Catherine Cyteval

Bilateral ischiofemoral impingement in a patient with hereditary multiple exostoses.

The skeletal anatomy of the hip provides two main locations for impingement: abnormal contact between the acetabulum and femur (femoroacetabular impingement) or between the ischium and femur (ischiofemoral impingement). We report a case of bilateral ischiofemoral impingement in a patient with hereditary multiple exostoses. The association of exostoses and femoral metaphyseal widening resulted in the narrowing of the ischiofemoral spaces. Pain was improved on the left side by resection of the ischial exostosis.

Imaging orthopedic implant infections

The diagnosis of infections associated with orthopedic implants is based on a combination of clinical signs, laboratory findings and imaging studies. There is no gold standard imaging technique: conventional radiography is indispensable, although 50% of the time the radiograph is normal. Computed tomography (CT), magnetic resonance imaging (MRI) and ultrasonography are valuable to detect soft tissue abnormalities. Bone scintigraphy (BS) rules out active infection. For infections involving the peripheral skeleton, labeled white blood cell (WBC) scintigraphy coupled with colloid scintigraphy is the reference technique, whereas a gallium scan is always necessary for imaging the spine or pelvis. To confirm or rule out infection, needle aspiration with analysis of aspirated fluid is the cornerstone of the diagnostic algorithm.

Hoffa's disease: A report on 5 cases

We report the case of five patients referred to our department with Hoffas disease: three patients were at the initial stage of the disease and the two others had reached the chronic stage. This condition is one of the less well-documented causes of pain in the anterior compartment of the knee. The pathophysiological mechanism is still unclear. It is probably caused by repetitive micro trauma resulting in inflammatory, haemorrhagic and fibrous changes to Hoffas fat pad. The final outcome of the disease is an osteochondroma. The diagnosis is established by MRI, which demonstrates inflammation of the fat pat. At the chronic stage, a standard X-ray is sufficient to demonstrate ossification of the fat pad.

Imaging of the postoperative knee

On sagittal images after anterior cruciate ligament (ACL) reconstructions, the femoral tunnel aperture should be at the junction of the line drawn along the posterior femoral cortex and the line drawn along the roof of the intercondylar notch (Bluemensaat line). The tibial tunnel aperture should be in the anterior portion of the second third, i.e. anterior aspect of the middle of the tibial epiphysis. An inaccurate placement of the femoral tunnel affects the graft isometry. A tibial tunnel too anteriorly placed results in intercondylar notch roof impingement. After meniscus surgery, first-line MRI is often sufficient to diagnose new tears; however, sometimes it is necessary to perform CT arthrography or MR arthrography. Surgical cartilage repair is evaluated based on articular congruity and on the appearance of the subchondral bone.

Tumors of the rib

The authors propose a pictorial review illustrating the imaging features of chest wall tumors and their specific features that discusses the main differential diagnoses. This review is based on published information and on our own experience.

Transient high density vertebral bone lesions

The contrast-enhanced CTexamination revealed sclerotic-like lesions associated with consecutive anterior and posterior elements from the fourth cervical vertebra to the fifth thoracic vertebra, without any lytic components, which could at first be considered as bony metastases (Fig. 1a–b). CT scan also highlighted significant collateral venous circulation secondary to a brachiocephalic left venous thrombosis. A PET-CT performed at the same time was negative. A non-contrast CT scan performed 10 days later did not reveal the initially noted bone lesions (Fig. 2a–b) and suggested diagnosis of intraosseous venous contrast media. The 1-year non-contrast CT follow-up did not show any progression of the disease. Given the lack of corresponding findings on the unenhanced CT, in the setting of central venous obstruction and collateral pathway formation, the high-attenuation lesions seen on the enhanced CTexamination can be explained by the presence of intraosseous venous collaterals. In fact, the left brachiocephalic vein obstruction was responsible for the development of an extensive collateral venous pathway (Fig. 2c–d) involving the mediastinum, anterior jugular veins, anterior, and basivertebral venous plexi. The venous pressure in the dilated capillaries allowed marrow enhancement through the anastomosis capillary sites: basivertebral veins bed (between the anterior external plexus and the posterior internal plexi) and pedicular sites (between the intervertebral veins and the vertebral plexi) (Fig. 3a–b). Our patient remained asymptomatic despite the huge collateral venous substitution. The rate of injection of contrast and the time of image acquisition following contrast injection might be factors influencing the appearance of these findings. Chest collateral veins usually occur in superior vena cava obstruction and then develop through four classic pathways: azygos and hemiazygos, internal thoracic and laterothoracic, superficial thoracoabdominal, and vertebral venous plexus (posterior way) [1, 2]. These patients usually present with a symptomatic superior vena cava syndrome [3]. Less frequently, chest collateral veins can develop secondary to unilateral thrombosis of the brachiocephalic venous trunk, as in our case where the posterior pathway was involved [4]. Several cases of visceral abnormalities related to superior vena cava syndrome, including pericardial and hepatic enhancement, have been described [5]. However, bone involvement is uncommon. Only, two cases of cervical vertebral bone high-density abnormalities have been described in the context of superior vena cava syndrome secondary to a mediastinal mass (epidermoid lung carcinoma and small-cell lung carcinoma) [6, 7]. To our knowledge, there are no reports of similar cases of vertebral marrow abnormalities in asymptomatic patients, without any mass syndrome or obstructed superior cava vein. In the case presented, the findings could be misinterpreted as lymphomatous bone marrow involvement because of the patient’s history even though bony features of osseous lymphoma are usually lytic and seldom sclerotic, with soft tissue involvement. In summary, the present case illustrates a benign lesion entity related to retrograde contrast filling in bone marrow. The case presentation can be found at doi: 10.1007/s00256-013-1619-2

