Figure 2: Mean + SD of % change in disc height indices of injured and uninjured control discs 12 weeks post-surgery. Panel (A) All lumbar discs subjected to the annular incision showed a significant decrease in DHI of 23.67% relative to non-injured control discs (p<0.0001). Panel (B) Individual DHI scores for the control (L1/2 and L5/6) discs and injured discs (L2/3, L3/4, L4/5) discs. No statistical difference was found between the two control levels (L1/2 and L5/6). The mean changes in DHI for the three injured discs (L2/3, L3/4, L4/5) were also NSD from each other.