Interdisciplinary consensus statements on imaging of DRUJ instability and TFCC injuries.

OBJECTIVES: The purpose of this agreement was to establish evidence-based consensus statements on imaging of distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) injuries by an expert group using the Delphi technique. METHODS: Nineteen hand surgeons developed a preliminary list of questions on DRUJ instability and TFCC injuries. Radiologists created statements based on the literature and the authors' clinical experience. Questions and statements were revised during three iterative Delphi rounds. Delphi panelists consisted of twenty-seven musculoskeletal radiologists. The panelists scored their degree of agreement to each statement on an 11-item numeric scale. Scores of "0," "5," and "10" reflected complete disagreement, indeterminate agreement, and complete agreement, respectively. Group consensus was defined as a score of "8" or higher for 80% or more of the panelists. RESULTS: Three of fourteen statements achieved group consensus in the first Delphi round and ten statements achieved group consensus in the second Delphi round. The third and final Delphi round was limited to the one question that did not achieve group consensus in the previous rounds. CONCLUSIONS: Delphi-based agreements suggest that CT with static axial slices in neutral rotation, pronation, and supination is the most useful and accurate imaging technique for the work-up of DRUJ instability. MRI is the most valuable technique in the diagnosis of TFCC lesions. The main indication for MR arthrography and CT arthrography are Palmer 1B foveal lesions of the TFCC. CLINICAL RELEVANCE STATEMENT: MRI is the method of choice for assessing TFCC lesions, with higher accuracy for central than peripheral abnormalities. The main indication for MR arthrography is the evaluation of TFCC foveal insertion lesions and peripheral non-Palmer injuries. KEY POINTS: • Conventional radiography should be the initial imaging technique in the assessment of DRUJ instability. CT with static axial slices in neutral rotation, pronation, and supination is the most accurate method for evaluating DRUJ instability. • MRI is the most useful technique in diagnosing soft-tissue injuries causing DRUJ instability, especially TFCC lesions. • The main indications for MR arthrography and CT arthrography are foveal lesions of the TFCC.

Physical activity increases synovial fluid in ankle tendon sheaths: an adjustment of MR Criteria is needed.

OBJECTIVES: To compare the amount of fluid in synovial sheaths of the ankle before and after running. Our hypothesis was that this amount would increase and that the threshold for what is normally acceptable should be adjusted after physical activity. METHODS: Twenty-one healthy volunteers (n = 42 ankles) ran for 40 min on a treadmill. They underwent 3 T MRI before and immediately after running using a dedicated ankle coil. The images were stored and subsequently measured in a standardized way and independently read by two readers for fluid in the tendon sheaths in the retro and inframalleolar area. Statistics were performed for each tendon (Wilcoxon signed rank test), and also for the pooled data. Intraclass correlation coefficients were calculated. RESULTS: For reader 1, for all tendons the values after running increased without reaching statistical significance. For reader 2 this was not the case for all tendons but for most. When all the data were pooled (n = 800 measurements), the statistical difference before and after running was significant (p < 0.001). CONCLUSION: Data pre and post-running show a trend of increasing synovial fluid, however, not significant for each individual tendon. The pooled data for all tendons, (n = 800) show a statistically significant increase after running (p < 0.001). The clinical implication is that the threshold for normally acceptable fluid should be adjusted if the patient undergoes an MR study after recent physical activity.

Interdisciplinary consensus statements on imaging of scapholunate joint instability.

