Imaging of stress fractures in runners

Bilateral Medial Tibial Plateau Stress Fractures: A Case Report

Medial tibial plateau stress fractures are rare and often misdiagnosed due to nonspecific symptoms and initially normal radiographs. This case report describes a rare instance of bilateral medial tibial plateau stress fractures in a 43-year-old overweight male police officer with comorbidities including diabetes. The patient developed progressive knee pain after abruptly increasing his running activity. Initial radiographs were inconclusive, but magnetic resonance imaging (MRI) revealed bone marrow edema and non-displaced fractures, highlighting the importance of advanced imaging for early diagnosis. Risk factors included his sudden activity change, high body mass index (BMI), and lower-normal vitamin D levels. Management involved conservative measures like activity modification, weight-bearing as tolerated, and vitamin D supplementation, leading to symptom resolution within three months. The report emphasizes the need for clinical suspicion in middle-aged individuals with persistent knee pain, particularly those with recent activity changes, and underscores MRI's role in early detection. Conservative treatment and patient education on gradual training progression are crucial for recovery and prevention of recurrence.

Sacral stress fracture in a young-adult, long-distance runner: an underestimated cause of low back pain

Sacral stress fractures (SSFs) in physically active young patients are frequently misdiagnosed due to the lack of specificity of signs and symptoms. Over the last years, these injuries have been described as rare, although some studies report that the incidence of an SSF in athletes may be as high as 20%.We describe a case of a male long-distance runner in his late 20s with a 1-month undiagnosed SSF. The patient complaints included insidious right low back and buttock pain without trauma that started after running a marathon. MRI revealed an extensive area of bone marrow oedema in the right sacral ala consistent with an SSF.This case highlights the importance of investigating SSF in young-athlete patients who were otherwise healthy, using appropriate imaging modalities to assess the presence and morphology of a fracture.

Relationship between Football-Specific Training Characteristics and Tibial Bone Adaptation in Male Academy Football Players

We examined the relationship between football-specific training and changes in bone structural properties across a 12-week period in 15 male football players aged 16 years (Mean ± 1 SD = 16.6 ± 0.3 years) that belonged to a professional football academy. Tibial scans were performed at 4%, 14% and 38% sites using peripheral quantitative computed tomography immediately before and 12 weeks after increased football-specific training. Training was analysed using GPS to quantify peak speed, average speed, total distance and high-speed distance. Analyses were conducted with bias-corrected and accelerated bootstrapped 95% confidence intervals (BCa 95% CI). There were increases in bone mass at the 4% (mean ∆ = 0.15 g, BCa 95% CI = 0.07, 0.26 g, g = 0.72), 14% (mean ∆ = 0.04 g, BCa 95% CI = 0.02, 0.06 g, g = 1.20), and 38% sites (mean ∆ = 0.03 g, BCa 95% CI = 0.01, 0.05 g, g = 0.61). There were increases in trabecular density (4%), (mean ∆ = 3.57 mg·cm^-3, BCa 95% CI = 0.38, 7.05 mg·cm^-3, g = 0.53), cortical dentsity (14%) (mean ∆ = 5.08 mg·cm^-3, BCa 95% CI = 0.19, 9.92 mg·cm^-3, g = 0.49), and cortical density (38%) (mean ∆ = 6.32 mg·cm^-3, BCa 95% CI = 4.31, 8.90 mg·cm^-3, g = 1.22). Polar stress strain index (mean ∆ = 50.56 mm³, BCa 95% CI = 10.52, 109.95 mm³, g = 0.41), cortical area (mean ∆ = 2.12 mm², BCa 95% CI = 0.09, 4.37 mm², g = 0.48) and thickness (mean ∆ = 0.06 mm, BCa 95% CI = 0.01, 0.13 mm, g = 0.45) increased at the 38% site. Correlations revealed positive relationships between total distance and increased cortical density (38%) (r = 0.39, BCa 95% CI = 0.02, 0.66), and between peak speed and increased trabecular density (4%) (r = 0.43, BCa 95% CI = 0.03, 0.73). There were negative correlations between total (r = -0.21, BCa 95% CI = -0.65, -0.12) and high-speed distance (r = -0.29, BCa 95% CI = -0.57, -0.24) with increased polar stress strain index (38%). Results suggest that despite football training relating to increases in bone characteristics in male academy footballers, the specific training variables promoting adaptation over a 12-week period may vary. Further studies conducted over a longer period are required to fully elucidate the time-course of how certain football-specific training characteristics influence bone structural properties.

