If this is something which a chiropractor ordinarily would have caught or noticed, and also his failure to do so has caused you either additional medical costs or other monetary losses (e.g. lost wages) or a significant impairment of your quality of life or ability to do normal life functions ("pain and suffering"), then yes, the chiropractor may have committed malpractice and you may have a lawsuit against him. Remember: it's not enought that he was careless, but you must also have been injured by that carelessness to have a viable lawsuit.