Knee chondrosarcoma secondary to Ollier's disease: a report of one case with twelve-year follow-up.

Management of low-grade chondrosarcomas secondary to Ollier's disease is generally radical. We report here a case of conservative treatment of a knee tumor with reconstruction of the lower femoral extremity with a hinged total knee prosthesis, cemented and coupled with a massive femoral allograft, with a twelve-year follow-up.