Intramedullary, periosteal, and extraskeletal Ewing sarcomas: retrospective study of a series of 126 cases in a reference center.

OBJECTIVE: To evaluate the proportion of extraskeletal, periosteal, and intramedullary Ewing sarcomas among musculoskeletal Ewing sarcomas. MATERIAL AND METHOD: Our single-center retrospective study included patients with musculoskeletal Ewing sarcoma diagnosed between 2005 and 2019 in our pathology center (cases from our adult bone tumor referral center and adult and pediatric cases referred for review). Recurrences, metastases, and visceral Ewing sarcomas were excluded. Intramedullary Ewing sarcomas were defined by involvement of the medullary cavity. Periosteal cases were defined by involvement of the subperiosteal area without extension to the medullary cavity. Extraskeletal cases were defined by the absence of involvement of the bone tissue and the subperiosteal area. RESULTS: Our series included 126 patients with musculoskeletal Ewing sarcoma, including 118 skeletal Ewing sarcomas (93.7%) and 8 extraskeletal Ewing sarcomas (6.3%). Of the 118 skeletal Ewing sarcomas 112 were intramedullary (88.9%) and 6 were periosteal (4.8%). Extraskeletal Ewing sarcomas were more common in women and in patients older than 40 (p < 0.05). DISCUSSION: The 6.3% proportion of extraskeletal Ewing sarcoma is lower than the median of 30% estimated from the literature. This difference could be explained by an overestimation of extraskeletal Ewing sarcomas of the chest wall (Askin tumors), an underestimation of periosteal cases confused with extraskeletal cases, and the presence of "Ewing-like" soft tissue sarcomas in previous series. Because of its prognostic and therapeutic impact, the distinction of morphologic subtypes requires the cooperation of experienced radiologists and pathologists.

The proximal vastus lateralis flap: An anatomical and radiological study.

INTRODUCTION: Soft-tissue reconstruction following acetabular or proximal femur resection for bone tumors is challenging. The vastus lateralis flap has been proposed as an advancement or rotational flap to cover soft-tissue defects for such locoregional indications. We performed an anatomical and a radiological study to assess the vascularization of the proximal vastus lateralis muscle achieved through the transverse branch of the lateral circumflex femoral artery in order to decrease the morbidity of the classical flap retrieval technique. MATERIAL AND METHODS: Five fresh adult cadavers were dissected bilaterally. Each vastus lateralis dissection was prealably injected with contrast-media agent through the lateral circumflex artery and CT scan images was recorded. A descriptive and an analytical study were carried out. RESULTS: The median length and width of the entire muscle were 31.2cm (Q1-Q3: 29.7-33.3) and 12.7cm (Q1-Q3: 7.0-14.9), respectively; the median surface area of the entire vastus lateralis muscle was 282cm2 (Q1-Q3: 172.6-455.6) cm2. The median length and width of the perfused area were 13.3cm (Q1-Q3: 12.3-16.6) and 9.4cm (Q1-Q3: 6.9-8.8) cm, respectively; the median surface of the perfused area was 89.4cm2 (Q1-Q3: 67.4-110.5) cm2. The mean length of the pedicle measured on the CT scan was 6.3cm (95% CI: 5.5-7.1). CONCLUSION: The proximal vastus lateralis flap as a pedicled muscular flap supplied by the transverse branch of the lateral circumflex femoral artery is a muscular flap that can be used by reconstructive and orthopaedic surgeons to repair soft-tissue defects around the hip joint without undue damage to the functional apparatus of the knee.

Parosteal osteosarcoma associated with a low-grade component mimicking well-differentiated liposarcoma: a case report.

Parosteal osteosarcomas and well-differentiated liposarcomas are both well-differentiated locally aggressive tumors. They both have simple karyotypes with amplification of the 12q13-15 regions including MDM2 and CDK4 genes. In this report, we describe the case of a parosteal osteosarcoma intertwined with a low-grade component similar to a well-differentiated liposarcoma. The association of a bone component with an adipose component was initially overlooked. We describe the histological, imaging, and molecular characteristics of this tumor stressing the importance of radio-pathological correlation. To our knowledge, this is the second report of a parosteal osteoliposarcoma. Awareness of this rare presentation may allow radiologists and surgeons to recognize the peripheral fatty component as an integral part of the tumor.

