Concentric and eccentric carved costal cartilage: a comparison of warping.

Objective: To determine if a systematic, concentric graft-carving technique results in less warping than eccentric carving.

Methods: Costal cartilage from ribs 3 through 9 were harvested from fresh human cadavers. Concentric dorsal grafts were carved from cartilage obtained from one side of the cadaver (n = 7) and eccentric grafts were carved from the opposite side (n = 11). After carving, grafts were placed in saline sponges (isotonic sodium chloride) for 1 hour, and photographs were then taken from a lateral and a frontal view. Identical photographs were taken after 2 weeks of incubation in saline (36.7 degrees C). The angle of curvature was measured from the photographs.

Results: More warping occurred in the eccentric group than the concentric group on lateral view at 1 hour (4.4 degrees vs 0.4 degrees; P<.001) and at 2 weeks (5.8 degrees vs 1.4 degrees; P = .003). Eccentric grafts progressively warped between the 1-hour and 2-week points.

Conclusion: Meticulous concentric carving of costal cartilage grafts may minimize the complication of graft warping.