Evaluation of an increased strut porosity silicate-substituted calcium phosphate, SiCaP EP, as a synthetic bone graft substitute in spinal fusion surgery: a prospective, open-label study

Purpose Silicate-substituted calcium phosphate-enhanced porosity (SiCaP EP, Inductigraft™, Altapore) is a synthetic bone graft material with enhanced strut porosity of 31–47%. SiCaP EP remains to be fully clinically evaluated in patients undergoing instrumented posterolateral fusion (PLF) surgery. We conducted a prospective, open-label, non-randomised, multicentre clinical study to evaluate efficacy of SiCaP EP as bone grafting material in PLF surgery with instrumentation for treatment of spinal disorders. Methods Patients with degenerative disc disease, spondylolisthesis or spinal stenosis underwent PLF surgery with SiCaP EP. The primary endpoint was evaluated in the per protocol population ( N = 102) as solid fusion at postoperative month 12 assessed using computed tomography scans, with motion assessed using flexion–extension radiographs. Clinical outcomes included the Oswestry Disability Index, 36-item short-form health survey for quality-of-life, visual analog scale for pain scores and neurological assessments. Adverse events were recorded. Results Successful fusion was achieved in 59/89 (66.3%) patients at month 6, 88/102 patients (86.3%) at month 12 (primary endpoint) and 87/96 (90.6%) patients at month 24. Disability and pain reduced following surgery. Quality-of-life improved and neurological function was maintained postoperatively. Forty-three (33.3%) of the 129 patients who underwent surgery experienced adverse events; back pain was most frequent ( n = 10); nine and 14 patients experienced serious adverse events judged related to device and procedure, respectively. Conclusions Enhanced strut porosity SiCaP EP provided high (month 12: 86.3%) spinal fusion success rates in PLF surgery. Fusion success was associated with improved clinical outcomes in patients within 12 months, relative to baseline. ClinicalTrials.gov identifier NCT01452022 Graphical abstract These slides can be retrieved under Electronic Supplementary Material.