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

Fracture sonography - Literature review and current recommendations

PURPOSE

Over the course of more than two years, an expert group of 9 professional societies has created the S2e guidelines for fracture sonography. This publication summarizes the key points regarding the individual indications.

MATERIALS AND METHODS

A systematic literature search was performed in PubMed, Google Scholar, and the Cochrane Database of Systematic Reviews from 2000 to March 2021 with evaluation of the literature lists. Randomized controlled clinical trials, observational clinical trials, meta-analyses, and systematic reviews were included. Guidelines, conferences, reviews, case reports, and expert opinions were excluded. Evidence was graded using the SIGN grading system 1999-2012, and the SIGN tables were then presented to the expert group. These were used to develop specific recommendations for the use of fracture sonography. All recommendations were discussed in detail and finally unanimously agreed upon.

RESULTS

Of the 520 primary literature sources found, 182 sources (146 clinical studies and 36 meta-analyses and systematic reviews) were evaluated after screening and content assessment. 21 indications that allow reasonable application of fracture sonography were identified.

CONCLUSION

Ultrasound is a sensible, easy-to-use diagnostic method that is feasible for a large number of indications.

Fractures in Thoroughbred racing and the potential for pre-race identification of horses at risk

Risk rates for and predisposing factors to fractures occurring in Thoroughbred racing that have been published in peer reviewed journals are documented. The potential for currently available techniques to identify horses at increased risk for fracture is discussed on the bases of principles, practicalities, advantages, disadvantages and current data. All are reviewed in light of justifiable decision making and importance of fractures to horseracing's social license.

Unusual Presentation of Hip Pain in a Pregnant Woman Due to Bilateral Cervical Neck Stress Fractures: A Case Report

CASE

We present an unusual case of bilateral femoral neck fatigue fractures in a 28-year-old pregnant woman at the 18th week of gestation successfully treated through operative intervention involving consecutive total hip arthroplasty and internal fixation within the same procedure, resulting in favorable clinical outcomes.

CONCLUSION

Current clinical practices suggest that a restricted use of plain radiographs, even those involving the pelvis in pregnant women carries a minimal risk to the fetus and is not contraindicated. Magnetic resonance imaging proved valuable for differential diagnosis, contrasting with sonography.

Exploring pre-MRI imaging tests: patient survey reveals potential implications for healthcare efficiency in Israel

BACKGROUND

Medical imaging tests are vital in healthcare but can be costly, impacting national health expenditures. Magnetic resonance imaging (MRI) is a crucial diagnostic tool for assessing medical conditions. However, the rising demand for MRI scans has frequently strained available resources. This study aimed to estimate the prevalence of different imaging tests in individuals who eventually had an MRI, in the Israeli public health system.

METHODS

An online survey of patient experience of scheduling an MRI was conducted in January-February 2023, among 557 Israeli adults, representing all four health maintenance organizations (HMOs). All participants had undergone an MRI in the public health system within the past year.

RESULTS

Results showed that 60% of participants underwent other imaging tests before their MRI scan. Of those, computed tomography (CT) scans (43%), X-rays (39%), and ultrasounds (32%) were the most common additional imaging procedures. In addition, of the 60% of participants, 23% had undergone more than one prior imaging examination.

CONCLUSIONS

These findings highlight the high prevalence of preliminary imaging tests prior to MRI, with many patients undergoing multiple tests for the same problem. The health system may need to evaluate whether current clinical guidelines defining the use of various imaging tests are cost-effective.

Stress fractures of the foot - current evidence on management

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

Serial Ultrasonography for the Assessment of Healing of Lower Extremity Bone Stress Injury and Correlation With Return to Sport/Exercise

BACKGROUND

Lower extremity bone stress injuries (BSIs) are common among athletes who participate in high-impact activities. Conventional imaging is limited in assessing healing of BSIs.

HYPOTHESIS

Serial ultrasonography (US) can identify changes in appearance of lower extremity BSIs over time that can be correlated with symptoms and return to exercise/sport.

STUDY DESIGN

Cohort observational study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Adults 18 to 50 years old with a recent exercise-associated BSI of distal tibia/fibula or metatarsals diagnosed by magnetic resonance imaging (MRI) were enrolled. US was performed every 2 weeks for 12 weeks. The sonographic appearance (soft tissue edema, periosteal reaction, hyperemia on power Doppler, callus) was correlated with the numerical rating scale (NRS) for pain and ability to return to sport/exercise.

RESULTS

A total of 30 patients were enrolled (mean age, 35.3 ± 7.7 years; 21 [70.0%] female). The tibia was most frequently affected (n = 15, 50.0%), followed by metatarsals (n = 14, 46.7%) and fibula (n = 1, 3.3%). At week 4, 25 of 30 (83.3%) had at least 1 US finding associated with the BSI. The degree of hyperemia was correlated with NRS at weeks 4 and 6 (Spearman correlations [ρ] 0.45 [0.09, 0.69] and 0.42 [0.07, 0.67], respectively), as well as return to sport/exercise at week 6 (ρ -0.45 [-0.68, -0.09]). US soft tissue edema was also correlated with NRS at week 6 (ρ 0.38 [0.02, 0.65]).

CONCLUSION

Serial US of lower extremity BSIs can provide objective measures of healing. US findings were correlated with clinical outcomes at multiple timepoints.

CLINICAL RELEVANCE

US may have advantages over conventional imaging for monitoring healing of lower extremity BSIs. Further research is needed to better understand the prognostic value of these sonographic indicators of BSI healing and role in assessing readiness for return to sport/exercise.

Atraumatic Bilateral Patella Fracture in Middle-Aged Female: A Rare Case Report

The patella is the largest sesamoid bone in the body and an important structure of the extensor apparatus which is under undue stress during flexion and extension of the knee. Bilateral fracture of the patella without trauma is a very rare event and may be multifactorial without a single cause. A repetitive stress reaction in a previously predisposed bone can be an important cause. We report a case of a 45-year-old female with a nontraumatic bilateral transverse patella fracture with loss of extensor mechanism. A stable surgical fixation for such a displaced fracture with a good rehabilitation program can lead to a good functional outcome.

