Hi there, thanks for your question at HCM. Pain in the groin due to hip often radiates to the knee, as the nerves supplying both are same.With th past history of injury , we can expect some kind of arthritis. Cartilage is a structure which covers the articulating bone ends( similar to the clothes we wear).Cartilage allows smoooth transmission of forces like weight bearing forces across the joint. When cartilage is destroyed, as in the case with your mother, the naked bone surfaces rub against each other with direct contact . This can be excruciatingly painful due to the exposed nerve endings. Total hip replacement is aboon in such cases , as the rubbing painfull surfaces are replacebey by artificial structures which do not feel pain. If the physician and anaesthetist feels your mother is fit to undergo the surgical procedure I feel a total hip has the potential of making tge remainder of her life pain free. Hope this helps. All the best. Regards. Dr.SBK. .