Which of the following is/are true?

B. By 2 days, the experimental burst strength of skin is minimal since collagen has been formed in the wound but has not yet cross-linked.

D. Wounds rarely, if ever, regain the strength of intact tissues.

DISCUSSION: Tensile strength measures load per cross-section area at rupture, whereas burst strength measures load required to break a wound, regardless of dimension. Therefore, skin wounds have comparable tensile strength, regardless of thickness. Collagen appears in the wound by 3 to 4 days. Minimal wound strength on day 2 is due to fibrin polymerization and adhesion of globular proteins. Wounds rapidly gain strength for about 4 months and then continue to gain strength at a slower rate for more than a year. Wounds do not regain the strength of normal tissue.