Pronounced femur malunion after pathological bone fracture due to a simple bone cyst in the shaft of the femur, treated using Ilizarov fixation: a case report oleh Toru Nishiwaki, Shinichi Uchikawa, Hiroshi Kusakabe, Atsuhito Seki, Yoshitaka Eguchi, Shinichiro Takayama, Akihito Oya, Masaya Nakamura, Morio Matsumoto, Arihiko Kanaji