately athletic performance.

The Effects of Endurance Sports on Children and Youth

In the United States, youth participation in sports continues to increase yearly. This increase in participation, in conjunction with the trend toward early sports specialization and year round training, has led to a similar increase in athletically developed injuries. These injuries vary in nature and acuity, with the type of injury often related to the athlete's age, sport, and level of training. Endurance athletes are at an elevated risk of injury as they frequently push their body to the limit during their arduous training. Pediatric endurance athletes can be particularly vulnerable, especially to overuse injuries, given their unique and ever-changing physiological state. It is important to understand the specific challenges facing not only the physical, but also the emotional well-being of these pediatric endurance athletes to maximize performance while minimizing injury and potential long-term sequelae.

Detecting stress injury (fatigue fracture) in fibular cortical bone using quantitative ultrashort echo time-magnetization transfer (UTE-MT): An ex vivo study

Bone stress injury (BSI) incidents have been increasing amongst athletes in recent years as a result of more intense sporting activities. Cortical bone in the tibia and fibula is one of the most common BSI sites. Nowadays, clinical magnetic resonance imaging (MRI) is the recommended technique for BSI diagnosis at an early stage. However, clinical MRI focuses on edema observations in surrounding soft tissues, rather than the injured components of the bone. Specifically, both normal and injured bone are invisible in conventional clinical MRI. In contrast, ultrashort echo time (UTE)-MRI is able to detect the rapidly decaying signal from the bone. This study aimed to employ UTE-MRI for fatigue fracture detection in fibula cortical bone through an ex vivo investigation. Fourteen human fibular samples (47 ± 20 years old, four women) were subjected to cyclic loading on a four-point bending setup. The loading was displacement controlled to induce -5000 ± 1500 μ-strain at 4 Hz. Loading was stopped when bone stiffness was reduced by 20%. Fibula samples were imaged twice, using UTE-MRI and micro-computed tomography (μCT), first pre-loading and second post-loading. After loading, the macromolecular fraction (MMF) from UTE-MT modeling demonstrated a significant decrease (12% ± 20%, P = 0.02) on average. Single-component T2 * also decreased significantly by BSI (12% ± 11%, P = 0.01) on average. MMF reduction is hypothesized to be a result of collagenous matrix rupture and water increase. However, faster T2 * decay might be a result of water shifts towards newly developed microcracks with higher susceptibility. Despite this good sensitivity level of the UTE-MRI technique, the μCT-based porosity at a voxel size of 9 μm was not affected by loading. UTE-MRI shows promise as a new quantitative technique to detect BSI.

Tension band plating of an anterior tibial stress fracture nonunion in an elite athlete, initially treated with intramedullary nailing: a case report

Background

Leg pain in athletes is a common condition and is often related to tibial stress fracture. When non-operative treatment fails, the optimal surgical treatment is controversial. The aim of this study was to report a case of tension band plating of an anterior tibial stress fracture nonunion, treated previously with intramedullary nailing. To the best of our knowledge, this is the first reported case in which tension band plating was placed without removing the preexisting intramedullary nail.

Case presentation

The tibial shaft is a common location of stress fracture in athletes. Anterior tibial stress fractures are difficult to manage. When conservative treatment fails, intramedullary nailing is the mainstay of treatment. However, nonunion is a serious complication. In our case, a non-united anterior tibial stress fracture, treated with intramedullary nailing, was addressed with the application of a compression prebended plate over the nail in a 23-year-old French man of African origin who is an elite football player. At 3-months postoperatively he was pain free and started light exercises. At 6-months postoperatively, complete radiologic union of the fracture was evident. He was symptom free; he resumed at that time a full training program and he returned to play football at preinjury high competition level.

Conclusions

Compression plating is a valuable method of treating non-united anterior tibial stress fractures. We believe that anterior tension band plating is superior to intramedullary nailing in managing anterior tibial stress fractures, not only after failure of intramedullary nailing, but also as a first-line surgical treatment. This technique offers advantages, such as no violation of the extensor mechanism and risk of anterior knee pain, and directly addresses the underlying problem of distraction forces acting on the anterior tibial cortex and compromising fracture healing. Especially in high-level athletes, who cannot tolerate prolonged inactivity, early surgical intervention of anterior tibial stress fractures with tension band plating is a reliable option that can accelerate recovery.