Measurement of Trabecular Bone Score of the Spine by Low-Dose Imaging System (EOS®): A Feasibility Study.

Purpose/Introduction: Measurement of trabecular bone score (TBS®) of the lumbar spine on dual energy X-ray absorptiometry (DXA) devices improves fracture risk prediction. We conducted a proof of concept study to assess the feasibility of TBS® measured on the low-dose imaging system EOS®. METHODS: TBS was assessed on both DXA and EOS® in 122 patients aged ≥ 50 yr, receiving no anti-osteoporotic treatment. The TBS® was computed on full-body EOS® images, focusing on the lumbar spine region. The patients were also scanned with a DXA bone densitometer (Hologic) and the spine and hip bone mineral density (g/cm²) were computed. RESULTS: TBS® measurement on EOS® was not possible in 34 patients due to technical problems. It could be measured on both DXA and EOS® in 88 patients (28 with severe low-trauma fracture and 60 without fracture). TBS-EOS values were significantly lower in fractured patients compared to nonfractured patients. TBS-EOS was associated with the presence of fractures as reported by an AUC of 0.70. Odds ratio of TBS-EOS for the presence of severe low-trauma fracture was 2.00 [1.24-3.25], p = 0.005. CONCLUSIONS: This proof of concept study, based on a prototype version of the TBS-EOS, demonstrated the feasibility of the measurement of TBS® on low-dose EOS® imaging devices. Results show that the TBS-EOS was lower in patients with severe low-trauma fractures compared to nonfractured patients independently from bone mineral density. Some technical issues need to be solved before its eventual use in routine clinical settings. Additional prospective studies are still needed to define the actual contribution of this new technique.

Therapeutic outcome of CT-guided radiofrequency ablation in patients with osteoid osteoma.

OBJECTIVE: To assess the long-term outcome of computed tomography-guided radiofrequency ablation (CT-guided RFA) in patients with suspected osteoid osteoma (OO). MATERIALS AND METHODS: Single-center retrospective study. Patients with clinical suspicion and imaging diagnosis of osteoid osteoma were treated by CT-guided RFA using the same device with either a 7- or 10-mm active tip electrode. Specific precautions were applied in case of articular or spinal OO. Patients were contacted by phone to evaluate the long-term outcome in terms of pain, ability to perform daily activities (including sports), and long-term complications. Success was defined as the absence of residual pain and ability to perform daily activities normally. RESULTS: From 2008 to 2015, 126 patients were treated by CT-guided RFA for OO in our institution. Mean patient age was 26.1 years (SD = 11, range 1-53); mean delay to diagnosis was 16.9 months (SD = 15.2, range 1-120). Among patients who answered the follow-up call (n = 88), the overall success rate was 94.3%: 79/88 (89.8%) had primary success of the procedure, and 4/88 (4.5%) had a secondary success (repeat-RFA after pain recurrence). Mean follow-up time was 34.6 months (SD = 24.7, range 3-90). Few complications occurred: two mild reversible peripheral nerve injuries, one brachial plexus neuropathy, one broken electrode tip fragment, and one muscular hematoma. CONCLUSION: Osteoid osteoma can be effectively and safely treated by CT-guided RFA using the presented ablation protocol. Beneficial effects of the treatment persist at long-term follow-up.

Sagittal balance of the spine in patients with osteoporotic vertebral fractures.

