A Retrospective Analysis of Early Outcomes from a Biphasic Calcium Phosphate Bone Graft With a Submicron, Needle-Like Surface Topography Used in Posterior Spinal Fusion Procedures

Study Design: A single-center retrospective assessment of spinal fusion. Objective: The aim of this study was to determine the fusion effectiveness of a biphasic calcium phosphate bone graft with a submicron, needle-like surface topography (BCP <µm , MagnetOs Easypack Putty) in posterior spinal fusion (PSF) procedures in high-risk patients. Background: Patient comorbidities can negatively affect spinal fusion surgery. In these patient populations, fixation failure is of greater concern. Therefore, the use of an evidence-based bone graft is necessary to accomplish successful fusion at earlier time points and mitigate the harmful outcomes associated with fixation failure. Materials and Methods: This data set was collected from the Springhouse Analytics Spine Registry to evaluate a biphasic calcium phosphate bone graft with a submicron, needle-like surface topography (BCP <µm ) as both a standalone graft as well as a graft mixed with autograft in PSF procedures. Fusion was determined at various time points postoperatively, specific to each patient. Results: The analysis comprised a review of 70 subjects receiving BCP <µm with a total of 134 spinal levels treated. The average age was 70.1 years (range: 40.3–89.7 yr old) with a population including 67% female and 33% male subjects. Sixty-four participants (91%) had one or more comorbidities, including heart disease (60%), obesity (54%), respiratory disease (31%), and diabetes mellitus type 2 (26%). X-rays were obtained after a median of 139 days (range: 42–507 d) postoperatively with over half of the subjects (38 patients, 54%) evaluated for fusion within 180 days postoperatively. The primary endpoint of fusion rate based on x-ray analysis was 87% (61/70 patients) based on the radiologic evidence of bone formation and lack of radiologic evidence of hardware failure. Subjects evaluated for fusion within 180 days postoperatively demonstrated a fusion rate of 84.2% (32/38 patients). Visual Analogue Scale (VAS) pain scores decreased an average of 19.7% from 6.9/10 preoperatively to 4.9/10 postoperatively, and Oswestry Disability Index (ODI) decreased an average of 11.3% from 50.1/100 to 38.8/100. Although the population included several comorbidities, no adverse events were attributed to bone graft. Conclusions: The high fusion rate observed in PSF procedures outlines the effectiveness of BCP <µm to fuse patients with comorbidities that may otherwise lead to fixation failure. Moreover, the majority of patients were evaluated before 180 days postoperatively, outlining the effectiveness of BCP <µm to fuse patients by 180 days.