Reproducibility and sensitivity to change of a new method of computer measurement of joint space width in hip osteoarthritis. Performance of three radiographic views obtained at a 3-year interval.

BACKGROUND: Measurement of radiographic joint space width (JSW) and of joint space narrowing (JSN) is the currently recommended method for assessment of anatomical severity and structural progression of osteoarthritis (OA), respectively. A standard radiographic view of the pelvis is commonly used for measurement of hip OA but other views are available. OBJECTIVES: To evaluate the inter-intra reader reproducibility and the sensitivity to change of a new automated method of measurement of the hip JSW and to assess which radiographic view [pelvis anteroposterior (AP) view, hip AP view, hip oblique view] provides the greatest accuracy for JSW and JSN measurements. MATERIAL AND METHODS: An AP pelvis radiograph, an AP radiograph centered on the target hip (AP hip) and an oblique view were performed at baseline (M0) and 3 years later (M36) in 50 hip OA patients. Two readers, blinded to each other's results and time sequence, measured twice, at a minimum 15 day interval, the six radiographs of each patient, using a novel version of a previously validated software program whose edge-based algorithm automatically detects the joint space contours. Inter-observer cross-sectional (M0+M36) and longitudinal (M0-M36) reproducibility of JSW measurement was assessed by the intra-class correlation coefficient (ICC) and the Bland-Altman method. Sensitivity to change was estimated by the standardized response mean (SRM). An ANOVA was used to analyze differences related to the observer and the view. RESULTS: Intra-observer reproducibility: For JSW measurement, the ICC value, for observers 1 and 2 respectively, were 0.92 and 0.83 for the pelvic view, 0.96 and 0.88 for the hip AP view, and 0.90 and 0.86 for the oblique view. For JSN, ICC was 0.94 and 0.82 for the pelvic view, 0.97 and 0.78 for the hip AP view, and 0.95 and 0.86 for the oblique view. Inter-observer reproducibility: For JSW measurement, ICC was 0.87 for the pelvic view, 0.98 for the hip AP view, and 0.87 for the oblique view. The mean inter-observer difference (SD) was 0.0 (0.31), -0.01 (0.15) and -0.04 (0.4)mm for pelvic, AP and oblique views respectively. For JSN, ICC was 0.91 for the pelvic view, 0.93 for the hip AP view, and 0.90 for the oblique view. Sensitivity to change: SRM values were 0.61 (observer 1) and 0.65 (observer 2) for the pelvic view, 0.68 and 0.75, respectively, for the hip AP view, 0.64 and 0.66, respectively, for the oblique view. JSN did not vary significantly with the observer and the view. In 27% of cases intervention by the observer was necessary to correct the computer's identification of the acetabular edge in the area of interest. CONCLUSION: Computer measurement of the radiographic hip joint space provided good intra- and inter-observer reproducibility and good sensitivity to change. However, it was necessary for the observer to intervene frequently to select the area of interest and adjust detection of the bone edge. The hip AP view performed better than the pelvis and oblique views, but not significantly so.

Superiority of the Lyon schuss view over the standing anteroposterior view for detecting joint space narrowing, especially in the lateral tibiofemoral compartment, in early knee osteoarthritis.

OBJECTIVE: To evaluate the validity of using the conventional anteroposterior (AP) radiograph of the knee in order to identify joint space narrowing (JSN) at an early stage of osteoarthritis (OA). METHODS: Grading of JSN using a 0-5 score and quantitative measurement of joint space width (JSW) of the medial and lateral compartments of the tibiofemoral joint in AP and fluoroscopically assisted posteroanterior Lyon schuss (LS) radiographs of 202 patients with knee OA. RESULTS: Knees without definite JSN (score <2) were twice as common in AP than in LS radiographs (36.1% vs 18.8%). The number of knees showing definite medial JSN was identical in both views but four knees showing a medial OA in AP view were classified differently in the LS radiographs (three bicompartmental OA and one lateral OA). The frequency of lateral JSN was approximately twice as great in the LS view as in the AP view. JSN score was significantly higher (p<0.001) and JSW was significantly smaller (p<0.01) in the LS view than in the AP view. In knees with definite JSN, JSW of the compartment with no narrowing was significantly (p<0.04) larger than in knees that did not exhibit definite JSN. Medial JSW and lateral JSW were inversely correlated (p<0.001). CONCLUSIONS: The standing AP radiograph performed poorly in identifying both the location of JSN in patients with early tibiofemoral OA (especially, lateral OA) and the severity of JSN. The LS radiographs are preferable to standing AP views for the selection of patients for therapeutic trials of structure-modifying OA drugs.

Epidemiological, clinical, biological and radiological differences between atrophic and hypertrophic patterns of hip osteoarthritis: a case-control study.

OBJECTIVE: Lack of osteophytes (atrophic form) has been shown to be a factor in the severity of hip osteoarthritis (OA). The aim of this study was to determine the epidemiological, radiological and biological differences between the hypertrophic and atrophic forms of hip osteoarthritis. METHODS: 25 patients with symptomatic hip OA (ACR criteria) and classified as having an atrophic form of OA based on the lack of osteophytes on standard radiograph of the pelvis, were matched for joint space width with 25 subjects with evidence of the hypertrophic form of hip OA. OA radiological severity was assessed using a scoring system and by computer measurement of the joint space width. Angles of hip dysplasia were measured. Serum hyaluronic acid, cartilage oligomeric matrix protein, collagenase, Type I procollagen, C-terminal crosslinking telopeptide of type I collagen and tissue inhibitor of métalloproteases-1 were assayed by immunoassay and C-reactive protein by ultrasensitive immunonephelemetry. Statistical analysis was performed using logistic regression, taking into account age, sex, body mass index, and bilaterality. RESULTS: Compared to hypertrophic OA, atrophic OA affected chiefly elderly women and was characterized by a smaller centre-edge angle and diffuse superior femoral head migration. It was less frequently bilateral. No statistically significant difference was found in the biological data between the two groups. CONCLUSION: An atrophic bone response in hip OA occurs chiefly in women and is associated with poor coverage of the femoral head. Serum biomarkers able to demonstrate differences between the atrophic and hypertrophic patterns of OA are lacking.

Bone metastases from bronchial carcinoid tumors. Two case-reports.

Two case-reports of metastatic bone disease in patients with bronchial carcinoid tumors illustrate the diagnostic challenges raised by these slowly-growing malignancies of which the primary frequently escapes early identification. The first patient had the typical picture of a primary with a single bone metastasis. Unusual features in the second patient were the large number of bone metastases, involvement of distal skeletal sites, and elevation of serotonin and 5-hydroxyindoleacetic acid levels.