SSR white paper: guidelines for utilization and performance of direct MR arthrography

OBJECTIVE

Direct magnetic resonance arthrography (dMRA) is often considered the most accurate imaging modality for the evaluation of intra-articular structures, but utilization and performance vary widely without consensus. The purpose of this white paper is to develop consensus recommendations on behalf of the Society of Skeletal Radiology (SSR) based on published literature and expert opinion.

MATERIALS AND METHODS

The Standards and Guidelines Committee of the SSR identified guidelines for utilization and performance of dMRA as an important topic for study and invited all SSR members with expertise and interest to volunteer for the white paper panel. This panel was tasked with determining an outline, reviewing the relevant literature, preparing a written document summarizing the issues and controversies, and providing recommendations.

RESULTS

Twelve SSR members with expertise in dMRA formed the ad hoc white paper authorship committee. The published literature on dMRA was reviewed and summarized, focusing on clinical indications, technical considerations, safety, imaging protocols, complications, controversies, and gaps in knowledge. Recommendations for the utilization and performance of dMRA in the shoulder, elbow, wrist, hip, knee, and ankle/foot regions were developed in group consensus.

CONCLUSION

Although direct MR arthrography has been previously used for a wide variety of clinical indications, the authorship panel recommends more selective application of this minimally invasive procedure. At present, direct MR arthrography remains an important procedure in the armamentarium of the musculoskeletal radiologist and is especially valuable when conventional MRI is indeterminant or results are discrepant with clinical evaluation.

Bone Marrow Lesions in Athletic Stress Injuries: An Overview

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

MRI findings prior to return to play as predictors of reinjury in professional athletes: a novel decision-making tool

BACKGROUND

Because MRI has shown great accuracy in assessing acute muscle injuries, identification of risk factors for reinjury before return to play (RTP) in professional athletes during the healing process could be very relevant. We assessed the value of MRI findings prior to RTP as predictors of reinjury.

METHODS

Retrospective observational study of 59 professional athletes, mean age 26 years, with first-time acute muscle injury and successful rehabilitation ready to RTP. They underwent MRI within 6 days of the injury and within 7 days prior to RTP. The primary outcome was reinjury. Risk of reinjury was assessed using radiological signs in control MRI scans before RTP. The risk was classified as low, medium or high when none, one or two radiological signs were observed, respectively.

RESULTS

Reinjury occurred in 9 participants, with a rate of 15.2%. None of the baseline MRI-related variables was significantly associated with reinjury. In the control MRI scan performed within 7 days prior to RTP, three independent findings were significantly associated with reinjury. These included transversal and/or mixed connective tissue gap (p = 0.002), intermuscular oedema (p = 0.015) and callus gap (p = 0.046). In the predictive model of the risk of reinjury, the presence of two of these radiological signs, together with interstitial feathery oedema, was associated with a high risk of recurrence (OR 29.58, 95% CI 3.86-226.64; p = 0.001).

CONCLUSIONS

In professional athletes with acute muscle injuries of the lower limbs successfully rehabilitated, some radiological signs on MRI performed shortly before RTP were associated with a high risk of reinjury.

The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 3: imaging techniques

OBJECTIVES

Imaging diagnosis of femoroacetabular impingement (FAI) remains controversial due to a lack of high-level evidence, leading to significant variability in patient management. Optimizing protocols and technical details is essential in FAI imaging, although challenging in clinical practice. The purpose of this agreement is to establish expert-based statements on FAI imaging, using formal consensus techniques driven by relevant literature review. Recommendations on the selection and use of imaging techniques for FAI assessment, as well as guidance on relevant radiographic and MRI classifications, are provided.

METHODS

The Delphi method was used to assess agreement and derive consensus among 30 panel members (musculoskeletal radiologists and orthopedic surgeons). Forty-four questions were agreed on and classified into five major topics and recent relevant literature was circulated, in order to produce answering statements. The level of evidence was assessed for all statements and panel members scored their level of agreement with each statement during 4 Delphi rounds. Either "group consensus," "group agreement," or "no agreement" was achieved.

RESULTS

Forty-seven statements were generated and group consensus was reached for 45. Twenty-two statements pertaining to "Imaging techniques" were generated. Eight statements on "Radiographic assessment" and 12 statements on "MRI evaluation" gained consensus. No agreement was reached for the 2 "Ultrasound" related statements.

CONCLUSION

The first international consensus on FAI imaging was developed. Researchers and clinicians working with FAI and hip-related pain may use these recommendations to guide, develop, and implement comprehensive, evidence-based imaging protocols and classifications.

KEY POINTS

• Radiographic evaluation is recommended for the initial assessment of FAI, while MRI with a dedicated protocol is the gold standard imaging technique for the comprehensive evaluation of this condition. • The MRI protocol for FAI evaluation should include unilateral small FOV with radial imaging, femoral torsion assessment, and a fluid sensitive sequence covering the whole pelvis. • The definite role of other imaging methods in FAI, such as ultrasound or CT, is still not well defined.

The Lisbon Agreement on femoroacetabular impingement imaging-part 2: general issues, parameters, and reporting

OBJECTIVES

Imaging assessment for the clinical management of femoroacetabular impingement (FAI) is controversial because of a paucity of evidence-based guidance and notable variability among practitioners. Hence, expert consensus is needed because standardised imaging assessment is critical for clinical practice and research. We aimed to establish expert-based statements on FAI imaging by using formal methods of consensus building.

METHODS

The Delphi method was used to formally derive consensus among 30 panel members from 13 countries. Forty-four questions were agreed upon, and relevant seminal literature was circulated and classified in major topics to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement (0-10). This is the second part of a three-part consensus series and focuses on 'General issues' and 'Parameters and reporting'.

