UW Surgeon Pioneers Spinal Fusion Technique

FOR IMMEDIATE RELEASE

Contact: Lisa Brunette Phone: (608) 263-5830

UW SURGEON PIONEERS SPINAL FUSION TECHNIQUE
Protein-soaked sponge replaces spinal bone

MADISON -- In what is believed to be the first clinical trial of its kind in the United States, a spine surgeon at University of Wisconsin Hospital and Clinics has begun using protein-saturated sponges placed in a patientπs spine to replace the disc removed during fusion surgery. The sponge contains bone growth factor, a substance expected to produce bone that will complete the fusion -- and eliminate the need to take bone from the patientπs body to replace the disc.

A 30-year-old Wisconsin man was the first patient in the nation to take part in a clinical trial of the procedure. Dr. Thomas Zdeblick, associate professor of surgery at University of Wisconsin Medical School, performed the procedure in early January. The patient left the hospital the next day.

About 150,000 patients nationwide undergo single-level (between two vertebrae) spinal fusion surgery annually in the United States, most often to correct damage from torn cartilage or ≥discs≤ between the bones of the spinal column. Surgeons remove the cartilage and part of the bone and fuse the two adjacent vertebrae together. The vertebral bone that is removed is usually replaced by bone fragments taken from another site in the patientπs body -- often the pelvis or rib cage -- and secured within a metal cage. The ≥harvesting≤ of the patientπs bone requires a second incision and lengthens both operating and recovery time.

In the new procedure, recently approved by the Food and Drug Administration for investigational study, surgeons use ≥bone morphogenic proteins≤ or BMPs, substances produced by the body when an injury occurs. In animal studies, many conducted at the UW, BMPs have been shown to seek out unspecialized cells and prompt them to reproduce and become bone and cartilage. The proteins, in a liquid solution, are first placed within a collagen sponge. The sponge is then placed into spinal fusion cages that are screwed into place. The cages replace the diseased disc. Within a few months, physicians will know if the BMPs have induced bone growth through the cages and promoted healing of the spine.

Zdeblick, who is also medical director of the UW Comprehensive Spine Center, says earlier studies have shown no significant side effects from use of the BMPs to induce bone growth. Genetic engineering techniques have allowed scientists to isolate BMPs and reproduce them in the laboratory.

Based on animal surgery results, Zdeblick expects the bone to heal more quickly than with conventional surgery. In addition, by eliminating the bone harvesting, patient recovery should be faster.

Although it is too early to predict the outcome of the new treatment, physicians hope that BMPs may eventually replace bone grafts in many instances. -30-