A three-dimensional measurement method on MR arthrography of the hip to classify femoro-acetabular impingement.

PURPOSE: (1) To investigate correlations between different types of FAI and the ratio of acetabular volume (AV) to femoral head volume (FV) on MR arthrography. (2) To assess 2D/3D measurements in identifying different types of FAI by means of cut-off values of AV/FV ratio (AFR). MATERIALS AND METHODS: Alpha angle, cranial acetabular version, acetabular depth, lateral center edge angle, AV, and FV of 52 hip MR arthrography were measured. ANOVA test correlated different types of FAI with AFR. ROC curves classified FAI by cut-off values of AFR. Accuracy of 2D/3D measurements was calculated. RESULTS: ANOVA test showed a significant difference of AFR (p value < 0.001) among the three types of FAI. The mean values of AFR were 0.64, 0.74, and 0.89 in cam, mixed, and pincer types, respectively. Cut-off values of AFR were 0.70 to distinguish cam types from mixed and pincer types, and 0.79 to distinguish pincer types from cam and mixed types. Cut-off values identified 100%, 73.9%, and 55.6% of pincer, cam, and mixed types. 2D and 3D classifications of FAI showed accuracy of 40.4% and 73.0%. CONCLUSIONS: 3D measurements were clearly more accurate than 2D measurements. Distinct cut-off values of AFR discriminated cam types from pincer types and identified pincer types in all cases. Cam and mixed types were not accurately recognized.

Diagnostic Accuracy of Magnetic Resonance Arthrography in Detecting Intra-articular Pathology Associated with Femoroacetabular Impingement.

Purpose The aim of this study was to assess the diagnostic accuracy of magnetic resonance arthrography (MRA) in the detection of intra-articular lesions of the hip in patients affected by femoroacetabular impingement (FAI) by using arthroscopy as reference standard. Methods Twenty-nine consecutive hip arthroscopies performed in 24 patients were considered for the study. Patients had a mean age of 38.3 years. Ultrasound-guided 1.5-T MRA was performed with precontrast short tau inversion recovery, T1-weighted and PD coronal, T1-weighted, and T2-weighted axial with 3-mm-thick slice sequences, and postcontrast T1-weighted fat saturation MRA (Fat-SAT) axial, coronal and oblique sagittal, and T1-weighted Vibe 3D coronal sequences with MPR sagittal, axial, and radial reconstructions with 2-mm-thick slice and coronal density protonil (DP) Fat-SAT. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRA were evaluated by comparison arthroscopy for the following intra-articular findings: acetabular and femoral chondral lesions, labral degeneration, labral tears, synovitis, ligamentum teres (LT) tears, CAM lesions, pincer lesions, loose bodies, and osteophytes. Results An absolute per cent agreement (100%) was observed for all the variables in the assessment of CAM lesions. Sensitivity, specificity, PPV, and NPV of MRA were 100, 68.4, 72.7, and 100%, respectively, for acetabular chondral lesions; 100, 50, 47.3, and 100%, respectively, for femoral chondral lesions; 33, 85, 20, and 91.6%, respectively, for labral tears; 95, 71, 91.3, and 83.3%, respectively, for labral degeneration; 100, 88, 57.1, and 100%, respectively, for LT tears; 33.3, 85, 50, and 73.9%, respectively, for pincer lesions; 50, 96, 66.6, and 92.3%, respectively, for intra-articular loose bodies; and 100, 73.9, 50, and 100%, respectively, for osteophytes. Conclusion MRA may play an important role in detecting intra-articular lesions associated with FAI. This might be helpful for the preoperative planning before hip arthroscopy. Level of Evidence This is a Level 2, diagnostic accuracy study compared with gold standard.

Talar fractures: radiological and CT evaluation and classification systems.

