Percutaneous cryoablation of osteoblastoma in the proximal femur.

A 37-year-old man presented with a 2-year history of left hip pain. Pretherapeutic imaging demonstrated a 4 cm osteoblastoma located in the intertrochanteric region of the proximal femur, surrounded by extensive bone marrow edema. After multidisciplinary meeting, percutaneous cryoablation was decided and performed under computed tomography guidance using three cryoprobes to match the exact size and shape of the tumor, resulting in complete resolution of symptoms. Magnetic resonance imaging follow-up demonstrated resolution of the bone marrow edema pattern and ingrowth of fat at the periphery of the ablation zone consistent with long-term healing of the tumor.

Anterolateral ligament of the knee: myth or reality?

PURPOSE: A ligament of the knee has recently drawn the attention: the rediscovered anterolateral ligament (ALL) of the knee. The tibial insertion of the ALL is torn off in the Segond fracture, pathognomonic of the anterior cruciate ligament tear. The ALL originates from the lateral femoral epicondyle and has fibers inserting on the lateral meniscus. It attaches distally to the tibial plateau, midway between the tip of the fibular head and Gerdy's tubercle. The purpose of this study was to evaluate the visibility of the ALL using routine MRI (1.5T) protocol. MATERIALS AND METHODS: In the first part of our study 10 cadaveric knee joints were examined using MR imaging to evaluate the visibility of the ALL. These cadaveric knees have been dissected to assess the presence of the ALL and to evaluate the accordance between MRI and anatomic dissection. In the second part of the study, 61 knee MRI of patients were examined to evaluate the visibility of the ALL using axial and coronal DP-FS weighted sequences. RESULTS: In all cadaveric knee MRI, the ALL was visualized (full visualization in 75 % and partial visualization in 25 % of the cases), with 100 % accordance between MRI and anatomic dissection. Two cadaveric knees where the ALL was not viewed were excluded of the radio-anatomic analysis. The ALL was visualized in 93.4 % (95 % CI = 84.1-98.2) of the knee MRI studies of the 61 patients included. The whole ligament was visualized in 82 % (95 % CI = 70-90.6) examinations and it was partially visualized in 11.5 % (95 % CI = 4.7-22.2). CONCLUSION: Our results show that the ALL of the knee can be identified using routine 1.5T MR imaging, which suggest that better radiological description of this underestimated anatomical structure may be beneficial in the preoperative planning of ACL tears.

[Lymphatic drainage of skin areas of head and neck: in vivo approach by the location of the sentinel node]. / Drainage lymphatique des territoires cutanés de la tête et du cou : approche in vivo par la localisation du ganglion sentinelle.

INTRODUCTION: The objective of the study was to determine the preferential territories of drainage of skin areas of the face and neck. This knowledge can guide the strategies of diagnostic (search for primary tumor skin to cervical lymphadenopathy) and treatment (determination of the extent of neck dissection to achieve in case of skin tumor). MATERIALS AND METHODS: This is a retrospective study of the surgical procedures of sentinel node research between January 2003 and April 2011. The lymphoscintigraphic and intraoperative localization of the initial tumor site and sentinel lymph node were collected. RESULTS AND DISCUSSION: One hundred and thirty-seven patients were included in the study. The parotid gland is a privileged territory of drainage of the head and neck skin. At cervical level, the submental region drains the lower and median part of the face (lips and chin). The posterior segments (IIb and V sector) were represented for the posterior locations of the head (ear, vertex), and cervical region.

Anatomical study of the dorsal cutaneous branch of the ulnar nerve using ultrasound.

OBJECTIVES: To determine whether ultrasound allows precise assessment of the course and relations of the dorsal cutaneous branch of the ulnar nerve (DCBUN). METHODS: This work, initially undertaken in cadavers, was followed by high-resolution ultrasound study in 20 healthy adult volunteers (40 nerves) by two musculoskeletal radiologists in consensus. Location and course of the DCBUN and its relations to adjacent anatomical structures were analysed. RESULTS: The DCBUN was consistently identified along its entire course by ultrasound. Mean cross-sectional area of the nerve was 1.6 mm(2) (range 1.1-2.2). The level at which the DCBUN branches from the ulnar nerve was located a mean of 57 mm (range 40-80) proximal to the ulnar styloid process and 11 mm (range 7-15) radial to the medial border of the ulna. The DCBUN then crossed the medial border of the ulna a mean of 14 mm (range 6-25) proximal to the ulnar styloid process. CONCLUSION: The DCBUN is clearly depicted by ultrasound. Precise mapping of its anatomical course could have significant clinical applications, such as preventing injury during surgery of the ulnar side of the wrist or helping in the diagnosis of chronic pain of the ulnar side of the hand. KEY POINTS: • The dorsal cutaneous branch of the ulnar nerve (DCBUN) is often injured. • The DCBUN originates from the ulnar nerve in the distal third of the forearm. • It can be clearly depicted by ultrasound. • The level at which the DCBUN crosses the ulna is variable. • Precise mapping of its anatomical course could have significant clinical applications.