[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.

[Contemporary imaging examinations for (suspected) stress fractures]

Stress fractures belong to the group of atraumatic fractures. A low-impact and repetitive load is the underlying cause and no fracture would occur under physiological circumstances. The conventional X‑ray examination remains the initial imaging modality when a stress fracture is suspected. In contrast, magnetic resonance imaging (MRI) is the gold standard and is also used to rule out other pathological changes. Computed tomography (CT) should be included if the MRI findings are unclear. New techniques, such as dual energy computed tomography (DECT) and magnetic resonance bone imaging (MR bone) should be used more frequently in practice in the future and become increasingly more important for the correct diagnosis.

Infrared Thermography-A Novel Tool for Monitoring Fracture Healing: A Critically Appraised Topic With Evidence-Based Recommendations for Clinical Practice

CLINICAL SCENARIO

Stress fractures are one of the most common injuries in athletes. Unfortunately, they are hard to diagnose, require multiple radiology exams and follow-up which leads to more exposure to radiation and an increase in cost. Stress fractures that are mismanaged can lead to serious complications and poorer outcomes for the athlete. During the rehabilitation process, it would be beneficial to be able to monitor the healing of fractures to know when it is safe to gradually allow a patient to a return to sport because the return to activity is not usually objective and based on pain level.

CLINICAL QUESTION

Can infrared thermography (IRT) be a useful tool to measure the pathophysiological state of the fracture healing? The aim of this critically appraised topic is to analyze the current evidence of IRT for measuring the temperature change in fractures to provide recommendations for medical practitioners.

SUMMARY OF KEY FINDINGS

For this critically appraised topic, we examined 3 articles that compared medical imaging and IRT over multiple time points during the follow-up. The 3 articles concluded that a 1 °C asymmetry in temperature followed by a return to normal (less than 0.3 °C) temperature during the healing process of fractures can be monitored using IRT.

CLINICAL BOTTOM LINE

Once the patient has been diagnosed with a fracture, IRT can safely be used to monitor the evolution of a fracture. When the thermogram progresses from a hot thermogram to a cold thermogram, the healing is considered good enough to return to sport.

STRENGTH OF RECOMMENDATION

Grade 2 evidence exists to support IRT being used by clinicians to monitor fracture healing. Due to the limited research and novelty of the technology, the current recommendations are for following the treatment of the fracture once the initial diagnosis is made.

Emerging role of bone scintigraphy single-photon emission computed tomography/computed tomography in foot pain management

Foot and ankle joints being weight-bearing joints are commonly subjected to wear and tear and are prone to traumatic and other pathologies. Most of these foot and ankle pathologies present with pain. The diagnosis of pathology and localization of pain generators is difficult owing to the complex anatomy of the foot and similar clinical presentation. This makes the management of foot pain clinically challenging. Conventional anatomical imaging modalities are commonly employed for evaluation of any anatomical defect; however, these modalities often fail to describe the functional significance of the anatomical lesions, especially in presence of multiple lesions which is common in ankle and foot; however, hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) by virtue of its dual modalities, that is, highly sensitive functional imaging and highly specific anatomical imaging can serve as a problem-solving tool in patient management. This review attempts to describe the role of hybrid SPECT/CT in overcoming the limitation of conventional imaging and describes its potential application in the management of foot and ankle pain.

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.

[Stress reactions and stress fractures]

Bone stress injuries is an umbrella term that encompasses repetitive microtraumatic events that accumulate to surpass the threshold of bone failure, which can range from bone marrow edema to frank stress fracture as the end point. Due to nonspecific clinical complaints and physical findings, imaging plays a central role in the diagnostic workup of these entities. Magnetic resonance imaging (MRI) is the most important imaging modality with a high sensitivity and specificity and allows for differential diagnosis of other diseases. Edema-sensitive with fat suppression and T1-weighted sequences are the core sequence types, and contrast-enhanced imaging-albeit displaying subtle fractures much more easily-is rarely necessary. Furthermore, MRI enables differentiation of injury severity, which has an impact on length of rehabilitation, therapeutic regimen, and the time to return to sports in athletes.

The Presence of Hip Joint Effusion on MRI Is Predictive of a Grade 4 Femoral Neck Stress Injury

INTRODUCTION

One of the most debilitating types of bone stress injuries is those occurring at the femoral neck. This problem occurs in the military population with much higher incidence than in the normal population and is of great concern to military medical providers. Early detection and accurate diagnosis are key in protecting soldiers and recruits from sustaining a potentially career-ending fracture. In a case study, a 16-year-old elite male distance runner presented with hip pain. MRI found hip joint effusion but was unremarkable for marrow edema and a low-signal fracture line. The initial diagnosis was acute arthritis; however, a follow-up radiograph 1 month later, after the patient had been refraining from running, confirmed a significant non-displaced compression-side Grade 4 femoral neck stress injury (FNSI). In light of the case study and our similar clinical experience, we tested the hypothesis that an MRI study positive for an FNSI, combined with the evidence of a hip joint effusion, is indicative of a Grade 4 FNSI, even without visualization of a low-signal intensity fracture line on T1 or short tau inversion recovery images.

MATERIALS AND METHODS

Recruits in Army Basic Combat Training were included in the investigation if 1) diagnosed with a unilateral FNSI, 2) had an initial positive MRI for an FNSI, 3) had a positive bone scan for uptake in the femoral neck area (to validate the diagnosis), 4) had no other hip/pelvis injuries, and 5) had a follow-up MRI within 60 days. Hip joint effusion was defined as 1) ≥2-mm measurable difference in the thickness of fluid along the length of the involved femoral neck when compared to the contralateral uninvolved femoral neck on the initial MRI; 2) visibly assessed as a prominent collection of fluid distending the posterior hip joint capsule on the initial MRI coronal short tau inversion recovery sequence (called the "flash sign").

