Lumbar (low back) fusions take an average of 6-12 months to become solid. Cervical (neck) fusions are usually healed by 3-6 months. Not surprisingly, different patients heal at different rates. Younger, healthier people might heal their fusions more quickly than older individuals with medical conditions. Activity, especially walking, seems to help fusions heal more rapidly and with better strength. Unless specifically directed by your surgeon, bed rest after surgery is not advised. Be sure to walk, sit, and stand as tolerated letting pain be your guide. You should avoid repetitive twisting and lifting more than  15 lbs for 6 weeks after surgery. Avoid running and other impact sports for 3 months following surgery.