Combination of texture analysis and bone mineral density improves the prediction of fracture load in human femurs.

UNLABELLED: Twenty-one excised femurs were studied using (1) a high-resolution digital X-ray device to estimate three textural parameters, (2) dual-energy X-ray absorptiometry (DXA) to measure bone mineral density (BMD), and (3) mechanical tests to failure. Textural parameters significantly correlated with BMD (p < 0.05) and bone strength (p < 0.05). Combining texture parameters and BMD significantly improved the fracture load prediction from adjusted r(2) = 0.74 to adjusted r(2) =0.82 (p < 0.05). INTRODUCTION: The purpose of this study is to determine if the combination of bone texture parameters using a new high-resolution X-ray device and BMD measurement by DXA provided a better prediction of femoral failure load than BMD evaluation alone. METHODS: The proximal ends of 21 excised femurs were studied using (1) a high-resolution digital X-ray device (BMA, D3A Medical Systems) to estimate three textural parameters: fractal parameter Hmean, co-occurrence, and run-length matrices, (2) DXA to measure BMD, and (3) mechanical tests to failure in a side-impact configuration. Regions of interest in the femoral neck, intertrochanteric region, and greater trochanter were selected for DXA and bone texture analysis. Every specimen was scanned twice with repositioning before mechanical testing to assess reproducibility using intraclass correlation coefficient (ICC) with 95% confidence interval. The prediction of femoral failure load was evaluated using multiple regression analysis. RESULTS: Thirteen femoral neck and 8 intertrochanteric fractures were observed with a mean failure load of 2,612 N (SD, 1,382 N). Fractal parameter Hmean, co-occurrence, and run-length matrices each significantly correlated with site-matched BMD (p < 0.05) and bone strength (p < 0.05). The ICC of the textural parameters varied between 0.65 and 0.90. Combining bone texture parameters and BMD significantly improved the fracture load prediction from adjusted r(2) =0.74 to adjusted r(2) = 0.82 (p < 0.05). CONCLUSION: In these excised femurs, the combination of bone texture parameters with BMD demonstrated a better performance in the failure load prediction than that of BMD alone.

Advanced hip osteoarthritis: magnetic resonance imaging aspects and histopathology correlations.

OBJECTIVES: To correlate magnetic resonance imaging (MRI) aspects of the femoral head with histological findings in advanced hip osteoarthritis (OA), with special emphasis on bone marrow edema (BME). METHODS: MRI was performed in patients with advanced hip OA scheduled for hip arthroplasty. Coronal T1-, fat-suppressed T2-, T1 with gadolinium intravenous injection sequences were obtained on a 1.5 T MR-scanner within 1 month before surgery. Coronal MR images corresponding to the ligamentum teres plane were analyzed by two independent readers blinded to histological data. Normal bone marrow, subchondral cyst, subchondral fracture, edema-like, necrosis-like, and necrosis MR patterns were reported on a synthesis scheme. After surgery, the femoral heads specimens were cut through the ligamentum teres plane and histologically analyzed for correlations. RESULTS: Twenty-three femoral heads were analyzed (female 56.5%, mean age 64.5 years). Edema-like MR pattern was correlated with histological (H) edema (Kappa (K): 0.77). Necrosis-like MR pattern was correlated with H fibrosis (K: 0.49) and with H necrosis (K: 0.24). Cyst MR pattern was correlated with H bone cysts (K: 0.58). Necrosis MR pattern corresponded to a mixture of histological lesions. Sensitivity and specificity of MRI varied from 26% to 80% and from 86% to 95% respectively. CONCLUSION: In advanced hip OA, the so-called "BME" MR lesion corresponds to a combination of edema, fibrosis, and necrosis at histopathology. When the classical "BME" is more specifically separated into edema-like and necrosis-like MR patterns, MR Imaging and histological findings show substantial agreement, with edema-like MR pattern mainly corresponding to histological edema.

[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.

[The lymph node of Mondor: myth or reality?]. / Le ganglion de Mondor : mythe ou réalité ?

