Surgeons can do a lot more than just reattach a severed body part back in its original place. Cross-transfer, or transplantation, is a surgical procedure in which, for example, surgeons amputate a healthy hand from a damaged arm and reattach it to a healthy arm with a damaged hand. While the palm of the hand would face the proper direction, the thumb would be where the pinkie was, and vice-versa. Also, if a patient had to lose most of his femur (thigh bone) -- including the knee -- but his lower tibia and fibula bones were undamaged, surgeons could reattach those bones facing backward to what remained of his femur. The procedure would allow him to use his ankle as a knee joint and his foot, with toes facing backward, as a support for a prosthetic lower leg [source: Smith].
Once the injured patient arrives at the hospital, it's time for the surgical team to work its magic -- and there's a complex series of steps they take in surgery to ensure the severed limb can survive once it's reattached. First they'll reattach the bone, using pins or wire to hold it together. Then specialists will restart blood flow by suturing the arteries and blood vessels. Next, surgeons begin the laborious process of reconnecting tendons, muscle tissue and nerves, although nerve reattachment can be saved for a later date. Finally, using grafts from other parts of the patient's body if necessary, the skin is stitched back together.
Limbs can be reattached as many as four days after amputation if refrigerated, but ideally surgery occurs within a day [source: Engber]. A lopped-off finger will still have a place on your hand for about 12 hours after amputation if not refrigerated, but a full limb like an arm or leg -- left at room temperature -- must be reattached within six to 12 hours, due to rapid death of muscle tissue.
After healing from both the original injury and the reattachment surgery, a person whose limb has been reattached faces a lengthy period of rehabilitation. Some patients find it emotionally and visually jarring when they see their reattached limb, since it may look, feel and function differently. Further surgeries may be required to repair nerves, tendons or joints.
Better than going through all of that, keep your limbs inside the rollercoaster car at all times, and see the next page for lots more information about limb reattachment.