The appropriate type of flap depends on the shape of the ulcer. Frequently suitable is the bilateral flap of buttock skin based on the in-ferior gluteal fold , and this double flap is especially useful in the sacral pressure sore in the non-paraplegic patient. If the shape and extent of the ulcer make this flap unsuitable, alternatives are the transposed or rotation flap using buttock skin, extending on to the lumbar region. Gluteus maximus has been incorporated into these flaps to add to their safety and effective-ness, and more recently flaps have been designed to use the gluteus maximus muscle in a more formal way.
Each muscle, together with a triangle of the overlying buttock skin, is detached from its sacral insertion and mobilised, preserving the inferior gluteal nerve and the gluteal vessels, and advanced to meet its fellow in the midline to reconstruct the postexcisional defect of the sacral ulcer, providing skin cover along with an underlying pad of muscle.
In using the glutei in this way there are several considerations which need to be taken into account, and which are not immediately appar-ent.
One concerns the fact that gluteus maximus is not an expendable muscle, and if the transfer will result in denervation it can only be used in the paraplegic patient. The advancement myocu-taneous flap as described should retain the nerve supply and can thus be used in the non-para-plegic. The entire area is also extremely vascular, and dissection involving gluteus maximus, indeed dissection generally in this area, both in the paraplegic and non-paraplegic patient, involves considerable blood loss.