OBJECTIVES: The purpose of this agreement was to establish evidence-based consensus statements on imaging of scapholunate joint (SLJ) instability by an expert group using the Delphi technique. METHODS: Nineteen hand surgeons developed a preliminary list of questions on SLJ instability. Radiologists created statements based on the literature and the authors' clinical experience. Questions and statements were revised during three iterative Delphi rounds. Delphi panellists consisted of twenty-seven musculoskeletal radiologists. The panellists scored their degree of agreement to each statement on an eleven-item numeric scale. Scores of '0', '5' and '10' reflected complete disagreement, indeterminate agreement and complete agreement, respectively. Group consensus was defined as a score of '8' or higher for 80% or more of the panellists. RESULTS: Ten of fifteen statements achieved group consensus in the second Delphi round. The remaining five statements achieved group consensus in the third Delphi round. It was agreed that dorsopalmar and lateral radiographs should be acquired as routine imaging work-up in patients with suspected SLJ instability. Radiographic stress views and dynamic fluoroscopy allow accurate diagnosis of dynamic SLJ instability. MR arthrography and CT arthrography are accurate for detecting scapholunate interosseous ligament tears and articular cartilage defects. Ultrasonography and MRI can delineate most extrinsic carpal ligaments, although validated scientific evidence on accurate differentiation between partially or completely torn or incompetent ligaments is not available. CONCLUSIONS: Delphi-based agreements suggest that standardized radiographs, radiographic stress views, dynamic fluoroscopy, MR arthrography and CT arthrography are the most useful and accurate imaging techniques for the work-up of SLJ instability. KEY POINTS: • Dorsopalmar and lateral wrist radiographs remain the basic imaging modality for routine imaging work-up in patients with suspected scapholunate joint instability. • Radiographic stress views and dynamic fluoroscopy of the wrist allow accurate diagnosis of dynamic scapholunate joint instability. • Wrist MR arthrography and CT arthrography are accurate for determination of scapholunate interosseous ligament tears and cartilage defects.

Hand Masses.

Hand and wrist soft tissue masses may be classified as pseudotumors, benign neoplasms, or malignant neoplasms. The vast majority of hand lesions are benign. Consideration of the location of the lesion and its imaging characteristics often leads to a specific diagnosis. Pseudotumors discussed in this article are ganglion cysts, accessory muscles, and inflammatory lesions. True tumors are described according to their tissue type: nerve sheath tumors, adipocytic tumors, so-called fibrohistiocytic tumors, pericytic tumors, and vascular lesions. We also outline the imaging features of masses encountered in the hand and wrist.

Extrinsic and Intrinsic Ligaments of the Wrist.

Carpal stability depends on the integrity of both intra-articular and intracapsular carpal ligaments. In this review, the role of the radial-sided and ulnar-sided extrinsic and intrinsic ligaments is described, as well as their advanced imaging using magnetic resonance arthrography (MRA) and contrast-enhanced magnetic resonance imaging (MRI) with three-dimensional (3D) scapholunate complex sequences and thin slices. In the last decade, the new concept of a so-called "scapholunate complex" has emerged among hand surgeons, just as the triangular ligament became known as the triangular fibrocartilage complex (TFCC).The scapholunate ligament complex comprises the intrinsic scapholunate (SL), the extrinsic palmar radiocarpal: radioscaphocapitate (RSC), long radiolunate (LRL), short radiolunate (SRL) ligaments, the extrinsic dorsal radiocarpal (DRC) ligament, the dorsal intercarpal (DIC) ligament, as well as the dorsal capsular scapholunate septum (DCSS), a more recently described anatomical structure, and the intrinsic palmar midcarpal scaphotrapeziotrapezoid (STT) ligament complex. The scapholunate (SL) ligament complex is one of the most involved in wrist injuries. Its stability depends on primary (SL ligament) and secondary (RSC, DRC, DIC, STT ligaments) stabilizers.The gold standard for carpal ligament assessment is still diagnostic arthroscopy for many hand surgeons. To avoid surgery as a diagnostic procedure, advanced MRI is needed to detect associated lesions (sprains, midsubstance tears, avulsions and chronic fibrous infiltrations) of the extrinsic, midcarpal and intrinsic wrist ligaments, which are demonstrated in this article using 3D and two-dimensional sequences with thin slices (0.4 and 2 mm thick, respectively).

Present Status of Musculoskeletal Radiology in Europe: International Survey by the European Society of Musculoskeletal Radiology.

