FIG. 5.

Segment contributions to total lumbar spine rigidity. Distribution of spinal rigidity is shown for the following segments of the lumbar spine: L1–2, L2–4, and L4–5. The rigidity of each segment is normalized for the rigidity of the entire lumbar spine and shown in percentages. The distribution of rigidity is shown for spines after injection of MSCs genetically engineered to express bone morphogenetic protein-2 (MSC/−DOX group); SSP group, and native spines. Vertical bars indicate SE (n = 7 in all group). Horizontal lines indicate significant differences (spinal fusion performed using stainless steel pins; p < 0.05).