The Failure of Ethylene Oxide Gas-Sterilized Freeze-Dried Bone Graft for Thoracic and Lumbar Spinal Fusion

Abstract

Thirty-seven patients underwent posterior and/or posterolateral spinal fusion using ethylene oxide gas-sterilized freeze-dried bank bone graft. Thirteen patients had discogenic back pain, eight with prior failed laminectomy procedures, and five undergoing initial spinal surgery. Six patients had isthmic spondylolisthesis, three with associated radicular complaints, and two patients had degenerative spondylolisthesis. Seven patients with spinal fractures and nine patients with scoliosis underwent spinal fusion with associated instrumentation. Pseudarthroses were detected in 28 patients (76%), and 18 patients (49%) underwent pseudarthrosis repair procedures using autogenous iliac bone graft. At surgery, the prior gas-sterilized freeze-dried bone graft was noted to have been almost completely resorbed. Ethylene oxide sterilization has been found experimentally in animal models to damage the osteoinductive ability of bone grafts. Ethylene oxide gas-sterilized freeze-dried bank bone graft is inferior to autogenous bone graft or bank bone graft preserved and/or sterilized by other methods. Its use in thoracic or lumbar posterior or posterolateral fusion cannot be recommended.