Vascular complication after percutaneous femoral cerclage wire.

Cerclage wire is an effective fracture fixation method. However, its mechanical benefits are countered by local ischemia. Its efficacy for treating femoral periprosthetic fractures has been demonstrated since femoral fixation is possible even there is a stem in the diaphysis. It securely holds the proximal femur typically with an additional plate. The development of minimally-invasive surgery with plate fixation has led to the cerclage wire being inserted percutaneously. Here, we report on a case of secondary femoral ischemia following percutaneous cerclage wire of a periprosthetic femoral fracture. This was a Vancouver type B1 fracture. On the 3rd day after admission, minimally-invasive fixation with a femoral locking plate was performed with five cerclage wires added percutaneously. During the immediate postoperative course, the patient developed ischemia of the operated leg that required vascular surgery after confirmation by CT angiography. An arterial stop was visible with deviation of the superior femoral artery, which was not properly surrounded by the cerclage wire. The latter pulled perivascular tissues towards the femur. When combined with reduced arterial elasticity due to severe atherosclerosis, it resulted in arterial plication. The postoperative course was marked by multiple organ failure and death of the patient. Percutaneous surgery is an attractive option but has risks. The presence of severe atherosclerosis is a warning sign for loss of tissue elasticity. This complication can be prevented by preparing the bone surfaces and carefully positioning the patient on the traction table to avoid forced adduction. The surgeon must also be familiar with alternative techniques to cerclage wire such as polyaxial screws and additional plates.

Ankle fusion in hemophilic patients.

INTRODUCTION: Hemophilic arthropathy is painful and disabling. We report a retrospective study of ankle fusion with intra- and peri-operative clotting factor perfusion. The objective was to assess the efficacy of maintaining perioperative clotting factor rates close to 100%, and report long-term results. The study hypothesis was that results would be good, without early hemorrhagic complications. MATERIAL AND METHOD: Between 2000 and 2013, 12 ankle fusions were performed in 9 patients, with a mean age of 39years (range, 19-58years). Anti-hemophilic factor perfusion was controlled by the reference physician of the Regional Hemophilia Treatment Center. Clinical AOFAS and Olerud scores and the Pettersson radiologic score were used for assessment. Mean preoperative AOFAS score was 22 (range, 2-55) and mean Olerud score 7 (range, 5-12). Mean preoperative factor VIII concentration was <1% (range, <1-3%). RESULTS: Mean follow-up was 8years (range, 2-16years). Mean AOFAS score at follow-up was 69 (range, 35-92) and mean Olerud score 70 (range, 30-100). Improvement mainly concerned the Pain dimension. Statistical analysis found a significant difference between pre- and post-operative clinical scores (AOFAS, P=0.004; Olerud, P=0.004). Mean factor VIII concentration at surgery was 90% (range, 24-117%), and 109% (range, 75-152%) the day following surgery. There were no cases of hematoma or surgical site infection. Radiologic fusion was systematic at a mean 3.5 months (range, 3-4months). CONCLUSION: The study hypothesis was confirmed. Ankle fusion in advanced hemophilic arthropathy improved function and quality of life. Perioperative clotting factor perfusion contributed to these good results, providing supplementary prevention of hemorrhagic risk. LEVEL OF EVIDENCE: IV, retrospective study.

Comparison between isotropic linear-elastic law and isotropic hyperelastic law in the finite element modeling of the brachial plexus.

Augmented reality could help the identification of nerve structures in brachial plexus surgery. The goal of this study was to determine which law of mechanical behavior was more adapted by comparing the results of Hooke's isotropic linear elastic law to those of Ogden's isotropic hyperelastic law, applied to a biomechanical model of the brachial plexus. A model of finite elements was created using the ABAQUS® from a 3D model of the brachial plexus acquired by segmentation and meshing of MRI images at 0°, 45° and 135° of shoulder abduction of a healthy subject. The offset between the reconstructed model and the deformed model was evaluated quantitatively by the Hausdorff distance and qualitatively by the identification of 3 anatomical landmarks. In every case the Hausdorff distance was shorter with Ogden's law compared to Hooke's law. On a qualitative aspect, the model deformed by Ogden's law followed the concavity of the reconstructed model whereas the model deformed by Hooke's law remained convex. In conclusion, the results of this study demonstrate that the behavior of Ogden's isotropic hyperelastic mechanical model was more adapted to the modeling of the deformations of the brachial plexus.

Chondroblastoma of the thoracic spine: a rare location. Case report with radiologic-pathologic correlation.