AIM OF THE STUDY: Lymph node involvement is one of the most significant prognostic factors of patients with rectal cancer. Despite major advances in our understanding of the propagation of the rectal cancer, the lymphatic drainage of the rectum remains unclear. This study was designed to assess the number of lymph nodes located around the superior rectal artery and to assess the frequency of Mondor's lymph nodes. PATIENTS AND METHODS: Twenty-five anatomic subjects were studied. All resections were performed using total mesorectal excision. Lymph nodes were sought in the tissue surrounding the superior rectal artery up to 2 cm under the ending of the superior rectal artery by manual dissection and were submitted for histological examination. The correlation between the number of lymph nodes, and the volume and weight of the tissue surrounding the superior rectal artery was evaluated by non-parametric Spearman test. RESULTS: The mean number of lymph nodes per specimen was 2.7 +/- 1.4. The size of the lymph nodes varied between 1 and 7 mm. The lymph nodes were mostly smaller than 3 mm (56%). The number of lymph nodes in the superior rectal mesentery was independent of its volume and its weight. Seven subjects had a Mondor's lymph node. The mean size of Mondor's lymph node was 3.4 +/- 2.1 cm. CONCLUSIONS: The number of NL located around the superior rectal artery is small, varying between 1 and 5. The Mondor's lymph node is an inconstant rectal NL. Its only characteristic is its location in the bifurcation or trifurcation of the superior rectal artery.

Assessment of proximal femur microarchitecture using ultra-high field MRI at 7 Tesla.

PURPOSE: The purpose of this study was to investigate bone microarchitecture of cadaveric proximal femurs using ultra-high field (UHF) 7-Tesla magnetic resonance imaging (MRI) and to compare the corresponding metrics with failure load assessed during mechanical compression test and areal bone mineral density (ABMD) measured using dual-energy X-ray absorptiometry. MATERIALS AND METHODS: ABMD of ten proximal femurs from five cadavers (5 women; mean age=86.2±3.8 (SD) years; range: 82.5-90 years) were investigated using dual-energy X-ray absorptiometry and the bone volume fraction, trabecular thickness, trabecular spacing, fractal dimension, Euler characteristics, connectivity density and degree of anisotropy of each femur was quantified using UHF MRI. The whole set of specimens underwent mechanical compression tests to failure. The inter-rater reliability of microarchitecture characterization was assessed with the intraclass correlation coefficient (ICC). Associations were searched using correlation tests and multiple regression analysis. RESULTS: The inter-rater reliability for bone microarchitecture parameters measurement was good with ICC ranging from 0.80 and 0.91. ABMD and the whole set of microarchitecture metrics but connectivity density significantly correlated with failure load. Microarchitecture metrics correlated to each other but did not correlate with ABMD. Multiple regression analysis disclosed that the combination of microarchitecture metrics and ABMD improved the association with failure load. CONCLUSION: Femur bone microarchitecture metrics quantified using UHF MRI significantly correlated with biomechanical parameters. The multimodal assessment of ABMD and trabecular bone microarchitecture using UHF MRI provides more information about fracture risk of femoral bone and might be of interest for future investigations of patients with undetected osteoporosis.

[Peripherally inserted central catheters (PICC): a promising technique]. / Cathéters centraux insérés par voie périphérique: une technique prometteuse.

To describe technical features and benefits from PICC lines.

[Prospective evaluation of PICC line related complications]. / Evaluation prospective des complications des PICCs.

PURPOSE: To report the occurrence of complications following placement of peripherally inserted central catheters (PICC). Materials and methods. A total of 127 PICC lines were placed in 115 patients for TPN (n=54), long-term antibiotics (n=29), chemotherapy (n=14) or miscellaneous intravenous therapy (n=18). RESULTS: All PICC lines were successfully inserted. PICC lines were used for a mean duration of 16 days (1-166 days). The following complications were recorded: occlusion (7%), rupture (1.6%), accidental withdrawal (2.4%), infection (3.1%) and venous thrombosis (2.4%). CONCLUSION: PICC lines are a simple, safe and effective alternative to conventional central venous catheters. The occurrence of complications, typically "mechanical", must be reduced and prevented by strict management of this type of central line by the treating team.

[Hand distal interphalangeal joints: sonographic anatomy]. / Echoanatomie des articulations interphalangiennes distales de la main.

PURPOSE: To determine normal anatomy of hand distal interphalangeal joints at ultrasonography, and to compare sonographic and anatomic findings. MATERIALS AND METHODS: Right hands of three embalmed cadavers and dominant hands of 10 asymptomatic volunteers were evaluated. Distal interphalangeal joints were scanned longitudinally and transversely with a high-frequency linear-array transducer. Sonographic appearances of intra-articular and periarticular structures were analysed in consensus by two musculoskeletal radiologists. Cadaveric dissection provided anatomic comparisons. RESULTS: Sagittal and transverse sonographic images enabled good analysis of the extensor tendon, the deep flexor tendon, and the palmar plate. The radial and ulnar collateral ligaments were identified on all coronal scans. Direct visualization of the dorsal triangular structure and of the middle phalanx head's cartilage was possible on longitudinal scans. The dorsal and palmar synovial recesses were better recognized when a small amount of fluid was present. CONCLUSION: Ultrasonography with a high-frequency linear-array transducer provides detailed anatomical information about intra-articular and periarticular structures of the hand distal interphalangeal joints.