RESULTS

A total of 162 recruits met the study inclusion criteria. For the detection of a Grade 4 FNSI on the first MRI, the sensitivity, specificity, and positive predictive value of the measured joint effusion criteria were 0.52, 0.94, and 0.89, respectively. or the non-measured flash sign, these values were 0.70, 0.83, and 0.80, respectively.

CONCLUSIONS

Both the measured hip joint effusion criteria and the non-measured flash sign were predictive of a Grade 4 FNSI and may be useful in clinical evaluation.

Extent of bone marrow edema on dual-energy CT aids in differentiation of acute from post-acute fractures of lower legs

OBJECTIVES

Bone marrow edema (BME) from dual-energy CT is useful to direct attention to radiographically occult fractures. The aim was to characterize utility of BME of lower extremity (LE) fractures with the hypothesis that stabilized and post-acute fractures exhibit decreased extent and frequency of BME than non-stabilized and acute fractures, respectively.

METHODS

An IRB-approved retrospective review of known LE fractures. A total of 141 cases met inclusion criteria, including 82 fractures without splint/cast stabilization, and 59 cases with stabilization. Two readers independently recorded BME, and its multiplicity and area (mm²). A separate reader assessed fracture location, comminution, and chronicity. Wilcoxon rank sum test, multiple regression, intraclass correlation (ICC), kappa statistics, and chi-square tests were used.

RESULTS

BME was significantly larger in non-stabilized (859.3 mm² (420.6-1451.8)) than stabilized fractures (493.5 mm² (288.8-883.2)), p = .011). Comminuted (p = 0.006), non-stabilized (p = 0.0004), and acute fractures (p = 0.036) were all associated with larger BME area. BME presence had excellent results for both stabilized (Cohen's Kappa = 0.81) and non-stabilized fractures (Cohen's Kappa = 0.84). ICC for BME area showed excellent correlation for both stabilized (ICC = 0.78) and non-stabilized groups (ICC = 0.86). BME multiplicity showed excellent agreement for stabilized (ICC = 0.81) and good agreement for non-stabilized (ICC = 0.67) fractures. Lastly, stabilized cases showed increased multiplicity of BME compared to non-stabilized fractures (p < 0.001).

CONCLUSIONS

BME evaluation can assist in differentiation of acute versus post-acute fractures. Extent of BME is reduced with splint/cast stabilization, which may limit its accuracy in detection of lower extremity fractures.

KEY POINTS

• Evaluation of bone marrow edema on dual-energy CT aids in differentiation of acute versus post-acute fracture. • Bone marrow edema evaluation is limited in the setting of post-acute or stabilized fractures. • There is decreased frequency and extent of bone marrow edema in post-acute, non-comminuted, and stabilized fractures.

How Advancement in Bone Science Should Inform the Examination and Treatment of Femoral Shaft Bone Stress Injuries in Running Athletes

Stress fractures likely have a 1-2% incidence in athletes in general. In runners, a more vulnerable population, incidence rates likely range between 3.2 and 21% with female runners having greater susceptibility. The incidence of femoral shaft stress fractures is less well known. New basic and translational science research may impact the way clinicians diagnose and treat femoral stress fractures. By using a fictitious case study, this paper applies bone science to suggest new approaches to evaluating and treating femoral shaft stress fractures in the running population.

Near-maximum rib dose is the most relevant risk factor for ipsilateral spontaneous rib fracture: a dosimetric analysis of breast cancer patients after radiotherapy

PURPOSE

Spontaneous rib fracture (SRF) is a common late complication in treated breast cancer patients. This study evaluated the incidence and risk factors of ipsilateral SRF after radiotherapy (RT) in breast cancer patients. In addition, we identified dosimetric parameters that were significantly associated with ipsilateral SRF.

METHODS

We retrospectively reviewed 2204 patients with breast cancer who underwent RT between 2014 and 2016, and were followed up with bone scans. We evaluated clinical risk factors for ipsilateral SRF. Dose-volume histogram analysis was also performed for patients (n = 538) whose dosimetric data were available. All ipsilateral ribs were manually delineated, and dosimetric parameters of the ribs were converted into the equivalent dose in 2 Gy fractions (EQD2).

RESULTS

Most of the patients with SRF (87.3%) were asymptomatic, and the remaining symptomatic patients complained of mild tenderness or chest wall discomfort; these symptoms all resolved within 6 months without any treatment. Ipsilateral SRF occurred in 14.5% of patients 3 years after RT. The median time to develop ipsilateral SRF was 15 months. In dosimetric analysis, near-maximum rib dose (D2cc) best predicted ipsilateral SRF. The cut-off value of D2cc was EQD2 52 Gy, as determined by receiver operating characteristic analysis. In multivariate analysis including dosimetric variables, D2cc EQD2 ≥ 52 Gy was the only significant risk factor for ipsilateral SRF.

CONCLUSION

Our data demonstrated that near-maximum rib dose was the best dosimetric parameter to predict ipsilateral SRF in RT-treated breast cancer patients. In addition, our results suggest that patients who received RT with exceeding rib dose cut-off value and had ipsilateral SRF on bone scan be recommended routine follow-up without additional imaging tests.

Isolated bilateral fibular insufficiency fractures: Case report of an unusual entity

Insufficiency fractures are a type of stress fractures that occur due to physiological stress on weakened bones. These have certain sites of predilection of which an uncommon site is fibular shaft. Isolated bilateral fibular fractures have previously only been reported twice, where the causes were repeated trauma and fatigue fracture. Insufficiency fractures of both fibula in isolation have not previously been reported. We present this case where a young patient presented with these fractures and was found to have vitamin D deficiency on subsequent investigations.

Comparison of Ultrasonography to MRI in the Diagnosis of Lower Extremity Bone Stress Injuries: A Prospective Cohort Study

OBJECTIVE

To determine the sensitivity and specificity of ultrasound imaging (USI) compared to the reference-standard of MRI in the diagnosis of bone stress injury (BSI).