No official data exist on the status of musculoskeletal (MSK) radiology in Europe. The Committee for National Societies conducted an international survey to understand the status of training, subspecialization, and local practice among the European Society of Musculoskeletal Radiology (ESSR) partner societies. This article reports the results of that survey. An online questionnaire was distributed to all 26 European national associations that act as official partner societies of the ESSR. The 24 questions were subdivided into six sections: society structure, relationship with the national radiological society, subspecialization, present radiology practice, MSK interventional procedures, and MSK ultrasound. The findings of our study show a lack of standardized training and/or accreditation methods in the field of MSK radiology at a national level. The European diploma in musculoskeletal radiology is directed to partly overcome this problem; however, this certification is still underrecognized. Using certification methods, a more homogeneous European landscape could be created in the future with a view to subspecialist training. MSK ultrasound and MSK interventional procedures should be performed by a health professional with a solid knowledge of the relevant imaging modalities and sufficient training in MSK radiology. Recognition of MSK radiology as an official subspecialty would make the field more attractive for younger colleagues as well as attracting the brightest and best, an important key to further development of both clinical and academic radiology. KEY POINTS: · Standardized training and/or accreditation methods in the field of MSK radiology is lacking at a national level.. · With certification methods, such as the European diploma in musculoskeletal radiology, a more homogeneous European landscape could be created in the future with a view to subspecialist training.. · Recognition of MSK radiology as an official subspecialty would make the field more attractive for younger colleagues as well as attracting the brightest and best, an important key to further development of both clinical and academic radiology..

Imaging of Articular and Extra-articular Sports Injuries of the Hip.

Sports-related articular and periarticular hip injuries are common in athletes. Knowledge of patient complaints and clinical findings are crucial for adequate interpretation of imaging examinations. However, asymptomatic athletes can present abnormal imaging findings, and clinical presentation of hip injuries may be nonspecific. Therefore, a thorough examination of the hip and surrounding soft tissue images is essential.This review describes the intra-articular pathologies encountered in sports activities including labrum or cartilage lesions, associated or not with femoroacetabular hip impingement syndromes, as well as ligament teres injuries, using magnetic resonance imaging (MRI) or computed tomography arthrography. Different causes of snapping hip syndrome (from intra- and extra-articular origins) are also discussed and illustrated. The extra-articular forms of hip impingement syndromes including ischiofemoral and subspine impingement are depicted with MRI and ultrasound. Diagnostic imaging of bone avulsions, greater trochanteric syndrome, athletic pubalgia, and myotendinous injuries is also described.

Fluid distribution in ankle tendon sheaths in healthy volunteers: MRI findings.

PURPOSE: To assess normal distribution of fluid in the tendon sheaths of the ankle. METHODS: 21 healthy volunteers were evaluated. Bilateral ankle MRI was performed on a 3T unit with PD-weighted images with fat saturation. The images were interpreted by two radiologists separately, and the short-axis dimension of fluid amount was measured. Bland-Altman plots and correlation plots were used to assess consistency between readers. RESULTS: There were 13 men and 8 women. The mean age was 24.7 years. Fluid in the retromalleolar part of the peroneus longus was seen in three ankles of three volunteers and in the inframalleolar part in three ankles of three volunteers. Fluid in the retromalleolar part of the peroneus brevis was seen in four ankles of three volunteers and in the inframalleolar part in three ankles of two volunteers. Fluid in the retromalleolar part of the tibialis posterior was seen in 37 ankles of 20 volunteers and in the inframalleolar part in 38 ankles of 21 volunteers Fluid in the retromalleolar part of the flexor digitorum was seen in 14 ankles of eight volunteers and in the inframalleolar part in 11 ankles of eight volunteers Fluid in the retromalleolar part of the flexor hallucis longus was seen in 23 ankles of 16 volunteers and in the inframalleolar part in 17 ankles of 11 volunteers. CONCLUSION: Fluid is common in the retro- and inframalleolar parts of the medial tendons. Fluid is virtually absent in the peroneal tendons and anterior tendon sheaths in normal volunteers.

Pseudo-tear appearance of the posterior tibiotalar ligament on fluid-sensitive sequences.

PURPOSE: This study aimed at studying the MR imaging appearance of the tibiotalar ligament in asymptomatic volunteers. MATERIALS AND METHODS: Fourty-two ankles were imaged on a 3T MR system using proton density weighted images with fat saturation (TR, 2969 ms; TE 30 ms; NA, 2; slice thickness, 2.5 mm). Subjects with acute ankle conditions or history of previous trauma were not included in the study group. Images were obtained in the three orthogonal planes. The posterior tibiotalar ligament was assessed on coronal imaging, by consensus of two radiologists. The signal intensity was recorded as isointense, hypointense, or hyperintense relative to muscle. The morphology of the ligament was classified as homogenous or striated. Descriptive statistics were obtained. RESULTS: There were 8 men and 14 women with a mean age of 24.7 years (range 19-43 years). The ligaments were classified as hyperintense in 30/42 (70%) of ankles and isointense in 9/42 (21%) of ankles. A striated appearance was seen in 34/42 (80%) of ankles. CONCLUSION: The posterior deep deltoid ligament is commonly hyperintense. It is usually striated although it can be homogeneously hyperintense. This appearance simulates a tear.

