Translation guide
The femur is the thigh bone. In Japanese, it is most commonly referred to as 大腿骨 (だいたいこつ), the anatomical term. In everyday conversation, people may simply say 太ももの骨 (ふともものほね), meaning 'thigh bone.'
Referring to the femur in medical, scientific, or formal contexts.
I fell and broke my thigh bone.