Thank you for your question! Regarding your concern I recommend you should perform a physical examination of your mother to a GP or vascular surgeon. It should rule out a thrombotic, thrombophlebitic or embolic event of the lower limb vessels that not rarely accompany orthopedic procedures. A vascular ultrasound of lower limb should be done also with routine blood tests. It is a medical urgency, you should take your mother as soon as possible to the doctor. Hope to have been helpful to you.