Forefoot Pain in the Lesser Toes: Anatomical Considerations and Magnetic Resonance Imaging Findings.

Various conditions may result in forefoot pain. Magnetic resonance (MR) imaging allows accurate assessment of many of these conditions. We provide an overview of forefoot disorders divided into bones, capsule and plantar plate, musculotendinous structures, neurovascular structures, and subcutaneous tissue. We review normal anatomical features as well as MR imaging findings of common disorders.

Fluid distribution in ankle and midfoot joints: MR findings in asymptomatic volunteers.

PURPOSE: The purpose of this study is to assess the amount of fluid in the joints of the ankle and midfoot on MR imaging in asymptomatic volunteers. MATERIALS AND METHODS: Twenty-one healthy asymptomatic volunteers (42 ankles) were evaluated with MRI imaging. There were 13 men and 8 women. The mean age was 24.7 years (19-42 years). MR imaging was performed on a 3T MR system using proton density weighted images with fat saturation (TR 2969, TE 30 ms, NA 2, slice thickness 2.5 mm). Images were obtained in three orthogonal planes. The images were interpreted by two radiologists in two sessions. The maximum size of the joint effusion was measured in one plane. Descriptive statistics and variation between interpretation sessions were calculated. RESULTS: Fluid in the anterior tibiotalar joint had a mean size of 2.0 mm (0.0-5.5 mm), in the posterior tibiotalar joint 3.1 mm (0.0-6.3 mm), in the talonavicular joint 0.7 mm (0.0-2.9 mm), and in the anterolateral recess 2.0 mm (0.0-4.3 mm). Fluid in the posterior aspect of the posterior subtalar joint had a mean size of 2.6 mm (0.0-9.4 mm), in the anterior aspect of the posterior subtalar joint 1.9 mm (0.0-6.6 mm), at the middle subtalar joint 0.1 mm (0.0-1.7 mm), and at the anterior subtalar joint 1.6 mm (0.0-6.0 mm). Fluid in the tibiofibular joint had a mean height of 8.1 mm (0.0-16.4 mm). CONCLUSION: In asymptomatic volunteers, moderate to large amounts of fluid were common in all joint recesses of ankle and midfoot, and most pronounced in the anterior and posterior tibiotalar joint, anterolateral recess, and posterior subtalar joint. This should not be mistaken for evidence of a pathological condition.

Ultrasound of the Distal Insertions of the Ankle and Foot Tendons With Anatomical Correlation: A Review.

The distal insertions of the tendons crossing the ankle as well as the tendons originating in the foot are less well known by radiologists. We review the anatomy and ultrasound appearance of these insertions using our own cadaveric sectioning and dissection. The ultrasound images were correlated with anatomical slices. Occasionally magnetic resonance images were also used for better understanding. Understanding the normal appearance of these tendon insertions is important for diagnosing pathology in this region.

Normal Anatomy and Compression Areas of Nerves of the Foot and Ankle: US and MR Imaging with Anatomic Correlation.

The anatomy of the nerves of the foot and ankle is complex, and familiarity with the normal anatomy and course of these nerves as well as common anatomic variants is essential for correct identification at imaging. Ultrasonography (US) and magnetic resonance (MR) imaging allow visualization of these nerves and may facilitate diagnosis of various compression syndromes, such as "jogger's heel," Baxter neuropathy, and Morton neuroma. It may be difficult to distinguish the nerves from adjacent vasculature at MR imaging, and US can help in differentiation. The authors review the normal anatomy and common variants of the nerves of the foot and ankle, with use of dissected specimens and correlative US and MR imaging findings. In addition, the authors illustrate proper probe positioning, which is essential for visualizing the nerves at US. The authors' discussion focuses on the superficial and deep peroneal, sural, saphenous, tibial, medial and lateral plantar, medial and inferior calcaneal, common digital, and medial proper plantar digital nerves.

Segond fracture: involvement of the iliotibial band, anterolateral ligament, and anterior arm of the biceps femoris in knee trauma.

