Comorbidity clusters in generalized osteoarthritis among female patients: A cross-sectional study.

OBJECTIVES: To investigate the prevalence of comorbidities among female patients with generalized osteoarthritis (GOA) in comparison to an age- and sex matched control group. To identify clusters of comorbidities in both groups. METHODS: An observational, cross-sectional study was conducted. Consecutive female patients with hand and knee osteoarthritis according to the American College of Rheumatology (ACR) classification criteria were invited to participate in the study. A control group of participants without musculoskeletal symptoms, history or evidence of osteoarthritis or inflammatory rheumatic disease were also included. Cardiovascular, obstructive pulmonary, gastrointestinal, endocrine, neurological, malignant diseases and depression were recorded in both groups. In both study groups comorbidity cluster and factor analysis was performed. RESULTS: The study population included 200 GOA and 200 control participants. The following comorbidities were observed adjusted to Bonferroni correction with a significantly higher prevalence among individuals with GOA: hypertension, uterine leiomyoma, gastroesophageal reflux disease, diverticulosis, upper gastrointestinal tract ulcers, depression, diseases with vertigo (benign paroxysmal positional vertigo and vertebrobasilar insufficiency) and surgery due to otoclerosis. In the GOA group 5 clusters were identified with different comorbidity patterns. CONCLUSION: We report a high comorbidity rate in GOA. Cluster analysis allowed us to identify different comorbidity subsets for vascular, gastrointestinal and malignant gynaecological disorders. Further research is required to understand the links between GOA and non-musculoskeletal comorbidities.

Atlas-based knee osteophyte assessment with ultrasonography and radiography: relationship to arthroscopic degeneration of articular cartilage.

OBJECTIVES: To investigate intra- and inter-reader agreement of ultrasonography (US) and conventional radiography (CR) for the evaluation of osteophyte presence and size within the tibiofemoral joint. In addition, to correlate these findings with arthroscopic degeneration of the articular cartilage. METHOD: Forty adult patients with knee pain were enrolled in this study. Knee CR and US scanning of the medial and lateral bone margins were performed on all patients. A novel atlas for the US grading of knee osteophytes was used in the evaluation. The number and size of the osteophytes were evaluated semi-quantitatively in two rounds from both the CR images (four readers) and the US images (14 readers). The Noyes grading system was used for the evaluation of arthroscopic degeneration of the articular cartilage in 26 patients. RESULTS: On average, intra- and inter-reader US and CR agreement was substantial and comparable to each other (κ = 0.60-0.72). US detected more osteophytes than CR at both the medial (65% vs. 48%) and lateral (70% vs. 60%) compartments. A statistically significant correlation between CR- or US-based osteophyte and arthroscopy grades was observed only for US at the medial compartment (rs = 0.747, p < 0.001). CONCLUSIONS: The detection of knee osteophytes using the novel US atlas is as reproducible as reading conventional radiographs. US is more sensitive to detect knee osteophytes than CR. Furthermore, osteophytes detected with US correlate significantly with arthroscopic cartilage changes at the medial knee compartment whereas those detected by CR do not.

Relationship between radiographic joint space narrowing, sonographic cartilage thickness and anatomy in rheumatoid arthritis and control joints.

OBJECTIVE: To validate ultrasound (US) for measuring metacarpal cartilage thickness (MCT), by comparing it with anatomical measurement using cadaver specimens. To correlate US MCT with radiographic joint space narrowing (JSN) or width (JSW) in patients with rheumatoid arthritis (RA). METHODS: Bilateral metacarpophalangeal (MCP) joints of 35 consecutive outpatients, with recent hand X-rays, were included in the analysis. Metacarpal and phalangeal cartilage of MCP 2-5 was assessed bilaterally by US. JSW and JSN were evaluated on X-rays by the van der Heijde modified Sharp method (vdHS). In addition, cadaver specimens of MCP 2-5 joints (n=19) were evaluated by anatomical measurement and US. RESULTS: The agreement (intraclass correlation coefficient) between sonographic and anatomical MCT on cadaver specimens of MCP joints was 0.61. MCT of individual MCP joints correlated with individual MCP JSN (r=-0.32, p<0.001) and individual MCP JSW (r=0.72, p<0.001). No correlation was found between phalangeal cartilage thickness and JSN in individual MCP joints. The US MCT summary score for MCP joints 2-5 correlated with summary scores for JSW (r=0.78, p<0.001), JSN (r=-0.5, p<0.001), erosion score of the vdHS (r=-0.39, p<0.001) and total vdHS (r=-0.47, p<0.001). CONCLUSIONS: Sonographic cartilage assessment in MCPs is closely related to anatomical cartilage thickness. Both JSW and JSN by radiography represent cartilage thickness in the MCP joints of patients with RA quite well. Thus, US is a valid tool for measuring MCT if radiographs are not available or in case of joint malalignment.

High resolution atmospheric transmission calculations down to 28.7 km in the 200-243-nm spectral range.

Decrease in stratospheric ozone absorption and increase in oxygen absorption with decreasing wavelength combine to produce a window of maximum atmospheric transmission near 210 nm. Since solar radiation in this spectral region dissociates molecular oxygen, the deep atmospheric penetration at this wavelength is of particular aeronomical interest. High resolution calculations of the transmittance down to 28.65 km were made for the 200-243-nm spectral range in this window region, in support of a stratospheric balloon flight from Fort Churchill in July 1974. The calculations were made by dividing the atmosphere into layers which were chosen so that each could be assumed homogeneous; optical depths were calculated separatelyfor each of these layers and then summed to obtain the over-all transmittance of the atmosphere. Absorptionby molecular oxygen (line and continuum) and by ozone was included, as well as extinction through Rayleigh scattering by air molecules. The calculated transmittances were combined with hig h altitude(above 100-km) rocket measurements of the sun-center spectrum and center-to-limb variations to give residual high resolution solar spectral flux for several altitudes and solar zenith angles.