In Brief:
The purpose of this study was to compare interbody fusion of an autologous tricortical iliac crest bone graft with two bioabsorbable cages made of 70/30 poly(l-lactide-co-d,l-lactide) or a polymer-calciumphosphate composite. After 12 weeks, there was no significant difference between the bioabsorbable poly(l-lactide-co-d,l-lactide) cage and the tricortical bone graft; however, the early appearance of large osteolysis associated with use of the poly(l-lactide-co-d,l-lactide) cage allows skepticism regarding the value of this bioabsorbable implant. In comparison to the tricortical bone graft, the bioabsorbable polymer-calciumphosphate composite cage showed significantly better distractive properties, a significantly higher biomechanical stiffness, and an advanced interbody fusion with only mild foreign body reactions.