OBJECTIVE: To evaluate the involvement of the iliotibial band (ITB), the anterolateral ligament (ALL), and the anterior arm of the biceps femoris in MRI-diagnosed Segond fracture and to evaluate other associated findings of Segond fracture. MATERIALS AND METHODS: We retrospectively reviewed the MRI of 13 cases of Segond fracture. The studies included proton density-weighted, T2-weighted, and proton density-weighted with fat saturation images in the three planes. We studied 2 cadaveric specimens with emphasis on the ALL. One cadaveric specimen was dissected while the other was sectioned in the sagittal plane. RESULTS: The mean age of the patients was 36 years (range, 17-52). There were 7 men and 6 women. The mean size of the Segond bone fragment was 8 × 10 × 2 mm. The distance from the tibia varied from 2 to 6 mm. Associated findings included anterior cruciate ligament (ACL) tear (n = 13), medial collateral ligament (MCL) tear (n = 8), meniscocapsular tear of the posterior horn of the medial meniscus (n = 5), and posterolateral corner involvement (n = 4). Bone marrow edema involved the mid-lateral femoral condyle and the posterior tibial plateau on both the medial and the lateral side. Edema at the Segond area was seen, but was limited. Fibular head edema was also seen. The ITB (11 out of 13) and ALL (10 out of 13) inserted on the Segond bone fragment. The anterior arm of the biceps tendon did not insert on the Segond fracture. CONCLUSION: Associated findings of Segond fracture include ACL tear, MCL tear, medial meniscus tear, and posterolateral corner injury. Both the ITB and the ALL may be involved in the Segond avulsion. The anterior arm of the biceps femoris tendon is not involved.

Advanced imaging of the scapholunate ligamentous complex.

The scapholunate joint is one of the most involved in wrist injuries. Its stability depends on primary and secondary stabilisers forming together the scapholunate complex. This ligamentous complex is often evaluated by wrist arthroscopy. To avoid surgery as diagnostic procedure, optimization of MR imaging parameters as use of three-dimensional (3D) sequences with very thin slices and high spatial resolution, is needed to detect lesions of the intrinsic and extrinsic ligaments of the scapholunate complex. The paper reviews the literature on imaging of radial-sided carpal ligaments with advanced computed tomographic arthrography (CTA) and magnetic resonance arthrography (MRA) to evaluate the scapholunate complex. Anatomy and pathology of the ligamentous complex are described and illustrated with CTA, MRA and corresponding arthroscopy. Sprains, mid-substance tears, avulsions and fibrous infiltrations of carpal ligaments could be identified on CTA and MRA images using 3D fat-saturated PD and 3D DESS (dual echo with steady-state precession) sequences with 0.5-mm-thick slices. Imaging signs of scapholunate complex pathology include: discontinuity, nonvisualization, changes in signal intensity, contrast extravasation (MRA), contour irregularity and waviness and periligamentous infiltration by edema, granulation tissue or fibrosis. Based on this preliminary experience, we believe that 3 T MRA using 3D sequences with 0.5-mm-thick slices and multiplanar reconstructions is capable to evaluate the scapholunate complex and could help to reduce the number of diagnostic arthroscopies.

Advanced imaging of the glenohumeral ligaments.

The glenohumeral ligaments (GHLs) are the most important passive stabilizers of the shoulder joint. Recognition of acute and chronic glenohumeral ligamentous lesions is very important in the preoperative work-up of shoulder instability and trauma. This article describes and depicts the normal anatomy of the GHLs and their appearance during arthroscopy and on MR and computed tomography arthrography (CTA). Pathologic findings of the superior, middle, and inferior GHLs are described and illustrated with MR and CTA and their corresponding intraoperative arthroscopic images. MR arthrography (MRA) is useful for direct visualization of all GHLs including most lesions of their intra-articular portion and associated capsulolabral pathologies. Sprains, midsubstance tears, avulsion, or fibrous infiltration of the GHL can be identified on MRA images using fast spin-echo sequences with and without fat saturation in the three planes. Although CTA is reputed to better depict associated bony and cartilage lesions, CTA allows only indirect evaluation of the GHLs by outlining their contour or showing contrast penetration. Normal variants may create pitfalls that one should be aware of. Signs of GHL pathology on imaging include: discontinuity, nonvisualization, changes in signal intensity (on MRA), contrast extravasation, contour irregularity, thickening, or waviness.

