Prospective ACDF Outcomes using Iliac Crest Autograft Versus Allograft with **Bone Morphogenic Protein

Introduction: Anterior cervical discectomy and fusion (ACDF) using iliac crest bone autograft (IBG) usually results in solid fusion. Donor site pain and morbidity have led some surgeons to use alternatives to IBG. Many alternatives result in delayed unions or greater non-union rates. Bone morphogenic protein (BMP)** studies have found high arthrodesis rates in lumbar fusions. This study assessed BMP/allograft (fibular cortical ring) as an alternative to IBG for ACDF by quantification of outcomes, fusion and complication rates, and hospital costs.

Methods: All patients (n=66) in the authors practice who had primary ACDF with iliac crest bone autograft or BMP/allograft (0.9mg BMP per level) were followed prospectively over a 2 year period with outcomes surveys (VAS pain, pain drawing, Oswestry Index, pain medication use, over-all opinion of treatment success, recovery of neurological deficits). Patients were categorized to IBG (n= 36) or BMP/allograft (n= 30), primary diagnosis (degenerative disc disease, herniated nucleus pulposus, or stenosis), number of levels treated, smoking and work-comp/litigation status. Exclusion criteria were prior ACDF, corpectomy, scoliosis, tumor, or discitis.

Results: Both IBG and BMP/allograft groups had significant improvement in all outcome scales over the follow-up periods and there was no difference between the groups. Neurological deficits uniformly resolved in both groups. The IBG group had one pseudarthrosis and two iliac donor site complications. Neck swelling was 4x as common in the BMP group with 3 patients readmitted but none required additional surgery. Length of stay and surgical blood loss were similar, yet implant and hospitalization costs were significantly higher in the BMP vs the IBG groups ($6840 vs $3366 respectively for 2-level implants). Cost/benefit ratio improved for 3-level ACDF.

Discussion: ACDF performed with BMP/allograft is as effective as IBG in terms of patient outcomes and fusion rates. Neck swelling and higher costs were associated with the BMP group.

FDA Diclosure Cleared: No ** Bone Morphogenic Protein