Chondroblastoma is a rare benign cartilage neoplasm that arises from the appendicular skeleton in the vast majority of the cases (80%). Chondroblastoma of the spine is an even more rare condition (30 cases reported), and vertebral chondroblastomas, unlike chondroblastomas of the extremities, present with the appearance of an aggressive tumor on CT and MR imaging and occur at least a decade later. Even though vertebral chondroblastomas are very uncommon tumors, they should nonetheless be included in the differential diagnosis when encountered with an aggressive vertebral mass, and a histological confirmation should be performed. We present a case of chondroblastoma of the thoracic spine of a 27-year-old female for which detailed radiologic-pathologic correlation was obtained.

Villonodular synovitis of the ankle. Analysis of the risk of recurrence.

INTRODUCTION: Villonodular synovitis (VNS) is a rare disease with an incidence of 1.8 per 1,000,000 inhabitants. VNS of the ankle has seldom been described and evaluated given its extreme rarity (2.5% of VNS cases). It presents an 11% recurrence rate. We report a continuous retrospective series with the main objective of clinically and radiologically evaluating these ankles searching for any risk factors of recurrence. At revision the study's main endpoint was the existence of local recurrence (radiological and clinical) and the secondary endpoint was the existence of tibiotalar osteoarthritis. The working hypothesis was that recurrence could be subclinical, warranting systematic imaging studies during follow-up. MATERIAL AND METHODS: The study was retrospective, conducted on seven patients (six males) whose mean age was 42 years treated over a period of 9 years (two diffuse forms and five localized forms). The initial treatment consisted in synovectomy via the conventional approach. Four patients also received adjuvant isotopic synoviorthesis treatment. The revision was clinical (MMTS, AOFAS, and OMAS scores) and radiological (standard and MRI) to evaluate the joint after-effects and search for recurrence. RESULTS: Six patients were seen at a mean 6.5 years of follow-up. One case of early recurrence (4 years) was noted, with a major clinical manifestation because it was associated with joint destruction requiring arthrodesis, and one case of late asymptomatic recurrence (9 years), diagnosed radiologically on the follow-up MRI. The functional results remained good at follow-up (MMTS 77%, AOFAS 71, OMAS 71). Five of the six patients returned to their daily activities. At revision, no sign of osteoarthritis was observed. No risk factor for recurrence was demonstrated. DISCUSSION/CONCLUSION: The hypothesis was confirmed with the existence of asymptomatic recurrence at revision, underscoring the value of systematic MRI at follow-up. Other than major joint destruction, the prognosis remains good even in case of recurrence. The literature emphasizes the existence of an initial diffuse form and partial surgical resection as risk factors of recurrence. None of the reports in the literature has proven that adjuvant treatment, whose modalities do not meet with consensus, reduces this risk. LEVEL OF EVIDENCE: Retrospective series, level IV.

Pelvic, acetabular and hip fractures: What the surgeon should expect from the radiologist.

Pelvic ring fractures when caused by trauma, either violent or in demineralized bone, generally consist of injuries in both the anterior (pubic symphysis and rami) and posterior (iliac wing, sacrum, sacroiliac joint) portions. Injury classifications are based on injury mechanism and pelvic stability, and are used to determine treatment. Acetabular fractures, associated or not to pelvic ring disruption, are classified on the basis of fracture line, into elementary fractures of the acetabular walls, columns and roof, and into complex fractures. Fractures of the proximal end of the femur occur often on demineralized bone following low-energy trauma. The fractures are categorized by anatomic location (neck, trochanter and subtrochanteric region) and degree of displacement. These variables determine the risk of osteonecrosis of the femoral head, which is the main complication of such fractures.

An illustrative review to understand and manage metal-induced artifacts in musculoskeletal MRI: a primer and updates.

This article reviews and explains the basic physical principles of metal-induced MRI artifacts, describes simple ways to reduce them, and presents specific reduction solutions. Artifacts include signal loss, pile-up artifacts, geometric distortion, and failure of fat suppression. Their nature and origins are reviewed and explained though schematic representations that ease the understanding. Then, optimization of simple acquisition parameters is detailed. Lastly, dedicated sequences and options specifically developed to reduce metal artifacts (VAT, SEMAC, and MAVRIC) are explained.

Acute traumatic knee radiographs: beware of lesions of little expression but of great significance.

