In Monahan v. Weichert (82 A.D.2d 102) the Fourth Department stated that the duty of due care "is not limited to diagnosis and treatment, but extends to instructions regarding posttreatment care" (82 A.D.2d at 106 ). In Monahan, the issues involved a claim of lack of informed consent and plaintiffs right to recover for negligent treatment that accelerated plaintiffs loss of mobility of both knees, a result that was inevitable due to disease.