Implementation of Z-scores as an age- and sex-independent parameter for estimating joint space widths in rheumatoid arthritis.

OBJECTIVE: To compare normative data of joint space distances (JSD) with the JSD of patients with rheumatoid arthritis (RA) as measured by computer-aided joint space analysis (CAJSA) at the metacarpophalangeal (MCP) articulations, and to differentiate age- and sex-related alterations from the disease-related joint space narrowing. METHODS: In total, 256 healthy subjects and 248 patients with verified RA (following revised ACR criteria) underwent computerized semiautomated measurements of JSD (CAJSA, version 1.3.6) at the MCP articulation (JSD-MCP) based on digital radiographs. The Z-score, a comparative parameter that differentiates joint space alterations caused by RA-related cartilage destruction from age- and sex-related changes, was calculated. RESULTS: Our data showed a relationship between measured joint space widths (MCP total and MCP thumb to little finger) and age for healthy subjects and also the RA group. The RA group revealed an age-related joint space narrowing that was surpassed by the RA-related narrowing of joint space widths classified by Sharp joint space narrowing score and resulting in smaller Z-scores for RA patients. CONCLUSION: The CAJSA technique seems to distinguish age-related JSD changes in healthy volunteers from RA-induced alterations. In addition the Z-score was also able to differentiate RA-dependent narrowing of JSD. Calculation of the Z-scores based on sex- and age-specific reference data may facilitate earlier identification of patients with RA, allowing initiation of a more optimal, individually adapted therapeutic strategy.

Impact of sex, age, body mass index and handedness on finger joint space width in patients with prolonged rheumatoid arthritis using computer-aided joint space analysis.

To evaluate the associations between sex, age, body mass index (BMI) and handedness regarding the radiogeometric detectable joint space distances of the finger articulations in patients suffering from a prolonged course of rheumatoid arthritis (RA). The joint space widths were measured by a new available Computer-aided joint space analysis (CAJSA); 128 patients with RA underwent computerized semi-automated joint space analysis of joint space distances at the metacarpal-phalangeal articulation (JSD-MCP II-V), proximal-interphalangeal joint (JSD-PIP II-V) and distal-interphalangeal joint (JSD-DIP II-V) based on digitally performed radiographs of the hand (Radiogrammetry Kit, Version 1.3.6; Sectra; Sweden). The joint space distance (JSD) of each articulation was expressed as JSD total in millimeter. The patient cohort was differentiated for gender, age, handedness and BMI (BMI < 20; BMI 20-25, BMI > 25). JSD revealed a significant age-related narrowing of 24.8% (JSD-MCP), 22.6% (JSD-PIP) and 28.7% (JSD-DIP) between the ages of 20 and 79. Additionally, males showed a significantly wider JSD compared to the female cohort for all age groups. All JSD-distances were varied between the right and left hand. The JSD-MCP demonstrated significant differences regarding the BMI groups. In contrast to JSD-MCP an effect of the BMI on measurements of JSD-PIP and JSD-DIP could not be observed. These influences must be differentiated from disease-related alterations caused by RA.

Normative reference values of joint space width estimated by computer-aided joint space analysis (CAJSA): the distal interphalangeal joint.

PURPOSE: The study introduces reference data for a computer-aided analysis. The semiautomated computer-aided diagnostic system provides the estimation of joint space width at the distal interphalangeal joints, considering gender-specific and age-related changes. PATIENTS AND METHODS: 869 subjects (351 female/518 male) with hand x-rays were included and underwent measurements of joint space distances at the distal interphalangeal articulation (JSD-DIP) of the second to the fifth finger using computer-aided joint space analysis (CAJSA). RESULTS: Data showed a notable age-related decrease of CAJSA parameters, and an accentuated age-related joint space narrowing in women. Males showed a significantly wider JSD-DIP (+ 16.7%) compared to the female cohort for all age groups. Both men and women revealed an accentuated decrease of JSD-DIP (total) in the age group from 10 to 15 years (for men -10.5% and for women -17.6%). After the age of 21 years a continuous decline of the JSD-DIP (total) is observed. CONCLUSION: Our data present gender-specific and age-related normative reference data for computer-aided joint space analysis, which provide a valid and reliable differentiation between disease-related joint space narrowing and age-related joint space narrowing, particularly in patients with osteoarthritis of the fingers.

Computer-aided joint space analysis (CAJSA) of the proximal-interphalangeal joint-normative age-related and gender specific data.

RATIONALE AND OBJECTIVES: To provide reference data for computer-aided joint space analysis (CAJSA) based on a semiautomated and computer-aided diagnostic system for the measurement of joint space widths (ie, proximal-interphalangeal joint), considering gender-specific and age-related differences. MATERIALS AND METHODS: A total of 869 subjects were enrolled (351 females/518 males) with radiographs of the hand. All participants underwent measurements of joint space distances at the proximal-interphalangeal articulation (JSD-PIP) of the second to fifth finger using CAJSA technology. RESULTS: The data verify a notable age-related decrease of CAJSA parameters, showing an accentuated age-related joint space narrowing in women. Additionally, males showed a significant wider JSD-PIP (+15.4%) compared with the female cohort for all age groups. CONCLUSIONS: Our data present gender-specific and age-related normative reference values for computer-aided joint space analysis of JSD-PIP and provide a valid and reliable quantification of disease-related joint space narrowing, particularly in patients with osteoarthritis and rheumatoid arthritis involving the peripheral small hand joints.

Normative data for digital X-ray radiogrammetry from a female and male German cohort.

This study presents German reference data for digital X-ray radiogrammetry (DXR) differentiated by males as well as females, and quantifies for gender-specific and age-related differences including all DXR parameters. This study also documents the effects of different X-ray settings (e.g., radiographs of the wrist or the hand) on DXR measurements. There were 2085 patients who were prospectively enrolled (954 females and 1131 males) from a data pool of 11,915 patients with radiographs of the nondominant hand or wrist. All patients underwent measurements of bone mineral density (BMD), cortical thickness, bone width, and the metacarpal index (MCI) using DXR technology. These data showed a continuous age-related increase of the DXR parameters to the point of peak bone mass, then a continuous decline beyond the peak bone mass with accentuated age-related cortical bone loss in women. Peak bone mass is reached at approximately 30-34 yr for women and 45-49 yr for men. In addition, men had a significantly higher DXR BMD (mean: +12.8%) compared with woman in all age groups. Regarding the impact of various X-ray settings (e.g., X-ray(wrist) vs. X-ray(hand)), no significant difference was observed between both groups, men as well as women. The development of digital imaging technology has enabled more precise measurements of several radio-geometric features. The present study estimated normative reference values for DXR in German Caucasian women and men. Based on this reference data, a valid and reliable quantification of disease-related demineralization based on measurements of DXR BMD and MCI is now available for the Caucasian ethnic group.