Effectiveness of various isometric exercises at improving bone strength in cortical regions prone to distal tibial stress fractures

A computational model was used to compare the local bone strengthening effectiveness of various isometric exercises that may reduce the likelihood of distal tibial stress fractures. The developed model predicts local endosteal and periosteal cortical accretion and resorption based on relative local and global measures of the tibial stress state and its surface variation. Using a multisegment 3-dimensional leg model, tibia shape adaptations due to 33 combinations of hip, knee, and ankle joint angles and the direction of a single or sequential series of generated isometric resultant forces were predicted. The maximum stress at a common fracture-prone region in each optimized geometry was compared under likely stress fracture-inducing midstance jogging conditions. No direct correlations were found between stress reductions over an initially uniform circular hollow cylindrical geometry under these critical design conditions and the exercise-based sets of active muscles, joint angles, or individual muscle force and local stress magnitudes. Additionally, typically favorable increases in cross-sectional geometric measures did not guarantee stress decreases at these locations. Instead, tibial stress distributions under the exercise conditions best predicted strengthening ability. Exercises producing larger anterior distal stresses created optimized tibia shapes that better resisted the high midstance jogging bending stresses. Bent leg configurations generating anteriorly directed or inferiorly directed resultant forces created favorable adaptations. None of the studied loads produced by a straight leg was significantly advantageous. These predictions and the insight gained can provide preliminary guidance in the screening and development of targeted bone strengthening techniques for those susceptible to distal tibial stress fractures.

Characterization and Comparison of Nutritional Intake between Preparatory and Competitive Phase of Highly Trained Athletes

Background and objective: For a high level athlete, it is essential to ensure optimal energy as well as macro- and micro-nutrient and fluid intakes, in order to improve their performance during training and competition. Protein intake should be 1.2⁻2.1 g/kg/d, whereas the requirements for carbohydrate and fat intakes should be >5g/kg/d and 20⁻35% of energy, respectively. The micronutrient and fluid intakes in athletes were compared to the Dietary Reference Intake (DRI) and European Food Safety Authority (EFSA) recommendations, respectively. This study aimed to characterize and compare the nutritional habits of athletes at the preparatory and competitive phase, and to test if their nutritional intakes were in accordance with the recommendations. Materials and methods: A total of 276 professional athletes were assessed. To evaluate their nutritional intake, the athletes completed a 7 days food record. Under reporting was defined using a ratio of energy intake to basal metabolic rate (BMR) of 1.1. Body composition was assessed using dual energy X-ray absorptiometry (DXA). Results: Almost half (49%) of the athletes from the final sample reported lower measured intakes of carbohydrates and 27% reported a higher consumption of proteins than what was recommended. In both the preparatory and competitive phases, the micronutrients with a higher mismatch between the actual and recommended intakes were vitamins D and E, magnesium, folate, calcium, and zinc for both sexes, and iron intake for females. A large proportion of athletes reported a lower water intake. Compared to the recommendations, males reported a higher intake of carbohydrates, lipids, vitamins E, calcium, and magnesium (p <0.05) in the competitive phase, while females reported a lower ingestion of water, vitamins A and D, and calcium (p <0.05) in the preparatory phase. Conclusions: Overall, in the preparatory and competitive phases of the season, athletes reported a macro- and micro-nutrient intake below the recommendations, especially in the female athletic population. Dietary intakes in athletes need to be optimized and adjusted to their requirements, according to sex and sport, so as to avoid compromising health and performance.

Femoral neck stress fracture in a young female recruit: case report

Introduction: Femoral neck stress fractures are uncommon and depending on their location, can be at high risk for non-union and significant morbidity.  Their prevalence is higher among runners and military recruits, and women seem to be at higher risk.

Methods: A 27-year-old female, who was enrolled in military recruit, reported left side groin pain after a strenuous running exercise. Due to persistent pain an X-Ray was ordered, which revealed no signs of acute lesions. Further imaging studies with CT scan and MRI identified a compression-type femoral neck stress fracture.

Results: The patient was submitted to conservative treatment consisting of restricting from full weight-bearing. Six weeks after she initiated partial weight-bearing, becoming asymptomatic at seven months. Follow-up imaging studies revealed union of the fracture.

