The Change of the Lumber Vertebra Bone Density under the State of the Osteophyte Formation

骨密度を測定する装置にDXA(Dual-energy X-ray absorptiometry)があるが，この装置の測定の精度を低下させる要因の一つに腰椎における骨棘の形成がある。今回の研究では骨棘が腰椎骨密度測定に及ぼす影響を調べるために，腰椎と橈骨1/3部位の骨密度の相関関係を腰椎の骨棘の長さ別に検討した。圧迫骨折，骨硬化がない女性52人(年齢50～80歳 平均64.6歳)において，骨棘の長さが13mm未満では腰椎と橈骨の骨密度には正の相関がみられたが，13mm以上ではその相関がみられなくなった。よって13mm未満の骨棘があってもほぼ正確な腰椎の骨密度が測定できることが明らかとなった。Bone mineral density (BMD) can be measured by dual-energy X-ray absorptiometry (DXA) . However, the osteophyte formation may disturb the accurate measurement of the BMD by DXA. To examine the influence of the osteophyte on the lumbar vertebra BMD measurement, BMDs of the lumbar vertebra and radius (1/3) were compared in 52 women in this study. No signs of the compression fracture and the osteosclerosis were confirmed, and the length of the osteophyte was measured by the lumbar spinal radiogram in those women. The BMDs of the lumbar spine and radius (1/3) were positively correlated if the length of the osteophyte was within 13mm, but the correlation was not observed in women whose length of the osteophyte were longer than 13mm. Thus, the BMD of the lumbar vertebra can be precisely measured if the length of the osteophyte was within 13mm