Jennifer Matthews: Peter Cross can now tackle the stairs with ease. A few months ago, it wasn't so easy.

Peter Cross: My legs were so bad that I was having a hard job going up and down stairs, carrying any weight. I couldn't do it anymore.

Jennifer Matthews: Surgery to repair both knees was one issue. His low blood count was another. Orthopedic surgeon Fred Cushner says the standard practice of having patients donate blood in case of emergency could have done Peter more harm than good.

Dr. Fred Cushner: Donating your blood, rather than building you up, actually makes you even lower.

Jennifer Matthews: Instead, Doctor Cushner turned to a natural hormone called erythropoietin, also called procrit.

Dr. Fred Cushner: When your body has a low blood count, it stimulates your kidneys to produce erythropoietin. Erythropoietin then goes to the bone marrow and stimulates the production of more red blood cells, so it kind of allows you to be your own blood bank.

Jennifer Matthews: Which simply means, you won't need a transfusion. A recent study shows blood donations before surgery actually created the need for a transfusion after surgery. Doctor cushner says procrit is more effective and one of the safest medicines available.

Dr. Fred Cushner: You'll probably see less reactions to erythropoietin than you will from a simple aspirin or Tylenol.

Jennifer Matthews: Peter received procrit, and his surgery was problem-free.

Peter Cross: I feel great now. I just got the 'okay' that I could go skiing. That really makes me feel good.

Jennifer Matthews: Peter is planning to hit the slopes again soon. This is Jennifer Matthews reporting.