Supracondylar fractures of the femur following total knee arthroplasty are rare complication with reported rates ranging from 0.3% to 2.5%. Union of the fracture in proper alignment, without disruption of prosthetic component fixation and with maintenance of 90 of knee motion, is impotant in treatment of this type of fracture. Modalties of treatment are conservative or operative methods and operative treatment are open reduction 4 internal fixation, intramedullary nailing, revision arthroplasty using a prosthesis with a long stem and closed reduction and external fixation, but there are controversies in the method of treatment. Between Apr. 1989 and Jul. 1994, 10 patients were treated for supracondylar fracture of the ipsilaterai femur following total knee atthroplasty and 2 cases of them had arthrop]asty at other hospital. Average age of patients was 53 years (29-68 years), nine patients were women and one was man. The preoperative diagnosis was rheumatoid arthritis in four, degenerative osteoaithritis in three, posttraumatic osteoarthritis in one and tuberculosis sequelae of the knee in two. In nine cases mechanism of injury were slip down and in one was fall down. The interval hetween arthroplasty and fracture was an average of 22 months (9-79months). Two cases we.re treated with closed reduction and cast immobilization, one case was treated with open eduction and in1ernal fixation and seven patients of' ten cases were treated with closed intramedullay Ender nailing. The average foIlow-up period after fracture was 25 months (3 - 74months). We evaluated the results as the range of motion, bony union at simple radiograph and Knee Rating Score of Hospital for Special Surgery at last follow up. Eight cases of supracondylar fracture occuned among 350 patients, 514 cases of total knee arthroplasty which were operated at Kyung Hee Univcrsity Hospital between Apr. 1989 and Jul. 1994 and incidence was 1.6%. At the last follow up, all 10 cases achieved bony union and 7 cases using Ender naiIing achieved clinical bony union which enabled patients to do weight-bearing without pain at postoperative 6-8 weeks and radiological union was achieved at postoperative 12 weeks. Range of motion were average 105 degrees (80 J.20 degrees) hefore fracture and 86 degrees (6S 120 degrees) at the last follow up and HSS Knee rating score were average 80.3 points (59 94 points) before fracture and average 78.8 points (66-89 points) at the last follow up. At 7 cases using Ender nailing, range of motion were average 106 degrees (90 11S degrees) hefore fracture and 91 degrees (6S-105 degrees) at last follow up and HSS Knee rating score were average 80.6 points (59-94 points) before fracture and average 80.3 points (72-89 poiints) at the last follow up. Closed iintramedullary Ender nailing is a gecommendable operative method in the treatment of supracondylar fracture following total knee arthroplasty considering to good bony union, satisfactory functional result, easy operative technique and less postoperative complication.