Spinal arthrodesis (the creation of a fusion) was developed for the treatment of instability and deformity due to tuberculosis, scoliosis, and traumatic injury. Modern spinal surgery was helped by the introduction in 1911 of the tibial graft by Albee and the iliac-crest graft by Hibbs. These techniques required prolonged postoperative bed rest and the use of braces and casts for immobilization, and their use was complicated by a rate of pseudarthrosis of at least 20 percent. Surgical implants for the spine were developed later in the century in an attempt to improve the rate of fusion and hasten the recovery . . .