METHODS

A prospective blinded cohort study was conducted. Thirty seven patients who presented to an academic sports medicine clinic from 2016 to 2020 with suspected lower-extremity BSI on clinical exam underwent both magnetic resonance imaging (MRI) and USI. Participant characteristics were collected including age, gender and sport. Exclusion criteria included contraindication for dedicated MRI, traumatic fracture, or severe tendon or ligamentous injury. The primary outcome measure was BSI diagnosis by USI. An 8-point assessment system was utilized on USI for diagnosis of BSI, and the Fredericson and Nattiv²² criteria were applied to classify MRI findings.

RESULTS

Thirty seven participants who met study criteria were consented to participate. All participants completed baseline measures. Using MRI, there were 30 (81%) athletes with a positive and seven participants with a negative BSI diagnosis. The most common BSIs in the study were in the metatarsal (54%) and tibia (32%). Compared to MRI, USI demonstrated 0.80 sensitivity (95% confidence interval [CI], 0.61-0.92) and 0.71 specificity (95% CI, 0.29-0.96) in detecting BSI, with a positive predictive value of 0.92 (95% CI, 0.75-0.99) and negative predictive value of 0.45 (95% CI, 0.17-0.77).

CONCLUSIONS

USI is a potentially useful point-of-care tool for practicing sports medicine providers to combine with their clinical evaluation in the diagnosis of BSIs. Further research is ongoing to determine the role of USI in follow-up care and return-to-play protocols.

Prospective Assessment of Clinical Tests Used to Evaluate Tibial Stress Fracture

Background:

Tibial stress fracture (SFx) is the most common SFx of the lower extremity. Presently, diagnostic accuracy of clinical examination techniques for tibial SFx remains suboptimal.

Purpose:

To assess the diagnostic effectiveness of 5 clinical tests for tibial SFx individually versus a test item cluster.

Study Design:

Cohort study (diagnosis); Level of evidence, 3.

Methods:

A total of 50 patients with tibial pain (17 with bilateral symptoms) were assessed with 5 clinical examination tests (tibial fulcrum test, focal tenderness to palpation, heel percussion test, therapeutic ultrasound test, and 128-Hz tuning fork test) before they underwent diagnostic imaging (radionuclide bone scan). The application of the clinical tests was counterbalanced to minimize the likelihood of carryover effects. Patients provided a pain rating immediately before and after the application of each clinical test.

Results:

The prevalence of tibial SFx among the study participants was 52.2%. High levels of specificity were produced by the therapeutic ultrasound test (93.8%), tuning fork test (90.6%), and percussion test (90.6%). The fulcrum test had moderate to high specificity (84.4%). All tests demonstrated low levels of sensitivity, with the highest levels found for focal tenderness to palpation (48.6%) and fulcrum (45.7%). The fulcrum test provided the highest positive likelihood ratio (2.93), followed by the therapeutic ultrasound test (2.30). The fulcrum test had the lowest negative likelihood ratio (0.64), with the focal tenderness to palpation and tuning fork tests having negative likelihood ratios >1.0. Combinations of these clinical tests did not improve the prediction of tibial SFx above that observed among the individual tests.

Conclusion:

The clinical tests evaluated were generally highly specific, but all had low sensitivity. The fulcrum test provided the highest level of diagnostic accuracy; however, it was inadequate for definitive clinical management. Combining tests did not improve the diagnostic accuracy of tibial SFx.

Retrospective Review of Radiographic Imaging of Tibial Bony Stress Injuries in Adolescent Athletes With Positive MRI Findings: A Comparative Study

BACKGROUND

It is difficult to diagnose and grade bony stress injury (BSI) in the athletic adolescent population without advanced imaging. Radiographs are recommended as a first imaging modality, but have limited sensitivity and, even when findings are present, advanced imaging is often recommended.

HYPOTHESIS

It was hypothesized that the significance of radiographs is underestimated for BSI in the adolescent with positive clinical examination and history findings.

STUDY DESIGN

Case series.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 80 adolescent athletes with a history of shin pain underwent clinical examination by an orthopaedic surgeon. On the day of clinical examination, full-length bilateral tibial radiographs and magnetic resonance imaging (MRI) scans were obtained. MRI scans were reviewed using Fredericson grading for BSI. At the completion of the study, radiographic images were re-evaluated by 2 musculoskeletal (MSK) radiologists, blinded to MRI and clinical examination results, who reviewed the radiographs for evidence of BSI. Radiographic results were compared with clinical examination and MRI findings. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated based on comparison with MRI.

RESULTS

All radiographs were originally read as normal. Of the tibia studied, 80% (127 of 160) showed evidence of BSI on MRI. None of the original radiographs demonstrated a fracture line on initial review by the orthopaedic surgeons. Retrospective review by 2 MSK radiologists identified 27% of radiographs (34 of 127) with evidence of abnormality, which correlated with clinical examination and significant findings on MRI. Review of radiographs found evidence of new bone on 0 of 28 Fredericson grade 0, 0 of 19 Fredericson grade I, 11 of 80 (13.7%) Fredericson grade II, 18 of 28 (64%) Fredericson grade III, and 5 of 5 (100%) Fredericson grade IV. Sensitivity of radiographs showed evidence of new bone on 27% (34 of 127) of initial radiographs, with presence more common with greater degree of BSI, as 23 of 33 (70%) were higher-grade injuries (III of IV) of BSI. Specificity and positive predictive value were 100%, while negative predictive value was 17%.

CONCLUSION

These findings highlight the importance of initial radiographs in identifying high-grade BSI. As radiographs are readily available in most office settings of sports medicine physicians, this information can influence the management of adolescent athletic BSI without the need to delay treatment to obtain an MRI.

CLINICAL RELEVANCE

Adolescent athletes with radiographic evidence of BSI should be treated in a timely and more conservative manner, given the likelihood of higher-grade BSI. In addition, clinicians knowledgeable of the radiographic findings of high-grade BSI should feel more confident that a negative initial radiograph is not likely to be a high-grade BSI and can modify their treatment plans accordingly.