Peak tibial acceleration should not be used as indicator of tibial bone loading during running

Peak tibial acceleration (PTA) is a widely used indicator of tibial bone loading. Indirect bone loading measures are of interest to reduce the risk of stress fractures during running. However, tibial compressive forces are caused by both internal muscle forces and external ground reaction forces. PTA might reflect forces from outside the body, but likely not the compressive force from muscles on the tibial bone. Hence, the strength of the relationship between PTA and maximum tibial compression forces in rearfoot-striking runners was investigated. Twelve runners ran on an instrumented treadmill while tibial acceleration was captured with accelerometers. Force plate and inertial measurement unit data were spatially aligned with a novel method based on the centre of pressure crossing a virtual toe marker. The correlation coefficient between maximum tibial compression forces and PTA was 0.04 ± 0.14 with a range of -0.15 to +0.28. This study showed a very weak and non-significant correlation between PTA and maximum tibial compression forces while running on a level treadmill at a single speed. Hence, PTA as an indicator for tibial bone loading should be reconsidered, as PTA does not provide a complete picture of both internal and external compressive forces on the tibial bone.  .

Surgical excision of bilateral patella stress fractures in an elite marathon runner

Vertical stress fractures of the patella are rare, with only a handful of bilateral cases reported. Stress fractures in the athletic community are often due to repetitive strain and submaximal loading, with minimal recovery time. An Olympic marathon runner in her 30s presented with right anterolateral knee pain. MRI revealed an acutely displaced vertical fracture of the lateral patella. After failure of non-operative treatment, she underwent surgical excision of the fracture fragment and lateral patellofemoral retinacular repair. Despite return to light training pain-free 3 weeks after surgery, she presented 2 months later with a contralateral vertical patella stress fracture. On this occasion, early operative treatment was performed with early return to training and resolution of symptoms.This is the first reported case of bilateral vertical patellar stress fractures in an athlete treated with excision of the fracture fragment. This is an excellent option for elite athletes who require a quick postoperative recovery, complete resolution of symptoms and early return to preinjury level of sport.

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.

Plantar Injuries in Runners: Is There an Association With Weekly Running Volume?

Running is an athletic activity that is increasingly gaining popularity. Despite its benefits, there are many suspected risk factors for running-related overuse injuries. The objective of this study is to describe injuries and clinical symptoms observed on the sole of the foot in runners, giving special attention to the weekly running volume. The literature presented in this narrative review is based on a non-systematic search of the Medline, Google Scholar, and ResearchGate databases and focuses on foot injuries (the full spectrum of the foot pathology from bones to tendons and plantar fascia, nerve, and joint disorders) in runners, which represents an important topic for both professional and recreational runners. The weekly running distance appeared to be one of the strongest predictors for future overuse injuries. Marathon training and average weekly running of over 20 km are possible predictive factors in the development of plantar foot injuries. The plantar medial aspect of the foot is the anatomic area of the foot that most frequently experiences pain, with numerous pathologic conditions. As a result, diagnosis is always a challenging task. The ability to obtain an accurate medical history and carefully perform a physical examination, together with good knowledge of the foot anatomy and kinesiology, are also proven to be key players in ensuring proper diagnosis.

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

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

SNPs in the vicinity of P2X7R, RANK/RANKL/OPG and Wnt signalling pathways and their association with bone phenotypes in academy footballers

CONTEXT

Genotype plays an important role in influencing bone phenotypes, such as bone mineral density, but the role of genotype in determining responses of bone to exercise has yet to be elucidated.

OBJECTIVE

To determine whether 10 SNPs associated with genes in the vicinity of P2X7R, RANK/RANKL/OPG and Wnt Signalling Pathways are associated with bone phenotypes in elite academy footballers (Soccer players) and to determine whether these genotypes are associated with training induced changes in bone. Design, participants, and methods: 99 elite academy footballers volunteered to participate. Peripheral computed tomography of the tibia (4%, 14%, 38% and 66% sites) was performed immediately before and 12 weeks after an increase in football training volume. Genotypes were determined using proprietary fluorescence-based competitive allele-specific PCR assays.

