Transverse Lengths of the Eleventh and Twelfth Floating Ribs in Humans

Montante, James, Adam Hassan, Brian Chang, Rami Shahrouri, and Michael Makowski

While previous work has found a correlation between asymmetries in the vertebral ribs with scoliosis, the normal morphometry of the floating ribs has not been thoroughly investigated. The lengths of sixty-six floating ribs from 20 cadavers were compared for sexual dimorphism and left/right asymmetry. Transverse lengths were measured along the superior and inferior margins from the anterior margin of the head to the both the osseous and chondral margins. Preliminary data shows sexual dimorphism in rib number 11, but no significant difference in the length of rib 12 between males and females. These results appear to conflict with previously published data.