Orthopedic surgeon Robinson describes three types of bones that break: ribs or skull, with which the underlying organs must be protected; facial bones, which require accurate, fine correction; and large, long bones, which must be held in place promptly and securely. Dr. Robinson shows x-rays of broken femurs and a diagram of how bone heals, explaining that the deformity must be corrected first and then held in place until a bridge of new bone is formed. A patient demonstrates the range of motion in his formerly fractured elbow that was held together with a metal plate and screws. Other x-rays display the intramedulary, a diamond-shaped stainless steel nail used to hold a femur fracture in place and allow weight bearing. A model of the hip joint and femur with surrounding muscles proves that without such a supportive rod, the muscles would override the bones and cause deformity or shorten the length of the leg. Dr. Southwick introduces former patient William Brown and explains how a metal rod was inserted.

Using a skeleton, Dr. Nachlas discusses the body's skeletal system and explains how bones' rigidity protects the body's vital organs and offers attachment for muscles. He shows how a broken bone must have approximate broken edges, proper alignment of broken pieces, and immobilization of the bones in order to heal properly. Since plaster casts cannot always accomplish this, Dr. Nachlas details how bones can be splinted and immobilized internally with such metals as vitalium, tantalum, and stainless steel, which do not corrode or cause infection. He shows an x-ray of fractured leg bones held in place by long, stainless steel rods running down the marrow cavities. He also describes the correction of a difficult forearm fracture using a rod and interviews the woman who had the operation to correct this problem to prove how the metal rod strengthened and straightened her arm. Dr. Nachlas gives another example of how a fragment of bone was replicated with vitalium.