RESULTS

Forty-seven statements were generated and group consensus was reached for 45. Twenty-five statements pertaining to 'General issues' (9 addressing diagnosis, differential diagnosis, and postoperative imaging) and 'Parameters and reporting' (16 addressing femoral/acetabular parameters) were produced.

CONCLUSIONS

The available evidence was reviewed critically, recommended criteria for diagnostic imaging highlighted, and the roles/values of different imaging parameters assessed. Radiographic evaluation (AP pelvis and a Dunn 45° view) is the cornerstone of hip-imaging assessment and the minimum imaging study that should be performed when evaluating adult patients for FAI. In most cases, cross-sectional imaging is warranted because MRI is the 'gold standard' imaging modality for the comprehensive evaluation, differential diagnosis assessment, and FAI surgical planning.

KEY POINTS

• Diagnostic imaging for FAI is not standardised due to scarce evidence-based guidance on which imaging modalities and diagnostic criteria/parameters should be used. • Radiographic evaluation is the cornerstone of hip assessment and the minimum study that should be performed when assessing suspected FAI. Cross-sectional imaging is justified in most cases because MRI is the 'gold standard' modality for comprehensive FAI evaluation. • For acetabular morphology, coverage (Wiberg's angle and acetabular index) and version (crossover, posterior wall, and ischial spine signs) should be assessed routinely. On the femoral side, the head-neck junction morphology (α° and offset), neck morphology (NSA), and torsion should be assessed.

Postoperative Knee and Shoulder

Arthroscopic surgery in the knee most commonly addresses ligament, meniscal, or articular cartilage abnormalities. Similarly, arthroscopic surgery of the shoulder most commonly addresses tendon and labral abnormalities. The expected postoperative MRI findings depend on both the procedure performed and the time since surgery. Identifying complications and failed procedures relies on both clinical and imaging evaluations.

Muscle Madness and Making a Case for Muscle-Specific Classification Systems: A Leap from Tissue Injury to Organ Injury and System Dysfunction

Despite the recent publication and subsequent clinical application of several muscle injury classification systems, none has been able to address the varying and often unique/complex types of injuries that occur in different muscles. Although there are advantages of using a unified classification, there are significant differences between certain muscles and muscle groups. These differences may complicate the clinical effectiveness of using a unified injury classification. This narrative explores the difficulties in using a single classification to describe the heterogeneous nature of muscle injuries. Within that context, the possibility of viewing muscles and muscle injuries in the same manner as other biological tissues, structures, organs, and systems is discussed. Perhaps, in addition to a unified classification, subclassifications or muscle specific classifications should be considered for certain muscles. Having a more specific (granular) approach to some of the more commonly injured muscles may prove beneficial for more accurately and effectively diagnosing and treating muscle injuries. Ideally, this will also lead to more accurate determination of the prognosis of specific muscle injuries.

ACE Genotype Distributions Differ between Sporadic and Familial Hypertrophic Cardiomyopathy

This study investigated the frequency of ACE genotypes in sporadic hypertrophic cardiomyopathy (HCM) and compared these frequencies to those found in the general population and in familial HCM. Delineation of the genotype of a 287 bp fragment in the ACE gene of 10 patients with confirmed sporadic HCM demonstrated that 2 (20%) were of the DD genotype, 5 (50%) of the ID genotype, and 3 (30%) of the II genotype. These genotype distributions did not differ significantly from controls (p < 0.57). Comparison of the present results with genotype frequencies in familial HCM reported in prior studies revealed a significant difference in genotype distribution between sporadic and familial HCM (p < 0.04). These findings indicate that the frequency of the ACE genotype does not appear to differ between patients with sporadic HCM and the general population. However, the results suggest that, with regard to the ACE polymorphism studied, genetic differences may exist between the sporadic and familial forms of HCM.

Correction to: The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 1: overview

The original version of this article, published on 14 May 2020, unfortunately contained a mistake.

The Lisbon Agreement on Femoroacetabular Impingement Imaging-part 1: overview

OBJECTIVES

Imaging assessment for the clinical management of femoroacetabular impingement (FAI) syndrome remains controversial because of a paucity of evidence-based guidance and notable variability in clinical practice, ultimately requiring expert consensus. The purpose of this agreement is to establish expert-based statements on FAI imaging, using formal techniques of consensus building.

METHODS

A validated Delphi method and peer-reviewed literature were used to formally derive consensus among 30 panel members (21 musculoskeletal radiologists and 9 orthopaedic surgeons) from 13 countries. Forty-four questions were agreed on, and recent relevant seminal literature was circulated and classified in five major topics ('General issues', 'Parameters and reporting', 'Radiographic assessment', 'MRI' and 'Ultrasound') in order to produce answering statements. The level of evidence was noted for all statements, and panel members were asked to score their level of agreement with each statement (0 to 10) during iterative rounds. Either 'consensus', 'agreement' or 'no agreement' was achieved.

RESULTS

Forty-seven statements were generated, and group consensus was reached for 45 (95.7%). Seventeen of these statements were selected as most important for dissemination in advance. There was no agreement for the two statements pertaining to 'Ultrasound'.

CONCLUSION

Radiographic evaluation is the cornerstone of hip evaluation. An anteroposterior pelvis radiograph and a Dunn 45° view are recommended for the initial assessment of FAI although MRI with a dedicated protocol is the gold standard imaging technique in this setting. The resulting consensus can serve as a tool to reduce variability in clinical practices and guide further research for the clinical management of FAI.

KEY POINTS

• FAI imaging literature is extensive although often of low level of evidence. • Radiographic evaluation with a reproducible technique is the cornerstone of hip imaging assessment. • MRI with a dedicated protocol is the gold standard imaging technique for FAI assessment.