UNLABELLED: This study aims to compare the sagittal global spinal balance of patients consulting for osteoporosis, aged above 50 years with and without osteoporotic vertebral fractures (VFs). Global spinal balance is abnormal even in subjects without VFs. VFs and age are determinants of sagittal global balance; however, pelvic parameters play a role in compensatory mechanisms. INTRODUCTION: This study aims to compare the spine curvatures, pelvic parameters, and the sagittal global spinal balance of patients aged above 50 years with and without osteoporotic vertebral fractures. METHODS: Two hundred patients (95 % women) aged 68.3 ± 9.5 years underwent full skeleton radiographs in the standing position, by EOS®, a low dose biplane X-ray imaging system. VFs were evaluated according to Genant's classification. Spinal (thoracic and lumbar Cobb's indices, thoracic and lumbar tilts) and pelvic (pelvic tilt, sacral slope, and pelvic incidence) parameters were measured. Sagittal spinal balance was measured using the C7 plumb line and the spinosacral angle (SSA). We compared these parameters in patients with and without vertebral fracture and assessed the determinants of abnormal sagittal spinal balance. RESULTS: Sixty-nine patients had at least one VF. The sagittal spinal balance was significantly altered in patients with at least one VF, and there was an effect of the number and severity of VFs on parameters. Discriminative value for identification of patients with at least one VF, assessed by Area Under the Curves (AUCs) was 0.652 and 0.706 for C7 plumbline and SSA, respectively. Using multivariate analysis, parameters significantly associated with abnormal spinal balance (SSA) were the presence of at least one VF (OR = 4.96, P < 0.0001), age (OR = 1.07, P = 0.0006), and high pelvic incidence as a protective factor (OR = 0.93, P < 0.0001). CONCLUSIONS: Global spinal balance is abnormal in subjects consulting for osteoporosis, even in subjects without VFs. VFs and age are determinants of abnormal sagittal global balance; however, pelvic parameters play a role in compensatory mechanisms.

Diagnosis of vertebral fractures using a low-dose biplanar imaging system.

UNLABELLED: Vertebral fractures (VFs) are independent risk factors for new fractures. However, spine radiographs cannot be used as a screening method. EOS® has a good diagnostic value for the diagnosis of VF with a better legibility of upper thoracic spine and a higher concordance between readers compared to vertebral fracture assessment (VFA). INTRODUCTION: Vertebral fractures (VFs) are risk factors for new fractures. However, spine radiographs cannot be used as a screening method for both cost and radiation concerns. EOS® X-ray imaging system which allows the acquisition of biplane images in an upright weight-bearing position with low radiation dose was used. The objective of this study was to compare EOS® to VFA for the diagnosis of VF. METHODS: We conducted a cross-sectional study in subjects aged above 50 years with indication for spine imaging. EOS® and VFA of the spine were performed the same day. Sensitivity (Se), specificity (Sp), negative predictive value (NPV), and the interobserver precision of EOS® were compared to VFA for the diagnosis of VF. RESULTS: Two hundred patients (mean age 66.2 years) were included. At the vertebral level, 2.4 and 3.6 % of vertebrae were not legible using EOS® and VFA, respectively (p = 0.0007). The legibility of spine was significantly affected by scoliosis (odds ratio (OR) = 2.8, p < 0.0001, for EOS®, and OR = 1.8, p = 0.0041, for VFA). Sixty-six patients (33.0 %) and 69 (34.5 %) had at least one VF using VFA and EOS®, respectively. At patient level, Se, Sp, and NPV for the diagnosis of VF of EOS® were 79.7, 91.6, and 99 %, respectively. Concordance between both observers was very good for EOS® (kappa-score = 0.89), higher than for VFA (κ = 0.67). CONCLUSIONS: This study shows that EOS® has a good diagnostic value for the diagnosis of VF with a better legibility of upper thoracic spine and a higher concordance between readers compared to VFA.

MDCT imaging of calcinosis in systemic sclerosis.

Calcinosis is a typical feature of systemic sclerosis (SSc) and can be found in many different tissues including the superficial soft tissues, periarticular structures, muscles, and tendons. It can also provoke erosive changes on bones. Investigation is conducted most often with plain radiographs. However, when a more detailed assessment is necessary, multidetector computed tomography (MDCT) is helpful owing to its multiplanar reformat (MPR) ability. The purpose of this review is to provide an overview of the various appearances of calcinosis in SSc patients as visualized at MDCT.