Distal insertions of the semimembranosus tendon: MR imaging with anatomic correlation.

OBJECTIVE: The purpose of this study is to investigate the distal insertions of the semimembranosus tendon with MR imaging, correlated with findings in cadavers. MATERIALS AND METHODS: Four fresh cadaveric specimens were studied with 3-T MR imaging. Sequences included proton density (PD) sequences (TE, 13; TR, 4957; FOV, 170 × 170; matrix, 424 × 413; NA, 2; slice thickness, 2.5 mm) in the axial, coronal, and sagittal planes and 3D fast field echo (FFE) sequences (TR 9.4; TE 6.9; FOV, 159 × 105; matrix, 200 × 211; NA, 2; slice thickness, 0.57 mm). One specimen was dissected and three specimens were sectioned with a bandsaw in the axial, coronal, and sagittal plane. The sections were photographed and correlated with MR images. To standardize the analysis, the semimembranosus muscle and tendon were assessed at seven levels for the axial sections, and at three levels for the coronal and sagittal sections. RESULTS: Anatomic dissection revealed six insertions of the distal semimembranosus tendon: direct arm, anterior arm, posterior oblique ligament extension, oblique popliteal ligament extension, distal tibial expansion (popliteus aponeurosis), and meniscal arm. Axial MR images showed five of six insertions: direct arm, anterior arm, oblique popliteal ligament extension, posterior oblique ligament extension, and distal tibial expansion. Sagittal MR images showed four of six insertions: direct arm, anterior arm, oblique popliteal ligament arm, and distal tibial expansion. Sagittal MR images were ideal for showing the direct arm insertion, but were less optimal than the axial images for showing the other insertions. The anterior arm was seen but volume averaging was present with the gracilis tendon. Coronal MR images optimally revealed the anterior arm, although magic angle artifact was present at its posterior aspect. The common semimembranosus tendon and meniscal arm were also well depicted. The division in anterior arm, direct arm, and oblique popliteal ligament arm was poorly seen on coronal images due to volume averaging. CONCLUSIONS: Although the anatomy of the distal semimembranosus tendon is complex, six different semimembranosus insertions can be identified on routine proton density and FFE sequences at 3 T. Analysis of images at defined levels in the three imaging planes simplifies MR interpretation of the anatomy of the distal semimembranosus tendon.

Ultrasound of the knee with emphasis on the detailed anatomy of anterior, medial, and lateral structures.

OBJECTIVE: To describe the detailed ultrasound anatomy of the anterior, medial, and lateral aspects of the knee and present the ultrasound examination technique used. MATERIALS AND METHODS: We present ultrasound using images of patients, volunteer subjects, and cadaveric specimens. We correlate ultrasound images with images of anatomical sections and dissections. RESULTS: The distal quadriceps tendon is made up of different laminas that can be seen with ultrasound. One to five laminas may be observed. The medial retinaculum is made up of three anatomical layers: the fascia, an intermediate layer, and the capsular layer. At the level of the medial patellofemoral ligament (MPFL) one to three layers may be observed with ultrasound. The medial supporting structures are made up of the medial collateral ligament and posterior oblique ligament. At the level of the medial collateral ligament (MCL), the superficial band, as well as the deeper meniscofemoral and meniscotibial bands can be discerned with ultrasound. The posterior part, corresponding to the posterior oblique ligament (POL), also can be visualized. Along the posteromedial aspect of the knee the semimembranosus tendon has several insertions including an anterior arm, direct arm, and oblique popliteal arm. These arms can be differentiated with ultrasound. Along the lateral aspect of the knee the iliotibial band and adjacent joint recesses can be assessed. The fibular collateral ligament is encircled by the anterior arms of the distal biceps tendon. Along the posterolateral corner, the fabellofibular, popliteofibular, and arcuate ligaments can be visualized. CONCLUSION: The anatomy of the anterior, medial, and lateral supporting structures of the knee is more complex than is usually thought. Ultrasound, with its exquisite resolution, allows an accurate assessment of anatomical detail. Knowledge of detailed anatomy and a systematic technique are prerequisites for a successful ultrasound examination of the knee.