We performed a retrospective analysis of twenty-five consecutive massive articulating endoprostheses that were inserted at our unit during the management of patients with Giant Cell Tumours of their distal femur. Fifteen of these implants were fixed hinge devices and ten were rotating hinge devices with HA collars (since 1993). None of these cases were revised for sepsis. There had been no cases of recurrent disease or amputation. The mean follow-up was 12 years (range = 5-18 years). The average age at time of insertion was 37 years. Young patients with fixed hinged devices developed a high incidence (33%) of aseptic loosening. They also had a significant rate of re-bushing. Results of the rotating hinge prosthesis with HA collar were much more promising. Functional scores were good after a period of 12 years despite the young age group.