New vertebral fractures after vertebroplasty: 2-year results from a randomised controlled trial.

UNLABELLED: A randomised controlled trial of vertebroplasty (VP) versus placebo assessed the effect of VP on the risk of further vertebral fractures. While no statistically significant between-group differences for new or progressed fracture risk at 12 and 24 months were observed, we observed a consistent trend towards higher risk of any type of fracture in the group undergoing VP. Our analysis was underpowered, and further adequately powered studies are needed to be able to draw firm conclusions about further vertebral risk with vertebroplasty. PURPOSE: This study seeks to assess the effect of VP on the risk of further radiologically apparent vertebral fracture within two years of the procedure. METHODS: We conducted a randomised placebo-controlled trial of VP in people with acute osteoporotic vertebral fracture. Eligible participants were randomly assigned to VP (n = 38) or placebo (n = 40). Cement volume and leakage were recorded for the VP group. Plain thoracolumbar radiographs were taken at baseline, 12 and 24 months. Two independent radiologists assessed these for new and progressed fractures at the same, adjacent and non-adjacent levels. RESULTS: At 12 and 24 months, radiographs were available for 45 (58 %) and 47 (60 %) participants, respectively. There were no between-group differences for new or progressed fractures: 32 and 40 in the VP group after 12 and 24 months compared with 21 and 33 in the placebo group (hazard ratio (HR) 1.80, 95 % confidence interval (CI) 0.82 to 3.94). Similar results were seen when considering only adjacent (HR (95 % CI) 2.30 (0.57 to 9.29)) and non-adjacent (HR (95 % CI) 1.45 (0.55 to 3.81) levels. In all comparisons, there was a consistent trend towards higher risk of any type of fracture in the group undergoing VP. Within the VP group, fracture risk was unrelated to total (HR (95 % CI) 0.91 (0.71 to 1.17)) or relative (HR (95 % CI) 1.31 (0.15 to 11.48)) cement volume or cement leakage (HR (95 % CI) 1.20 (0.63 to 2.31)). CONCLUSION: For patients undergoing VP, our study did not demonstrate significant increases in subsequent fracture risk beyond that experienced by those with vertebral fractures who did not undergo the procedure. However, because of the non-significant numerical increases observed, studies with adequate power are needed to draw definite conclusions about fracture risk.

Plain radiography is effective for the detection of calcinosis cutis occurring in association with autoimmune connective tissue disease.

BACKGROUND: Studies on the radiological findings of calcinosis cutis in patients with autoimmune connective tissue disease (ACTD) are limited. OBJECTIVES: To describe imaging findings and radiological patterns of calcinosis cutis occurring with ACTD. METHODS: We retrospectively reviewed the cases of 37 patients with imaging studies assessing for calcinosis cutis associated with ACTD at our institution between 1996 and 2009. A formal blinded review of available images (i.e. radiographs, computed tomography scans) for all 37 patients was performed by radiologists. RESULTS: Of 37 patients, 30 (81%) were female. The mean age at diagnosis of calcinosis cutis was 43·4 years. Patients had the following ACTDs: dermatomyositis (n = 17) with classic (n = 9), juvenile (n = 7) and amyopathic (n = 1) subtypes; systemic sclerosis with limited cutaneous scleroderma (n = 8); undifferentiated connective tissue disease (n = 4); mixed connective tissue disease (n = 3); systemic lupus erythematosus (n = 2); lupus panniculitis (n = 1); overlap connective tissue disease (n = 1); and polymyositis (n = 1). Plain radiographs detected calcinosis in all 37 patients; a nodular pattern of calcification was most commonly observed (31/37; 84%). Two or more morphological patterns of calcification were present in 19 patients (51%). In general, individual patterns were not specific to a particular ACTD subtype. CONCLUSIONS: Radiography detected calcinosis in all patients and is recommended for initial imaging of calcinosis. Multiple morphological patterns of calcification were observed across ACTD subtypes. Further studies should correlate radiological studies with treatment of calcinosis and underlying ACTD.

Lipoma arborescens: comparison of typical and atypical disease presentations.

AIM: To determine whether the aetiology differed between typical cases of lipoma arborescens with unilateral knee involvement and atypical cases involving joints other than the knee, polyarticular disease, and disease outside of the knee joint. MATERIALS AND METHODS: Cases of lipoma arborescens involving the knee joint were evaluated for the distribution of the disease and severity of degenerative arthritis. Joints other than the knee were evaluated for the presence and severity of degenerative arthritis, and the distribution was classified as either intra-articular, extra-articular, or both. Clinical history was reviewed for patient age at presentation, a history of inflammatory arthritis, diabetes mellitus, and known steroid use. Fisher's exact test was used to determine whether there was a statistically significant difference between typical and atypical presentations of the disease. RESULTS: Lipoma arborescens was identified in 45 joints in 39 patients. Twenty-eight patients were classified as "typical" and 11 patients had "atypical" disease. There was no significant difference in age at presentation, presence of degenerative arthritis, or known inflammatory arthritis when comparing typical and atypical presentations of the disease. CONCLUSION: Twenty-eight percent of patients in the present study had atypical presentation of lipoma arborescens with multifocal lipoma arborescens or disease in joints other than the knee. There was no significant difference in age at presentation, presence of degenerative arthritis, or known inflammatory arthritis when comparing typical and atypical presentations of the disease. Of the 39 patients, only three had no evidence of degenerative arthritis, which suggests that many cases of lipoma arborescens are secondary to chronic reactive change in association with degenerative arthritis.

Statistics and vertical directionality of low-frequency ambient noise at the North Pacific Acoustic Laboratory site.

We examine statistical and directional properties of the ambient noise in the 10-100 Hz frequency band from the NPAL array. Marginal probability densities are estimated as well as mean square levels, skewness and kurtoses in third octave bands. The kurotoses are markedly different from Gaussian except when only distant shipping is present. Extremal levels reached approximately 150 dB re 1 micro Pa, suggesting levels 60dB greater than the mean ambient were common in the NPAL data sets. Generally, these were passing ships. We select four examples: i) quiescent noise, ii) nearby shipping, iii) whale vocalizations and iv) a micro earthquake for the vertical directional properties of the NPAL noise since they are representative of the phenomena encountered. We find there is modest broadband coherence for most of these cases in their occupancy band across the NPAL aperture. Narrowband coherence analysis from VLA to VLA was not successful due to ambiguities. Examples of localizing sources based upon this coherence are included. kw diagrams allow us to use data above the vertical aliasing frequency. Ducted propagation for both the quiescent and micro earthquake (T phase) are identified and the arrival angles of nearby shipping and whale vocalizations. MFP localizations were modestly successful for nearby sources, but long range ones could not be identified, most likely because of signal mismatch in the MFP replica.

Laser-Doppler measurement of crosswind velocity.

There is a need for the remote sensing of local wind velocities over distances of hundreds of meters, and laser-Doppler anemometry (LDA) has been suggested as a suitable measuring technique. In this paper the major features of an LDA system optimized for crosswind velocity measurements are presented. Computer programs based on Mie scattering theory are used to predict the performance of such systems and to extend the experimentally verified information to larger distances. A complete system for the measurement of the crosswind velocity component is described, and measurements up to 106 m verifying its performance and corresponding predictions are presented and discussed. Suggestions for further studies and developments are given.