Patient-reported outcome measures for hip-related pain: a review of the available evidence and a consensus statement from the International Hip-related Pain Research Network, Zurich 2018

Hip-related pain is a well-recognised complaint among active young and middle-aged active adults. People experiencing hip-related disorders commonly report pain and reduced functional capacity, including difficulties in executing activities of daily living. Patient-reported outcome measures (PROMs) are essential to accurately examine and compare the effects of different treatments on disability in those with hip pain. In November 2018, 38 researchers and clinicians working in the field of hip-related pain met in Zurich, Switzerland for the first International Hip-related Pain Research Network meeting. Prior to the meeting, evidence summaries were developed relating to four prioritised themes. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of PROMs to assess disability in young and middle-aged active adults with hip-related pain. Our process to gain consensus had five steps: (1) systematic review of systematic reviews; (2) preliminary discussion within the working group; (3) update of the more recent high-quality systematic review and examination of the psychometric properties of PROMs according to established guidelines; (4) formulation of the recommendations considering the limitations of the PROMs derived from the examination of their quality; and (5) voting and consensus. Out of 102 articles retrieved, 6 systematic reviews were selected and assessed for quality according to AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). Two showed moderate quality. We then updated the most recent review. The updated literature search resulted in 10 additional studies that were included in the qualitative synthesis. The recommendations based on evidence summary and PROMs limitations were presented at the consensus meeting. The group makes the following recommendations: (1) the Hip and Groin Outcome Score (HAGOS) and the International Hip Outcome Tool (iHOT) instruments (long and reduced versions) are the most appropriate PROMs to use in young and middle-aged active adults with hip-related pain; (2) more research is needed into the utility of the HAGOS and the iHOT instruments in a non-surgical treatment context; and (3) generic quality of life measures such as the EuroQoL-5 Dimension Questionnaire and the Short Form Health Survey-36 may add value for researchers and clinicians in this field. We conclude that as none of the instruments shows acceptable quality across various psychometric properties, more methods studies are needed to further evaluate the validity of these PROMS—the HAGOS and iHOT—as well as the other (currently not recommended) PROMS.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018

There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

Standardised measurement of physical capacity in young and middle-aged active adults with hip-related pain: recommendations from the first International Hip-related Pain Research Network (IHiPRN) meeting, Zurich, 2018

Hip-related pain can significantly impact quality of life, function, work capacity, physical activity and family life. Standardised measurement methods of physical capacity of relevance to young and middle-aged active adults with hip-related pain are currently not established. The aim of this consensus paper was to provide recommendations for clinical practice and research on standardised measurement methods of physical capacity in young and middle-aged active adults with hip-related pain. Four areas of importance were identified: (1) clinical measures (range of motion, muscle strength, functional impairments), (2) laboratory-based measures (biomechanics and muscle function (muscle activity, size and adiposity)), (3) physical activity, and (4) return to sport/performance. The literature was reviewed, and a summary circulated to the working group to inform discussion at the consensus meeting. The working group developed clinical and research recommendations from the literature review, which were further discussed and modified within the working group at the consensus meeting. These recommendations were then presented to all 38 International Hip-related Pain Research Network (IHiPRN) participants for further discussion, refinement and consensus voting. Therefore, the recommendations voted on were based on a combination of current evidence and expert opinion. The consensus meeting voted on 13 recommendations, six of which were clinically orientated, and seven more research specific. We recommended that clinicians working with young and middle-aged active adults with hip-related pain assess strength using objective methods of measurement, and clinically assess performance of functional tasks, including walking and running. Physical activity should be quantified using both self-reported and objective measures, and patient expectations of recovery should be quantified prior to treatment. It was recommended that return to physical activity (including sport and occupation) be quantified, and sport-specific activities should be assessed prior to return to sport. The IHiPRN participants were uncertain regarding recommendations for range of motion assessment. Research recommendations were that the measurement properties of range of motion, strength and functional performance tests be investigated, reported and improved in both clinical and research settings. Reporting of movement-related parameters (biomechanics and muscle function) should be standardised and the relationship among movement-related parameters, symptoms, function, quality of life, and intra-articular and imaging findings should be investigated. Quantification of return to physical activity (including sport and occupational demands) is required in future research, and the return to sport continuum should be used. Future research is required to determine the best criteria for rehabilitation progression and return to physical activity following hip-related pain management.

Physiotherapist-led treatment for young to middle-aged active adults with hip-related pain: consensus recommendations from the International Hip-related Pain Research Network, Zurich 2018

The 1st International Hip-related Pain Research Network meeting discussed four prioritised themes concerning hip-related pain in young to middle-aged adults: (1) diagnosis and classification of hip-related pain; (2) patient-reported outcome measures for hip-related pain; (3) measurement of physical capacity for hip-related pain; (4) physiotherapist-led treatment for hip-related pain. Thirty-eight expert researchers and clinicians working in the field of hip-related pain attended the meeting. This manuscript relates to the theme of physiotherapist-led treatments for hip-related pain. A systematic review on the efficacy of physiotherapist-led interventions for hip-related pain (published separately) was conducted and found that strong evidence for physiotherapist-led treatments was lacking. Prior to the meeting, draft consensus recommendations for consideration in the meeting were also developed based on the systematic review. The draft consensus recommendations were presented to all of the meeting participants via email, at least 1 week prior to the meeting. At the meeting, these recommendations were discussed, revised and voted on. Six recommendations for clinical practice and five recommendations for research were included and all gained consensus. Recommendations for clinical practice were that (i) Exercise-based treatments are recommended for people with hip-related pain. (ii) Exercise-based treatment should be at least 3 months duration. (iii) Physiotherapist-led rehabilitation after hip surgery should be undertaken. (iv) Patient-reported outcome measures, measures of physical impairment and measures of psychosocial factors should be used to monitor response to treatment. (v) Physical activity (that may include sport) is recommended for people with hip-related pain. (vi) Clinicians should discuss patient expectations, use shared-decision making and provide education. Recommendations for research were (i) Reporting of exercise programmes: Exercise descriptors such as load magnitude, number of repetitions and sets, duration of whole programme, duration of contractile element of exercise, duration of one repetition, time under tension, rest between repetitions, range of motion through which the exercise is performed, and rest between exercise sessions should be reported. (ii) Research should investigate the optimal frequency, intensity, time, type, volume and progression of exercise therapy. (iii) Research should examine the effect of patient education in people with hip-related pain. (iv) Research should investigate the effect of other treatments used in people with hip-related pain (for example: manual therapy, medications, injections). (v) Research should examine the impact of comorbidities and social determinants on treatment effectiveness in people with hip-related pain. Clinicians and researchers working with young to middle-aged active adults with hip-related pain may use these consensus recommendations to guide, develop, test and implement individualised, evidence-based physiotherapist-led rehabilitation programmes.

