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.

Treatment of degenerative meniscal tear with intrameniscal injection of platelets rich plasma.

PURPOSE: The purpose of this retrospective study was to describe our preliminary results of intra-meniscal administration of platelet rich plasma (PRP) in patients with degenerative meniscal tears of the knee. MATERIAL AND METHOD: Ten patients with degenerative meniscal tears according to the Stoller classification and without knee osteoarthritis were included. There were 7 men and 3 women with a mean age of 40.4±13.6 [SD] years (range: 18-59 years). Patients were prospectively assessed at baseline and 3- and 6-months after intra meniscal PRP administration. Evaluation included the knee injury and osteoarthritis outcome score (KOOS), pain visual analog scale, and return to competition and training. MRI follow-up was performed 6 months after PRP administration. Adverse events were recorded. RESULTS: Volume of injected PRP was standardized to 4.0mL. Adverse events during PRP administration was moderate pain in 8 patients (8/10; 80%). Mean KOOS total score significantly improved from 56.6±15.7 (SD) to 72.7±18.5 (SD) (P=0.0007). All six patients practicing sports regularly were able to recover competition or training. In seven patients who underwent MRI follow-up at 6 months, MRI showed stability of the meniscal tears and similar Stoller grades. CONCLUSION: Intra-meniscal administration of PRP under ultrasound guidance directly into meniscal degenerative lesions is feasible and safe. Further randomized controlled studies are needed to definitely confirm the effectiveness of this procedure.

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.

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.

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.