['To assess the efficacy of the extra long scapular-lateral thoracic-ilioinguinal siamese flap to repair the contracture deformity of perineal scar caused by burn and to discuss its characteristics.', 'From January 2008 to August 2009, 9 patients with contracture deformity of perineal scar after deep II degree to III degree burn were treated. There were 7 males and 2 females aged from 22 to 54 years (35.4 years on average). The course of disease ranged from 8 months to 5 years. All cases had central type of perineal scar. Among the cases, 3 cases were complicated by abdominal scar, 4 cases by legs scar, and 2 cases by abdominal and legs scar. Scar ulcer was observed in 2 cases. The opening-closing angle of bilateral lower extremities was (29.4 +/- 8.8) degrees. And anus could not expose entirely so that squatting and relieving the bowels were difficult in 6 cases. Defect areas after scar resection ranged from 20 cm x 6 cm to 28 cm x 8 cm. The size of extra long scapular-lateral thoracic-ilioinguinal siamese flap ranged from 35 cm x 12 cm to 58 cm x 15 cm. The donor sites were sutured directly.', 'Blister and necrosis occurred in 1 case and was cured after dressing changed, and others flaps survived with wounds primary healing. Incision at donor site healed by first intention. All cases were followed up 6-12 months. The perineal function improved and the partial deformities were corrected. The opening-closing angle of bilateral lower extremities increased to (75.6 +/- 11.3) degrees, showing significant difference between pre- and post-operation (P < 0.05). The functions of squatting and relieving the bowels recovered well. The perineal scar adhesion recurred in 2 cases after 6 months of operation and were cured after scar resection and expanding flaps transposition.'] Do [ Repair contracture deformity of perineal scar caused by burn with extra long scapular-lateral thoracic-ilioinguinal Siamese flap ]?