The keystone flap and its simplified version for malignant skin tumor defects of the lower limbs: A review of 25 cases

Skin tumors commonly occur on the legs and are treated in first line by surgery. Several techniques are available to repair lower limb defects: secondary-intention healing, partial closure, primary closure with or without an s-plasty, or a skin graft. The lack of tissue laxity of the surrounding skin does not allow several local flaps (advancement, rotation, or transposition). Closing large skin defects at this site may be challenging. We retrospectively reviewed a series of consecutive patients undergoing malignant tumor wide excision on lower limbs, with a keystone flap or its simplified technique (releasing incision) for closure of a skin defect. Twenty-five patients, 17 women and 8 men, ranging from 19 to 95 years old (mean age: 70 years) were included. Keystone flap reconstruction on the lower limbs was performed in 19 cases and the simplified technique in 6. The excised tumors were as follows: squamous cell carcinoma (n=6), basal cell carcinoma (n=9), melanoma (n=9) and Bowen's disease (n=1). Three local complications were observed. No cases of recurrence were observed. Keystone flap is a reliable surgical method for reconstruction of lower limb skin defects. Aesthetic results are better than when a skin graft is used, complications are uncommon, and prolonged operative time is avoided.