Evaluation of an osteostimulative putty in the sheep spine

Abstract

The objective of this study is to evaluate local response to a bioactive glass based composite putty (NovaBone Putty) in a vertebral body defect model in sheep, as compared to NovaBone, a bioactive glass particulate. Two time periods were used for the study, 6 and 12 weeks. Empty defects were also used as a control. In comparing the three test groups, the relative amount of new bone for both grafted defects was substantially greater than for the empty controls (P < 0.05). At 6 weeks, the bone formation was 42% for NovaBone Putty, 27% for NovaBone and 1.2% for the ungrafted empty defect. At 12 weeks, the bone formation was 51.4% for NovaBone Putty, 47.3% for NovaBone and 5.1% for the empty defect. NovaBone Putty, the test material, had greater bone content than the NovaBone, both of which were significantly greater than the empty control.

BAG S53P4 putty as bone graft substitute – a rabbit model

“…Both the test and the control samples were biocompatible and showed high new bone formation along with high vascularization and periosteal growth. With the BAG S53P4 putty, no indication of possible disturbed bone formation by the PEGglycerol binder was seen, which is in line with earlier studies [17,29]. We also found that the bioactive glass granules in the BAG S53P4 putty showed a slightly higher in-tramedullary ossification than the controls, but no difference in the cortical ossification was seen.…”

“…Similar findings at 6 and 12 weeks after surgery with NovaBone putty have been shown revealing a greater bone content in the putty group than in the particulate group [29]. As stated by Wang et al, a possible explanation for the increased bone formation with the putty material could be that addition of the carrier maintains a better spatial distribution of the particles [29]. Altogether, the novel BAG S53P4 putty can be considered to be biocompatible and non-toxic as earlier demonstrated for BAG in general [33].…”

“…We also found that the bioactive glass granules in the BAG S53P4 putty showed a slightly higher in-tramedullary ossification than the controls, but no difference in the cortical ossification was seen. Similar findings at 6 and 12 weeks after surgery with NovaBone putty have been shown revealing a greater bone content in the putty group than in the particulate group [29]. As stated by Wang et al, a possible explanation for the increased bone formation with the putty material could be that addition of the carrier maintains a better spatial distribution of the particles [29].…”

“…However, a sheep vertebral body defect model used to compare the local response of Nova- Bone Putty and NovaBone BAG particulates indicated that the putty group had a greater bone content than the particulate group at 6 and 12 weeks post-implantation [29]. On the other hand, in comparison, when utilizing a rabbit cranial defect model, the OsteoSelect demineralized bone matrix (DBM) putty was associated with significantly more bone formation than the synthetic NovaBone Putty [30].…”

“…In this study, neither signs of inflammation nor migration of the particulates were observed. Due to its physical properties, unlike the granules, the putty can be shaped so that the bone defect can be filled easily with little residual implant migrating into the undesirable areas [29]. Besides, the increase in early bone deposition rate might also allow subjects to start functional recovery training as early as possible [29].…”