Characterizing and quantifying low-value diagnostic imaging internationally: a scoping review

BACKGROUND

Inappropriate and wasteful use of health care resources is a common problem, constituting 10-34% of health services spending in the western world. Even though diagnostic imaging is vital for identifying correct diagnoses and administrating the right treatment, low-value imaging-in which the diagnostic test confers little to no clinical benefit-is common and contributes to inappropriate and wasteful use of health care resources. There is a lack of knowledge on the types and extent of low-value imaging. Accordingly, the objective of this study was to identify, characterize, and quantify the extent of low-value diagnostic imaging examinations for adults and children.

METHODS

A scoping review of the published literature was performed. Medline-Ovid, Embase-Ovid, Scopus, and Cochrane Library were searched for studies published from 2010 to September 2020. The search strategy was built from medical subject headings (Mesh) for Diagnostic imaging/Radiology OR Health service misuse/Medical overuse OR Procedures and Techniques Utilization/Facilities and Services Utilization. Articles in English, German, Dutch, Swedish, Danish, or Norwegian were included.

RESULTS

A total of 39,986 records were identified and, of these, 370 studies were included in the final synthesis. Eighty-four low-value imaging examinations were identified. Imaging of atraumatic pain, routine imaging in minor head injury, trauma, thrombosis, urolithiasis, after thoracic interventions, fracture follow-up and cancer staging/follow-up were the most frequently identified low-value imaging examinations. The proportion of low-value imaging varied between 2 and 100% inappropriate or unnecessary examinations.

CONCLUSIONS

A comprehensive list of identified low-value radiological examinations for both adults and children are presented. Future research should focus on reasons for low-value imaging utilization and interventions to reduce the use of low-value imaging internationally.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020208072.

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

BACKGROUND

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

PURPOSE

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

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

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

RESULTS

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

CONCLUSION

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

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies

The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice.

[Fracture sonography of the extremities]

In this article the basic principles of fracture sonography and meaningful areas of application in children and adults are explained. The sonographic fracture signs are presented and the typical areas of application, i.e. clavicular fracture, acromioclavicular (AC) joint dislocation, proximal humerus fracture, elbow fracture, wrist fracture, metacarpal 5 fracture, palmar plate, femoral bulge fracture, proximal tibia fracture, midfoot V fracture, toddler's fracture and march fracture, are outlined and known diagnostic algorithms are listed. When used correctly, fracture sonography is a safe, gentle and rapid diagnostic method.

Sacral stress fractures in athletes

PURPOSE

Fatigue stress fractures are a common overuse injury, frequently associated with high load-bearing endurance activities such as running, military training and aerobic exercise. While these fractures can arise at any site, sacral stress fractures are poorly studied with evidence consisting mainly of case reports and limited case series. This review aims to analyze and summarize all reports published to date describing cases of sacral stress fracture in athletes.

METHODS

PubMed, Embase, Web of Science and the Cochrane Database were systematically searched for studies reporting on Stress Fractures of the Sacrum. Insufficiency fractures of the elderly were excluded.

RESULTS

The literature review revealed 49 studies reporting on 124 cases of sacral stress fractures. Seventy-six patients (61%) were professional or collegiate level athletes, and 37 (30%) were military recruits or police officers in training. Seventeen female athletes were identified as suffering from low bone mineral density (25%), 9 of which reported menstrual irregularities. Thirteen female patients (19%) had a history of eating disorders.

CONCLUSION

While most sacral stress fractures occur in normal bones exposed to abnormal repetitive loads, the high percentage of lower bone mineral density can blur the lines between fatigue fractures and insufficiency fractures. The causes of these fractures are multifactorial. High endurance sports and the features of the female athlete triad were found in high percentage of the cases. Conservative treatment is the mainstay of treatment, consisting of ceasing of training and a period of rehabilitation and gradual return to training and competition.

Preliminary image findings of lower limb stress fractures to aid ultrasonographic diagnoses: A systematic review and narrative synthesis

INTRODUCTION

This systematic review investigates which image appearances are most common when diagnosing lower limb stress fractures using ultrasound imaging, with the aim of outlining an image critique guideline for operators to support confident diagnoses.

METHOD

A comprehensive literature search of medical databases and handsearching was undertaken to identify relevant studies. All studies were critically examined for quality using the CASP critical appraisal tool. Results from eight studies were combined and interpreted using a narrative synthesis.

FINDINGS

A clear outline of common stress fracture appearances using ultrasound were identified in a combined total of 119 participants. Each finding was ranked according to its popularity. Periosteal thickening (78/119) and cortical disruption/irregularity (83/119) were noted in all eight studies. Hypervascularity of the periosteum visualised by colour Doppler imaging (66/119) was reported in six of the eight studies. Soft tissue hypervascularity (13/119), bony callus formation (5/119) and cortical break (22/119) were seen in three studies.

CONCLUSIONS

Based on the findings, we offer a guideline of the most significant preliminary image findings to be utilised by operators when examining athletes suspected of having lower limb stress fractures. The results show a gap in research for evaluating changes in appearance depending on the injury severity. Further research into distinguishing stress fractures from pathological involvement may in future reduce reliance on plain film radiography.

Dual-Energy CT to Diagnose Occult Femoral Neck Fracture in MRI-Contraindicated Patient: A Case Report

CASE

A 79-year-old woman presented after a ground level fall with the inability to bear weight on her right hip. Radiographs and computed tomography (CT) imaging were negative for a femoral neck fracture. Her medical comorbidities precluded magnetic resonance imaging (MRI), so dual-energy CT with focused evaluation for bone edema was performed, identifying a femoral neck fracture that was stabilized surgically.

CONCLUSION

Dual-energy CT with processing for edema can successfully identify nondisplaced femoral neck fractures in MRI-contraindicated patients. This imaging modality could be useful for diagnosing femoral neck stress fractures and ipsilateral femoral neck fractures in patients sustaining high-energy femoral shaft fractures.

