The Ninth and Tenth Costal Cartilages Are Available and Safe Options for Rhinoplasty: A Cadaveric Anatomical Study

Overview

Rib cartilage is a major graft source in rhinoplasty, and some surgeons prefer the ninth rib because of its natural taper. Few anatomical studies had examined its dimensions or the safety of taking it. The authors dissected twelve fresh cadavers, measuring the ninth and tenth costal cartilages and the muscle lying beneath them.

Sections of note

• Design: cadaveric anatomical study, 12 fresh cadavers, 24 ribs.
• Measurements were taken at three points: the osteochondral junction where bone meets cartilage, the midpoint, and the tip.
• Mean length: ninth cartilage 99.1 millimeters, tenth cartilage 60.6 millimeters.
• Ninth cartilage width at the three points: 11.8, 9.0 and 2.5 millimeters. Tenth cartilage width: 9.9, 7.1 and 2.7 millimeters.
• Ninth cartilage thickness: 8.4, 6.4 and 2.4 millimeters. Tenth cartilage thickness: 7.0, 5.1 and 2.3 millimeters.
• Transversus abdominis thickness beneath the ninth cartilage: 2.1, 3.7 and 4.5 millimeters; beneath the tenth: 1.9, 2.9 and 3.7 millimeters.
• Key point: if that muscle is breached during harvest, the abdominal cavity is entered but the chest cavity is not, so pneumothorax risk at this level is very low.

What it means for a patient

• The ninth and tenth ribs are lower on the chest than the ribs usually harvested, which changes what lies underneath and lowers the risk of a punctured lung.
• The natural taper of these cartilages suits grafts that need to be thin at one end.
• This is a cadaver study. It reports no operations, no complication rates in living patients, and no results from grafts made this way, and does not capture how the cartilage warps once implanted.

Why this paper matters

Pneumothorax is the complication surgeons and patients fear most when rib is harvested for a nose. Documenting that these lower cartilages sit below the chest cavity gives an anatomical basis for choosing them. Whether grafts from these ribs perform as well as grafts from higher ribs is untested here.

Terms

• Costal cartilage: the cartilage connecting a rib to the breastbone or the rib above.
• Osteochondral junction: the point where bone transitions into cartilage.
• Pneumothorax: air leaking into the chest cavity, causing lung collapse.
• Transversus abdominis: the deepest of the flat abdominal wall muscles.
• Cadaveric study: research performed on donated human bodies.