Fusion Rate of Biphasic Calcium Phosphate Bone Graft with Needle-Shaped Submicron Surface Topography in Interbody Lumbar Fusion for Degenerative Disc Disease: A Single-Center Retrospective Review.

Abstract

Calcium phosphate bone grafts are emerging as alternatives to autologous bone grafts in lumbar spinal fusion. This study evaluates the 12-month fusion rate and clinical outcomes of lumbar interbody fusion using synthetic biphasic calcium phosphate with submicron needle-shaped surface topography (BCP<μm). A retrospective review identified patients who underwent lumbar interbody arthrodesis with BCP<μm, with or without autograft. Fusion was assessed by an independent neuroradiologist using a computed tomography alphanumeric classification based on bridging bone on 12-month postoperative computed tomography. Secondary outcomes included changes in visual analog scale, length of stay, and fusion of all treated levels. Fifty-five patients with 93 treated levels were analyzed (average age: 62.78 years; body mass index: 28.73 kg/m²). Patients had an average of 3 comorbidities and a median of 2 levels fused. Procedures included anterior (52 levels), transforaminal (22 levels), and lateral lumbar interbody fusion (19 levels). Fusion occurred in 95.70% of levels without evidence of fixation failure. Fusion rates were unaffected by procedure type (P = 0.965) or supplemental autograft use (P = 1.00). Complications were reported in 4 patients. Six-month postoperative visual analog scale improved by a mean of 25.10 (P < 0.0001). This study demonstrates a high fusion rate (95.70%) and low complication rate in a diverse patient population with multiple comorbidities, suggesting BCP<μm is a viable graft material for lumbar interbody fusion.