Do ribs actually have a bare area? A new analysis.

Recognition of macroscopic rib pathology requires an in-depth understanding of anatomy, especially of the attachment of muscle tendons and aponeuroses. Distinguishing periosteal reaction from residual aponeurotic tissues and the rugosity associated with muscle attachments, requires knowledge of these structures. The ribs of twenty cadavers were examined to establish the distribution of muscle attachments and aponeuroses, and their variations. A unique observation was that the entire rib surface is covered by tendon attachments and aponeuroses, without evidence of bare areas that are so prominent in other parts of the skeleton. Discrepancies between rugose regions and the extent of tendon attachments were occasionally noted, with the tendons or aponeuroses extending beyond the areas of attachments of the muscle fibers. Variable dessication of aponeurotic tissues can compromise appearance of normal bone, and may be responsible for past overdiagnosis of periosteal reaction.