Faculty of Medicine, Department of Surgery, University of Málaga, Bulevar Louis Pasteur, 32, 29010 Málaga, Spain; Hospital Regional Universitario de Malaga, Avenida Carlos Haya SN, Malaga, 29010, Spain.
Hospital Regional Universitario de Malaga, Avenida Carlos Haya SN, Malaga, 29010, Spain.
Injury. 2020 Apr;51 Suppl 1:S12-S18. doi: 10.1016/j.injury.2020.02.014. Epub 2020 Feb 16.
The risk of femoral neck fracture progressively increases with age. However, the reasons behind this consistent increase in the fracture risk can't be completely justified by the decrease in the bone mineral density. The objective of this study was to analyze the correlation between various bone structural features and age.
STUDY DESIGN & METHODS: A total of 29 consecutive patients who suffered an intracapsular hip fracture and underwent joint replacement surgery between May 2012 and March 2013 were included in this study. A 2 cm × 1 cm Ø cylindrical trabecular bone sample was collected from the femoral heads and preserved in formaldehyde. Bone mineral density (BMD), microarchitecture, organic content and crystallography were analyzed using a Dual-energy X-ray absorptiometry scan, micro-CT scan, and high resolution magic-angle-spinning-nuclear magnetic resonance (MAS-NMR), respectively. Statistical correlations were made using Spearman´s or Pearson´s correlation tests depending on the distribution of the continuous variables.
The mean patient age was 79.83 ± 9.31 years. A moderate negative correlation was observed between age and the hydrogen content in bone (H), which is an indirect estimate to quantify the organic matrix (r = -0.512, p = 0.005). No correlations were observed between BMD, trabecular number, trabecular thickness, phosphorous content, apatite crystal size, and age (r = 0.06, p = 0.755; r = -0.008, p = 0.967; r = -0.046, p = 0.812; r = -0.152, p = 0.430, respectively). A weak positive correlation was observed between Charlson´s comorbidity index (CCI) and c-axis of the hydroxiapatite (HA) crystals (r = -0.400, p = 0.035).
The femoral head relative protein content progressively decreases with age. BMD was not correlated with other structural bone parameters and age. Patients with higher comorbidity scores had larger HA crystals. The present results suggest that the progressive increase in the hip fracture risk in elderly patients could be partially explained by the lower bone protein content in this age group.
股骨颈骨折的风险随年龄的增长而逐渐增加。然而，骨密度下降并不能完全解释骨折风险持续增加的原因。本研究的目的是分析各种骨结构特征与年龄之间的相关性。
本研究共纳入 29 例 2012 年 5 月至 2013 年 3 月因囊内髋部骨折行关节置换术的患者。从股骨头采集 2cm×1cmØ 圆柱状小梁骨样本，用甲醛保存。采用双能 X 射线吸收法扫描、微 CT 扫描和高分辨率魔角旋转核磁共振（MAS-NMR）分别分析骨矿物质密度（BMD）、微观结构、有机含量和晶体学。根据连续变量的分布，使用 Spearman 或 Pearson 相关检验进行统计相关性分析。
患者平均年龄为 79.83±9.31 岁。年龄与骨内氢含量（H）呈中度负相关，H 是定量有机基质的间接指标（r=-0.512，p=0.005）。BMD、小梁数量、小梁厚度、磷含量、磷灰石晶体大小与年龄之间无相关性（r=0.06，p=0.755；r=-0.008，p=0.967；r=-0.046，p=0.812；r=-0.152，p=0.430）。Charlson 合并症指数（CCI）与羟磷灰石（HA）晶体 c 轴呈弱正相关（r=-0.400，p=0.035）。
股骨头相对蛋白质含量随年龄增长而逐渐下降。BMD 与其他结构骨参数和年龄无相关性。合并症评分较高的患者 HA 晶体较大。本研究结果表明，老年患者髋部骨折风险的逐渐增加部分可以用该年龄段骨蛋白含量较低来解释。
