橈骨遠位端骨折後のビスホスホネート早期投与は廃用性萎縮を予防できるか―DXA法による第2中手骨骨密度を用いた検討

Preventive Effect of Early Bisphosphonate Treatment on Disuse Atrophy Following a Distal Radial Fracture Assessed by Measurement of the Bone Mineral Density of the Second Metacarpal by Dual X-ray Absorptiometry

　はじめに：廃用性萎縮にビスホスホネート(BP)が有効とされるが，橈骨遠位端骨折後の保存治療患者(本対象)における報告はない．

　目的：DXA法による第2中手骨骨密度(本法)を用い，本対象に対するBP早期投与の廃用性萎縮の予防効果を検討した．

　対象・方法：本対象19例をコントロール群(C群)とBP投与群(BP群)に分け，受診時と1.5，3，6カ月時の骨密度変化を観察した．

　結果：患側骨密度は，C群92.2％，86.0％，90.7％，BP群91.6％，87.0％，89.8％と経時的に低下した．

　考察：BPの予防効果はなかったが，本法は廃用性萎縮の評価に有効なツールとなる．

　Introduction：Although bisphosphonates (BP) have been shown to be an effective means of treating disuse atrophy, their use in patients with conservatively treated distal radial fractures has never been reported.

　Objective：To evaluate the preventive effect of early BP treatment in patients with disuse atrophy assessed by bone mineral density (BMD) measurements of the second metacarpal by dual X-ray absorptiometry (DXA).

　Materials and Method：Patients (n＝19) with a conservatively treated distal radial fracture were divided into a control group and a BP treatment group (BP group), and BMD at 1.5, 3, and 6 months after the injury was compared with BMD at the time of injury.

　Results：BMD on the affected side decreased over time in both the BP group (91.6%, 87.0%, and 89.8%, respectively) and control group (92.2%, 86.0%, and 90.7%, respectively.)

　Discussion：Measurement of BMD by DXA would be an effective tool for assessing disuse atrophy.　BP treatment did not have a preventive effect on disuse atrophy secondary to a conservatively treated distal radial fracture.