男性骨质疏松患者股骨头松质骨微结构区域差异的研究

The trabecular heterogeneity of femoral head in male osteoporotic fracture

目的 探讨中国男性骨质疏松股骨颈骨折患者股骨头松质骨微结构的区域差异,明确微结构差异对股骨颈骨折的影响.方法 18例中国男性股骨颈骨折患者股骨头标本,根据脆性骨折分为骨质疏松骨折（11例）和外伤骨折（7例）2组.定位标记后取6 mm×6 mm×7mm的松质骨骨块9块,其中1块为主应力区标本,其他8块为非主应力区标本.行显微CT扫描,测量各骨块三维骨微结构参数.用t检验分析两组主应力区、非主应力区和所有标本平均值松质骨的微结构参数.结果 骨质疏松骨折组,非主应力区与主应力区相比,体积骨密度[非主应力区为（182.15 ±66.00）mg/mm^3,主应力区为（223.97±70.92）mg/mm^3,t=3.041]、组织骨密度[非主应力区为（538.76±64.72）mg/mm^3,主应力区为（580.01±63.86）mg/mm^3,t=3.160]、骨体积分数[非主应力区为（0.22±0.06）%,主应力区为（0.26±0.07）%,t=2.821]、骨小梁厚度[非主应力区为（161.07±42.75）μm,主应力区为（205.47±74.44）μm,t=3.233]显著下降,骨表面体积比[非主应力区为（13.75 ±2.55）mm^-1,主应力区为（12.28±2.70）mm^-1,t=-2.777]显著增加,差异均有统计学意义（P值均〈0.05）.在非主应力区,骨质疏松骨折组与外伤骨折组比较,体积骨密度[外伤骨折组为（248.05±105.48）mg/mm^3,t=-3.598]、组织骨密度[外伤骨折组为（570.54 ±100.32）mg/mm^3,t=-2.108]、骨体积分数[外伤骨折组为（0.28±0.12）%,t=-3.466]、骨小梁厚度[外伤骨折组为（200.31±96.63）μm,t=-2.866]、骨小梁数量[骨质疏松骨折组为（1.46±0.23）个/mm3,外伤骨折组为（1.57±0.29）个/mm^3,t=-2.396]显著下降,骨小梁间隔[骨质疏松骨折组为（780.82±144.85）μm,外伤骨折组为（653.09±119.64）μm,t=5.470]、各向异性度（骨质疏松骨折组为1.57±0.20,外伤骨折组为1.47±0.18,t=2.930）显著增加,差异有统计学意义（P值均〈0.05）.所有18个标本主应力区骨小梁厚度[（199.37±68.22）μm]与非主应力区[（176.33±71.21）μm]比较显著增加,差异有统计学意义（t=2.060,P〈0.05）.结论 骨质疏松患者股骨头松质骨骨量的丢失和微结构的改变存在区域差异,非主应力区的退变更加明显.股骨头部位骨小梁厚度的改变可能是与股骨颈骨折关系最密切的微结构指标.

Objective The aim of this study was to investigate the femoral head trabecular heterogeneity in Chinese male patients with osteoporotic fracture and their effects on osteoporotie fracture.Methods Human femoral heads were obtained from 11 male osteoporotie fracture （OP） patients ranged from 51 to 82 years old [average age （65±9 ） years old], and 7 male trauma （ TM ） patients ranged from 46 to 75 years old [average age （61±11 ） years old] who underwent total hip arthroplasty within two hours after either osteoporotic or trauma hip fracture.The OP was defined as having a fragility fracture.After laying femoral head as living body position and locating mark, nine trabecular specimens were obtained from femoral heads, each of 6 mm × 6 mm× 7 mm.The cortical shell was not included in each specimen.One cube was selected as the primary compressive trabecular region and the other 8 specimens as non-primary compressive trabecular region.These cubes were scanned using high-resolution microcomputed tomography scanner （μCT）.After scanning, the data of total cubes, primary compressive trabecular region and noncompressive trabecular region were used for analysis by t test.Results In OP group volumetric bone mineral deosity（vBMD） [（ 182.15±66.00） mg/mm^3 vs （223.97±70.92） mg/mm^3, t =3.041], tissue bone mineral density （tBMD） [（538.76±64.72） mg/mm3 vs （580.01±63.86 ） mg/mm^3, t = 3.160],bone volume fraction （TV/BV） [（0.22 ± 0.06） % vs （0.26 ± 0.07 ） %, t = 2.821], trabecular thickness （Tb.Th.） [（ 161.07 ±42.75 ） μm vs （ 205.47 ± 74.44 ） μm, t = 3.233] were significantly decreased while bone surface/bone volume （ BS/BV ） [（ 13.75 ± 2.55 ） mm^-1 vs （ 12.28 ± 2.70 ） mm^-1, t =-2.777] was significantly increased in the non-primary compressive trabecular region than that in the primary compressive trabecular region （ P 〈 0.05 ）.vBMD [（ 182.15 ± 66.00） mg/mm^3 vs （ 248.05 ±105.48） mg/mm3, t = - 3.598], tBMD [（538.76 ± 64.72） mg/mm3 vs （ 570.54 ± 100.32） mg/mm3,t=-2.108],TV/BV [（0.22±0.06） % vs （0.28±0.12） %, t= -3.466], Tb.Th.[（161.07±42.75） μm vs （200.31 ±96.63） μm, t= -2.866], trabecular number （Tb.N.）[（1.46±0.23）/mm^3 vs （ 1.57 ± 0.29）/mm^3, t = - 2.396] were significantly decreased while trabecular separation （ Tb.Sp.） [（780.82 ± 144.85 ）μm vs （ 653.09 ± 119.64） μm, t = 5.470], degree of anisotropy （DA） （ 1.57±0.20 vs 1.47±0.18, t = 2.930 ） were significantly increased in OP than in TM in the non-compressive trabecular region（ P 〈 0.05 ）.No significant differents were found between OP and TM for any of the parameters measured in the primary compressive trabecular region.Tb.Th.[（199.37±68.22）μm vs （176.33 ±71.21 ）μm, t = 2.060,P 〈 0.05] were significantly increased in the primary compressive trabecular region than that in the non-primary compressive trabecular region and no significant differences were found in the other parameters in the all 18 specimens.Conclusions The femoral head trabeculae had a heterogenic distribution in OP.Bone loss in OP primarily takes place in non-compressive trabecular region.Femoral neck fracture cannot be prevented though the bone microstructure do not loss in the primary compressive trabecular region.Tb.Th.in the femoral head could be an interesting parameter which is closely related to the femoral neck fracture.