Background: Several studies have documented anatomical variations of the sternum. Because of its central role as an anchor of various abdominal muscles we have investigated a possible correlation between xiphoid length and body habitus indices, in both males and females.

Method: Measurements of sternal length were obtained prior to median sternotomy during cardiac surgery. Body Surface Area (BSA) was calculated from height and weight, using standard tables. A xiphoid 1cm or less in length was considered vestigial.

Results: The xiphoid was significantly longer in males. There was a positive significant correlation between xiphoid length and patient height and BSA in males, but not in females. Vestigial xiphoid was significantly commoner in females.

Conclusion: Our results demonstrate a marked gender difference in xiphoid morphology, with proportional scaling only exhibited in males. The absence of this scaling in females suggests an alternative mechanism behind vestigial xiphoid.