Knee radiographs are the first imaging modality performed in acute knee trauma, and in most of cases, the findings are obvious. Nevertheless, sometimes, only subtle clues can indicate a potentially more severe underlying abnormality, such as ligamentous, tendinous or meniscal tears. Knowledge of the origin of such signs and of the related underlying injury mechanism, might lead to additional imaging investigation, which may facilitate appropriate patient work-up and prevent consequences of delayed treatment.

Satisfactory long-term MRI after autologous chondrocyte implantation at the knee.

PURPOSE: Autologous chondrocyte implantation (ACI) to address isolated condylar lesions is supposed to limit degenerative deterioration in neutrally aligned knees. Here, we report long-term results of the first-generation ACI technique with periosteal flap. METHODS: Twelve patients, 29 years old on average, were included on the basis of pre-operative MRI selection of lesions >2 cm2. Cartilage carrots were harvested arthroscopically, then cultured and finally re-implanted within a mean time interval of 12 weeks. Ten-year MRI results were analysed according to a semi-quantitative scale, along with functional assessment based on International Knee Documentation Committee score, Lysholm et al. score and the Tegner et al. activity scale. RESULTS: One patient secondarily required valgus tibial osteotomy with mosaic plasty. Another incurred graft hypertrophy that necessitated arthroscopic peeling. MRI showed that cartilage repair filled more than 50% of the initial defect in 9 patients. Standard radiographs revealed slight narrowing of the joint line. Overall, functional scores improved durably by 50%, although activity level decreased substantially. CONCLUSION: ACI contained degenerative changes within moderate stages while maintaining durable functional improvement. However, in the absence of controls, it was difficult to differentiate between these findings and the spontaneous evolution of non-treated lesions. LEVEL OF EVIDENCE: Case series, Level IV.

Sentinel lesions in osteoarticular traumatology: signs to watch out for.

Sentinel lesions are lesions of the bone or soft tissue, visible in standard X-rays carried out within a traumatic context, indicating bone or more severe capsular ligament lesions not visible on these X-rays. A detailed review of the peripheral joints as well as the spine is carried out with an example of each type of lesion in a standard X-ray. Confrontation with the reference examination, CT or MRI, depending on the case, is then carried out.

Focal dependent pleural thickening at MDCT: pleural lesion or functional abnormality?

PURPOSE: To describe the characteristics of reversible focal pleural thickenings (PTs) mimicking real plaques, that firstly suggest asbestos exposure or pleural metastasis; to propose an imaging strategy and propose an explanation for their mechanism of formation. PATIENTS AND METHODS: Retrospective review of data from 19 patients with PTs fitting the description of pleural plaques at chest computed tomography (CT) and presenting modifications (clearance or appearance) of at least one PT at an additional chest examination in prone position. RESULTS: A total of 152 PTs were recorded on the first chest CT examinations with a range of two to 19 pleural opacities per patient. All PTs had a posterior distribution in the lower lobes. On the additional acquisitions, 144 PTs disappeared. Seventeen patients presented complete regression of PTs and two patients presented persistence of eight PTs. CONCLUSION: Additional low dose acquisition in prone position should be performed in all patients presenting with focal PT in a dependent and basal location. This may allow to exclude a pleural plaque in case of asbestos exposure but also a pleural metastasis in oncologic patients. These reversible dependent PTs could be related to physiological focal accumulation of lymphatic fluid in subpleural area.

Diffusion-weighted MRI, dynamic susceptibility contrast MRI and ultrasound perfusion quantification of denervated muscle in rabbits.

OBJECTIVE: The purpose of this study was to assess denervated muscle perfusion using dynamic susceptibility contrast MRI (DSCMRI) and contrast-enhanced ultrasound (CEUS), and to measure denervated muscle apparent diffusion coefficient (ADC) on b1000 diffusion-weighted MRI (DWMRI) at 3 T in order to clarify whether muscle denervation leads to an increase in the extracellular extravascular space, or an increase in blood flow-or both. MATERIALS AND METHODS: Axotomy of the right sciatic nerve of six white rabbits was performed at day 0. At day 9, hind limb muscles MRI and CEUS were performed to assess the consequences of denervation and both semimembranosus muscles of each rabbit were explanted for histological studies. Signal intensity on T2- and T1-weighted MRI, ADC on DWMRI, maximum signal drop (MSD) on DSCMRI and the area under the curve (AUC) on CEUS were measured over circular regions of interest (ROI), in both semimembranosus muscles. Non-parametric Wilcoxon matched-pairs tests were used to assess the mean differences between denervated and normal muscles. RESULTS: T2 fat-saturated (FS) MRI studies showed a strong signal in the right semimembranosus muscles compared with the left side, and gadolinium enhancement was observed on T1 FS MRI. Denervated muscles show a significant increase in ADC on DWMRI (p < 0.01) and a significant signal enhancement on DSCMR imaging (p < 0.05) and on first-pass CEUS (p < 0.05). CONCLUSION: The results of this study--based on perfusion- and diffusion-weighted images--suggest that, after denervation, both increased blood flow through muscle tissue and expansion of the extracellular water volume are present.

