PMC4724723_01
(A) InQu resorption/consolidation assessment by subject over time. Each line lies in the upper half of the graph demonstrating that there is no significant initial resorptive phase, only intervals of increasing consolidation over time. (B) beta-TCP resorption/consolidation assessment by subject over time. A flat line demonstrates for most of the beta-TCP-treated fusion segments between days 91-135 no change in radiographic appearance from surgery. Once the mineral content has been cleared, an increase in the height of the plotted lines (consolidation) was observed for one or more time intervals in 21 of 28 fusion segments. However, from day 135 and on, 7 of 28 fusion segments (25%) showed a steady decline in line height toward the negative portion of the graph, indicating that more resorption had occurred than consolidation.
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F4
For sides receiving beta-TCP extender (Figure 4B), a different picture was observed that is consistent with the beta-TCP mechanism of action.
Comparative radiography depicting resorption and consolidation of two bone graft extenders. A 46-year-old female with history of active tobacco use and diabetes underwent PL fusion of the lumbar spine at L2-3 and L5-S1. AP radiographs at L2-3 are shown over time. Left side received bone autograft, BMA, and beta-TCP putty. Right side received equal mix of bone autograft, BMA, and InQu putty. Sequential assessment over 24 weeks illustrates marked resorption of ceramic bone graft, whereas the opposite side receiving hybrid extender showed consolidation of applied graft at 6 weeks, with sustained bone volume at 24 weeks.
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F5
A representative example of this resorption phase, identified only for sides receiving beta-TCP extender, is illustrated in Figure 5.