Measures of spinal canal stenosis and relationship to spinal cord structure in patients with cervical spondylosis.

OBJECTIVES: Spinal canal stenosis is often measured on anatomical magnetic resonance imaging (MRI) to estimate the degree of spinal cord compression. This study examined whether two quantitative measures of spinal canal stenosis taken from anatomical MRI are related to spinal cord white-matter integrity in patients with cervical spondylosis measured by diffusion tensor imaging (DTI). PATIENTS AND METHODS: DTI and T2-weighted MRI of the cervical spinal cord were performed in 15 patients with cervical spondylosis and ten healthy control subjects of similar age. Severity of stenosis was calculated using Pavlov's ratio and the space-available-for-cord (SAC) technique. RESULTS: Patients had significantly lower Pavlov's ratios and SAC (C2-C3, C4-C5 and C6-C7), lower fractional anisotropy (FA; C2-C3 and C4-C5) and higher radial diffusivity (C2-C3, C4-C5 and C6-C7) than the controls. In patients, only Pavlov's ratio correlated with mean FA (R=0.66, P=0.008). Variations in Pavlov's ratio and FA also showed a similar pattern across cervical levels. CONCLUSION: Pavlov's ratio is a better predictor of spinal cord integrity than the SAC and, therefore, may be more relevant clinically for the evaluation of stenosis in patients with cervical spondylosis.

Preoperative ultrasonography and magnetic resonance imaging evaluation of the position of the neurovascular bundle for Dupuytren's disease of the fifth digit.

BACKGROUND: Dupuytren's contracture (DC) is a fibrosing disor-der that produces pathological subcutaneous nodules and cords in the normal fascia. The isolated occurrence of Dupuytren's disease of the fifth digit is uncommon. This study is aimed to describe the imaging features of an isolated digital cord of the small finger and its relationship with the neurovascular bundle. METHODS: A total of 13 hands in 13 patients who were clinically diagnosed with an isolated occurrence of Dupuytren's disease of the small finger were included between October 2008 and October 2013. Two independent radiologists used ultrasound and magnetic reso-nance imaging (MRI) to record size, signal or echogenicity, contrast enhancement or hyperemia, calcification, and anatomical features of the cord and its relationship with the neurovascular bundle. RESULTS: We found that ultrasound and MRI were accurate for the detection of the cords and neurovascular bundles in the small finger. The intermodality agreement between MRI and ultrasound was 100% for the detection of 6 spiraling bundles containing 13 isolated cords (46.2%). Among the subjects examined, 100% of the hands had ab-ductor digiti minimi (ADM) area involvement, and the distal insertion of the cord was on the ulnar side of the base of the middle phalanx. On MRI, all of the cords showed predominantly low signal intensity on both T1- and T2-weighted images. On ultrasound, the ulnar cord showed a hyperechoic or isoechoic appearance in 69.3% of hands and a hypoechoic appearance in 30.7% of hands. CONCLUSIONS: The spiraling of the bundle in the isolated occurrence of Dupuytren's disease at the small finger is a frequent occurrence. MRI and ultrasound are good imaging modalities for the evaluation of the relationship between the neurovascular bundle and the isolated cord.

[US evaluation of the hands and feet in rheumatoid arthritis]. / Comment je fais un bilan échographique des mains et des pieds dans la polyarthrite rhumatoïde?

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by progressive damage of synovial-lined joints and variable extra-articular manifestations. Synovitis is usually found in the wrist, metacarpophalangeal, proximal interphalangeal and metatarsophalangeal joints. For these reasons, we believe that ultrasound with power doppler can be used for the detection and monitoring of synovitis with a simplified "hands and feet" protocol. In this article, we will describe this protocol used daily in our institution for early diagnosis and therapeutic management of this disease.

[MR Imaging of the spine and sacroiliac joints in ankylosing spondylitis]. / IRM du rachis et des articulations sacro-iliaques dans la spondylarthrite ankylosante.

