A split-thickness skin graft is harvested from the anterolateral thigh. By what mechanism does the resulting donor site defect heal, and over what typical timeframe?
- A Re-epithelialisation from residual adnexal structures such as hair follicles, over 7 to 14 days ✓
- B Contraction mediated by myofibroblasts alone, over 6 to 8 weeks
- C Granulation tissue formation requiring skin grafting of the donor site itself
- D Migration of keratinocytes exclusively from the wound edges, over 4 to 6 weeks
Correct answer: A. Re-epithelialisation from residual adnexal structures such as hair follicles, over 7 to 14 days
Explanation
Because an STSG leaves parts of the deeper dermis containing hair follicles, sebaceous glands, and sweat duct remnants behind, epithelial cells migrate outward from these adnexal islands and resurface the donor site in about 7 to 14 days, faster for thinner grafts. This is why donor sites heal without grafting, unlike a full-thickness donor defect which lacks adnexae and must be closed directly. Edge migration alone would be far too slow for a broad area.
Reference: Bailey and Love's Short Practice of Surgery, 27th ed.
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Written and medically reviewed by the StethoPrep medical team.