Hip Hype: FAI Syndrome, Amara's Law, and the Hype Cycle

Femoroacetabular impingement (FAI) has taken us on a roller-coaster ride of innovation, heightened expectations, disillusionment, and confusing diagnostic and treatment pathways. This article reviews and analyzes the phases of FAI diagnosis and treatment over the past 15 years and discusses its parallels to Amara's law and Gartner's hype cycle.

Percutaneous radiofrequency ablation in osteoid osteoma: Tips and tricks in special scenarios

OBJECTIVES

To define specific characteristics of osteoid osteomas treated with radiofrequency ablation, that may benefit from special technical recommendations.

METHODS

Retrospective analysis of all radiofrequency ablations performed by our group from January 2001 to March 2015. A descriptive study was conducted. We compared our results with the available literature to determine the most frequent special scenarios.

RESULTS

207 radiofrequency ablations were performed in 200 patients. We defined the following scenarios: osteoid osteomas located in the spine, close to neurovacular structures, osteoid osteomas in small bones (hands and feet), intra-articular, deeply located or superficial and lesions with extensive periosteal reaction.

CONCLUSIONS

The scenarios defined required special considerations and technical variations. Implementing the different tips and tricks shown in the article, the most complex osteoid osteomas could be successfully ablated.

Current Concepts in Extra-articular Impingement of the Hip: Clinical Diagnosis, Imaging, and Treatment

Hip impingement syndromes, particularly femoroacetabular impingement syndrome, have attracted tremendous attention in the past decade. We address some of the less common hip impingement syndromes, mainly the extra-articular hip impingement syndromes. The clinical presentation, imaging, and treatment of anterior, posterior, and lateral hip impingement syndromes are discussed.

The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement

The 2016 Warwick Agreement on femoroacetabular impingement (FAI) syndrome was convened to build an international, multidisciplinary consensus on the diagnosis and management of patients with FAI syndrome. 22 panel members and 1 patient from 9 countries and 5 different specialties participated in a 1-day consensus meeting on 29 June 2016. Prior to the meeting, 6 questions were agreed on, and recent relevant systematic reviews and seminal literature were circulated. Panel members gave presentations on the topics of the agreed questions at Sports Hip 2016, an open meeting held in the UK on 27-29 June. Presentations were followed by open discussion. At the 1-day consensus meeting, panel members developed statements in response to each question through open discussion; members then scored their level of agreement with each response on a scale of 0-10. Substantial agreement (range 9.5-10) was reached for each of the 6 consensus questions, and the associated terminology was agreed on. The term 'femoroacetabular impingement syndrome' was introduced to reflect the central role of patients' symptoms in the disorder. To reach a diagnosis, patients should have appropriate symptoms, positive clinical signs and imaging findings. Suitable treatments are conservative care, rehabilitation, and arthroscopic or open surgery. Current understanding of prognosis and topics for future research were discussed. The 2016 Warwick Agreement on FAI syndrome is an international multidisciplinary agreement on the diagnosis, treatment principles and key terminology relating to FAI syndrome.Author note The Warwick Agreement on femoroacetabular impingement syndrome has been endorsed by the following 25 clinical societies: American Medical Society for Sports Medicine (AMSSM), Association of Chartered Physiotherapists in Sports and Exercise Medicine (ACPSEM), Australasian College of Sports and Exercise Physicians (ACSEP), Austian Sports Physiotherapists, British Association of Sports and Exercise Medicine (BASEM), British Association of Sport Rehabilitators and Trainers (BASRaT), Canadian Academy of Sport and Exercise Medicine (CASEM), Danish Society of Sports Physical Therapy (DSSF), European College of Sports and Exercise Physicians (ECOSEP), European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA), Finnish Sports Physiotherapist Association (SUFT), German-Austrian-Swiss Society for Orthopaedic Traumatologic Sports Medicine (GOTS), International Federation of Sports Physical Therapy (IFSPT), International Society for Hip Arthroscopy (ISHA), Groupo di Interesse Specialistico dell'A.I.F.I., Norwegian Association of Sports Medicine and Physical Activity (NIMF), Norwegian Sports Physiotherapy Association (FFI), Society of Sports Therapists (SST), South African Sports Medicine Association (SASMA), Sports Medicine Australia (SMA), Sports Doctors Australia (SDrA), Sports Physiotherapy New Zealand (SPNZ), Swedish Society of Exercise and Sports Medicine (SFAIM), Swiss Society of Sports Medicine (SGMS/SGSM), Swiss Sports Physiotherapy Association (SSPA).

