Talk to Orthopedic Surgeon on Not Walking Properly Feel Pain In RIGHT KNEE

My father syed Muhammad shakir age 69 yrs old he don’t have any other health issue but before 5 years he had pain in right knee then we went on so many orthopaedic surgeon and get medications but there is no profit for this then 2024 Karachi AO CLINIC suggest to TKR surgery so please as per request I need suggestion from surgeons is there any risk? Or life time issues ? Or any problems what we will face in future if we will do this surgery? Kindly guide me and suggest me a best way to do this for my father .