Evaluation of 70/30 poly (L-lactide-co-D,L-lactide) for use as a resorbable interbody fusion cage.

Abstract

Titanium lumbar interbody spinal fusion devices are reported to be 90% effective in cases requiring single-level lumbar interbody arthrodesis, although radiographic determination of fusion has been debated. Using blinded radiographic, biomechanical, histological, and statistical measures, researchers in the present study evaluated a radiolucent 70/30 poly(L-lactide-co-D,L-lactide) interbody fusion device packed with autograft or recombinant human bone morphogenetic protein-2 on a collagen sponge in 25 sheep at 3, 6, 12, 18, and 24 months. A trend of increased fusion stiffness, radiographic fusion, and histologically confirmed fusion was demonstrated at 3 months to 24 months postimplantation. Device degradation was associated with a mild to moderate chronic inflammatory response at all postoperative sacrifice times. Use of this material in interbody fusion may be a viable alternative to metals.