Plasma S100β is not a useful biomarker for tumor burden in neurofibromatosis

OBJECTIVES

Neurofibromatosis 1 (NF1), NF2, and schwannomatosis are characterized by a predisposition to develop multiple neurofibromas and schwannomas. Currently, there is no blood test to estimate tumor burden in patients with these disorders. We explored whether S100β would act as a biomarker of tumor burden in NF since S100β is a classic immunohistochemical marker of astrocytes, oligodendrocytes and Schwann cells and a small study showed S100β concentrations correlate with the volume of vestibular schwannomas.

DESIGN AND METHODS

We calculated whole-body tumor burden in subjects with NF1, NF2, and schwannomatosis using whole-body MRI (WBMRI) and measured the concentration of S100β in plasma using ELISA. We used chi-square tests and Spearman rank correlations to test the relationship between S100β levels and whole-body tumor burden.

RESULTS

127 consecutive patients were enrolled in the study (69 NF1 patients, 28 NF2 patients, and 30 schwannomatosis patients). The median age was 40years, 43% were male, and median whole-body tumor volume was 26.9mL. There was no relationship between the presence of internal tumors and the presence of detectable S100β in blood for the overall group or for individual diagnoses (p>0.05 by chi-square for all comparisons). Similarly, there was no correlation between whole-body tumor volume and S100β concentration for the overall group or for individual diagnoses (p>0.05 by Spearman for all comparisons).

CONCLUSIONS

Plasma S100β is not a useful biomarker for tumor burden in the neurofibromatoses. Further work is needed to identify a reliable biomarker of tumor burden in NF patients.

Relationship between whole-body tumor burden and quality of life in patients with neurofibromatosis

6136

Background: NF1, NF2, and schwannomatosis are a group of related genetic disorders in which affected individuals share the predisposition to develop multiple nerve sheath tumors. While previous studies have investigated the relationship between cutaneous tumor burden and quality of life, the relation between internal tumors and quality of life is unknown. Methods: As part of an IRB-approved research study, we performed whole-body MRI and administered the short form (SF)-36 to 245 adult subjects with NF. The number and location of internal nerve sheath tumors in each patient was identified by a board-certified radiologist and tumor volume was calculated using semi-automated volumetric analysis. One sample t-tests were used to compare subjects’ SF-36 scores to general population means. Independent linear regression analyses controlling for age and gender effects were used to relate whole-body tumor count, volume, and distribution (via Gini coefficient) to each domain of the SF-36. Results: 245 patients (142 with NF1, 53 with NF2, 50 with schwannomatosis) completed the study. On the SF-36, subjects with NF1 showed reduced quality of life in the physical role, emotional role, and mental health domains compared to the normal population (p<0.05). Subjects with NF2 showed reductions in the physical functioning, physical role, general health, and social functioning domains while subjects with schwannomatosis showed reductions in the physical role and bodily pain domains (p<0.05). In linear regression analysis, increased tumor number, increased tumor volume, and decreased Gini coefficient were correlated with decreased physical functioning in patients with NF2 (p<0.01). There was also a trend for increasing tumor volume to be correlated with decreased physical role and increased bodily pain in patients with NF1 and with increased bodily pain in patients with schwannomatosis (p<0.10). Conclusions: In our multi-institutional cohort, patients with all forms of neurofibromatosis show selected deficits in quality of life. Internal tumor burden does not correlate with these deficits, with the exception of physical function in NF2 patients.

Quantitative assessment of whole-body tumor burden in adult patients with neurofibromatosis

PURPOSE

Patients with neurofibromatosis 1 (NF1), NF2, and schwannomatosis are at risk for multiple nerve sheath tumors and premature mortality. Traditional magnetic resonance imaging (MRI) has limited ability to assess disease burden accurately. The aim of this study was to establish an international cohort of patients with quantified whole-body internal tumor burden and to correlate tumor burden with clinical features of disease.

METHODS

We determined the number, volume, and distribution of internal nerve sheath tumors in patients using whole-body MRI (WBMRI) and three-dimensional computerized volumetry. We quantified the distribution of tumor volume across body regions and used unsupervised cluster analysis to group patients based on tumor distribution. We correlated the presence and volume of internal tumors with disease-related and demographic factors.

RESULTS

WBMRI identified 1286 tumors in 145/247 patients (59%). Schwannomatosis patients had the highest prevalence of tumors (P = 0.03), but NF1 patients had the highest median tumor volume (P = 0.02). Tumor volume was unevenly distributed across body regions with overrepresentation of the head/neck and pelvis. Risk factors for internal nerve sheath tumors included decreasing numbers of café-au-lait macules in NF1 patients (P = 0.003) and history of skeletal abnormalities in NF2 patients (P = 0.09). Risk factors for higher tumor volume included female gender (P = 0.05) and increasing subcutaneous neurofibromas (P = 0.03) in NF1 patients, absence of cutaneous schwannomas in NF2 patients (P = 0.06), and increasing age in schwannomatosis patients (p = 0.10).

CONCLUSION

WBMRI provides a comprehensive phenotype of neurofibromatosis patients, identifies distinct anatomic subgroups, and provides the basis for investigating molecular biomarkers that correlate with unique disease manifestations.

Bone marrow changes in stress injuries

Stress injuries and associated bone marrow changes are a common finding in athletes of all levels. Magnetic resonance imaging (MRI) is the imaging modality of choice for detecting characterizing and staging these injuries. However, because bone marrow edema patterns may also be seen in asymptomatic athletes, it is imperative for the sports medicine physician and the radiologist to closely correlate the imaging findings with the clinical signs and symptoms to assess the clinical significance of the imaging findings. This article reviews the pathophysiology, MRI findings, and clinical implications of stress injuries in athletes.

