Assessment of BioPlex interbody fusion device in a sheep lumbar fusion model

The purpose of this study was to evaluate the bioPlex bioresorbable interbody device in a sheep lumbar fusion model and compare it to the concorde, a standard carbon fiber interbody cage.

Lumbar interbody fusion devices are made from a variety of materials, including titanium alloys, carbon-fiber, and PEEK. The BioPlex Continuous Phase Composite (CPC) is a unique bioresorbable material comprised of Pro Osteon 500R and 70:30 Poly (L/D, L-lactic acid). The BioPlex device is radiolucent, resorbable and due to its bulk nanoporosity of 8%, has a more consistent degradation profile as compared to a polymer alone.

A total of twenty five male Suffolk sheep were used in this study; nineteen of which were implanted with a bioPlex or concorde device at the L3-L4 and L5-L6 levels using a modified transforaminal/lateral approach. A discectomy was performed and each implant (filled with autologous bone) was placed within the disc space. The sheep were sacrificed at 6, 12, 24 months postimplantation. Fusion was assessed via motion, radiographic and histological data.

The BioPlex and Concorde implanted levels had significantly less motion (p<0.05) than the normal controls in flexion/extension and lateral bending at 6, 12, and 24 months. No significant difference in motion was detected between the bioPlex and concorde implants. CT fusion scores correlated with the motion analysis in all the three cases.

In comparison to the concorde device, the bioPlex implant appears to have equivalent radiographic and biomechanical fusion success.