[Pain management in oncology]. / Traitement de la douleur en oncologie.

Several interventional radiology procedures are available for the management of cancer pain. In this article, we will briefly review the different procedures and their value in the setting of cancer pain management under two main categories: indirect action (regional anesthesia from neurolysis) and direct action on the tumor. Percutaneous ablation of bone tumors: alcohol, laser, radiofrequency, microwaves, ultrasound, and cryoablation. Several indications have previously been validated, including thermal ablation of bone metastases with results superior to conventional therapies. Additional applications should be validated over the next few years.

Can injection CT scan assess the residual femoral head vascularity after acute neck fracture?

INTRODUCTION: Femoral neck fracture jeopardizes the vital prognosis of the elderly subject and the functional prognosis of the young subject. The vascular consequence is important, with the risk of osteonecrosis of the femoral head. In young patients, predicting the risk of necrosis at the acute stage seems warranted so as to optimize the choice of therapy. CT with injection could be useful to study the residual bone vascularity after an acute fracture of the femoral neck. HYPOTHESIS: The CT scan with injection can diagnose ischemia of the femoral head after neck fracture by demonstrating hypoperfusion and thus estimating the risk for osteonecrosis. PATIENTS AND METHOD: A CT scan with injection was performed prospectively in 20 adult patients who had given informed consent after verification of the inclusion and exclusion criteria. Ten presented femoral neck fracture and 10 a pertrochanteric fracture, the latter making up the control group. The second control group was the healthy side of patients presenting a femoral neck fracture. The images were analyzed after delineating a region of interest as a volume at the center of the femoral head. The results were analyzed after modeling based on the physical principle of diffusion. RESULTS: No differences were found between the "healthy hip," "fractured hip," "femoral neck fracture," and "trochanteric region fracture" groups. The only statistically significant correlation was found between the "fractured hip" and "healthy hip" of the same patient independently of the type of fracture. DISCUSSION: The results do not confirm the working hypothesis. This study was mainly limited by the small number of patients included, but this did not substantially effect the study's conclusions. According to the results, it seems that this study provided a CT evaluation of bone mineral density. At the end of the study, it seems that CT with injection is not well adapted in assessing residual femoral head vascularity or estimating the risk of progression towards avascular necrosis. According to the literature, only dynamic MRI with injection seems to be effective in this assessment and estimation. LEVEL OF EVIDENCE: Level III prospective comparative diagnostic.

Scaphotrapezial ligament: normal arthro-CT and arthro-MRI appearance with anatomical and clinical correlation.

The purpose of our study was to demonstrate and describe the MR and arthro-CT anatomic appearance of the scaphotrapezial ligament and illustrate some of the pathologies involving this structure. This ligament consists of two slips that originate from the radiopalmar aspect of the scaphoid tuberosity and extend distally, forming a V shape. The ulnar fibers, which are just radial to the flexor carpi radialis sheath, inserted along the trapezial ridge. The radial fibers were found to be thinner and inserted at the radial aspect of the trapezium. Twelve fresh cadaver wrists were dissected, with close attention paid to the scaphotrapezio-trapezoidal (STT) joint. An osseoligamentous specimen was dissected with removal of all musculotendinous structures around the STT joint and was performed with high-resolution acquisition in a 128-MDCT scanner. Samples of the wrist area were collected from two fetal specimens. A retrospective study of 55 patients with wrist pain that were submitted to arthrography, arthro-CT, and arthro-MRI imaging was performed (10 patients on a 3-T superconducting magnet and 45 patients on a 1.5-T system). Another ten patients had high-resolution images on a 3-T superconducting magnet without arthrographic injection. MR arthrography and arthro-CT improved visualization and provided detailed information about the anatomy of the scaphotrapezial ligament. Knowledge of the appearance of this normal ligament on MRI allows accurate diagnosis of lesions and will aid when surgery is indicated or may have a role in avoiding unnecessary immobilization.

[Muscular metastasis from primary lung cancer: about seven cases]. / Métastases musculaires de cancers bronchiques: à propos de sept cas.