Obturator externus bursa: prevalence of communication with the hip joint and associated intra-articular findings in 200 consecutive hip MR arthrograms

The purpose of the study was to demonstrate the prevalence of communication between the hip joint and the obturator externus bursa on hip MR arthrography. Following institutional review board approval, 200 hip MR arthrograms in 196 subjects were independently reviewed by two musculoskeletal radiologists. Discrepancies were resolved by adjudication. The presence or absence of communication between the hip joint and the obturator externus bursa was recorded. Associated lesions involving the acetabular labrum and articular cartilage were recorded. The obturator externus bursa was shown to communicate with the hip joint in 11 of the 200 (5.5%) hip MR arthrograms. Of these, six were in men and five were in women. The age range was 15-63 years with a mean age of 34 years. All 11 patients had labral tears. Eight of the 11 had cartilage lesions. The obturator externus bursa can be seen to communicate with the hip joint in 5.5% of hip MR arthrograms. Associated labral and cartilage lesions are common.

Whole-body MRI evaluation of tumor burden in the neurofibromatosis tumor suppressor syndromes

2074

Background: Neurofibromatosis 1 (NF1), NF2, and schwannomatosis are a group of related genetic disorders in which affected individuals share the predisposition to develop multiple neurofibromas and schwannomas. The prevalence of internal tumors is not known because current estimates are based on regional MRI scans that may not detect occult tumors. A rapid and sensitive method to detect internal tumors is highly desirable since they can cause neurologic dysfunction, compress vital structures, or transform into malignant tumors. Whole-body MRI (WBMRI) is an imaging technique by which the entire body can be imaged in a relatively short time without the use of ionizing radiation. Methods: We performed WBMRI in subjects with NF1, NF2, or schwannomatosis as part of an IRB-approved research study. Each subject was imaged from head to ankles in the supine position using a 1.5 Tesla magnet, integrated body coil, and no intravenous contrast. Using five acquisitions, the entire body was imaged using a fat suppressed fluid sensitive STIR sequence. The images were then fused into a single whole body DICOM image. The number and type of tumors (discrete vs. plexiform) were identified by a board-certified radiologist and tumor volume was calculated using semi-automated analysis. Results: A total of 100 subjects were imaged (NF1–50; NF2–25, schwannomatosis-25). Sixty-one percent of subjects had ≥1 internal tumor. The median number of tumors in affected individuals was 5 (range, 1 to 63 tumors). Overall, the legs harbored the greatest number of tumors (33%), followed by the pelvis (18%), thorax (15%), abdomen (12%), arms (10%), and head/neck (7%). Only 40% of internal tumors were classified as plexiform yet these tumors contributed 78% of the tumor burden by volume. Conclusions: WBMRI scan is a powerful tool to evaluate the number, size, and distribution of internal tumors in patients with neurofibromatosis. This technique provides unique phenotypic information for genetic studies on NF1, NF2, and schwannomatosis. In addition, WBMRI may prove useful in identifying individual patients at high risk for complications (such as neurologic dysfunction or malignant transformation) due to heavy internal tumor burden and in determining the efficacy of antitumor drugs in this unique patient population.

No significant financial relationships to disclose.

Femoroacetabular impingement: presentation, diagnosis, and management

Femoroacetabular impingement (FAI) is an often overlooked cause of hip pain in patients of all ages. The clinical signs and symptoms, multimodality imaging findings, treatment options, intraoperative findings, and expected outcomes for patients with FAI are illustrated and discussed.

Evaluation of radial-sequence imaging in detecting acetabular labral tears at hip MR arthrography

OBJECTIVE

In recent years, radial imaging has been advocated for improved visualization of the acetabular labrum in magnetic resonance arthrography of the hip. The purpose of this study was to investigate whether radial imaging demonstrates labral tears not visible on standard imaging planes.

METHODS

Fifty-four consecutive magnetic resonance (MR) arthrograms of the hip that included radial imaging over 2 years were retrospectively analyzed by two radiologists. Standard imaging planes and radial imaging were reviewed for identification of labral tears in four specific areas of the labrum: anterosuperior, posterosuperior, anteroinferior, and posteroinferior. The standard imaging sequences include fat-saturated spin-echo T1-weighted images in the coronal and oblique axial planes, non-fat-saturated T1-weighted images in the coronal and sagittal planes, and T2-weighted sequence in the axial plane. Radial imaging was performed as previously described using fat-saturated T1-weighted sequences.

RESULTS

Using standard imaging planes, 50 anterosuperior, 31 posterosuperior, 10 anteroinferior, and 9 posteroinferior labral tears were detected in 54 MR arthrograms of the hip. Using radial sequences alone, 44 anterosuperior, 25 posterosuperior, 9 anteroinferior, and 5 posteroinferior labral tears were detected. In all four areas of the labrum, the radial imaging did not show any labral tear not seen on standard imaging planes.

DISCUSSION

In MR arthrography of the hip, radial imaging did not reveal any additional labral tears. Standard imaging planes sufficiently demonstrate all acetabular labral tears.

Re-examining the association of os acromiale with supraspinatus and infraspinatus tears

PURPOSE

To re-evaluate the relationship between os acromiale and rotator cuff tears.

METHODS

We retrospectively analyzed 84 magnetic resonance imaging studies of the shoulder. Forty-two subjects with os acromiale (n = 42; 32 men and ten women, age 25-81 years, mean 47.6 years) were compared with age- and gender-matched subjects with no evidence of os acromiale (controls). Arthroscopy data were available in 19 os acromiale and 12 control subjects. Statistical analyses were performed to determine differences between groups regarding rotator cuff tears affecting the supraspinatus and infraspinatus tendons detected by magnetic resonance imaging and arthroscopy. Analysis of os acromiale type, ossicle synchondrosis edema, acromioclavicular joint degenerative changes and step-off deformity at the synchondrosis were tabulated.

