The difference in anatomy of the lumbar anterior longitudinal ligament in young African-Americans and Scandinavians.

OBJECTIVE

To examine possible structural differences in the lumbar anterior longitudinal ligament between young African-American and Scandinavian people.

DESIGN

The lumbar anterior longitudinal ligament was examined in 48 African-American and Scandinavian young men and women (17 to 30 years old). Apart from the selection of gender, age, height, and weight, all subjects were recruited consecutively during routine forensic autopsies. Sections of the ligament were obtained from the L1 and the L5 vertebra for thickness and width measurements and histologic preparations. The measurements were performed with a digital vernier caliper with an accuracy of 0.1 mm.

RESULTS

The width of the L1 part of the lumbar anterior longitudinal ligament in the African-American group (27.5+/-1.8mm) was greater than that in the Scandinavian group (17.7+/-1.5mm) (p < .001), and the thickness of the L1 part in the African-American group (3.8+/-0.4mm) was greater than that in the Scandinavian group (3.3+/-0.3mm) (p < .001). The width of the L5 part in the African-American group (34.1+/-2.0mm) was greater than that in the Scandinavian group (25.0+/-1.5mm) (p < .001), and the thickness of the L5 part in the African-American group (3.3+/-0.3mm) was greater than that in the Scandinavian group (2.2+/-0.3mm) (p < .001). The cross-sectional area was greater in the African-American group in both sections (L1, African-American 106.4+/-13.7mm2 vs Scandinavian 52.8+/-7.9mm2; L5, African-American 112.2+/-14.6mm2 vs Scandinavian 55.6+/-6.7mm2) (p < .001). No histologic differences between the two groups were observed.

CONCLUSIONS

The lumbar anterior longitudinal ligament was considerably wider and thicker, which yielded a markedly greater cross-sectional area, in African-American than in Scandinavian subjects. In contrast, the ligament appears to be histologically similar in the two groups. These are previously unrecognized differences in anatomy between young African-American and Scandinavian people.