The goal of the study is to examine the possibility that if ketamine is administered in the pre-operative period, as a topical ointment, this will induce changes in the patient's sensation of pain, his own satisfaction, and possibly his family's satisfaction as well. The basis of this contention is that by administering less morphine (which is given to the patient in the immediate post-operative period through PCA [Patent-Controlled Analgesia]), with or without changes in pain, might have positive effects on the patient's well being and his family's. This issue will be assessed by a verbal questionnaire and based and on a visual analog scale (VAS).