Imaging of tumors and tumor-like lesions of the knee

Tumors and tumor-like lesions of the knee are common conditions. Because the synovial membrane covers a large part of the knee, tumors and tumor-like lesions of the knee are mostly synovial. Magnetic resonance imaging (MRI) plays a major role in the assessment and characterization of these lesions. However, the diagnostic approach of these lesions must be performed systematically. First, the lesion must be precisely located, and then the anatomical structure involved must be determined. Finally, clinical background that includes the age of the patient, frequency of the disease and, if any, associated signs as well as MRI characteristics must be analyzed. In this review, we describe the anatomy of the knee and its compartments and provide a description of the main tumors and tumor-like lesions of the knee. We present a diagnostic approach based on the location within the knee of the lesions and the anatomical structures involved.

Prevalence and topographic distribution of spinal inflammation on MR imaging in patients recently diagnosed with axial spondyloarthritis.

OBJECTIVE The primary goal of this study was to determine the prevalence and topographic distribution of spinal lesions in lower thoracic and lumbar spine on magnetic resonance imaging (MRI) in patients with recently diagnosed with spondyloarthritis. The secondary goal was to identify variables associated with vertebral patterns consistent with spondyloarthritis on MRI. PATIENTS AND METHODS A total of 112 HLA-B27 positive patients with recently diagnosed spondyloarthritis were retrospectively included. There were 70 women and 42 men, with a mean age of 41 years±12 (SD) (range: 17-70years). Mean symptom duration was 1year (range: 0-7years). MRI examinations of sacroiliac joints and thoracolumbar spine were reviewed for the presence of bone marrow edema, chronic structural abnormalities, and vertebral patterns consistent with spondyloarthritis. Age, gender and disease duration of patients with vertebral patterns on MRI consistent with spondyloarthritis were compared with those without MRI signs of spondyloarthritis. RESULTS Thirty-six patients (32.1%) showed spinal patterns of spondyloarthritis, including 16 patients (14.3%) with no associated inflammatory sacroiliitis. Posterior inflammatory lesions were present in 20.5% of patients. Posterior spinal inflammatory lesions were significantly associated with vertebral corner inflammatory lesions (P=0.03). There were no differences in age, sex or mean duration of symptoms between the two groups of patients. CONCLUSION Spinal involvement is observed in 32.1% of HLA-B27 positive patients with recently diagnosed spondyloarthritis and is not associated with sacroiliitis in 14.3%. Age, gender or symptom duration are not associated with spinal involvement on MRI.

MRI for diagnosis of axial spondyloarthritis: major advance with critical limitations ‘Not everything that glisters is gold (standard)’

Recognition of axial spondyloarthritis (SpA) remains challenging, as no unique reference standard is available to ascertain diagnosis. Imaging procedures have been used for long in the field, in particular pelvic radiography, to capture structural changes evocative of sacroiliitis, the key feature in SpA. The introduction of MRI of the sacroiliac joints (SIJs) has led to a major shift in recognition of the disorder. MRI has been shown to detect the initial inflammatory processes, in particular osteitis depicted by bone marrow oedema, even in patients having not yet developed structural lesions. In addition, MRI has revealed a previously under-recognised very early clinical phase of the disease where patients have symptomatic axial involvement, but no structural changes. However, what constitutes a ‘positive MRI’ in SpA remains controversial, since both sensitivity and specificity show limitations, and interpretation of MRI lesions in daily practice is critically dependent on the clinical context. There is growing evidence that integration of the assessment of structural changes on dedicated T1 weighted-sequences on MRI may enhance diagnostic utility. The performance of MRI in detecting structural lesions in the SIJs may even be superior to traditional evaluation by pelvic radiography. These findings launched a debate on imaging in SpA, whether MRI, which is advancing early recognition of disease and shows superiority to detect structural changes, should replace traditional conventional radiography of the SIJs.

Anti-NXP2 antibody-associated extensive subcutaneous calcinosis in adult-onset myositis

A 68-year-old woman was followed since 1988 for DM. A combined therapy of corticosteroids and MTX controlled muscle involvement. In 1993, multiple subcutaneous nodules of calcinosis appeared on the limbs, chest and abdomen. In 2013, extensive calcinosis severely impaired the patient’s quality of life while myositis was under control (Fig 1). In 2016, a blood sample was collected in which circulating anti-NXP2 antibodies were detected. Anti-NXP2 antibodies were first identified in 1997. Today, 25% of patients with juvenile DM demonstrate these autoantibodies in their blood samples, indicating a poor prognosis [1]. Anti-NXP2 antibodies are detected in only 1% of cases of adult patients with myositis, and are likely linked to the occurrence of neoplasms [2]. Therefore, although typical in paediatric patients, an extensive form of calcinosis in an adult case of anti-NXP2 antibody-associated myositis is extremely rare. In our case, the evolution of calcinosis is independent from muscle involvement. Furthermore, MTX, corticosteroids and IVIGs were inefficient in preventing the spreading of calcinosis. Currently, a topical sodium thiosulphate treatment is being trialled. Thus, an early detection of anti-NXP2 antibodies could help identify a subset of adult patients at risk of developing calcinosis during the early stages of DM.