BACKGROUND: In previous studies, we succeeded in repairing a long bone defect with tissue-engineered periosteum (TEP), fabricated by incorporating rabbit mesenchymal stem cells with small intestinal submucosa. In this study, we investigated the feasibility of allogeneic irregular bone defect repair using TEP. METHODS: We performed a subtotal resection of the scapula in 36 rabbits to establish a large irregular bone defect model. The rabbits were then randomly divided into three groups (n = 12 per group) and the defects were treated with TEP (Group 1), allogeneic deproteinized bone (DPB) (Group 2) or a hybrid of TEP and DPB (Group 3). At 4, 8, and 12 weeks after surgery, the rabbits were sacrificed, and the implants were harvested. X-ray radiographic and histological examinations were performed to detect bone healing. Ink-formaldehyde perfusion was introduced to qualitatively analyze vascularization in TEP engineered new bone. RESULTS: The repair of scapular defects was diverse in all groups, shown by radiographic and histological tests. The radiographic scores in Group 1 and Group 3 were significantly higher than Group 2 at 8 and 12 weeks (p < 0.05).Histological scores further proved that Group 1 had significantly greater new bone formation compared to Group 3 (p < 0.05), while Group 2 had the lowest osteogenesis at all time-points (p < 0.001). Ink-formaldehyde perfusion revealed aboundant microvessels in TEP engineered new bone. CONCLUSION We conclude that TEP is promising for the repair of large irregular bone defects. As a 3D scaffold, DPB could provide mechanical support and a shaping guide when combined with TEP. TEP engineered new bone has aboundant microvessels.

BACKGROUND: In previous studies, we succeeded in repairing a long bone defect with tissue-engineered periosteum (TEP), fabricated by incorporating rabbit mesenchymal stem cells with small intestinal submucosa. In this study, we investigated the feasibility of allogeneic irregular bone defect repair using TEP. METHODS: We performed a subtotal resection of the scapula in 36 rabbits to establish a large irregular bone defect model. The rabbits were then randomly divided into three groups (n = 12 per group) and the defects were treated with TEP (Group 1), allogeneic deproteinized bone (DPB) (Group 2) or a hybrid of TEP and DPB (Group 3). At 4, 8, and 12 weeks after surgery, the rabbits were sacrificed, and the implants were harvested. X-ray radiographic and histological examinations were performed to detect bone healing. Ink-formaldehyde perfusion was introduced to qualitatively analyze vascularization in TEP engineered new bone. RESULTS: The repair of scapular defects was diverse in all groups, shown by radiographic and histological tests. The radiographic scores in Group 1 and Group 3 were significantly higher than Group 2 at 8 and 12 weeks (p < 0.05).Histological scores further proved that Group 1 had significantly greater new bone formation compared to Group 3 (p < 0.05), while Group 2 had the lowest osteogenesis at all time-points (p < 0.001). Ink-formaldehyde perfusion revealed aboundant microvessels in TEP engineered new bone. CONCLUSION We conclude that TEP is promising for the repair of large irregular bone defects. As a 3D scaffold, DPB could provide mechanical support and a shaping guide when combined with TEP. TEP engineered new bone has aboundant microvessels.

Objective To explore the effect of spinal sagittal balance on secondary vertebral fracture after percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCF).Methods The data were reviewed of the patients with single segmental OVCF who had undergone PKP at Department of Spine Surgery,Second Hospital of Lanzhou University from March 2014 to December 2015.Of them,21 had secondary vertebral fracture after PKP.As an observational group,they were matched with another 21 patients without secondary vertebral fracture after PKP as a control group (ratio:1:1) for age,gender,body mass index (BMI) and bone mineral density (BMD).Their standard standing plain radiographs of the whole spine were used to measure the parameters of spine-pelvis sagittal balance.The 2 groups were compared in sagittal balance parameters.Results The sagittal vertical axis (26.86 ± 33.55 mm) and thoracic kyphosis (47.62° ± 10.73°) in the observational group were significantly larger than those (4.05 ± 31.93 mm and 41.10 °±8.17°) in the control group (P ＜0.05);the lumbar lordosis (35.29°±8.77 °),sacral slope (22.71 ° ± 5.80°) and pelvic incidence (45.38° ± 7.49°) in the former were significantly smaller than those in the control group (41.71°±9.19°,27.43°±5.29° and 51.19°±8.44°) (P ＜0.05);there were no significant differences between the 2 groups in pelvic tilt or thoracolumbar kyphosis (P ＞ 0.05).Conclusions The OVCF patients with larger sagittal vertical axis,larger thoracic kyphosis and smaller lumbar lordosis may be more likely to suffer secondary vertebral fracture after PKP.A larger pelvic incidence may be a protective factor against secondary vertebral fracture after PKP for OVCF patients.