發生髖部骨折的老年婦女之髖部骨密度研究

Hip Bone Mineral Density in the Elderly Patients with Hip Fracture

老年人發生髖部骨折的發生率很高，其發生率隨著年紀之增高而急遽增高。髖部骨折與老年人的骨質疏鬆症有關，因此本研究目的在探討發生髖部骨折的老年婦女病患之髖部骨密度的情形。本研究使用Norland 2600雙光子骨吸收測量儀來評估81位髖部骨折病患未發生骨折的健康側髖部骨骼之骨密度值，並且與77位類似年紀之正常中國婦女的髖部骨密度值比較。在本研究中，發生髖部骨折的病患年紀為73.5 ± 6.6歲（平均值 ± 標準差），而對照組的年紀則為69.2± 6.9歲。所有病患的骨折都是因為輕微傷害所造成，包括跌倒或滑倒等。本研究所測定的髖部骨骼部位依儀器電腦所訂定之標準區域而測得，包括股骨頸部，轉子間區，和Ward氏三角區。結果顯示髖部骨折病患的髖部骨密度值比對照組為低，且統計上具有意義。利用線性迴歸的分析顯示，發生骨折的機率隨著年紀增高與低骨密度值而呈指數性增高。病患各單一部位的骨密度值皆比對照組的相對部位骨密度值低，病患股骨頸骨密度值為0.556 g/cm2，對照組為0.624 g/cm2；病患股骨轉子間區骨密度值為0.505 g/cm2，對照組為0.566 g/cm2；病患Ward氏三角區骨密度值為0.432 g/cm2，對照組為0.485 g/cm2(p <0.0001)。若以0.65 g/cm2作為分界點，且假定髖部骨折盛行率5%和20%時，所計算得的陰性預測值和陽性預測值皆在可接受的程度內。因此，本研究的結果為發生髖部骨折的病患，其發生髖部骨骼骨質疏鬆的程度比對照組嚴重。

In order to examine the status of osteoporosis of patients with hip fracture, we assessed the bone mineral density (BMD) of the contralateral hip of 81 elderly Chinese women with hip fracture and in 77 normal Chinese women. The age of fracture patients was 73.5 ± 6.6 (mean ± standard deviation) years, whereas that of control subjects was 69.2 ± 6.9 years. All fractures were caused by minor trauma, such as falls or slips on the ground. The Norland 2600 dual-photon absorptiometer was used to evaluate the BMD in the femoral neck, the trochanter, and Ward's triangle. The BMD of the fracture patients was significantly lower than that of the controls. By linear regression, the probability of fracture increased exponentially with age and decreasing BMD. The mean BMD of the femoral neck of the fracture patients vs control hips was: 0.556 vs. 0.624 g/cm2; for trochanter: 0.505 vs. 0.566 g/cm2; for Ward's triangle: 0.432 vs. 0.485 g/cm2(p< 0.0001). Both negative predictive value and positive predictive value were acceptable at a hip fracture prevalence of 5% or 20%, and at BMD cutoff point of 0.65 g/cm2. Our findings suggest that the degree of relative osteoporosis in patients with hip fractures is more severe than in controls.