RESULTS

No statistically significant difference between the os acromiale and control groups was noted, either on magnetic resonance imaging or arthroscopy, with regard to tears of the supraspinatus (P = 1.000 and 0.981, respectively) and infraspinatus (P = 1.000 and 0.667, respectively) tendons. There was a statistically significant increased number of supraspinatus (P = 0.007) and infraspinatus (P = 0.03) tears in a comparison of subjects with os acromiale and step-off deformity (10/42) vs os acromiale without step-off deformity (32/42).

CONCLUSION

The presence of os acromiale may not significantly predispose to supraspinatus and infraspinatus tendon tears. However, subjects with step-off deformity of an os acromiale are at greater risk of rotator cuff tears than are similar subjects without such deformity.

Cystic Changes at Supraspinatus and Infraspinatus Tendon Insertion Sites: Association with Age and Rotator Cuff Disorders in 238 Patients

PURPOSE

To retrospectively determine the frequency of posterior and anterior cystic abnormalities at rotator cuff insertion site on the greater tuberosity and to determine their relationship to patient age and rotator cuff disorders.

MATERIALS AND METHODS

Institutional review board approval was given; informed consent was waived. The study was HIPAA compliant. In 238 patients with rotator cuff diagnoses at surgery, preoperative magnetic resonance (MR) imaging studies were reviewed to localize osseous cystic changes as anterior (supraspinatus insertion site) or posterior (infraspinatus insertion site) on the greater tuberosity. If rotator cuff tear was present, tendon retraction and location of partial tear (articular or bursal surface) were recorded. Two radiologists reached conclusions by consensus. Locations of cysts were correlated to surgical cuff diagnoses: no tear, tendinopathy, partial-thickness tear, and complete tear. Prospective interpretations from original MR reports were compared with surgical results. Statistical analyses included one-way analysis of variance, chi(2), Fisher exact, and Student t tests, as well as logistic regression and receiver operating characteristic curve comparison.

RESULTS

There were 238 consecutive patients (150 men, 88 women; mean age, 43 years). Cysts were located at or near footprint of cuff tendon and demonstrated fluid or soft-tissue signal intensities. Posterior cysts occurred in 56.7% of shoulders and showed no statistical correlation to age or cuff diagnosis. Anterior cysts occurred in 22.7% of shoulders and were strongly associated with cuff disorders (P<.001). Controlling for cuff disorders, there was no relationship between anterior cysts and age (P>.50). Anterior cysts were more common in partial-thickness articular (48%) than in bursal (13%) tears (P<.001).

CONCLUSION

Posterior cysts were more common than anterior cysts and showed nearly random distribution among patients, regardless of age and cuff diagnosis. Anterior cysts were closely associated with cuff disorders.

Femoroacetabular impingement

Femoroacetabular impingement is a relatively recently appreciated "idiopathic" cause of hip pain and degenerative change. Two types of impingement have been described. The first, cam impingement, is the result of an abnormal morphology of the proximal femur, typically at the femoral head-neck junction. Cam impingement is most common in young athletic males. The second, pincer impingement, is the result of an abnormal morphology or orientation of the acetabulum. Pincer impingement is most common in middle-aged women. This article reviews the imaging findings of cam and pincer type femoroacetabular impingement. Recognition of these entities will help in the selection of the appropriate treatment with the goal of decreasing the likelihood of early degenerative change of the hip.

Hip MR arthrography and femoroacetabular impingement

Hip pain is a common complaint among athletes of all ages. Advances in imaging and treatment are changing the paradigm of evaluation and management of hip pain. The role of abnormal femoral and acetabular morphology and lesions of the acetabular labrum and cartilage is increasingly recognized as being crucial in the development of degenerative change. In addition, femoroacetabular impingement is increasingly recognized as an etiologic factor in hip pain. This article discusses techniques of hip magnetic resonance (MR) arthrography, normal anatomy seen at hip MR arthrography, common intra-articular pathologies in patients with hip pain, and imaging findings of femoroacetabular impingement.

Distal clavicular osteolysis: MR evidence for subchondral fracture

PURPOSE

To investigate the association between distal clavicular osteolysis and subchondral fractures of the distal clavicle at MRI.

MATERIALS AND METHODS

This study was approved by the hospital human research committee, which waived the need for informed consent. Three radiologists retrospectively analyzed 36 shoulder MR examinations in 36 patients with imaging findings of distal clavicular osteolysis. The presence of a subchondral fracture of the distal clavicle, abnormalities of the acromioclavicular joint, rotator cuff tears and labral tears were assessed by MRI. These cases were then compared with 36 age-matched controls.

RESULTS

At MRI, 31 of 36 patients (86%) had a subchondral line within the distal clavicular edema, consistent with a subchondral fracture. Of the 36 patients, 32 (89%) had fluid in the acromioclavicular joint, while 27 of 36 patients (75%) had cysts or erosions in the distal clavicle. There were 13 patients (36%) with associated labral tears, while eight patients (22%) had partial-thickness rotator cuff tears. In the control group one of 36 (3%) had a subchondral line (P<0.05), while ten of 36 (28%) had rotator cuff tears and 13 of 36 (36%) had labral tears. These latter two were not statistically significant between the groups.

CONCLUSION

A distal clavicular subchondral fracture is a common finding in patients with imaging evidence of distal clavicular osteolysis. These subchondral fractures may be responsible for the propensity of findings occurring on the clavicular side of the acromioclavicular joint.

MRI of Shoulder Trauma

Magnetic resonance imaging (MRI) is an invaluable tool for evaluating traumatic injuries of the shoulder. This article discusses MRI of shoulder trauma based on mechanism of injury. Acute direct traumatic injuries, acute indirect traumatic injuries, and repetitive microtraumatic injuries (impingement/traction) are discussed. Finally, common pitfalls in shoulder imaging are addressed.