Teriparatide and stress fracture healing in young adults (RETURN - Research on Efficacy of Teriparatide Use in the Return of recruits to Normal duty): study protocol for a randomised controlled trial

Background

Stress fractures are a common and potentially debilitating overuse injury to bone and occur frequently among military recruits and athletes. Recovery from a lower body stress fracture typically requires several weeks of physical rehabilitation. Teriparatide, a recombinant form of the bioactive portion of parathyroid hormone (1–34 amino acids), is used to treat osteoporosis, prevent osteoporotic fractures, and enhance fracture healing due to its net anabolic effect on bone. The study aim is to investigate the effect of teriparatide on stress fracture healing in young, otherwise healthy adults undergoing military training.

Methods

In a two-arm, parallel, prospective, randomised controlled, intention-to-treat trial, Army recruits (n = 136 men and women, 18–40 years) with a magnetic resonance imaging (MRI) diagnosed lower body stress fracture (pelvic girdle, sacrum, coccyx, or lower limb) will be randomised to receive either usual Army standard care, or teriparatide and usual Army standard care. Teriparatide will be self-administered by subcutaneous injections (20 μg/day) for 16 weeks, continuing to 24 weeks where a fracture remains unhealed at week 16. The primary outcome will be the improvement in radiological healing by two grades or more, or reduction to grade zero, 8 weeks after randomisation, assessed using Fredericson grading of MRI by radiologists blind to the randomisation. Secondary outcomes will be time to radiological healing, assessed by MRI at 8, 10, 12, 14, 16, 20 and 24 weeks, until healed; time to clinical healing, assessed using a clinical severity score of injury signs and symptoms; time to discharge from Army physical rehabilitation; pain, assessed by visual analogue scale; health-related quality of life, using the Short Form (36) Health Survey; and adverse events. Exploratory outcomes will include blood and urine biochemistry; bone density and morphology assessed using dual-energy X-ray absorptiometry, peripheral quantitative computed tomography (pQCT), and high-resolution pQCT; physical activity measured using accelerometers; and long-term future fracture rate.

Discussion

This study will evaluate whether teriparatide, in addition to standard care, is more effective for stress fracture healing than standard care alone in Army recruits who have sustained a lower body stress fracture.

Trial registration

ClinicalTrials.govNCT04196855. Registered on 12 December 2019.

Radiography Versus Sonography in the Detection of Acute Fractures: A Case Series

Plain radiography is often considered a first-line diagnostic tool and gold standard for bony fractures. This case series and brief literature review highlight the need for increased training in musculoskeletal sonography. A case is presented of a distal radial fracture that was not detected on radiography but diagnosed with sonography on the same day. Similarly, two fractures of the distal fibula were diagnosed using sonography after negative radiographs at follow-up appointments, led to misdiagnoses and mismanagement. A fourth case is presented to show an acute rib fracture diagnosed by sonography. These cases emphasize the importance of musculoskeletal sonography training in the diagnosis of acute fractures and its underutilization at the bedside. Collaboration between sonographers and physicians may increase utilization of musculoskeletal sonography which in turn may improve patient care and outcomes.

Atraumatic fractures of the femur

Atraumatic fractures of femur, although not as common as traumatic fractures, are frequently encountered in the clinical practice. They present with non-specific symptoms and can be occult on initial imaging making their diagnosis difficult, sometimes resulting in complications. Overlapping terminologies used to describe these fractures may hamper effective communication between the radiologist and the clinician. In this article, we review various atraumatic fractures of femur, terminologies used to describe them, their imaging findings and differential diagnosis. The article also describes the aetiology, pathophysiology and relevant biomechanics behind these fractures. An approach to atraumatic femoral fractures has been outlined.

Ulnar shaft stress fractures in fast-pitch softball pitchers: a case series and proposed mechanism of injury

BACKGROUND

Stress fractures of the upper extremities in athletes are important injuries for radiologists to appreciate despite being far less common than stress fractures of the lower extremities. Among upper extremity stress fractures, those involving the olecranon have been well described in overhead pitching athletes. Isolated stress fractures of the ulnar shaft however are less commonly reported in the literature and considered to be rare. We have observed a correlation between young patients with ulnar shaft stress fractures and the activity of fast-pitch softball pitching.

CASE REPORTS

In this series, we present the imaging findings in four cases of ulnar shaft stress fractures in softball pitchers who presented with insidious onset forearm pain. Furthermore, a review of the literature focusing on softball pitching mechanics is provided to offer a potential underlying mechanism for the occurrence and location of these injuries.

CONCLUSION

An awareness of the imaging appearance of ulnar shaft stress fractures along with an understanding of its proposed mechanism will facilitate accurate and timely imaging diagnosis of this injury by the radiologist.

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

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

Use of Magnetic Resonance Imaging for Orthopedic Trauma and Infection in the Emergency Department

Conditions affecting the musculoskeletal system constitute a significant portion of medical emergencies in the United States, with traumatic injury and infection being two of the most common etiologies. Although physical examination and plain radiographs are often sufficient to guide diagnosis and treatment, there are myriad traumatic and infectious pathologies that are commonly missed or simply not detectable on plain radiographs. Advanced imaging is subsequently warranted for additional workup.Magnetic resonance imaging (MRI) has become an increasingly used imaging modality for musculoskeletal complaints in the emergency department due to its superior visualization of soft tissues, focal edematous changes, and occult osseous insults often not visible on plain radiographs. Although multiple studies have evaluated its utility in the workup of emergency musculoskeletal complaints, there remains a dearth of literature examining the use of MRI for certain occult diagnoses.Radiologists, emergency clinicians, and orthopedic surgeons must be knowledgeable of the indications for MRI in the emergency setting, as delayed diagnosis may contribute to increased morbidity and possibly mortality. This review summarizes the use of MRI in diagnoses relating to trauma or infection among patients presenting to the emergency department with a musculoskeletal complaint.

High Number of Daily Steps Recorded by Runners Recovering from Bone Stress Injuries

BACKGROUND

Bone stress injuries (BSIs) are common among runners for which activity modification is the primary treatment. The clinical utility of measuring activity during recovery has not been evaluated.

