High-Field MRI Advantages and Applications in Rheumatology.

Imaging of rheumatologic diseases has historically been performed using conventional radiography. MRI offers an opportunity for detection of altered marrow signal in early disease that is not visible on other imaging modalities such as radiography, computed tomography, or sonography. This review describes the advantages of current MRI techniques in the diagnosis and treatment monitoring of rheumatologic diseases. In addition, this review discusses novel MRI techniques at high-field magnetic strength which may be deployed in the future to allow for improved imaging resolution and quantitative assessment of both axial and peripheral joints.

Dysbaric osteonecrosis (DON) among the artisanal diving fishermen of Yucatán, Mexico.

INTRODUCTION: Artisanal diving fishermen in Yucatán, Mexico have high rates of decompression sickness as a result of frequently unsafe diving practices with surface supplied compressed air. In this study, we investigated the prevalence of dysbaric osteonecrosis (DON), a type of avascular necrosis, in the most susceptible joints in a cohort of these fishermen. METHODS: We performed radiographs of bilateral shoulders, hips, and knees of 39 fishermen in Mexico and surveyed them about their medical and diving histories. We performed pairwise correlations to examine if the fishermen's diving behaviours affected the numbers of joints with DON. RESULTS: The radiographs revealed Grade II or higher DON in 30/39 (76.9%) of the fishermen. Twenty-two of 39 fishermen (56.4%) had at least two affected joints. The number of joints with DON positively correlates with the lifetime maximum diving depth and average bottom time. CONCLUSIONS: These findings represent among the highest prevalence rates of DON in divers and reflect the wide-spread scale of decompression sickness among these fishermen. Through this work, we hope to further educate the fishermen on the sequelae of their diving with the aim of improving their diving safety.

Periosteal stripping in high ankle sprains: An association with osteonecrosis.

OBJECTIVE: We present a series of 20 cases of a sleeve-type injury of the distal tibia characterized by traumatic periosteal stripping caused by a high ankle sprain. We characterize the magnetic resonance imaging findings associated with this injury and highlight its association with distal tibial osteonecrosis. MATERIALS AND METHODS: We collected 20 cases of high ankle sprains with periosteal stripping of the distal tibia through teaching files and a search through our PACS database. We recorded the presence and pattern of syndesmotic ligamentous injury and the presence or absence of syndesmotic widening in patients with periosteal stripping. The presence or absence of associated fractures and osteonecrosis was noted and characterized by location. RESULTS: The most commonly torn ligament was the anterior inferior tibiofibular ligament. 25% (5/20) of the patients in our series developed osteonecrosis. Osteonecrosis developed as early as 3-4 weeks following the initial injury. Of the patients with osteonecrosis, 40% (2/5) had fractures of the posterior malleolus. All patients with osteonecrosis had widening of the syndesmosis. Two of the five patients with osteonecrosis were in the pediatric age group. CONCLUSION: In contrast to conventional syndesmotic and interosseous ligamentous tearing, high ankle injuries with tibial periosteal stripping may result in avulsion of the extra-osseous vasculature supplied by the periosteum, leading to osteonecrosis. This pattern of injury has not been emphasized in the literature. Our findings underscore the importance of the integrity of the periosteum for maintaining adequate vascularity of the distal tibia.

Accessory anterolateral talar facet associated with tarsal coalition: prevalence and cross-sectional characterization.

OBJECTIVE: The accessory anterolateral talar facet (AALTF) is a developmental entity described as a potential cause for rigid, painful flat foot. This study evaluates the possible association between the AALTF and other flat foot etiologies, specifically different types of tarsal coalitions. MATERIALS AND METHODS: We evaluated patients with tarsal coalition or sinus tarsi syndrome for an AALTF on CT and MRI. Exclusion criteria included acute ankle trauma, recent surgery, motion or metal artifacts. We evaluated the AALTF length and height, and the lateral talocalcaneal structures for associated findings. The presence of calcaneonavicular (CNC), intra-articular middle facet talocalcaneal (MFTCC), posterior facet talocalcaneal (PFTCC), extra-articular posteromedial talocalcaneal (EATCC) and other rare coalitions were also evaluated. RESULTS: One hundred eighty-seven patients were included (age range 14-91 years; mean ± SD; 50 ± 17 years). The AALTF prevalence in the study population was 31.55% (59/187), 40.91% in men, and 23.23% in women. The AALTF average length was 4.5 ± 1.1 mm, and average height was 8.9 ± 3.4 mm. The AALTF was found to be significantly associated with lateral talocalcaneal osseous changes such as cortical thickening and cystic changes (34/59 and 24/59 respectively, P < 0.01). The AALTF was also found to be significantly associated with sinus tarsi edema on MRI (45/52, P < 0.05). The AALTF was also significantly associated with EATCC (19/59, P < 0.01) and MFTCC (7/59, P < 0.05). No significant association was found with CNC, PFTCC or other rare coalitions. CONCLUSION: The AALTF is common and significantly associated with some tarsal coalitions, specifically EATCC and MFTCC. When an AALTF or coalition is identified, special attention should be made to evaluate for other associated pathologies, as this could potentially affect management.

