Extremity radiation results in substantial complications in 6% to 10% of patients and includes fracture, edema, pain, fibrosis, neuropathy, arterial thrombosis, joint immobility, soft-tissue necrosis, and chronic infection. Chronic ulceration and infection of an irradiated joint is considered a particularly challenging problem for the reconstructive surgeon, and results of surgical management of these complications have not been reported previously in the medical literature. Two patients are presented with large ulcerated and necrotic radiation wounds of the knee, with chronic contamination, osteomyelitis, and involvement of the joint space. Both patients were treated successfully with debridement and coverage with free tissue transfer. They obtained stable, healed wounds, became pain free, and were able to ambulate on long-term follow-up. Adherence to principles established previously for the management of radiation-induced ulcers on other parts of the body not involving joint spaces (namely, thorough wound debridement and coverage with nonirradiated, well-vascularized tissue) can allow successful extremity salvage even in the presence of joint exposure, contamination, and osteomyelitis.