Discussion: This diagnosis should be considered when evaluating military and athlete populations. Early recognition of these injuries is crucial because complication and morbidity rates are high.

Outcome of surgical management of stress fractures in high demand individuals

Stress fractures represent one-fifth of overuse injuries in sport. Successful healing of stress fractures in high demand individuals is important to prevent complications upon early return to activity. This article reviews the literature on outcomes of surgical management of stress fractures in high demand individuals. An online literature search was carried out for articles published up to and including January 2017. Twenty five papers were reviewed. In the majority of studies, no complications were reported, clinical and radiographic healing was achieved, and patients returned to their premorbid level of activity. Current literature suggests good outcomes after surgical management of stress fractures in high demand individuals, particularly those in whom conservative treatment has failed. Further studies comparing surgical techniques are necessary to demonstrate the most efficacious.

Negative magnetic resonance imaging in three cases of anterior tibial cortex stress fractures

Anterior mid-tibial cortex stress fractures (ATCSF) are uncommon and notoriously challenging to treat. They are termed high risk due to their predilection to prolonged recovery, nonunion and complete fracture. Early diagnosis is essential to avoid progression and reduce fracture complications. Imaging plays a key role in confirming the diagnosis. Magnetic resonance imaging (MRI) is accepted as the gold standard modality due to its high accuracy and nonionizing properties. This report describes three cases of ATCSFs in recreational athletes who had positive radiographic findings with no significant MRI changes. Two athletes had multiple striations within their tibias. Despite the radiographic findings, their severity of symptoms were low with mild or no tenderness on examination. Clinicians should be mindful that the ATCSFs may not present with typical acute stress fracture symptoms. We recommend that plain radiographs should be used as the first line investigation when suspecting ATCSFs. Clinicians should be aware that despite MRI being considered the gold standard imaging modality, we report three cases where the MRI was unremarkable, whilst radiographs and computed tomography confirmed the diagnosis. We urge clinicians to continue to use radiographs as the first line imaging modality for ATCSFs and not to directly rely on MRI. Those who opt directly for MRI may be falsely reassured causing a delay in diagnosis.

Risk Factors for Reoperation and Performance-Based Outcomes After Operative Fixation of Foot Fractures in the Professional Athlete: A Cross-Sport Analysis

Background:

Professional athletes are predisposed to fractures of the foot due to large stresses placed on the lower extremity. These players are concerned with efficiently returning to play at a high level. Return-to-play rates after operative treatment have been previously reported, yet performance outcomes after such treatment are generally unknown in this population.

Hypothesis:

Overall, professional athletes sustaining a foot fracture would return to play at high rates with little impact on postoperative performance or league participation. However, National Football League (NFL) athletes would have a significantly greater decline in performance due to the high-impact nature of the sport.

Study Design:

Case series.

Level of Evidence:

Level 4.

Methods:

Athletes in the National Basketball League (NBA), NFL, Major League Baseball (MLB), and National Hockey League (NHL) undergoing operative fixation of a foot fracture were identified through a well-established protocol confirmed by multiple sources of the public record. Return-to-play rate and time to return were collected for each sport. League participation and game performance data were collected before and after surgery. Statistical analysis was performed, with significance accepted as P ≤ 0.05.

Results:

A total of 77 players undergoing 84 procedures met the inclusion criteria. Overall, 98.7% (76/77) of players were able to return to play, with a median time to return across all sports of 137 days. Players returned to preoperative performance levels within 1 season of surgery. Six players (7.8%) sustained refracture requiring reoperation, all of whom were in the NBA. Percentage of games started during the season after primary operative treatment was a predictive factor for reinjury (99% vs 40%, P = 0.001).

Conclusion:

Athletes returned to play at a high rate after foot fracture fixation, with excellent postoperative performance levels, regardless of sport and fracture location. NBA athletes sustaining fifth metatarsal and navicular fractures are at greater risk of reinjury compared with other athletes. Returning to high levels of athletic participation soon after surgery may predispose athletes to refracture and subsequent reoperation.

Clinical Relevance:

Players, coaches, and team physicians should be aware of the impact of foot fractures on career performance and longevity to best guide therapy.