Figure 3

Volume of the BMP induced fusion mass was assessed via microCT using a Skyscan 1174 scanner. A fusion mass was only produced in groups in which BMP was implanted. No new bone was observed at 1 week post op, while maximum fusion volume was achieved by week 2 and maintained at week 3. Decortication of the articular processes alone was insufficient to achieve new bone formation. A reconstructed sagittal view of a fused spine at 3 weeks is shown at the lower right. The section is taken from the midline, a dense fusion mass uniting the vertebrae of L1-L5.