What exactly does that mean? I would suspect the phrase "use the knife" means something much more specific than "make any use whatsoever of any implements that could be characterized as knives".
Also, the language "will withdraw in favor of such men as are engaged in this work". Who would those men be?
Well, you have to remember that the original Hippocratic Oath was a pagan oath whose text has survived in writing to the present time and dealt with medicine as practiced in ancient Greece.
By "use of the knife" the original ancient Greek oath meant the practice of surgery.
Today, surgery is an integral part of medicine and relatively safe. In the ancient Greek days, medicine was separate from surgey. In other words, the Hippocratic Oath was meant for the "pill pushers" as oposed to the surgeons who, as they like to say, "heal with cold steel".
The Hippococratic Oath required the physician to swear that he would never perform surgery and required them to leave potential surgical problems to "such men as are engaged in this work".
The classic Hippocratic Oath was so specific to it's time and place that any M.D. who is now a surgeon, an abortionist, practices European style euthanesia or does not provide free medical education to his med school professor's children would be in violoation of it. Nowhere does the original Hippocratic Oath prohibit the ancient Greek physician from strapping on his armor and fighting in the hoplite ranks of his fellow Greek citizens if the Persians or some other enemy threatened the freedom and safety of their homeland.
The latest "modern" version of the Hippocratic Oath bears little resemblance to the classic oath and is a collection of common sense platitudes. The "modern" oath again makes no mention of military service. It also has dropped the prohibitions of the original oath in regards to abortion, euthanasia and even engaging in sexual relations with your patients.