RESULTS

No significant genotype by time interactions were shown for any of the SNPs analysed (P > .05). A main effect of genotype was shown. SOST SNP rs1877632 (trabecular density), P2X7R SNPs rs1718119 (cortical thickness and CSA), rs3751143 (SSI, CSA, cortical CSA and periosteal circumference) RANK/RANKL/OPG SNPs rs9594738 (periosteal circumference), rs1021188 (cortical thickness and CSA) and rs9594759 (cortical density) were associated with bone phenotypes (P < .05).

CONCLUSIONS

No association was shown between P2X7R, RANK/RANKL/OPG and Wnt Signalling SNPs and a change in bone phenotypes following 12 weeks of increased training volume in elite academy footballers. However, SNPs were associated with bone phenotypes pre training. These data highlight the complexity of the interaction between SNPs in the vicinity of the RANK/RANKL/OPG, P2X7R and Wnt metabolic regulatory pathways and bone phenotypes in elite academy footballers.

Calcaneal fractures: radiological and CT evaluation and classification systems

Background and aim of the work: The calcaneus, the more lower bone of the body, has the task of supporting the axial load from the weight of the body. Calcaneal fractures represent about 1-2% of all fractures and 60% of the tarsal bones fractures. The articular involvement has been associated with a poor functional outcome. The aim of this work is to describe the radiologic evaluation, the classification systems, the morphological preoperative diagnostic imaging features of calcaneal fractures, highlighting the correlation with the choice of treatment and predictive capacity for the fracture surgical outcome. Methods: A PubMed search was performed for the terms Imaging calcaneus fracture, selecting articles in English language, published in the last two years, where preoperatively diagnostic imaging of fractures of the calcaneus are described. Case reports have not been included. Results: We have collected a number of data that provide important help in preoperative evaluation of calcaneal fractures, such as the new classification system created by Harnroongroj et al, the association of calcaneal fractures with fractures of other bone structures or soft tissue impairment, the use of calcaneotalar ratio in assessing the length of heel. Conclusions: These data suggest an approach geared to the specific choice of treatment and to improving patient outcomes. (www.actabiomedica.it)

Sports Injuries about the Hip: What the Radiologist Should Know

Injuries of the hip and surrounding structures represent a complex and commonly encountered scenario in athletes, with improper diagnosis serving as a cause of delayed return to play or progression to a more serious injury. As such, radiologists play an essential role in guiding management of athletic injuries. Familiarity with hip anatomy and the advantages and limitations of various imaging modalities is of paramount importance for accurate and timely diagnosis. Magnetic resonance (MR) imaging is often the modality of choice for evaluating many of the injuries discussed, although preliminary evaluation with conventional radiography and use of other imaging modalities such as ultrasonography (US), computed tomography, and bone scintigraphy may be supplementary or preferred in certain situations. Stress fractures, thigh splints, and posterior hip dislocations are important structural injuries to consider in the athlete, initially imaged with radiographs and often best diagnosed with MR imaging. Apophyseal injuries are particularly important to consider in young athletes and may be acute or related to chronic repetitive microtrauma. Femoroacetabular impingement has been implicated in development of labral tears and cartilage abnormalities. Tear of the ligamentum teres is now recognized as a potential cause of hip pain and instability, best evaluated with MR arthrography. Greater trochanteric pain syndrome encompasses a group of conditions leading to lateral hip pain, with US playing an increasingly important role for both evaluation and image-guided treatment. Muscle injuries and athletic pubalgia are common in athletes. Lastly, snapping hip syndrome and Morel-Lavallée lesions are two less common but nonetheless important considerations. ^©RSNA, 2016.

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, part 1: biomechanics of bone and principles of imaging and treatment

A stress fracture is a focal failure of bone induced by the summation of repetitive forces, which overwhelms the normal bone remodeling cycle. This review, the first of two parts, discusses the general principles of stress fractures of the foot and ankle. This includes bone structure, biomechanics of stress applied to bone, bone remodeling, risk factors for stress fracture, and general principles of imaging and treatment of stress fractures. Cortical bone and trabecular bone have a contrasting macrostructure, which leads to differing resistances to externally applied forces. The variable and often confusing imaging appearance of stress fractures of the foot and ankle can largely be attributed to the different imaging appearance of bony remodeling of trabecular and cortical bone. Risk factors for stress fracture can be divided into intrinsic and extrinsic factors. Stress fractures subject to compressive forces are considered low-risk and are treated with activity modification and correction of any modifiable risk factors. Stress fractures subject to tensile forces and/or located in regions of decreased vascularity are considered high risk, with additional treatment options including restricted weight-bearing or surgery.

Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study

AIM

To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI).

METHODS

A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI.

RESULTS

Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI.

CONCLUSION

We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau.

Stress fracture in athletes

Stress fractures are widely encountered in sport medicine and rheumatology. Stress fractures result from abnormal and repetitive loading on normal bone that lead to microdamage and then fracture. They occur after sudden increase in physical activity. They appear mostly at lower limbs. Women are at higher risk than men. Patients complain of mechanical pain. Clinical findings include focused pain and sometimes swelling. No biological test is useful for diagnosis. Plain radiographs are normal in early stage disease. MRI is the gold standard to confirm stress fracture. Treatments of stress fracture always involve rest and analgesics. Non-steroidal anti-inflammatory should be use cautiously because they may inhibit callus formation. Extracorporeal shockwave may be a new approach for SF not healing with rest. Surgical treatment is often needed in high risk stress fracture of delayed healing, non-union or complete fracture.

Young man with sudden severe hip pain secondary to femoral neck stress fracture

Femoral neck stress fractures have been described in military recruits and athletes. Early recognition and aggressive treatment are important, as femoral neck stress fractures have a high potential for complications and even uncomplicated fractures require an extensive course of rehabilitation. Tension-side (superolateral) stress fractures of the femoral neck are at high risk for complications such as displacement, non-union and avascular necrosis, and need to be treated surgically, while compression-side (inferomedial) fractures can be treated conservatively. We describe a case illustrating a typical presentation of insidious hip pain culminating in sudden onset of severe hip pain in a healthy young man. We perform a literature review of studies showing epidemiology, treatment algorithms and rehabilitation.

Core Injuries Remote from the Pubic Symphysis

The core, or central musculoskeletal system of the torso, is essential for participating in sports and other physical activities. Core injuries are commonly encountered in athletes and active individuals. The importance of the midline pubic plate and rectus abdominis-adductor aponeurosis for core stability and function is discussed in the literature. This review article examines other important core injuries remote from the pubic symphysis, relevant clinical features, and preferred approaches to imaging. Several specific syndromes encountered in the core are reviewed. By protocoling imaging studies and identifying pathology, radiologists can add value to the clinical decision-making process and help guide therapeutic options.

[Femoral neck fractures in young patients]

Femoral neck fractures in young patients are rare but of high clinical relevance due to the complexity of risk factors and complications. Early stabilization and accurate reduction are of high priority. Femoral head-preserving stabilization by dynamic hip screws or threefold screw osteosynthesis are the methods of choice. Postoperative results should be closely controlled in every case in order to be able to treat possible complications in time.

Sacral fatigue fractures in children with sacral spina bifida occulta

In this report, we present two cases of 9-year-old children with spina bifida occulta (SBO) of the sacrum, who were diagnosed with sacral fatigue fractures. In both patients, MRI showed a linear signal void and high signal in sacral ala on the short tau inversion recovery sequence. Sacral SBO at the same level of the sacral fracture was observed in each patient on computed tomography images. These lesions healed with rest. This is the first literature reporting cases with sacral stress fractures who had SBO at the same level of fracture.

Stress fractures: pathophysiology, clinical presentation, imaging features, and treatment options

Stress fracture, in its most inclusive description, includes both fatigue and insufficiency fracture. Fatigue fractures, sometimes equated with the term "stress fractures," are most common in runners and other athletes and typically occur in the lower extremities. These fractures are the result of abnormal, cyclical loading on normal bone leading to local cortical resorption and fracture. Insufficiency fractures are common in elderly populations, secondary to osteoporosis, and are typically located in and around the pelvis. They are a result of normal or traumatic loading on abnormal bone. Subchondral insufficiency fractures of the hip or knee may cause acute pain that may present in the emergency setting. Medial tibial stress syndrome is a type of stress injury of the tibia related to activity and is a clinical syndrome encompassing a range of injuries from stress edema to frank-displaced fracture. Atypical subtrochanteric femoral fracture associated with long-term bisphosphonate therapy is also a recently discovered entity that needs early recognition to prevent progression to a complete fracture. Imaging recommendations for evaluation of stress fractures include initial plain radiographs followed, if necessary, by magnetic resonance imaging (MRI), which is preferred over computed tomography (CT) and bone scintigraphy. Radiographs are the first-line modality and may reveal linear sclerosis and periosteal reaction prior to the development of a frank fracture. MRI is highly sensitive with findings ranging from periosteal edema to bone marrow and intracortical signal abnormality. Additionally, a brief description of relevant clinical management of stress fractures is included.

