Intervertebral disc transplantation: a new dimension in the treatment of degenerative spinal disease

Abstract

Objectives. To review the process of development of the concept of intervertebral disc allograft transplantation from primate experiments to a pilot human trial. To determine the feasibility and long term clinical results of this innovative treatment option in the human. Methods. A prospective, non-blinded study of outcomes in patients who received a fresh-frozen allogenic intervertebral disc transplantation in the cervical spine. Five patients, 4 males and 1 female, average age 47 years, with cervical disc herniation underwent anterior disc excision and transplantation of a fresh-frozen endplate-disc-endplate composite disc allograft obtained from healthy donors. No internal fixation or perioperative immunosuppressant was used. Serial MRI, static and dynamic radiographs were used to monitor the status of the grafts. Results. At a minimum follow up of 5 years, all patients had improvement of the preoperative myelopathic or radiculopathic symptoms. Good union between the recipient bone and the graft endplates were seen after two months with no graft migration or subsidence. No serological suggestion of immuno-reaction was found. There was reduction of the disc height at the early postoperative period and mild degenerative changes at the final follow up. However, all except one of the transplanted discs showed preservation of mobility without olisthesis in the flexion-extension radiographs at the final follow up. One patient resulted in auto-fusion two years after operation. MRI at the final follow up showed preservation of hydration in at least 2 of the discs. Discussion. Fresh-frozen allogenic intervertebral disc transplantation has been successfully performed in a pilot human series without immunologic reaction. Despite radiological signs of disc degeneration, the motion and stability of the functional spinal unit was preserved. This is the first report of a successful disc transplantation in the human and represents an innovative new dimension in the management of degenerative spinal disease in the future.