We hypothesize patients undergoing spinal fusion who receive peri-operative MMA will have:
1. decreased post-operative pain compared to patients receiving usual care for pain management.
2. shorter hospital LOS compared to patients receiving usual care pain management.
3. fewer analgesic-related post-operative complications (urinary retention, ileus, etc) compared to patients receiving usual care pain management.
4. improved physical functioning at the time of hospital discharge compared to patients receiving usual care pain management.
5. better short and long term outcomes. Subjects will be randomized to MMA (Group 1) or usual care (Group 2). The unit of randomization will be a week (Monday through Sunday). Each week will randomly be assigned to MMA or usual care. Subjects who are hospitalized into a consecutive week will continue with the pain regimen they were assigned upon hospitalization.