Simultaneous Bilateral Femoral Neck Stress Fracture in a Young Stone Mason

Unilateral stress fractures of the femoral neck are very uncommon and bilateral involvement is even rarer. They commonly occur in athletes, military recruits, older persons, or individuals with underlying metabolic disorders and very seldom in normal individuals. We present a rare case of simultaneous bilateral fracture neck of femur in a 25-year-old man who came with complaints of pain in bilateral groin for 1 month. There was no history of trauma or history suggestive of excessive activity prior to the onset of pain, but there was history of lifting heavy weights daily. On evaluation with MRI scan bilateral fracture of the femur neck was diagnosed and patient was operated on bilaterally with internal fixation done using dynamic hip screw. Patient then regained his routine activity over a period of 6 months and on follow-up at 1 year no avascular necrosis changes were seen in the femur head. We presented this case because of its unusual presentation and the diagnostic challenge it poses.

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

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

Imaging of sports-related midfoot and forefoot injuries

Sports-related injuries of the foot are common and may result in significant morbidity, particularly if inaccurate or delayed diagnosis leads to improper management. While less common than injuries of the ankle, sports-related foot injuries account for 2% to 18% of athletic injuries. Injury may occur as a result of acute trauma or chronic overuse, and high-impact sports that involve running, jumping, or contact place the athlete at higher risk for injury. Accurate and timely diagnosis of injury is the key to proper management, and diagnostic imaging studies often play a critical role in this regard. While radiographs, computerized tomography scans, and ultrasound are useful in the evaluation of the foot, magnetic resonance imaging provides superior tissue contrast as well as the ability to detect stress reaction in bone that precedes discernible fracture line on radiographs, allowing accurate detection of both osseous and soft tissue pathology. This review focuses on imaging of common sports-related injuries of the midfoot and forefoot, including osseous, ligamentous, and tendinous pathology, with emphasis on magnetic resonance imaging diagnosis.

Sacral fatigue fracture in an amateur soccer player

Sacral fatigue fractures represent a frequently overlooked cause of low-back and buttock pain in athletes. A high index of clinical suspicion and MRI utilization can provide the accurate diagnosis. A 38-year-old male amateur, midfielder, soccer player presented to our department with aggravating right buttock pain during the previous month, following an increase in training intensity and frequency on an artificial turf field. A point of maximal tenderness was demonstrated over the area of the right sacroiliac joint. No radiographic abnormalities were observed. MRI of the pelvis revealed the presence of a stress fracture in the right sacral ala. The patient underwent conservative treatment and resumed playing soccer 12 weeks later, with no residual or recurrent clinical complaints. Apart from the recent change in training regimen, decreased shock absorption related to the physical properties of old generation artificial turf may have also been involved in this case.

Symptomatic Hallucal Interphalangeal Sesamoid Bones Successfully Treated with Ultrasound-guided Injection - A Case Report -

The hallucal interphalangeal sesamoid bone is usually asymptomatic, but it is not uncommon for it to be symptomatic in cases of undue pressure, overuse, or trauma. Even in symptomatic cases, however, patients often suffer for extended periods due to misdiagnosis, resulting in depression and anxiety that can steadily worsen to the extent that symptoms are sometimes mistaken for a somatoform disorder. Dynamic ultrasound-guided evaluations can be an effective means of detecting symptomatic sesamoid bones, and a simple injection of a small dose of local anesthetics mixed with steroids is an easily performed and effective treatment option in cases, for example, of tenosynovitis.

Subchondral impaction fractures of the non-weight-bearing portion of the lateral femoral condyle

OBJECTIVE

To document the first report of intra-articular, non-weight-bearing, impaction fractures of the lateral femoral condyle.

MATERIALS & METHODS

Institutional Review Board and Regional Ethics Committee approval for this study was obtained and patient informed consent deemed unnecessary. We prospectively documented all potential cases of non-weight-bearing posterior subchondral impaction fractures of the femoral condyles diagnosed on magnetic resonance imaging (MRI) of the knee performed at our institution between January 2006 and December 2011. The cases were reviewed and discussed by three experienced musculoskeletal radiologists and only cases satisfying pre-defined MRI criteria were included.