The new diagnostic criteria for spondyloarthropathy include MRI. MRI frequently allows early diagnosis of inflammatory lesions of the spine and sacroiliac joints in patients with normal plain films. Moreover, MRI is useful for the detection and quantification of inflammatory and structural lesions, and to assess disease activity.

[Spondyloarthropathy: MR imaging features]. / IRM et spondylarthropathie.

The new diagnostic criteria for ankylosing spondylitis include MRI. MRI frequently allows early diagnosis of inflammatory lesions in patients with normal plain films. In addition, MRI is useful for the detection and quantification of inflammatory and structural lesions, and to assess disease activity.

[Dedifferentiated chondrosarcoma: radiologic-pathologic correlation]. / Chondrosarcomes dédifférenciés: revue iconographique radio-pathologique.

Dedifferentiated chondrosarcomas are highly malignant tumors characterized by conventional low-grade chondrosarcoma with abrupt transition to foci that have dedifferentiated into a higher-grade noncartilaginous more aggressive sarcoma. The dedifferentiated component, an osteosarcoma or fibrosarcoma, determines the prognosis. Its identification is key for management. A diagnosis of dedifferentiated chondrosarcoma should be suggested by the presence of "tumoral dimorphism" with cartilaginous component and aggressive lytic component invading adjacent soft tissues.

Do Curve Characteristics Influence Stenosis Location and Occurrence of Radicular Pain in Adult Degenerative Scoliosis?

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The aim of this study was to describe the various locations of spinal stenosis (LSS) in lumbar scoliosis and its related clinical symptoms. INTRODUCTION: Adults with lumbar scoliosis often present with pain and disability. Association of scoliosis and stenosis is not rare, but remains sparsely explored. Consequences of scoliosis on stenosis location and treatment remain debatable. METHODS: Patients operated for symptomatic LSS with lumbar scoliosis (Cobb angle >20°) from 2015 to 2016 were included. All patients completed preoperative clinical and neurologic examination. Coronal and sagittal radiographic parameters, rotatory subluxation (RS), and spondylolisthesis were analyzed on full spine radiographs. Computed tomographic scan multiplanar reconstructions were performed to measure central, foraminal, and lateral recess stenosis, from T10 to the sacrum. RESULTS: A total of 76 patients were included (69 ± 9 years old, 77% female). Sixty percent had neurogenic claudication, and L5 was the most common radicular pain (41%). The mean Cobb angle was 33° ± 16°. Overall, 35 (46%) patients had coronal malalignment; in 69%, side of the coronal tilt corresponded to side of the concavity of the lumbosacral curve. Sixty patients had RS (most frequent level L3-L4). In 50% of the cohort, RS was located at the junction between the lumbar and lumbosacral curves. In 70% (n = 53) of the patients, central stenosis occurred at the junction between the lumbar and lumbosacral curves. Foraminal and lateral stenosis were most frequently observed in the concavity of the distal lumbosacral curve. L5 radicular pain was significantly more frequent in case of lumbosacral contra-curve and right coronal malalignment. CONCLUSION: LSS is frequent in lumbar scoliosis. Relationships exist between curve characteristics and symptomatic LSS in lumbar scoliosis; especially, concavity of the lumbosacral contra-curve and the junctional level between the lumbar curve and the lumbosacral contra-curve. Therefore, accurate analysis of stenosis in ASD seems mandatory, to at least perform decompression because perfect planned treatment for stenosis and scoliosis correction might not always be possible because of the patient's general health status. LEVEL OF EVIDENCE: Level 4.

[Fissures of the posterior labrum and associated lesions: CT arthrogram evaluation]. / Fissures du labrum glénoïdal postérieur et lésions associées de l'épaule: une étude en arthroscanner.