[The rotator interval: hidden lesions?]. / L'intervalle des rotateurs: des lésions cachées?

The rotator interval corresponds to a defined triangular shaped anatomical region at the anterosuperior portion of the shoulder where specific pathological processes may occur. First, the morphological and functional anatomy of the region will be reviewed. Then, the role of different imaging modalities will be described along with pathological imaging features. Normal structures of the rotator interval may be imaged with modern techniques, including MR and CT arthrography. On the other hand, clinical evaluation of rotator interval pathology remains difficult; and no consensus exists concerning their management. Imaging characterization of rotator interval pathology could be a key factor for pre-therapeutic work-up.

[Anatomic variants of the biliary tree with MR Cholangiography: feasibility and surgical applications]. / Variations anatomiques des voies biliaires en cholangio-IRM: faisabilité et intérêt chirurgical.

PURPOSE: To assess the usefulness of MR Cholangiography for evaluation of anatomic variants of the biliary tree before biliary surgery. MATERIALS AND METHODS: Our study group consisted of 45 consecutive patients (29 males, 16 females; mean age 57 years), who were referred for MR evaluation of malignant (n=26) and benign (n=19) cholangiopancreatic diseases. MR Cholangiography studies were independently reviewed by two radiologists. RESULTS: Anatomic variants of the biliary tree were observed in 9 patients (20%); 6 variants involved the biliary confluence and 4 the cystic duct (one patient had both). Anatomic variants involved principally the right posterior duct: 1 (2,2%) drainage of right posterior duct into left hepatic duct; 2 (4,4%) triple confluence of right posterior duct, right anterior duct, and left hepatic duct, and 3 (6,6%) aberrant drainage of right posterior duct into common hepatic duct. Observed cystic duct anomalies included: 2 (7,44%) low insertion of the cystic duct into the common hepatic duct and 3 (11,1%) medial insertion of the cystic duct into the common hepatic duct. CONCLUSION: MR Cholangiography accurately shows anatomic variants of the biliary tree. Noninvasive preoperative evaluation of the biliary anatomy may be important for the detection of anatomic variants that may increase the complexity of hepatic surgical procedures and biliary interventions.

Biomechanical causes of trapeziometacarpal arthroplasty failure.

Trapeziometacarpal joint prosthesis revision has been widely reported, mainly due to loosening of the trapezium cup. Our hypothesis is that current prostheses do not sufficiently respect the kinematics of this joint. CT scan acquisitions enabled us to determine the position of the first metacarpal relative to the trapezium in three different characteristic postures, in subjects in different stages of arthrosis. A CAD model of a current prosthesis was inserted into the numerical 3D model of the joint under the different postures. In the numerical model, we observe penetration of the cup by the head of the prosthesis. This virtual penetration could, in vivo, amount to overstressing the prosthetic elements, which would lead to loosening of the cup or of the metacarpal stem and luxation of the prosthesis.

[Stent-graft treatment of a ruptured aortic graft: a case report]. / Traitement endovasculaire d'une rupture de pontage aortique.

The authors report the clinical and imaging features of a patient with rupture of an aortoiliac graft successfully treated by endovascular approach. The endovascular treatment is easy to perform and effective. The main pitfall of this technique is the limited availability of stent-grafts.

The contribution of MRI to the diagnosis of traumatic tears of the anterior cruciate ligament.

When faced with a clinical suspicion of knee ligament injury, MRI nowadays has a central role in the diagnostic strategy. In particular, it is essential for assessing the cruciate ligaments and any associated meniscal tears. The objective of this review is to present the various direct and indirect MRI signs of tearing of the anterior cruciate ligament (ACL) and then describe the lesions associated with it. The anatomical and clinical aspects are also discussed so that the contribution of MRI to the diagnosis and therapeutic management of an ACL tear can be better understood.

[Endovascular management of arteriovenous malformations]. / Traitement radiologique des malformations artérioveineuses périphériques.

Management of high-flow arteriovenous malformation remain often problematic. Complete eradication of the nidus is the only potential cure, but this, however, is often difficult if not impossible. Frequently, a multidisciplinary approach is required. In these article, techniques and results of the endovascular management of MAV are discussed.