As far back as 1898, the precise nature and definition of medical malpractice was set forth in the case of Pike v Honsinger, 155 NY 201 (1898): "A physician and surgeon, by taking charge of a case, impliedly represents that he possesses, and the law places upon him the duty of possessing, that reasonable degree of learning and skill that is ordinarily possessed by physicians and surgeons in the locality where he practices ..." (see Pike v Honsinger, 155 NY 201 [1898]).
Upon consenting to treat a patient, it becomes his duty to use reasonable care and diligence in the exercise of his skill and the application of his learning to accomplish the purpose for which he was employed. He is under the further obligation to use his best judgment in exercising his skill and applying his knowledge. The law holds him liable for an injury to his patient resulting from want of the requisite knowledge and skill, or the omission to exercise reasonable care, or the failure to use his best judgment.
The rule in relation to learning and skill does not require the surgeon to possess that extraordinary learning and skill which belong only to a few men of rare endowments, but such as is possessed by the average member of the medical profession in good standing. Still, he is bound to keep abreast of the times, and a departure from approved methods in general use, if it injures the patient, will render him liable, however good his intensions may have been. The rule of reasonable care and diligence does not require the exercise of the highest possible degree of care, and, to render a physician and surgeon liable, it is not enough that there has been a less degree of care than some other medical man might have shown, or less than even he himself might have bestowed, but there must be a want of ordinary and reasonable care, leading to a bad result...The rule requiring him to use his best judgment does not hold him liable for a mere error of judgment, provided he does what he thinks is best after careful examination.
But knowing the definition of medical malpractice does not resolve the question. How is medical malpractice different from negligence? Does it matter if the plaintiff states his or her claim as one for medical malpractice or negligence? The answer to the latter questions is yes. Medical malpractice and negligence claims are different. There are statutes and rules which apply to medical malpractice cases and not to negligence actions.
