Amputating the wrong limb because of medical negligence is not a common error, but it is one that sadly occurs, nonetheless. The Agency for Healthcare Research and Quality (AHRQ) calls these egregious medical errors "never events" because they are never supposed to happen. Amputating the wrong limb is classified as a "sentinel event," which the Joint Commission defines as "an unexpected occurrence involving death or serious physiological or psychological injury, or the risk thereof." The AHRQ reports that wrong site, wrong patient, or wrong procedure errors occur approximately once in 112,000 surgical procedures. While the numbers show this is an unlikely event, when it is your perfectly healthy leg that was taken by mistake, those statistics offer you no solace whatsoever.