Introduction The sacrum is a large triangular bone formed by fusion of five sacral vertebrae [1]. Anatomy of sacral vertebra is complex [2]. Technically, the placement of pedicle screw into S1 vertebra is a difficult surgical procedure. Therefore it is important to know the anatomy of S1 vertebra [3]. First sacral vertebra possesses the features of typical vertebra in modified form. Thus it con...

Spinal fusion, ending caudally at L5 rather than at the sacrum, is recommended for selected patients with scoliosis due to Duchenne muscular dystrophy. We present a retrospective review of 48 patients operated on for this condition. Patients having spinal curvature with a Cobb angle of less than 40 degrees and with less than 10 degrees between a line tangential to the superior margins of both i...

In order to study the formation of the sacrum during the primate evolution, a new way of numbering mammalian vertebrae is presented; this demonstrates that the thoracolumbosacral complex is fixed at 22 vertebrae in 80% and at 22 +/- 1 in 100% of the cases. The shift of a vertebra from one type to another occurs either at the thoracolumbar or at the lumbosacral junction and not at the cervicotho...