QUESTIONS/PURPOSES

We sought to measure the physical activity of runners recovering from BSIs and determine if activity can be correlated with symptoms.

METHODS

A prospective observational pilot study was performed of runners with a new lower extremity BSI treated non-surgically. For 30 days, activity of runners was measured with a physical activity tracker and daily pain scores were collected.

RESULTS

We enrolled 18 runners (average age, 33 years; 72% female). Twelve had stress fractures and six had stress reactions. The average daily steps of all runners during the observation period was 10,018 ± 3232, and the runner with the highest daily steps averaged 15,976. There were similar average daily steps in those with stress fractures versus reactions, 10,329 versus 9965, respectively. There was no correlation between daily steps or relative change in daily steps with pain or relative change in pain scores.

CONCLUSION

Runners with BSIs averaged over 10,000 steps per day during early recovery. Clinicians may not be aware of the amount of activity runners maintain after being diagnosed with a BSI. Although daily steps and symptoms could not be correlated in this study, objectively measuring activity may assist clinicians in guiding runners recovering from BSIs.

ACR Appropriateness Criteria® Chronic Foot Pain

Chronic foot pain is a frequent clinical complaint, which can significantly impact the quality of live in some individuals. These guidelines define best practices with regards to requisition of imaging studies based on specific clinical scenarios, which have been grouped into different variants. Each variant is accompanied by a brief description of the usefulness, advantages, and limitations of different imaging modalities. The present narrative is the result of an exhaustive assessment of the available literature and a thorough review process by a panel of experts on Musculoskeletal Imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Spontaneous Rib Fractures After Breast Cancer Treatment Based on Bone Scans: Comparison Of Conventional Versus Hypofractionated Radiotherapy

BACKGROUND

Spontaneous rib fractures (SRFs) are defined as fractures without apparent blunt force trauma. This study evaluated the incidence and risk factors of SRFs after treatment of patients with breast cancer based on bone scans. In addition, we analyzed radiation-associated SRFs and identified radiotherapy (RT) factors related to SRF.

PATIENTS AND METHODS

We retrospectively reviewed 1265 patients with breast cancer who underwent surgery in 2015 at our institution, and were followed-up with at least 3 bone scans. Bone scans were conducted approximately every 12 months after breast cancer treatment. The endpoint was SRF detected by bone scan. In this study, 754 (60%) patients were treated with chemotherapy, 867 (69%) with RT, and 946 (75%) with anti-hormone therapy.

RESULTS

The median follow-up duration was 37.5 months. A total of 209 (16.5%) patients experienced SRFs during follow-up. The incidence of SRFs increased sharply during the 3-year follow-up period after completion of treatment. In multivariate analyses, abnormal bone density, chemotherapy, and RT were significant risk factors for SRFs. In patients treated with RT (n = 867), 159 (18%) rib fractures occurred: 127 (80%) in the ipsilateral breast and 32 (20%) in the contralateral breast. Among the patients with ipsilateral SRFs who received tumor bed boost (n = 84), the SRF occurred inside the boost field in 80 (95%) cases. Multivariate analysis of RT subgroups showed that hypofractionated RT increased the rate of SRFs (P = .002).

CONCLUSIONS

Most of the rib fractures that occurred after treatment were spontaneous. Hypofractionated RT increased the risk of ipsilateral rib fractures in RT-treated patients.

Evaluating an Algorithm and Clinical Prediction Rule for Diagnosis of Bone Stress Injuries

BACKGROUND

A novel algorithm and clinical prediction rule (CPR), with 18 variables, was created in 2014. The CPR generated a bone stress injury (BSI) score, which was used to determine the necessity of imaging in suspected BSI. To date, there are no validated algorithms for imaging selection in patients with suspected BSI.

HYPOTHESIS

A simplified CPR will assist clinicians with diagnosis and decision making in patients with suspected BSI.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A total of 778 military trainees with lower extremity pain were enrolled. All trainees were evaluated for 18 clinical variables suggesting BSI. Participants were monitored via electronic medical record review. Then, a prediction model was developed using logistic regression to identify clinical variables with the greatest predictive value and assigned appropriate weight. Test characteristics for various BSI score thresholds were calculated.

RESULTS

Of the enrolled trainees, 204 had imaging-confirmed BSI in or distal to the femoral condyles. The optimized CPR selected 4 clinical variables (weighted score): bony tenderness (3), prior history of BSI (2), pes cavus (2), and increased walking/running volume (1). The optimized CPR with a score ≥3 yielded 97.5% sensitivity, 54.2% specificity, and 98.2% negative predictive value. An isolated measure, bony tenderness, demonstrated similar statistical performance.

CONCLUSION

The optimized CPR, which uses bony tenderness, prior history of BSI, pes cavus, and increased walking/running volume, is valid for detecting BSI in or distal to the femoral condyles. However, bony tenderness alone provides a simpler criterion with an equally strong negative predictive value for BSI decision making.

CLINICAL RELEVANCE

For suspected BSI in or distal to the femoral condyles, imaging can be deferred when there is no bony tenderness. When bony tenderness is present in the setting of 1 or more proven risk factors and no clinical evidence of high-risk bone involvement, presumptive treatment for BSI and serial radiographs may be appropriate.

Isolated Distal Fibular Stress Fracture after Total Hip Arthroplasty in a Patient with Developmental Dysplasia of the Hip

Stress fractures following total hip arthroplasty in the lower limbs away from the surgical area are very rare. We report a case of stress fracture in the isolated distal fibula that presented five months after total hip arthroplasty in a patient with developmental dysplasia of the hip. A 67-year-old woman diagnosed with coxarthrosis of the right hip joint, classified as Crowe's group 3, underwent total hip arthroplasty with acetabular reconstruction using a bulk bone graft. The surgery successfully treated the preoperative leg length discrepancy and flexion and external rotation contractures. The alignment of the right lower limbs changed from slight varus to valgus knee following surgery. The postoperative process went well; however, she experienced lateral ankle pain on the affected side five months after surgery. No obvious fracture was observed via radiograph; however, she received a subsequent diagnosis of isolated distal fibula stress fracture. Additionally, she was diagnosed with vitamin D deficiency. Valgus alignment change of the knee joint and vitamin D deficiency were considered the main causes of the stress fracture. Stress fractures should be suspected in patients complaining of unexpected pain following total hip arthroplasty, even in distant areas of the affected limb, especially in osteoporotic patients.