Isolated peroneal tenosynovial lipoma arborescens: multimodality imaging features.

Synovial lipoma arborescens is a rare and benign fatty proliferative lesion of the synovium that is most commonly seen within the suprapatellar pouch of the knee, but increasingly reported to involve tendon sheaths, including those of the ankle. We present the third known case of tenosynovial lipoma arborescens isolated to the peroneal tendon sheath without ankle joint involvement. To our knowledge, this is the first to report this entity utilizing a unique combination of radiographic, sonographic, and MR imaging, along with intraoperative and histologic correlation. Knowledge of this case is important when interpreting radiographic or sonographic images of this condition to raise the possibility of the rare entity of lipoma arborescens involving the peroneal tendon sheath.

Abnormal Bone Marrow Signal Intensity in the Phalanges of the Foot as a Manifestation of Raynaud Phenomenon: A Report of Six Patients.

OBJECTIVE: The objectives of our study were to describe the MRI findings of pedal phalangeal bone marrow edema in patients with Raynaud phenomenon (RP) and discuss the clinical implications of these MRI findings. CONCLUSION: There is a progressive distal-to-proximal pattern of pedal phalangeal bone marrow edema on MRI in patients with RP. This knowledge may allow early diagnosis and treatment of rheumatologic disorders that are potentially associated with RP.

Intramedullary fat globules related to bone trauma: a new MR imaging finding.

OBJECTIVE: The purpose of this study is to describe intraosseous fat globules related to bone trauma that are detectable with magnetic resonance imaging (MRI), to define the relationship of this finding to fracture and bone contusion, to establish the frequency and associated findings. A proposed pathogenesis is presented. MATERIALS AND METHODS: We retrospectively reviewed 419 knee MRI examinations in patients with a history of recent injury and MRI findings of fracture or bone contusion. As a control population, 268 knee MRI examinations in patients without MRI findings of recent bone injury were also reviewed. RESULTS: Eight of 419 (1.9%) patients with acute or subacute knee injury with positive findings of osseous trauma on MRI demonstrated intraosseous fat globules. The mean age of patients with fat globules was greater than that of those without fat globules, and the finding was more commonly seen in women. Fat globules were hyperintense to the normal fatty marrow present elsewhere in the bone on TI-weighted imaging and had a surrounding halo of high signal intensity on fluid-sensitive imaging. CONCLUSIONS: Intramedullary fat globules related to bone injury visible on MRI are thought to be due to coalesced fat released by the necrosis of fatty marrow cells. The pathogenesis is supported by histologic studies of fat globules related to osteomyelitis, bone contusions and fractures. As the medullary cavity of long bones in older patients contains more fat than hematopoetic bone marrow, it is likely that this finding is more common with advancing age.

MRI of the metatarsophalangeal joints: improved assessment with toe traction and MR arthrography.

OBJECTIVE: This study evaluates the impact of toe traction and direct MR arthrography on the assessment of articular cartilage and plantar plates of the first and second metatarsophalangeal joints. MRI of five cadaveric feet was obtained utilizing four techniques: before arthrography without and with traction and after arthrography without and with traction. CONCLUSION: The combination of toe traction and MR arthrography is perceived to be superior in the articular cartilage and plantar plate evaluation.

Superior labrum anterior and posterior lesions and microinstability.

The glenohumeral joint provides the greatest range of motion of any joint in the human body. Over the past several decades, histologic studies, biomechanical studies, and improved arthroscopic techniques have contributed to improved knowledge and treatment of glenohumeral joint abnormalities. Continuing advances in magnetic resonance technology have allowed for improved noninvasive visualization of the stabilizers of the shoulder. This article reviews the concept of glenohumeral joint microinstability and its relationship with superior labrum anterior and posterior (SLAP) lesions, reviews the role of the labrum as a stabilizer of the shoulder, and focuses on the diagnosis and classification of SLAP lesions.

Effects of repeated distension arthrographies combined with a home exercise program among adults with idiopathic adhesive capsulitis of the shoulder.

OBJECTIVE: The purpose of this study was to measure the effect of repeated distension arthrographies combined with a home exercise program on impairments and disability of the upper limb in subjects with adhesive capsulitis of the shoulder. DESIGN: A total of 15 subjects with idiopathic adhesive capsulitis participated in the study. Intervention consisted of three distension arthrographies with steroid, done at 3-wk intervals, and a home exercise program. The repeated-measures design included five clinical evaluations with disability, pain, range of motion, and pain-free static strength outcomes. Two evaluations done before the first arthrography verified the stability of the condition. RESULTS: There was a significant improvement of all outcomes at the end of intervention. The greatest effects occurred after the first distension arthrography. After the second, less marked, albeit significant, changes were observed in three motions of the shoulder and in the pain level. After the third distension arthrography, very small changes were noted. A comparison between sides revealed incomplete recovery of the range of motion on the affected side. CONCLUSIONS: These findings showed that two distension arthrographies with steroid combined with a home exercise program reduce shoulder disability and impairments. Adding a third distension arthrography does not seem to provide any further benefit.