Schreiber Joseph J, Kamal Robin N, Yao Jeffrey
Stanford University Medical Center, Redwood City, CA.
Stanford University Medical Center, Redwood City, CA.
J Hand Surg Am. 2017 Apr;42(4):244-249. doi: 10.1016/j.jhsa.2017.01.012. Epub 2017 Feb 24.
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.
TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.
骨质疏松症和脆性骨折对个体及整个医疗保健系统均会产生影响。虽然双能X线吸收法（DXA）是评估骨密度（BMD）的参考标准，但其他更简单的工具或许能够初步筛查骨质情况并提示干预需求。我们推测，根据手部或腕部标准X线片计算得出的第二掌骨皮质百分比（2MCP）与DXA测量的髋部骨密度相关，且可为骨质疏松症提供一种简单的筛查工具。
本研究纳入了200例在1年内先后进行过手部或腕部X线片检查及髋部DXA扫描的患者。第二掌骨干中部的2MCP计算为皮质直径与总直径之比。我们评估了2MCP与全髋骨密度之间的相关性。根据髋部t值将受试者分为正常、骨量减少和骨质疏松队列，并确定阈值以优化筛查的敏感性和特异性。
第二掌骨皮质百分比与髋部骨密度及t值显著相关。2MCP阈值小于60%时，区分骨量减少与正常受试者的敏感性（88%）和特异性（60%）最佳；而阈值小于50%时，区分骨质疏松与正常受试者的敏感性（100%）和特异性（91%）最佳。
这些数据表明，通过手部和腕部X线片可评估整体骨密度，提示手部和腕部X线片在准确筛查骨量减少和骨质疏松症方面可能具有作用。这项简单的检查已广泛应用于手部或腕部疾病患者，可识别脆性骨折风险患者并进行适当转诊或治疗。
研究类型/证据水平：诊断性研究II级
