Medical device maker Medtronic Inc. says it paid nearly $800,000 over the past three years to a former Army surgeon accused of fabricating a study that reported positive results for one of the company's key spine products.

Some of the consulting payments occurred during the time that the surgeon, Timothy R. Kuklo, was shopping his favorable study of Medtronic's Infuse bone-graft product to medical journals. The paper, ultimately published last August in the Journal of Bone and Joint Surgery, reported advantages in healing...