Abstract： Objective To explore surgical techniques and clinical efficacy of repairing posttraumatic massive soft tissue defects at extremity by a combination of free tissue flap,free skin graft and vacuum sealing drainage(VSD). Methods From January 2008 to December 2011,43 patients with posttraumatic massive soft tissue defects at extremity were repaired by free tissue flap and free skin graft covered by VSD around the flap.They were 32 males and 11 females,with an average age of 32.5 years (range,from 5 to 66 years).Ten cases had the defects at the upper extremity and 33 below the knee.The wounds varied from 20 cm × 7 cm to 52 cm × 22 cm.Thirty-one cases had a concomitant fracture and 18 concomitant chronic osteomyelitis.After thorough debridement,external fixation or simple internal fixation was applied for skeletal reconstruction.VSD was used to treat the wounds. After fresh granulation tissue grew,different types of free tissue flap,like perforator flap,myocutaneous flap and muscle flap,were harvested to repair the exposed wounds of deep tissue,especially the exposed bone.Meanwhile,the remaining wounds around the tissue flap were repaired with free skin graft covered by VSD. Results The 43 patients underwent VSD for 1 to 3 times (average,1.8 times),and each VSD lasted for 5 to 21 days after debridement (average,10.5 days).The granulation tissues grew well and wound infections got controlled. All patients obtained an average follow-up of 12.6 months (from 5 to 32 months).Free tissue flaps survived in 40 cases,venous crisis occurred only in one case whose flap survived after surgical exploration,and marginal necrosis occurred in 2 flaps.Finally,all the free tissue flaps transplanted and the skin grafts covered by VSD around the free tissue flap effectively repaired the limb wounds,curing the infection and restoring satisfactory outline and function of the limb injured.Conclusion Patients with posttraumatic massive soft tissue defects at extremity can be effectively repaired by primary debridement plus VSD and secondary free tissue flap plus free skin graft covered by VSD around the tissue flap,leading to maximum functional recovery of the affected limb.