Tibial bone stress injury: diagnostic performance and inter-reader agreement of an abbreviated 5-min magnetic resonance protocol

OBJECTIVE

To compare the diagnostic performance and inter-reader agreement of an abbreviated (5 min) MR protocol compared to a complete (25 min) protocol, for evaluation of suspected tibial bone stress injury.

MATERIALS AND METHODS

This IRB-approved retrospective study consisted of 95 consecutive MR examinations in 88 patients with suspected tibial bone stress injury. Three musculoskeletal radiologists independently classified all examinations utilizing both an abbreviated protocol consisting only of axial T2-weighted images with fat suppression, and after a washout period again classified the complete examinations. Accuracy was calculated as proportion of cases classified exactly, within 1 grade, within 2 grades, and also utilizing a simplified "clinically relevant" classification combining grades 2, 3, and 4A into a single group. Significance testing was performed with the chi-test, and a post-hoc power analysis was performed. Inter-reader agreement was calculated with Kendall's coefficient of concordance, with significance testing performed utilizing the z-test after bootstrapping to obtain the standard error.

RESULTS AND CONCLUSIONS

There was no significant difference in accuracy of grading tibial bone stress injuries between complete and abbreviated examinations. For complete exams, pooled exact accuracy was 47.8%; accuracy within 1 grade was 82.8%; and accuracy within 2 grades was 96.1%. For the abbreviated protocol, corresponding accuracies were 50.2, 82.0, and 93.9%. With the "clinically relevant" simplified classification, accuracy was 58.6% for complete exams and 64.2% for abbreviated exams. There was no significant difference in inter-reader agreement, with substantial agreement demonstrated for both complete (Kendall coefficient of concordance 0.805) and abbreviated examinations (coefficient of 0.767).

Unexpected Hurdle in the Race: Hypophosphatasia Unmasked by the Female Athlete Triad

Hypophosphatasia should be considered for any patient who presents with multiple metatarsal stress fractures and a low alkaline phosphatase.

Imaging Features and Management of Stress, Atypical, and Pathologic Fractures

Traumatic and atraumatic fractures are entities with distinct but often overlapping clinical manifestations, imaging findings, and management protocols. This article is a review of terminology, etiology, and key imaging features that affect management of atraumatic fractures including stress fractures, atypical femoral fractures, and pathologic fractures. The terminology of atraumatic fractures is reviewed, with an emphasis on the distinctions and similarities of stress, atypical, and pathologic fractures. The basic biomechanics of normal bone is described, with an emphasis on the bone remodeling pathway. This framework is used to better convey the shared etiologies, key differences, and important imaging findings of these types of fractures. Next, the characteristic imaging findings of this diverse family of fractures is discussed. For each type of fracture, the most clinically relevant imaging features that guide management by the multidisciplinary treatment team, including orthopedic surgeons, are reviewed. In addition, imaging features are reviewed to help discriminate stress fractures from pathologic fractures in patients with challenging cases. Finally, imaging criteria to risk stratify an impending pathologic fracture at the site of an osseous neoplasm are discussed. Special attention is paid to fractures occurring in the proximal femur because the osseous macrostructure and mix of trabecular and cortical bone of the proximal femur can function as a convenient framework to understanding atraumatic fractures throughout the skeleton. Atraumatic fractures elsewhere in the body also are used to illustrate key imaging features and treatment concepts. ^©RSNA, 2018.

Orthopaedic Residents' Interpretation of Point-of-Care Assessment of Distal Radial Fractures with Use of Pocket-Sized Ultrasound Devices

BACKGROUND

Musculoskeletal ultrasonography is a tool that is being used increasingly. However, the interpretation of ultrasound images of fractures is not incorporated into orthopaedic training programs. This paper presents the results of an initiative to train orthopaedic surgery residents to accurately interpret images of distal radial fractures in adults and to assess their confidence levels and attitudes regarding their future use of ultrasonography.

METHODS

Six junior residents were given a pretest with 100 distal radial images that had been made with a pocket-sized ultrasound device; they were asked to determine fracture versus nonfracture cases (50 cases) as well as reduced fracture versus nonreduced fracture cases (50 cases). Following the pretest, residents completed a 30-minute tutorial (didactic and practical) on distal radial ultrasonography. The residents then completed a period of self-practice during 2 separate trauma rotations (a total of 14 to 16 weeks in a single academic year). Following completion of their second trauma rotation, the residents completed a posttest. Comfort level using a pocket-sized ultrasound device also was assessed during pretesting and posttesting.

RESULTS

The median number of days from the pretest to the posttest was 212 days (range, 175 to 225 days). Residents demonstrated an overall improvement in positive predictive value (PPV) of identifying a fracture from the pretest (86.0%; range, 77.5% to 93.1%) to the posttest (93.5%; range, 91.4% to 94.2%). The overall negative predictive value (NPV) for identifying a fracture also improved from the pretest (69.4%; range, 60.0% to 76.9%) to the posttest (81.0%; range, 76.4% to 86.7%; p = 0.04). The overall PPV for detecting a reduced fracture improved from 67.1% with the pretest (range, 54.2% to 82.4%) to 88.9% with the posttest (range, 83.3% to 94.1%; p = 0.04). The comfort level with using the ultrasound device also increased between pretesting and posttesting, and the residents felt that ultrasonography would be useful in the care of distal radial fractures.

CONCLUSIONS

After a focused training session and a period of self-practice, orthopaedic residents improved their interpretation of ultrasound images and their comfort level using pocket-sized ultrasound devices with adult patients with distal radial fractures. Residents felt that a pocket-sized ultrasound device was useful for fracture diagnosis and evaluation of reduction.