Delsmann Maximilian M, Leonhardt Leon-Gordian, Alimy Assil-Ramin, Hoenig Tim, Beil Frank Timo, Püschel Klaus, von Brackel Felix N, Amling Michael, Viezens Lennart, Thiesen Darius M, Rolvien Tim
Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
Institute of Legal Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.
JBMR Plus. 2024 Jul 12;8(9):ziae094. doi: 10.1093/jbmrpl/ziae094. eCollection 2024 Sep.
Sacral insufficiency fractures are known to occur primarily in older women without adequate trauma. While an association with low bone mineral density (ie, osteoporosis) has been reported, more detailed information on local bone quality properties in affected patients is not available. In the present study, core biopsies were obtained from the S1 sacral ala in patients with a bilateral sacral insufficiency fracture (type IV according to the fragility fractures of the pelvis classification) who required surgical stabilization. Dual energy X-ray absorptiometry (DXA) and laboratory bone metabolism analyses were performed. For comparison, control biopsies were acquired from skeletally intact age- and sex-matched donors during autopsy. A total of 31 biopsies (fracture: = 19; control: = 12) were evaluated by micro-computed tomography, histomorphometry on undecalcified sections, and quantitative backscattered electron imaging (qBEI). DXA measurements showed mean T-scores in the range of osteoporosis in the fracture cohort (T-score -2.6 ± 0.8). Biochemical analysis of bone metabolism parameters revealed high serum alkaline phosphatase and urinary deoxypyridinoline/creatinine levels. In the biopsies, a loss of trabecular microstructure along with increased osteoid values were detected in the fracture patients compared with controls (osteoid volume per bone volume 5.9 ± 3.5 vs. 0.9 ± 0.5%, <.001). We also found evidence of microfractures with chronic healing processes (ie, microcallus) as well as pronounced hypomineralization in the biopsies of the fracture cohort compared with the controls as evidenced by lower CaMean measured by qBEI (22.5 ± 1.6 vs. 24.2 ± 0.5 wt%, =.003). In conclusion, this high-resolution biopsy study provides evidence of local hypomineralization in patients with sacral insufficiency fractures, pointing to reduced fracture resistance but also a distinct phenotype other than the predominant loss of trabeculae as in postmenopausal osteoporosis. Our data highlight the importance of therapies that promote bone mineralization to optimally treat and prevent sacral insufficiency fractures.
已知骶骨不全骨折主要发生在未遭受足够创伤的老年女性中。虽然已有报告称其与低骨矿物质密度（即骨质疏松症）有关，但关于受影响患者局部骨质量特性的更详细信息尚不可得。在本研究中，从需要手术固定的双侧骶骨不全骨折患者（根据骨盆脆性骨折分类为IV型）的S1骶骨翼获取了核心活检样本。进行了双能X线吸收测定法（DXA）和实验室骨代谢分析。为作比较，在尸检期间从骨骼完整、年龄和性别匹配的供体获取了对照活检样本。通过微计算机断层扫描、未脱钙切片的组织形态计量学和定量背散射电子成像（qBEI）对总共31份活检样本（骨折样本：n = 19；对照样本：n = 12）进行了评估。DXA测量显示骨折队列中的平均T值处于骨质疏松范围内（T值为 -2.6±0.8）。骨代谢参数的生化分析显示血清碱性磷酸酶和尿脱氧吡啶啉/肌酐水平较高。在活检样本中，与对照组相比，骨折患者中检测到小梁微结构丧失以及类骨质值增加（每骨体积的类骨质体积为5.9±3.5% 对 0.9±0.5%，P <.001）。我们还发现与对照组相比，骨折队列活检样本中有微骨折伴慢性愈合过程（即微骨痂）以及明显的矿化不足的证据，qBEI测量的较低CaMean证明了这一点（22.5±1.6对24.2±0.5 wt%，P =.003）。总之，这项高分辨率活检研究提供了骶骨不全骨折患者局部矿化不足的证据，表明抗骨折能力降低，但也表明存在一种不同于绝经后骨质疏松症中主要小梁丧失的独特表型。我们的数据强调了促进骨矿化的疗法对最佳治疗和预防骶骨不全骨折的重要性。