INTRODUCTION: The talus is the second largest bone of the foot. It is fundamental to ensure normal ankle-foot movements as it connects the leg and the foot. Talar fractures are usually due to high energy traumas (road accidents, high level falls). They are not common as they account for 3-5% of ankle and foot fractures and 0.85% of all body fractures. However, talar fractures not correctly diagnosed and treated can lead to avascular necrosis of the astragalus, pseudoarthrosis, early osteoarthrisis and ankle instability, declining the quality of life of patients. METHODS: A PubMed search was performed using the terms "talus" "talus AND radiology", "talar fractures", and "talar fractures classification", selecting articles published in the last 98 years. We selected articles about pre-treatment and post-surgery talar fractures diagnostic imaging. We also selected articles about talar fractures complications and traumatic talar dislocations. Case reports have not been included. AIM OF THE WORK: to describe radiological evaluations, classification systems, and biomechanical patterns involved in talar fractures. Also we will briefly describe talar fractures complications and treatment option and strategies. CONCLUSIONS: This work suggests a radiological approach aimed to classify talar fractures and guide treatment strategies, improving patient outcomes.

Calcaneal fractures: radiological and CT evaluation and classification systems.

BACKGROUND AND AIM OF THE WORK: The calcaneus, the more lower bone of the body, has the task of supporting the axial load from the weight of the body. Calcaneal fractures represent about 1-2% of all fractures and 60% of the tarsal bones fractures. The articular involvement has been associated with a poor functional outcome. The aim of this work is to describe the radiologic evaluation, the classification systems, the morphological preoperative diagnostic imaging features of calcaneal fractures, highlighting the correlation with the choice of treatment and predictive capacity for the fracture surgical outcome. METHODS: A PubMed search was performed for the terms Imaging calcaneus fracture, selecting articles in English language, published in the last two years, where preoperatively diagnostic imaging of fractures of the calcaneus are described.  Case reports have not been included. RESULTS: We have collected a number of data that provide important help in preoperative evaluation of calcaneal fractures, such as the new classification system created by Harnroongroj et al, the association of calcaneal fractures with fractures of other bone structures or soft tissue impairment, the use of calcaneotalar ratio in assessing the length of heel. CONCLUSIONS: These data suggest an approach geared to the specific choice of treatment and to improving patient outcomes.

Severe osteoporosis: diagnosis of femoral fractures.

In the diagnosis of femoral fractures, Radiodiagnostic has a role in the different phases of the natural history of these lesions:- in diagnosis and characterization of fractures,- in follow up of the efficacy of therapy, evolution of fractures and any complications,- in studies of risk factors of fractures.Diagnostic imaging employs method of investigation as Conventional Radiology, still crucial in detection, characterization and control of fracture, Computed Tomography (CT) and Magnetic Resonance (MR), essential in doubt of occult fracture and in differential diagnosis between the possible causes of pathologic fracture. Finally, Dual X-ray Absorptiometry (DXA is still the fundamental methodic in diagnosis and assessment of osteoporosis, while QCT, pQCT and HR-CT are experimental techniques used to study in vivo bone microarchitecture and its metabolic and pathological changes.

Bone fragility and imaging techniques.

Bone fragility is a silent condition that increases bone fracture risk, enhanced by low bone mass and microarchitecture deterioration of bone tissue that lead to osteoporosis. Fragility fractures are the major clinical manifestation of osteoporosis.A large body of epidemiological data indicates that the current standard for predicting fragility fracture risk is an areal BMD (aBMD) measurement by DXA. Although mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Thus, bone strength is explained not only by BMD but also by macrostructural and microstructural characteristics of bone tissue. Imaging diagnostics, through the use of X-rays, DXA, Ultrasonography, CT and MR, provides methods for diagnosis and characterization of fractures, and semi- and quantitative methods for assessment of bone consistency and strength, that become precious for bone fragility clinical management if they are integrated by clinical risk factors. The last employment of sophisticated non-invasively imaging techniques in clinical research as high-resolution CT (hrCT), microCT (µ-CT), high-resolution MR (hrMR) and, microRM (µRM), combined with finite element analysis methods, open to new challenges in a better bone strength assessment to enhance the comprehension of biomechanical parameters and the prediction of fragility fractures.