Stem cell therapy has been advanced yet again by work from University of California at Davis. Neurosurgery researchers from the UC Davis Health System have used stem cell therapies to promote the growth of bone tissue following the removal of cervical discs (those cartilage cushions between the bones in the neck). In doing so, they were able to relive chronic, debilitating pain.
The procedure they employed was pioneered by Kee Kim and Rudolph Schrot, professors of neurosurgery at UC Davis. They used bone marrow-derived adult stem cells to promote the growth of spinal bone tissue after surgery. These experiments are actually part of a nationwide, multicenter clinical trial of this particular therapy. Removal of the cervical disc relieves pain, since it eliminates nerve compression, and also, possibly friction between vertebrae. Fusion of the vertebrae (spinal fusion), following surgery for degenerative disc disease, removes the cushioning cartilage disc that has eroded away. Removal of the cartilage disc now leaves bone to rub against bone, which can accelerate inflammation and bone erosion. Therefore, the discs are usually fused together after the disc is removed. .
Kee Kim, chief of spinal neurosurgery at UC Davis noted: “We hope that this investigational procedure eventually will help those who undergo spinal fusion in the back as well as in the neck, and the knowledge gained about stem cells also will be applied in the near future to treat without surgery those suffering from back pain.”
Millions of Americans are affected by spinal conditions. Approximately 40 percent of all spinal fusion surgeries address cervical problems with spinal fusion procedures. Some 230,000 patients are candidates for spinal fusion, and the numbers of potential patients increases by 2 to 3 percent each year as the nation’s population ages. Subsets of stem cells in the bone marrow, like mesenchymal stem cells (MSCs) can form bone. In this study, they were used to promote the growth of vertebral bone and accelerate vertebral fusion, which is a new and extremely promising area of clinical study in regenerative medicine.
In early August, researchers at UC Davis operated on a 53-year-old patient with degenerative disc disease. They conducted an “anterior cervical discectomy,” in which a cervical disc or multiple discs are removed via an incision in the front of the neck. The stem cell therapy was applied to promote fusion of the vertebrae across the space created by the disc removal. The stem cells are derived from a healthy single adult donor’s bone marrow, and are grown in culture to high concentration. Adequate spinal fusion fails to occur in 8 to 35 percent or more of patients and persistent pain occurs in up to 60 percent of patients with fusion failure, which often necessitates additional surgeries.
According the study’s co-author Rudolph Schrot, “A lack of effective new bone growth after spine fusion surgery can be a significant problem, especially in surgeries involving multiple spinal segments. This new technology may help patients grow new bone, and it avoids harvesting a bone graft from the patient’s own hip or using bone from a deceased donor.”
Current methods of promoting spinal fusion include implanting bone tissue from the patient’s hip or a cadaver to encourage bone regrowth as well as implanting bone growth-inducing proteins (BMPs). However, the Food and Drug Administration has not approved the use of bone morphogenetic proteins for cervical spinal fusion, since their use has been associated with life-threatening complications (particularly in the neck).
This stem cell procedure is part of a prospective, randomized, single-blinded controlled study to evaluate the safety and preliminary efficacy of an investigational therapy: modified bone marrow-derived stem cells combined with the use of a delivery device as an alternative to promote and maintain spinal fusion. The study includes 10 investigational centers nationwide. The UC Davis Department of Neurological Surgery anticipates enrolling up to 10 study participants who will be treated with the stem cell therapy and followed for 36 months after their surgeries. A total of 24 participants will be enrolled nationwide.