Uterine lipoleiomyosarcoma: Complete medullary compression as presentation of a solitary metastasis.

•A rare case of lipoleiomyosarcoma.•Patient presented at our center with paraplegia caused by a solitary vertebral metastasis of a uterine cancer.•Lobectomy performed for a solitary lung metastasis.

Total knee arthroplasty with a novel navigation system within the surgical field.

Total knee arthroplasty is a common procedure, and current navigation systems are gradually gaining acceptance for improving surgical accuracy and clinical outcomes. A new navigation system used within the surgical field, iAssist, has demonstrated reproducible accuracy in component alignment. All orientation information is captured by small electronic pods and transmitted via a local wireless network, which directs the surgical workflow automatically to the femoral and tibial resection instruments. This simple and accurate navigation system used completely in the surgical field, without optical trackers or preoperative imaging, seems to be the latest generation of smart instrumentation for total knee arthroplasty.

Malignant perineurioma (malignant peripheral nerve sheath tumor with perineural differentiation).

The great majority of malignant peripheral nerve sheath tumors (MPNST) exhibit Schwannian differentiation. In recent years, a subset of perineurial MPNST (malignant perineurioma) has been identified based on their histologic, immunohistochemical and ultrastructural features. Immunopositivity for epithelial membrane antigen (EMA), glut-1 and claudin-1, is characteristic. Such tumors must be distinguished from benign perineurioma and a variety of atypical or malignant soft tissue tumors featuring EMA positivity. Herein, we report a perineurial MPNST involving the buttock of a 42-year-old woman. Nerve involvement was noted. The clinicopathologic features of reported examples are ummarized and key differential diagnoses are discussed.

Human hip joint cartilage: MRI quantitative thickness and volume measurements discriminating acetabulum and femoral head.

This paper aims at developing a quantitative system for measuring human hip cartilage thickness and volume using magnetic resonance imaging (MRI). A new MRI-acquisition technique, named axial rotation, where the acquisition planes are organized around a virtual axis, was used. The MRI protocol consists of a 2-D multiple-echo data image combination (MEDIC) using water excitation. Inner and outer interface contours of acetabulum and femoral head cartilage are obtained using a semiautomated 3-D segmentation method and combined to form 3-D surfaces. A local spherical coordinate system computed from the original contours enables cartilage thickness and volume computation. An anatomical labeling is performed automatically for thickness and volume measurements in predefined subregions: inferior, anterior, superior, and posterior. A registration module is introduced allowing the assessment of cartilage changes over time. Validation of the system was conducted with three protocols each involving data obtained from nine subjects: 1) registration process accuracy; 2) intrareader reproducibility; and 3) intervisit coefficient of variation. Data showed excellent correlation coefficients for either the intrareader (r>or=0.0942, p<0.0001 ) or intervisit (r>or=0.0837, p<0.005) protocols. This noninvasive system, which enables the quantification of cartilage thickness and volume in the human hip joint using MRI, is the first to discriminate the acetabular and femoral head cartilage throughout the entire hip without the use of an external device, and to implement hip registration for follow-up studies on the same subject.

Risk factors associated with the loss of cartilage volume on weight-bearing areas in knee osteoarthritis patients assessed by quantitative magnetic resonance imaging: a longitudinal study.

The objective of this study was to identify, on a symptomatic knee osteoarthritis (OA) cohort, the risk factors associated with the progression of the disease. More specifically, we investigated the correlation between knee cartilage volume loss from subregions over the span of 24 months by means of quantitative magnetic resonance imaging (qMRI) with demographic, clinical, radiological, and MRI structural changes. A cohort of 107 patients with knee OA selected from a large trial evaluating the effect of a bisphosphonate underwent x-rays and MRI of the knee at baseline and 24 months. Joint space width (JSW) and joint space narrowing (JSN) and cartilage volume loss over time in subregions of the tibial plateaus and femoral condyles were quantitated. Structural changes in the subchondral bone (hypersignal) and in the menisci (tear and extrusion) were also evaluated. The greatest cartilage volume loss was found in the medial compartment, and risk factors included female gender, JSW, meniscal lesions, and bone changes at baseline. Subregion analysis revealed that the greatest cartilage volume loss at 24 months was found in the central area of the medial tibial plateau (15%; p < 0.0001) and of the medial femoral condyle (12%; p < 0.0001). These findings were associated with the presence at baseline of meniscal extrusion, particularly severe meniscal extrusion, medial and severe meniscal tear, bone hypersignal, high body mass index (BMI), smaller JSW, increases in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and patient global scores over time, and greater JSN. Parameters predicting medial central femoral condyle cartilage volume loss at 24 months were lateral meniscal tear, SF-36 and BMI at baseline, and JSN. At the medial central tibial plateau, the parameters were severe meniscal extrusion, severe lateral meniscal tear, and bone hypersignal in the lateral compartment at baseline, and WOMAC pain change. Meniscal damage and bone changes are the features most closely associated with the greatest subregional cartilage volume loss. Interestingly, for the first time, JSN was strongly associated with cartilage loss in the central areas of plateaus and condyles. This study also further confirms the correlation between cartilage volume loss and JSN and symptomatic changes at 24 months.

