Surface anatomy and relations of the eighth and ninth costochondral junctions: cadaveric dissection and computed tomographic study

Introduction: Costochondral junctions have been used as a source of graft material in reconstructive surgery, owing to their abundance and accessibility.Aim of the study: To determine the location of the 8th and 9th costochondral junctions on the skin surface of the anterolateral chest wall and their relation to the spine by cadaveric dissection and CT imaging.Materials: This was a 2-part study, twelve preserved human cadavers (7 males and 5 females) were used in the first part of the study. Fifty retrospective computed tomography chest radiographs of fifty patients (25 males and 25 females) were used in the second part of the study.Methods: The chest type and the projection of both the 8th and 9th costochondral junctions to the spine were identified. Then measurements were recorded on body surface in both cadaveric and CT studies to locate both 8th and 9th costochondral junctions on the chest wall in relation to the spine.Results: The 8th and 9th costochondral junctions are covered by external oblique muscle. The former lies at a point between the anterior 1/3 and posterior 2/3 of the chest hemi-perimeter at the level of T12. The 9th costochondral junction is closer to the spine and at the level of L1. There was a difference in the location of both 8th and 9th costochondral junctions between males and females.Discussion: The study provides accurate landmarks for harvesting the graft from the 8th and 9th costochondral junctions. Determining their exact site would minimize the incidence of post-harvesting complications.