Ideal graft for leg injury with 10 x 10 cm. exposed bone
For a skin graft (Full thickness or split thickness or amniotic membrane) to survive, it must be revascularized by recipient bed. Radiation damaged tissues and relatively avascular structures such as bone, tendon, cartilages are therefore poor recipient sites.
So an exposed bone surface is covered by a graft which has its own blood supply. Such grafts are k/a flaps or pedicle grafts.
Sabiston writes - "Pedicle graft or flap is a partially or completely isolated segment of tissue with its own blood supply."

"Absolute indications for flaps -
exposed bone, radiated vessels, brain, an open joint or nonbiological implants materials. Pressure sores where a bony prominence is exposed."
Amniotic member graft
Pedicle graft
Full thickness graft
Split thickness skin graft