RESULTS

Sixteen cases of intra-articular impaction fractures in a posterior, non-weight-bearing area of the lateral femoral condyle were diagnosed in patients with a mean age of 40. Eight were associated with recreational sports activities and 4 with repeated kneeling. There were no fractures documented in the non-weight-bearing aspect of the medial femoral condyles. Proposed underlying mechanisms for development of this type of fracture are presented.

CONCLUSION

Awareness, along with a high level of suspicion, that non-specific knee pain, especially in patients involved in athletic activities, could be due to intra-articular impaction fractures of the non-weight-bearing posterior aspect of the lateral femoral condyle is essential and MRI is the mainstay of diagnosis.

Unusual supero-medial iliac fatigue stress fracture

Fatigue stress fractures are quite common in athletes, especially in women. They typically involve the lower extremities, but they have also been described in the pelvis and sacrum. Most of the time, they are radiographically occult at the beginning, and become visible only when the callus is detected. They are suspected owing to their clinical features, and investigated using magnetic resonance imaging (MRI) and computed tomography (CT). We present a case of unusual supero-medial iliac fatigue stress fracture in a 58-year-old amateur marathon runner woman presenting with a history of 1-month's worsening pain in the right buttock. Diagnosis was challenging. The early radiograph was normal, and the stress fracture was suspected by clinical features and MRI. Although the fracture was evident on the MRI, the findings were subtle and overlooked. The fracture was later confirmed by CT and radiograph, showing the reparative process.

ULTRASONOGRAPHY AS A DIAGNOSTIC MODALITY OF TIBIAL STRESS FRACTURES

Tibial stress fractures (SFs) are a common orthopedic problem during military basic training. Bone scan is considered the gold standard for diagnosing this condition. Several case reports have described sonographic features of stress fractures. This is a prospective, double-blind study to compare diagnostic ultrasound (US) examination with isotope bone scan in diagnosing SF. Thirty-one soldiers who were referred to the nuclear medicine service for a bone scan to rule out tibial SF participated in this study. The SF lesions of the lower extremities were classified according to the classification criteria introduced by Zwas et al.20 US examination was performed on the same day. Areas of cortical thickening and other pathologies like bone surface irregularity and bone discontinuity were recorded. Each examination was graded as either normal or suggestive of representing a SF. Thirty of 62 tibiae were diagnosed as having SF according to bone scan, whereas US examination suggested SF in 35 tibiae. US examination was positive in 20 of 30 tibiae with SF (67% sensitivity, 53% specificity). Although US correctly diagnosed SF in 20 tibiae, bone scan remains the chosen imaging modality to detect SF in soldiers. US was not found to be a reliable modality to diagnose SF.

Análise do impacto mecânico nas próteses de um sujeito bi-amputado durante a marcha

Observa-se o aumento do uso da acelerometria (medida de impactos) na aplicação clínica, especialmente para estudos da marcha acoplando-se os acelerômetros na tíbia. Entretanto, não se tem observado estudos sobre os efeitos dessas vibrações no sistema locomotor de usuários de prótese do membro inferior. O objetivo deste estudo foi medir a quantidade de impacto durante a marcha de um sujeito amputado bilateral transtibial. As coletas foram realizadas durante a marcha do sujeito caminhando a 4 km/h em uma distância de 8 metros com dois acelerômetros piezoelétricos uniaxiais fixados em dois locais distintos da prótese: inicialmente nos encaixes das próteses e posteriormente fixou-se nas hastes metálicas. Utilizou-se estatística descritiva exploratória com Anova One-Way e Post Hoc de Tukey. Constatou-se diferenças significativas com o teste Anova One-Way entre as 10 aquisições em cada local de fixação do acelerômetro. Através do Post Hoc de Tukey observou-se maiores picos de aceleração no encaixe esquerdo (p < 0,005), indicando uma maior admissão de impacto pelo coto esquerdo que possuía maior comprimento. Os maiores picos de aceleração médio encontrados durante a marcha foram: 3,57g para a prótese direita com o acelerômetro fixado na haste metálica e 5,70g para a prótese esquerda com a fixação no encaixe da prótese. Conclui-se que esta metodologia de avaliação pode ser utilizada para acompanhar o processo de reabilitação protética de sujeitos com amputação de membro inferior.

