Characterization of cortico-cancellous bone along the iliac crest: focus on graft harvesting

The iliac crests are rich sources of cortical as well as cancellous bone. Though the proportions of cortico-cancellous tissue vary along the crest, a detailed morphometric characterization of the osseous tissue along the iliac crest is hard to come across in literature. This paucity of anatomical data on the quantity of cortical and cancellous bone along the iliac blade has prompted this study.

Male [n = 40] and female [n = 40] pelvises were obtained from fresh cadaveric material. Two parallel strips of bones, each 15 mm high, were cut along the iliac crest. Each of these segments was divided into three (anterior, intermediate and posterior) approximately equal parts and measured for: (a) length, (b) width, (c) thickness, of the outer and inner shell of cortical bones, (d) thickness of the cancellous tissue between the outer and inner cortices, and (e) the volume of available cancellous bone in each part was calculated.

The upper segment was found to be wider than the lower segment. The intermediate part of the upper segment was the widest and possessed the thickest and most voluminous content of cancellous tissue. The posterior parts of both the segments were thin. Cortical bones gradually thinned out posteriorly. The outer cortices were thicker than the inner ones. Parameters in the males generally measured higher than the females; the right side had higher values than the left.

Strategies for graft harvesting from the iliac crests should be based upon the morphological assessment of the bone at the desired site of harvest.