What is the ruling regarding the prayer of a sick person who has undergone thigh surgery and is unable to bow, and what is the ruling regarding ritual impurity (janabah) and the inability to perform the major ablution (ghusl) for it?

If a person has a wound on their side, not on the limbs of ablution (wudu'), they must wash all their sound body parts and perform tayammum for the wounded limb, as Allah Almighty says: "So fear Allah as much as you are able" [At-Taghabun: 16].

This is also supported by the agreed-upon Hadith of Jabir, that a man sustained a head injury and then had a wet dream. His companions advised him to perform ghusl (full body ablution). He did so and died. The Prophet, peace and blessings be upon him, said: "They killed him, may Allah kill them! Why did they not ask if they did not know? Indeed, the cure for ignorance is asking. It would have been sufficient for him to perform tayammum, wring out or bandage his wound with a cloth, then wipe over it and wash the rest of his body."