Muscular metastasis from primary bronchial carcinoma are rare. We report seven cases with different clinical features. In most cases, these metastasis first manifested as a painful mass and revealed the cancer. Localisation of muscular metastasis was assessed by various imaging techniques (RMI, CT scan and ultrasonography). All cases were assessed by biopsy and were associated with primary adenocarcinoma or undifferentiated large cell carcinoma of the lung. Three patients underwent wide excision, leading to an improvement of general condition. All patients were treated with platinum-based chemotherapy. With reference to our cases, imaging of the metastases will be illustrated and clinical and therapeutic features will be discussed.

Survivor of a traumatic atlanto-occipital dislocation.

Atlanto-occipital dislocation is a devastating ligamentous injury that most often turns fatal. However, because of on-site resuscitation improvements, the emergency teams are increasingly dealing with this condition. We report a rare case of atlanto-occipital dislocation (AOD) in a surviving patient with more than one-year follow-up. The mechanism of injury appears to be an extreme hyperextension applied to the head. This injury occurs more frequently in children since they are anatomically predisposed (flat articulation between the occiput and the atlas, increased ligamentous laxity). The diagnosis should be suggested by severe neurological injury after high trauma but also post-traumatic cardiorespiratory deficit. There have been reports of atlanto-occipital dilocations without neurologic impairment. A radiographic examination must be performed and lateral cervical radiographs should be acquired. However, additional imaging with CT or MRI may be required to aid diagnosis of AOD in cases in which radiographic findings are equivocal. Once the diagnosis of AOD has been confirmed, an anatomical classification should be made according to the magnitude of displacement. Fatal lesions are of neurological and vascular origin and some authors advocate the systematic use of angiography. Consensus regarding the management of AOD in adults has been achieved. Occipito-cervical arthrodesis is the recommended treatment option. We advocate a two-stage surgery: the patient is initially fitted with a halo vest then occipitocervical fusion is performed. Surgical treatment should be combined with cardiorespiratory management. The emergency teams should get familiar with this injury since they will be increasingly confronted to it. Early recognition and standard appropriate management is essential to avoid delayed treatment and complications.

Early prediction of femoral head avascular necrosis following neck fracture.

Femoral neck fracture puts at risk functional prognosis in young patients and can be life-threatening in the elderly. The present study reviews methods of femoral head vascularity assessment following neck fracture, to address the following issues: what is the risk of osteonecrosis? And what, in the light of this risk, is the best-adapted treatment to avoid iterative surgery? Femoral head vascularity depends on retinacular vessels and especially the lateral epiphyseal artery, which contributes from 70 to 80% of the femoral head vascular supply. Fracture causes vascular lesions, which are in turn the prime cause of necrosis. Other factors combine with this: hematoma tamponade effect, reduced joint space and increased pressure due to lower extremity positioning in extension/internal rotation/abduction during surgery. Head deformity is not due to direct cell death but to the repair process originating from the surrounding living bone. In post-traumatic necrosis, proliferation rapidly invades the head, with significant osteogenesis. Pathologic fractures occur at the boundary between the new and dead bone. Many techniques have been reported to help assess residual hemodynamics and risk of necrosis. Some are invasive: superselective angiography, intra-osseous oxygen pressure measurement, or Doppler-laser hemodynamic measurement; others involve imaging: scintigraphy, conventionnal or dynamic MRI. The future seems to lie with dynamic MRI, which allows a new classification of femoral neck fractures, based on a non-invasive assessment of femoral head vascularity.

[Infrapatellar fat pad: anterior crossroads of the knee]. / Le corps adipeux infra-patellaire: carrefour antérieur du genou.

The infrapatellar fat pad or Hoffa's fat pad is a cylindrical extrasynovial collection of fat located in the infrapatellar region. Anatomical, biomechanical and imaging data show that the infrapatellar fat pad constitutes a true crossroads between patella, femur and tibia and helps in understanding if not describing regional pathology. Intrinsic lesions (with abnormal signal on MRI) such as hoffitis, anterolateral impingement, plica syndrome, post-arthroscopic changes, trauma, patellar dislocation and extrasynovial tumors are less frequent. On the other hand, extrinsic lesions are more frequent and may affect the synovium, patellar ligament, vascular structures, and bursae. Mucoid and parameniscal cysts may develop in the infrapatellar fat pad. In this article, the anatomical and imaging features of the infrapatellar fat pad will be summarized and the most common lesions will be illustrated.