Recently, several investigators reported that costal cartilage does not overgrow in pectus excavatum (PE). We wished to clarify whether costochondral length is longer in PE than the normal thorax and we tried to clarify the change of the shape of precordial concavity according to the growth in PE.
We evaluated 243 CT axial images of patients with PE and 246 CT axial images of patients without thoracic deformity. We divided the fifth costal cartilage into several lengths. We considered each part to be a straight line and calculated the length of the lines. We compared the approximate costochondral length between PE and normal thorax. We analyzed the distance between both anterior tips of fifth rib, and the ratio of the width and the depth of concavity to thoracic diameter in PE.
The costochondral length in patients with PE is highly likely to be longer than that of the normal thorax. The length of costal cartilage may be longer in asymmetric PE than symmetric PE. It may start in infantile period in PE that the thoracic shape turns into asymmetry from symmetry. The precordial concavity of PE may be shaped by overgrowth of both costal cartilages and ribs.