Today's News

Saturday, February 15, 1997

Study finds human BMP safe for spinal fusion

A short-term, as well as 10-year follow-up of spinal fusion patients by University of California-Los Angeles (UCLA) researchers shows that purified native human bone morphogenetic protein extract (hBMP) was implanted along the spinal column with no adverse consequences.

"We did not find any evidence of infection, host rejection, osteolysis or tumor induction," said Harvinder S. Sandhu, MD, who presented the results Friday in poster exhibit B 073. Dr. Sandhu is assistant professor of orthopaedic surgery, department of orthopaedic surgery, UCLA Medical Center-UCLA Comprehensive Spine Center.

Because hBMP stimulates new bone growth, it may one day replace or augment the traditional bone grafts currently used in spinal fusion, Dr. Sandhu said.

According to the study, the therapeutic potential of both native (extracted) and recombinant forms of bone morphogenetic protein has been demonstrated in pre-clinical animal models. From January 1984 to March 1985 a clinical trial utilizing native BMP for human spinal fusions was conducted. The research team followed seven patients (long-term cohort) as well as two patients treated since July 1995 (short-term cohort). The patients ranged in age from five to 72 years.

Five of the seven were being treated for pseudarthrosis following prior surgery. One patient had congenital scoliosis. Another had spinal stenosis and adjacent level degeneration following lumbar fusion.

A purified extract containing hBMP from allograft cadaver bone was used, Dr. Sandhu said. Three of the four pseudarthroses in the 10-year cohort successfully fused. One patient, with three prior surgeries, failed pseudarthrosis repair. "The patient with congenital scoliosis achieved fusion but required additional surgery to correct crankshaft deformity," Dr. Sandhu said. "No inflammatory reactions or infections were apparent, although one patient had transient wound drainage from a sterile hematoma."

The researchers did not find any short- or long-term osteolysis. One patient died of lung cancer two years after surgery. Dr. Sandhu reported that over-all in the cohort, there has been no evidence of systemic or neoplastic illness resulting from implantation of hBMP.

"In the short-term cohort, neither patient had overt immune response or infection in the immediate postoperative period," Dr. Sandhu said. "No adverse neurologic sequelae has occurred in the patient with concomitant laminectomy."

"This study addresses safety issues regarding use of BMPs along the spinal column and represents the longest followup of patients with native BMP implants," Dr. Sandhu said.

Co-authors of the study with Dr. Sandhu are: Linda E.A. Kanim, M.A., research associate; Edgar G. Dawson, MD, clinical professor of orthopaedic surgery; and Marshall R. Urist, MD, professor emeritus, all from the UCLA department of orthopaedic surgery.

Two other co-authors are Joseph M. Lane, MD, attending orthopaedic surgeon and director, applied orthopaedic clinical research, Hospital for Special Surgery, New York, N.Y. and Arya N. Shamie, MD, second year resident in orthopaedic surgery, St. Mary's Medical Center, University of California, San Francisco.