Objective To study the ectopic osteogenesis and vascularization ofthe tissue engineered bone promoted by an artificial bone composite that consists of coral hydroxyapatite (CHA), 1,25-(OH)2 D3, human marrow stromal osteoblast (hMSO), and human umbilical vein endothelial cell (hUVEC).Methods After the isolation and the culture in vitro, hMSO and hUVEC were obtained. Then, hMSO (5×105/ml) and hUVEC (2.5×105/ml) were seeded at a ratio of 2∶1 onto the CHA scaffolds coated with 1,25-(OH)2 D3 (the experimental group) or onto the CHA scaffolds without 1,25-(OH)2 D3 (the control group). The scaffolds were culturedin vitro for 3 days, and then the scaffolds were implanted into the pockets that had beenmade on the backs of 18 nude mice. Then, 6 of the mice were implanted with one experimental engineered bone bilaterally; another 6 mice were implanted with onecontrol engineered bone bilaterally; the remaining 6 mice were implanted with one experimental engineered bone and one control engineered bone on each side. At4, 8 and 12 weeks after operation, the retrieved scaffolds and cells were examined by the nake eye and histology as well as by the scanning electron microscopy. The quantitative assessment of the newly-formed bone and the quantitative analysis of the newly-formed blood vessels were performed. Results The evaluationsby the histology revealed that at 4 weeks the original bone tissues grew into the scaffolds in all the groups, but significantly more newly-formed bone tissuesand newly-formed blood vessels were found in the experimental group. At 12 weeks the newly-formed bone tissues were found in all the groups, but there was a typical bone unit found in the experimental group. There was a significantly smaller amount of capillary vessels in the control group than in the experimental group at all the time points. The evaluations by the scanning electron microscopy revealed that at 4 weeks in the experimental group there were great amounts of extracelluar matrix that embedded the cells, and plenty of capillary vessels were found on the surface of the implanted bone materials and some of them grew into the materials; however, in the control group there was a smaller amount of capillary vessels although much extracelluar matrix was still found there. At 8 weeks sarciniform osteoids were found on some of the implanted materials, with much extracelluar matrix and many newly-formed capillary vessels in the experimental group; however, in the control group there were fewer capillary vessels and lower degrees of the bone maturity. The quantitative assessment of the newly-formed bone showed that the newformed bones were 3.1±0.52 in the experimental group but2.30±0.59 in the control group at 8 weeks (Plt;0.05), and 4.63±0.55 vs. 3.53±0.62 at 12 weeks. There was a significant difference at these two time points between the two groups (Plt;0.05). The quantitative analysis of the newly-formed blood vessels showed that the vascular areas were 28.74％±7.81％i n the experimental group but 19.52％±4.57% in the control group at 4 weeks (Plt;0.05), and 24.66％±7.38％ vs. 1784%±5.22% at 12 weeks. There was a significant difference at these two time points between the two groups (Plt;0.05). Conclusion 1,25-(OH)2 D3 as an active factor can increase the interaction between hMSO and hUVEC, and thus promote the ectopic osteogenesis and vascularization in the tissue engineered bone.
Objective To review the research progress of the vacuum phenomenon in spine. Methods The recent articles about the vacuum phenomenon in spine were reviewed; the features of imaging and the cl inical correlation were summarized. Results The vaccum phenomenon has been described in every segment of the spine. This phenomenon occurs mostly to the disc space and represents a transparent area on radiograph. Conclusion The causes of the vacuum phenomenoninclude degeneration of the anatomic structures of spine, trauma, and other pathologic changes. The vacuum phenomenon has important diagnostic and cl inical significances.
Objective To evaluate the efficacy of percutaneous kyphoplasty (PKP) in hyperextension position for the treatment of osteoporotic vertebral compression fracture (OVCF) with vacuum phenomenon. Methods Between April 2004and August 2009, 35 patients who suffered from OVCF with vacuum phenomenon were treated with PKP in hyperextension position, 8 patients were excluded because of lost follow-up. In 27 follow-up cases, there were 9 males and 18 females with an average age of 75 years (range, 58-90 years) and with an average disease duration of 9.8 months (range, 2-17 months). One vertebral body was involved in 26 cases and 2 vertebral bodies were involved in 1 case. According to the imaging examination and Krauss et al. criterion, all patients were diagnosed as having vertebral vacuum phenomenon. Refer to the lateral X-ray views, the height and the kyphotic angle of the involved vertebral body were measured pre- and postoperatively. The surgical outcomes were evaluated by using visual analogue scale (VAS) and Oswestry disabil ity index (ODI) system. Results All operations were performed successfully with no severe compl ication. The mean follow-up of 27 patients was 32 months (range, 24-58 months). The mean cl inical heal ing time of OVCF was 4 months (range, 3-6 months). The VAS score, ODI system, anterior and medial height of involved vertebral body, kyphotic angle of involved vertebral body were improved significantly at 1 week after operation and at last follow-up (P lt; 0.05); there was no significant difference between at 1 week after operation and at last follow-up (P gt; 0.05). There was no significant difference in the posterior height of involved vertebral body among different postoperative time-points (P gt; 0.05). Asymptomatic cement leakage occurred in 3 patients. Adjacent vertebral fracture occurred in 1 patient at 7 months. Intravertebral vacuums showed a compact and sol id cement fill ing pattern. Conclusion PKP in hyperextension position can significantly rel ieve back pain, restore vertebral height, and correct local kyphosis in the treatment of OVCF with vacuum phenomenon.