Outcome Analysis for Minimally Invasive Spine Surgery

STUDY RATIONALE AND PRIMARY OBJECTIVE/HYPOTHESIS To assess the clinical and radiographic
outcome of spinal fusion procedures using Silicate-Substituted Calcium Phosphate (Si-CaP), a
newer-generation of synthetic ceramics designed to maximize osteoinduction and
osteoconduction.

STUDY DESIGN Retrospective Study

PURPOSE OF THE STUDY Providing compelling evidence for the efficacy of Si-CaP in terms of
resulting in satisfactory fusion.

SUMMARY OF METHODS A prospectively collected database will be reviewed retrospectively, to
retrieve data of 200 patients who have undergone different spinal fusion procedures using
Silicate-Substituted Calcium Phosphate (Si-CaP). An average follow up duration of at least 12
months will be considered. Clinical outcomes will be assessed using the visual analog scale
(VAS), Oswestry Disability Index (ODI), and Neck Disability Index (NDI). Pre-operative scores
will be compared to the latest follow-up scores. A board certified Neuro-radiologist will
assess the fusion rate. Fusion will be determined by the presence of bony bridging on 2
consecutive sections in at least 2 planes on computed tomographic imaging.

SECONDARY ENDPOINTS AND EXPECTED RESULTS The purpose of this study is to evaluate the level
of clinical and radiographic improvement in patients implanted with Silicate-Substituted
Calcium Phosphate (Si-CaP) as a bone graft substitute material for spinal fusions. More
comprehensive long term studies will be able to provide compelling evidence for the efficacy
of Si-CaP in terms of resulting in satisfactory fusion. They can more strongly support the
previously published data implying that Si-CaP can be utilized as an alternative to
autogenous bone graft in spinal arthrodesis procedures.

Inclusion Criteria:

- Patients with different spinal fusion procedures (including AxiaLIF (axial lumbar
interbody fusion), TLIF (transforaminal lumbar interbody fusion), ELIF (extreme lateral
interbody fusion), PCF (posterior cervical fusion), and ACDF (anterior discectomy and
fusion)) using Silicate-Substituted Calcium Phosphate (Actifuse®, Baxter, Deerfield, IL) as
a bone graft substitute.

Exclusion Criteria:

- Utilization of any other bone extenders in addition to Si-CaP as a bone graft substitute.