Simple Assessment of Global Bone Density and Osteoporosis Screening Using Standard Radiographs of the Hand

Purpose Osteoporosis and fragility fractures have consequences both at the individual level and to the overall health care system. Although dual-energy x-ray absorptiometry (DXA) is the reference standard for assessing bone mineral density (BMD), other, simpler tools may be able to screen bone quality provisionally and signal the need for intervention. We hypothesized that the second metacarpal cortical percentage (2MCP) calculated from standard radiographs of the hand or wrist would correlate with hip BMD derived from DXA and could provide a simple screening tool for osteoporosis. Methods Two hundred patients who had hand or wrist radiographs and hip DXA scans within 1 year of each other were included in this series. Mid-diaphyseal 2MCP was calculated as the ratio of the cortical diameter to the total diameter. We assessed the correlation between 2MCP and total hip BMD. Subjects were stratified into normal, osteopenic, and osteoporotic cohorts based on hip t scores, and thresholds were identified to optimize screening sensitivity and specificity. Results Second metacarpal cortical percentage correlated significantly with BMD and t scores from the hip. A 2MCP threshold of less than 60% optimized sensitivity (88%) and specificity (60%) for discerning osteopenic subjects from normal subjects, whereas a threshold of less than 50% optimized sensitivity (100%) and specificity (91%) for differentiating osteoporotic from normal subjects. Conclusions By demonstrating that global BMD may be assessed from 2MCP, these data suggest that radiographs of the hand and wrist may have a role in accurately screening for osteopenia and osteoporosis. This simple investigation, which is already used ubiquitously for patients with hand or wrist problems, may identify patients at risk for fragility fractures and allow for appropriate referral or treatment. Type of study/level of evidence Diagnostic II. Osteoporosis and fragility fractures have consequences both at the individual level and to the overall health care system. Although dual-energy x-ray absorptiometry (DXA) is the reference standard for assessing bone mineral density (BMD), other, simpler tools may be able to screen bone quality provisionally and signal the need for intervention. We hypothesized that the second metacarpal cortical percentage (2MCP) calculated from standard radiographs of the hand or wrist would correlate with hip BMD derived from DXA and could provide a simple screening tool for osteoporosis. Two hundred patients who had hand or wrist radiographs and hip DXA scans within 1 year of each other were included in this series. Mid-diaphyseal 2MCP was calculated as the ratio of the cortical diameter to the total diameter. We assessed the correlation between 2MCP and total hip BMD. Subjects were stratified into normal, osteopenic, and osteoporotic cohorts based on hip t scores, and thresholds were identified to optimize screening sensitivity and specificity. Second metacarpal cortical percentage correlated significantly with BMD and t scores from the hip. A 2MCP threshold of less than 60% optimized sensitivity (88%) and specificity (60%) for discerning osteopenic subjects from normal subjects, whereas a threshold of less than 50% optimized sensitivity (100%) and specificity (91%) for differentiating osteoporotic from normal subjects. By demonstrating that global BMD may be assessed from 2MCP, these data suggest that radiographs of the hand and wrist may have a role in accurately screening for osteopenia and osteoporosis. This simple investigation, which is already used ubiquitously for patients with hand or wrist problems, may identify patients at risk for fragility fractures and allow for appropriate referral or treatment.