PURPOSE: To describe osseous, chondral and tendinous lesions associated with fissures of the posterior labrum. To better understand the pathological processes leading to fissure of the posterior labrum. Materials and methods. Retrospective study of 43 CT arthrograms performed in 43 patients that showed a fissure of the posterior labrum. The following associated lesions were noted: osseous and chondral remodeling of the humeral head and/or glenoid and articular surface fissures of the rotator cuff. Based on type of associated lesions, patients were separated into one of four pathological subgroups: posterior instability, posterosuperior or internal impingement, anterior instability and isolated fissure of the posterior labrum. RESULTS: Sixteen patients (37.2%) of patients showed posterior instability, 12 (27.9%) showed lesions of internal impingement, and 11 (25.6%) showed lesions of anterior instability. Only 4 patients (9.3%) had an isolated fissure of the posterior labrum. CONCLUSION: Posterior instability, internal impingement and anterior instability are the main pathologies leading to fissure of the posterior labrum, which seldom occurs in isolation. Evaluation of these associated lesions allows understanding of the underlying pathological processes leading to fissure of the posterior labrum.

[Harmonic sonography of rotator cuff tendons: are cleavage tears visible at last?]. / Echographie des tendons de la coiffe en mode harmonique: les clivages sont-ils enfin visibles?

PURPOSE: For some, cleavage tears remain a pitfall of sonography (US). The purpose of this study is to demonstrate the visibility of intratendinous tears of the supraspinatus and infraspinatus tendons and describe their imaging features on tissue harmonic US. MATERIALS AND METHODS: Prospective study of 52 patients with suspected cuff pathology who underwent US prior to CT-arthrography, CT-bursography or MR arthrography. The US examinations were performed using 7-15 MHz transducers with tissue harmonic mode (pulse subtraction). An intratendinous tear was suggested by the presence of a hypoechoic intratendinous line, extending from a partial or full thickness tear. Results from US were correlated to contrast material enhanced CT or MR findings. RESULTS: Ten cases of cleavage tears were detected on US compared to 18 on arthrographic examinations. False negative results occurred in poor US candidates (n=4), excessively retracted tendons (n=2) or postsurgical cuffs (n=2). Sensitivity was 55% and specificity was 94%, with PPV of 83% and NPV of 80% for the detection of intratendinous tear. The accuracy of US was lower for intratendinous tear associated with full thickness tears (5/11) compared to intratendinous tears associated with partial thickness tears (5/6). CONCLUSION: We demonstrate that cleavage tears are now visible on US using high-frequency transducers and tissue harmonic mode. However, the sensitivity remains too low, especially in patients with full thickness tear, postsurgical patients and patients that are poor candidates to US.

[Nerve and vascular entrapment in athletes]. / Syndromes canalaires du sportif.

Peripheral nerve entrapment syndromes involve the compression of a short segment of a nerve at a specific site, as a result of the vulnerability of that nerve as it passes through a fibroosseous tunnel or an opening in fibrous or muscular tissue. Injury of the nerve may occur as a result of compression by the overlying structures. Another mechanism of injury is traction of the nerve, with or without friction of the nerve, as it travels and sharply changes direction around critical points. Imaging can be particularly helpful for the diagnosis of these uncommon injuries. Percutaneous decompression of a ganglion cyst or perineural injection for therapeutic purposes with the aid of fluoroscopy, CT, or ultrasound guidance can be performed in specific areas.

[Imaging of wrist injuries in athletes]. / Imagerie du poignet du sportif.

Wrist imaging is currently used for diagnosis of sport injuries as part of a global strategy of rapid recovery. Standard x-rays are the first step in this procedure. Although arthrography is still the reference for the diagnosis of intrinsic ligament and cartilaginous lesions, MRI can sometimes be sufficient. Ultrasonography is a dynamic process and is accurate in detecting tendon injuries. Wrist sport injuries are frequent and often asymptomatic. Here we review the usual aspects of bone, ligament, and tendon lesions encountered in each sport, while providing advice on the most appropriate imaging for each clinical symptom.

Sacroiliac joints imaging in axial spondyloarthritis.

Imaging of the sacroiliac joints is the key point in diagnosing and classifying spondyloarthritis. Since the integration of MRI criteria to the Assessment of Spondyloarhtitis Society (ASAS) classification in 2009, the attention was focused on the presence of bone marrow edema to characterize sacroiliitis. However, returning to basics and analysing structural signs is of utmost importance to avoid overdiagnosis of spondyloarthritis.