Background Perforator flaps are used extensively in repairing soft tissue defects.Superior gluteal artery perforatorflaps are used for repairing sacral defects,but the tension required for direct closure of the donor area after harvesting ofrelatively large flaps carries a risk of postoperative dehiscence.This research was to investigate a modified superiorgluteal artery perforator flap for repairing sacrococcygeal soft tissue defects.Methods From June 2003 to April 2010,we used our newly designed superior gluteal artery perforator flap for repair of sacrococcygeal soft tissue defects in 10 patients (study group).The wound and donor areas were measured,and the flaps were designed accordingly.Wound healing was assessed over a follow-up period of 6-38 months.From January 1998 to February 2003,twelve patients with sacrococcygeal pressure sores were treated with traditional methods,VY advancement flaps or oblong flaps,as control group.Results After debridement,the soft tissue defects ranged from 12 cm × 10 cm to 26 cm × 22 cm (mean 16.3 cm x 13.5cm).Four patients were treated using right-sided flaps ranging from 15 cm × 11 cm to 25 cm × 20 cm (mean 18.2 cm × 14cm).Four patients were treated using left-sided flaps,and two were treated using both right-and left-sided flaps.Suction drains were removed on postoperative Days 3-21 (mean 5.9) and sutures were removed on postoperative Days 12-14.Each flap included 1-2 perforators for each of the donor and recipient sites.Donor sites were closed directly.All flaps survived.In eight patients,the wounds healed after single-stage surgery.After further debridement,the wounds of the remaining two patients were considered healed on postoperative Days 26 and 33,respectively.The rate of first intention in the study group (80％,8/10) significantly increased than that of control group ((25％,3/12),X2=4.583,P=-0.032).Follow-up examinations found that the flaps had a soft texture without ulceration.In the two patients without paraplegia,the range of motion of the hip joints was not affected.Conclusion The use of the quadrilobed superior gluteal artery perforator flap can overcome the disadvantages of traditional perforator flaps and represents an improved approach for repairing soft tissue defects in the sacrococcygeal region.