Generational changes in lumbar spinal canal dimensions: Findings from a U.S. population

Objective: Evaluation of lumbar canal dimensions in a Chicago population born in 2 different decades. Methods: This is a retrospective chart review analyzing computed tomography reconstruction from patients born between 1940 and 1949 (older group) and 1970 and 1979 (younger group). The cross-sectional area (CSA) and anterior-posterior diameter (APD) of the lumbar bony canal was measured at each lumbar level at the level of the pedicle. Results: Our study includes 918 patients, 372 in the young group and 546 in the older group. Older patients have significantly larger CSA and APD at all lumbar levels compared with younger patients. Further, CSA and APD comparisons between ethnicities demonstrate significant differences between individuals of Caucasian, Asian, Hispanic, African American, and Other ethnicities. Lastly, there were no differences in CSA or APD compared with factors known to affect bone health (smoking, steroid use, osteoporosis, cancer history). Conclusions: As seen in European cohorts, our data suggest that patients born in the 1940s have both larger canal area and larger anterior-posterior diameter compared with the younger generation. These data suggest that significant differences exist between ethnicities. These differences highlight the importance of studying normal anatomical dimensions within different geographical populations and the importance of studying non-modifiable factors as they relate to spinal dimensions and spine patients. Furthermore, spinal canal growth seems to be negatively influenced in younger generations, a rather unexpected but worrying finding.研究目的：评估芝加哥两个不同出生年代人群的腰椎椎管尺寸。 研究方法：本研究为回顾性病历分析，对1940至1949年（年长组）及1970至1979年（年轻组）出生患者的计算机断层扫描（computed tomography, CT）重建影像进行分析。在各腰椎节段的椎弓根层面，测量腰椎骨性椎管的横截面积（cross-sectional area, CSA）与前后径（anterior-posterior diameter, APD）。 研究结果：本研究共纳入918例患者，其中年轻组372例，年长组546例。相较于年轻组，年长组患者在所有腰椎节段的椎管横截面积与前后径均显著更大。此外，不同种族间的横截面积与前后径比较显示，白种人、亚洲人、西班牙裔、非裔美国人及其他种族个体间存在显著差异。最后，椎管横截面积与前后径在已知影响骨骼健康的相关因素（吸烟、糖皮质激素使用、骨质疏松症、癌症病史）间未表现出显著差异。 结论：与欧洲队列研究结果一致，本研究数据表明，1940年代出生的人群相较于年轻一代，其椎管横截面积与前后径均更大。本研究数据显示不同种族间存在显著差异。这些差异凸显了针对不同地理人群开展正常解剖尺寸研究的重要性，以及探究与脊柱尺寸及脊柱疾病患者相关的不可干预因素的必要性。此外，年轻一代的椎管生长似乎受到负面影响，这一发现虽出人意料但令人担忧。