A 40-year-old employee of a New York municipality sustained a torn ligament in his left ankle when he stepped in a hole in the course of his work. He sought treatment from our client, an orthopedic surgeon. He alleged in the malpractice action that the doctor’s decision to place him, initially, in an air cast, and, days later, in a Cam boot for more complete immobilization of the injured ankle, and the doctor’s omission to prescribe any anticoagulant (blood-thinning) medication given the supposed risks of those modalities of treatment, represented departures from the accepted standard of care and caused the plaintiff’s development a month later of a blood clot in his leg which then resulted in a pulmonary embolism. He further alleged that it caused him to develop complex regional pain syndrome (also known as reflex sympathetic dystrophy) in the affected leg, rendering him permanently disabled. Our motion for summary judgment was granted by the court, which agreed that the plaintiff and his expert had not raised any genuine question of fact requiring a jury’s consideration, as there was nothing wrong with having prescribed an air cast or a Cam boot to immobilize the injured ankle, and there existed no medical standard requiring the prescription of an anticoagulant medication to a thin, fit, non-diabetic, non-smoking, otherwise healthy and relatively young man who had not been been instructed to remain in bed, but to stand and weight-bear to tolerance. In granting the motion, the judge also disqualified that part of the affirmation of the plaintiff’s expert, an internal medicine physician, that included opinions in the field of orthopedic surgery, as the expert had provided no valid foundation in his affirmation to establish his competency to offer those opinions.