The classification systems of stress fractures: a systematic review

BACKGROUND

Stress fractures of the upper and lower extremity are troublesome overuse injuries in athletes and nonathletes alike. These injuries have a broad spectrum of severity and prognosis. We performed a systematic search of the literature, which revealed multiple classification systems; however, we did not uncover a general system that offered both validated radiographic and clinical parameters.

METHODS

A literature search was conducted using Ovid/Medline, Embase, and the Cochrane Library, with publication dates ranging from 1960 to December 2009. Inclusion criteria included all studies and review articles regarding stress or fatigue fractures and their classification.

RESULTS

Forty-three studies and/or articles were identified for this review. Of these articles, 27 classification systems were referenced. Sixteen of the systems were applicable to any injury location, and 1 applied to specific bones (femoral neck, tibia, tarsal navicular, pars interarticularis, and fifth metatarsal). Four classification systems were referenced more often than others. Of the classification systems, 11 were based on radiographs alone, while the other 16 used a variety of radiographic modalities, including radiographs, bone scans, computed tomography, ultrasound, and magnetic resonance imaging.

CONCLUSION

There are many different stress fracture classification systems in the literature. These systems employ various imaging modalities, but few include clinical parameters. Many are site specific. Of those that are widely applicable, no general classification system has been shown to be reproducible, easily accessible, safe, inexpensive, and clinically relevant. A gold standard classification system for describing stress fractures has yet to be determined.

Post-operative stress fractures complicating surgery for painful forefoot conditions

A stress fracture is caused by repetitive or unusual loading of a bone leading to mechanical failure. Fatigue type stress fractures occur in normal bone exposed to abnormally high repetitive loads, whereas insufficiency type stress fractures occur in abnormal bone exposed to normal loads. We describe three cases of insufficiency stress fractures that have complicated surgery for painful forefoot conditions. The diagnosis and management of these cases are discussed. Stress fractures should be included in the differential diagnosis of any patient who continues or develops pain after surgery to the forefoot.

Imaging in sports medicine: an overview

Increasing sports participation, and the inevitable sports injury, is a significant contributor to total healthcare expenditure in the United States. With sports-related injury ever increasing, and technology rapidly expanding in the areas of diagnosis and treatment of musculoskeletal trauma, a continual revisiting of the latest in technology is critical for the sports physician. Advances particularly in the areas of magnetic resonance imaging, diagnostic office ultrasound, and 3-dimensional reconstruction computed tomography, offer the clinician a myriad of diagnostic options in patient evaluation. Care must be exercised, however, as one pursues additional radiographic data in the patient care arena. The information must be interpreted with a firm foundation and understanding of not only the patient history and physical examination, but also the availability, indications, contraindications, sensitivity, specificity, and even the cost implications of the great spectrum of diagnostic options.

Imaging of painful conditions of the hallucal sesamoid complex and plantar capsular structures of the first metatarsophalangeal joint

Numerous injuries and pathologic conditions can involve the hallucal sesamoidal complex and plantar capsular structures of the first metatarsophalangeal joint. Although clinical history and presentation are important in developing a reasonable differential diagnosis, there is often considerable overlap in the clinical presentation and physical findings between various pathologic entities. Imaging plays an important role in narrowing the differential diagnosis and in directing appropriate therapy. This article reviews the normal anatomy of the hallucal sesamoidal complex and the plantar capsular structures of the first metatarsophalangeal joint. Typical clinical presentations are discussed for various pathologic entities that involve this area of the hallux, followed by a summary of the various imaging findings that occur when using conventional radiography, nuclear medicine bone scan, CT and MR imaging. Finally, general treatment guidelines are discussed for each entity.

Stress fractures of the second metatarsal base occur in nondancers

Stress fractures of the base of the second metatarsal are common in ballet dancers and essentially are unreported in nondancers. We presumed base of the second metatarsal stress fractures in nondancers occur in a wide variety of individuals regardless of demographics, are highly associated with athletic activities, and have specific examination findings and poor clinical outcomes. Using a retrospective chart review, we identified 12 stress fractures at the base of the second metatarsal (nine patients) in nondancers. Our review suggests second metatarsal base stress fractures occur in nondancers in a diverse population, and nonoperative treatment provides limited success. Advanced radiographic study, specifically MRI, is useful to assist the early diagnosis and prognostication. All of the stress fractures were treated nonoperatively; six fractures (50%) developed nonunion and five underwent subsequent surgery. The surgery for nonunion provided successful outcomes; however, risk factors such as low bone mass and comorbidities may have played important roles in the prognosis.