Biomechanical alterations in normal skin and hypertrophic scar after thermal injury.

Functional recovery after burn injury can be significantly limited by scar contraction and contracture. Mechanisms to explain these problems are not well described. Surface (shear) waves were generated in normal skin and hypertrophic burn scar with a newly described device. The velocity of propagation was used to examine biomechanical changes after burn injury. Shear wave velocity was markedly higher in scar and slightly higher in injured tissue without obvious scarring, verifying increased skin stiffness. Normal skin anisotrophy was exaggerated in scar tissue and not seen in the uninjured skin adjacent to hypertrophic scar. This result suggests the reorganization of normal tissue attempts to compensate for scar contraction. Measurements of shear wave velocity objectively document changes in skin properties that affect the recovery from thermal injury. Use of this or alternate technologies may increase understanding of postburn skin dysfunction, improving our ability to treat such patients.