Treatment of major wound necrosis following total knee arthroplasty

Following total knee arthoplasty, seven patients developed significant wound necrosis and dehiscence, requiring wound coverage with soft tissue flaps. Three patients had rheumatoid arthritis, three had degenerative arthritis, and one had osteosarcoma of the distal femur. Five different prostheses were used and the wound problems were discovered on average 21 days after arthroplasty. The average wound size was 6.0 cm2. Five were infected, four with Staphylococcus epidermidis and one with Staphylococcus aureus. All patients were treated with antibiotics and local debridement for an average of 10 days prior to the flap procedure. Medical gastrocnemius muscle flaps were used in two patients, unipedicle flaps transposed from the lateral thigh in three, and bipedicle flaps shifted from the medial thigh in two. Flaps were done an average of 56 days after arthroplasty, and knee rehabilitation was delayed an average of 76 days after arthroplasty. Patients were followed an average of 48 months after the flap procedure. Six patients had mild or no knee pain and one who remained infected had moderate constant pain. Three of the patients had greater than 90 degrees of knee motion and one had 75 degrees of motion. The remaining three had only 35 degrees of motion, due in part to significant preoperative contractures, infection, local radiation, and chemotherapy. Late infection developed in two patients at 20 and 45 months following the flap procedure. There was one excellent, three good, two fair, and one poor result using the Hospital for Special Surgery knee rating system at final follow-up examination.