SF-36 Outcomes and Fusion Rates After Multilevel Laminectomies and 1 and 2-level Instrumented Posterolateral Fusions Using Lamina Autograft and Demineralized Bone Matrix

Abstract

Short-Form 36 (SF-36) outcomes and fusion rates were assessed after multilevel laminectomies and 1 (95 patients) or 2-level (45 patients) instrumented fusions. The posterolateral fusion mass consisted of lamina autograft and demineralized bone matrix (Osteofil/ICM: Sofamor Danek, Memphis, TN) in a 50:50 mix. SF-36 questionnaires were administered preoperatively and 3, 6, and 12 months postoperatively. Two independent neuroradiologists (blinded to study design) separately documented fusion on both dynamic x-rays and two-dimensional-computed tomography (2D-CT) studies performed 3, 6, and up to 12 months postoperatively until arthrodesis was demonstrated. Patients were followed an average of 3 years in both fusion series (minimum of 1.5 y). One-year postoperatively, comparably improved outcomes were observed for both groups on 6 of 8 Health Scales of the SF-36. 2D-CT studies documented 1-level fusion an average of 5.2 months (Standard Deviation 1.8) postoperatively in 88 (92.6%) of 95 cases, whereas dynamic x-rays confirmed fusion in 93 (98%) patients. For 2 patients undergoing 1-level fusions, both 2D-CT and dynamic x-ray documented pseudarthrosis/instability; both patients required secondary surgery an average of 8 months postoperatively. 2D-CT documented 2-level fusion an average of 6.1 months (Standard Deviation 1.9) postoperatively in 41 of 45 (91.2%) patients, whereas dynamic x-rays confirmed fusion in 43 (96%) patients. For 2 patients undergoing 2-level fusions, both 2D-CT and dynamic x-rays documented pseudarthrosis/instability; both patients required secondary fusion an average of 10 months postoperatively. High fusion rates and adequate outcomes were observed after multilevel laminectomies and 1 and 2-level instrumented posterolateral fusions performed using lamina autograft and demineralized bone matrix: Osteofil/ICM.