Incidence and MR imaging features of fractures of the anterior process of calcaneus in a consecutive patient population with ankle and foot symptoms

OBJECTIVE

To determine the incidence, appearances and associated injuries of fractures affecting the anterior process of calcaneus from a general population with foot and ankle symptoms.

DESIGN AND PATIENTS

A retrospective review of foot and ankle MR imaging procedures was performed for detection of cases with a fracture affecting the anterior process of calcaneus over a four year period. Radiographs, MR imaging studies, radiology reports, medical records, and operative notes were reviewed. Imaging analysis included fracture pattern, displacement, associated fractures, and presence of tendon and ligamentous injuries.

RESULTS

The incidence of anterior process of calcaneus fracture on MR imaging was 0.5% (14/2577). Fractures were more common in female subjects (71%, 10/14). Fracture orientation was predominantly vertical (93%, 13/14). No comminuted fractures were seen and only three fractures were displaced. Three of the eight MR imaging evident fractures of anterior process of calcaneus were seen on radiographs. Associated fractures of the talus (n=5), navicular bone (n=3), cuboid (n=2), and calcaneal body (n=1) were noted. Associated injuries to the anterior talofibular ligament (n=3) and tears of the peroneus brevis (n=3) and peroneus longus (n=1) tendons were present. All fractures were treated non-operatively. Two patients had subtalar joint steroid injection for symptomatic relief.

CONCLUSIONS

Fractures of the anterior process of the calcaneus are uncommon in MR examinations of a general population of patients with foot and ankle symptoms. Although anterior process of calcaneus fractures are rare, there was a moderately high incidence of associated bone and soft-tissue injuries.

Femoroacetabular impingement

Femoroacetabular impingement, both cam and pincer types, is a recently appreciated cause of hip pain, acetabular cartilage and labral damage, and hip degenerative change. Abnormalities in the morphology of the acetabulum or the proximal femur may be the primary predisposing factor. This article reviews the imaging findings and treatment strategies of cam- and pincer-type femoroacetabular impingement.

MR imaging of the rotator cuff

MR imaging is the optimal method for evaluating suspected rotator cuff pathology. Current techniques of fast spin-echo imaging without and with fat suppression allow accurate identification and characterization of tendinous and myotendinous abnormalities of the rotator cuff. Impingement disorders, tendon degeneration, instability,and trauma comprise the multifactorial nature of rotator cuff disease. This article addresses the role of MR imaging in evaluating the rotator cuff and the importance of MR imaging in identifying other lesions that may mimic rotator cuff pathology. A rationale for protocol design, including MR arthrography and the use of specialized positioning, such as abduction and external rotation (ABER), are discussed.

The accuracy of computed tomography for the diagnosis of tibial nonunion

BACKGROUND

When a patient is seen with a possible tibial nonunion and equivocal findings on plain radiographs, the surgeon may choose to obtain a computed tomography scan to better delineate the bone anatomy. However, the sensitivity and specificity of computed tomography in this setting is not known. We investigated the accuracy of computed tomography for detecting nonunion in this clinical situation.

METHODS

Thirty-five patients with equivocal findings on plain radiographs underwent computed tomography scanning. The patients were first seen at an average of 9.7 months after the injury and had undergone a mean of 2.6 prior operations. A so-called gold standard of union or nonunion was determined by either surgical findings (for twenty-five patients who were operatively treated) or six months of clinical observation (for ten patients who had nonoperative treatment). Computed tomography scans were assessed by two radiologists and one orthopaedic surgeon who were blinded to the clinical outcome.

RESULTS

Computed tomography scans displayed very good diagnostic accuracy. Intraobserver agreement was high (intraclass correlation coefficient = 0.89), the sensitivity for detecting nonunion was 100%, and the overall accuracy was 89.9%. Computed tomography was limited by a low specificity of 62%, as three patients who were diagnosed as having tibial nonunion with computed tomography underwent surgery and were found to have a healed fracture.

CONCLUSIONS

Computed tomography displays very good accuracy in the evaluation of tibial fracture-healing. However, it is limited by low specificity and may sometimes misrepresent a healed fracture as a nonunion. Surgeons must be aware of this pitfall in order to accurately determine which patients need surgical intervention.

Imaging of the overhead throwing athlete

Knowledge of overhead throwing biomechanics is crucial to understand specific injuries encountered in throwing athletes on diagnostic imaging. Most specific injuries of overhead throwing athletes occur at the shoulder and elbow. Throwing athletes are susceptible to rotator cuff tears from tensile overload and external and internal impingement. The labrum is also commonly degenerated or torn secondary to overuse syndrome, internal impingement, and microtrauma. The elbow is typically injured secondary to excessive valgus forces during throwing. The ulnar collateral ligament, ulnar nerve, and common flexor tendon origin are all at increased risk of injury. Capitellar osteochondral injuries and loose intra-articular bodies are also frequent. Knowledge of injury pathophysiology is crucial to understanding the treatment rationale in throwing athletes.

Synovial inflammatory processes in the hand

The numerous synovial articulations and tendon sheaths of the hand afford it a central role in the diagnosis and management of inflammatory arthropathies. Inflammation may be idiopathic, infectious, post-traumatic, or secondary to deposition diseases. In most cases, synovial inflammation represents the primal event in the onset of destructive arthropathies. We review the imaging features of acute and chronic synovitis in the hand. Magnetic resonance imaging is very sensitive to the earliest changes of synovitis and provides a modality for early detection of disease. Additionally, once a diagnosis is established, magnetic resonance imaging has an emerging role in rapid assessment of response to therapy. Positron emission tomography and ultrasound also show promise in the evaluation and treatment of inflammatory arthropathies. Although highly sensitive to the presence of inflammation these more advanced imaging techniques often lack specificity. Therefore, the radiographic evaluation of the pattern of bone destruction remains critical to distinguishing among the different synovial inflammatory processes.