Long term evaluation of disease progression through the quantitative magnetic resonance imaging of symptomatic knee osteoarthritis patients: correlation with clinical symptoms and radiographic changes.

The objective of this study was to further explore the cartilage volume changes in knee osteoarthritis (OA) over time using quantitative magnetic resonance imaging (qMRI). These were correlated with demographic, clinical, and radiological data to better identify the disease risk features. We selected 107 patients from a large trial (n = 1,232) evaluating the effect of a bisphosphonate on OA knees. The MRI acquisitions of the knee were done at baseline, 12, and 24 months. Cartilage volume from the global, medial, and lateral compartments was quantified. The changes were contrasted with clinical data and other MRI anatomical features. Knee OA cartilage volume losses were statistically significant compared to baseline values: -3.7 +/- 3.0% for global cartilage and -5.5 +/- 4.3% for the medial compartment at 12 months, and -5.7 +/- 4.4% and -8.3 +/- 6.5%, respectively, at 24 months. Three different populations were identified according to cartilage volume loss: fast (n = 11; -13.2%), intermediate (n = 48; -7.2%), and slow (n = 48; -2.3%) progressors. The predictors of fast progressors were the presence of severe meniscal extrusion (p = 0.001), severe medial tear (p = 0.005), medial and/or lateral bone edema (p = 0.03), high body mass index (p < 0.05, fast versus slow), weight (p < 0.05, fast versus slow) and age (p < 0.05 fast versus slow). The loss of cartilage volume was also slightly associated with less knee pain. No association was found with other Western Ontario McMaster Osteoarthritis Index (WOMAC) scores, joint space width, or urine biomarker levels. Meniscal damage and bone edema are closely associated with more cartilage volume loss. These data confirm the significant advantage of qMRI for reliably measuring knee structural changes at as early as 12 months, and for identifying risk factors associated with OA progression.

Quantitative magnetic resonance imaging evaluation of knee osteoarthritis progression over two years and correlation with clinical symptoms and radiologic changes.

OBJECTIVE: To evaluate the change in osteoarthritic (OA) knee cartilage volume over a two-year period with the use of magnetic resonance imaging (MRI) and to correlate the MRI changes with radiologic changes. METHODS: Thirty-two patients with symptomatic knee OA underwent MRI of the knee at baseline and at 6, 12, 18, and 24 months. Loss of cartilage volumes were computed and contrasted with changes in clinical variables for OA and with standardized semiflexed knee radiographs at baseline at 1 and 2 years. RESULTS: Progression of cartilage loss at all followup points was statistically significant (P < 0.0001), with a mean +/- SD of 3.8 +/- 5.1% for global cartilage loss and 4.3 +/- 6.5% for medial compartment cartilage loss at 6 months, 3.6 +/- 5.1% and 4.2 +/- 7.5% at 12 months, and 6.1 +/- 7.2% and 7.6 +/- 8.6% at 24 months. Discriminant function analysis identified 2 groups of patients, those who progressed slowly (<2% of global cartilage loss; n = 21) and those who progressed rapidly (>15% of global cartilage loss; n = 11) over the 2 years of study. At baseline, there was a greater proportion of women (P = 0.001), a lower range of motion (P = 0.01), a greater circumference and higher level of pain (P = 0.05) and stiffness in the study knee, and a higher body mass index in the fast progressor group compared with the slow progressor group. No statistical correlation between loss of cartilage volume and radiographic changes was seen. CONCLUSION: Quantitative MRI can measure the progression of knee OA precisely and can help to identify patients with rapidly progressing disease. These findings indicate that MRI could be helpful in assessing the effects of treatment with structure-modifying agents in OA.