Objective To study the vascularization of the compositeof bone morphogenetic protein 2 (BMP-2) gene transfected marrow mesenchymal stem cells (MSCs) and biodegradable scaffolds in repairing bone defect. Methods Adenovirus vector carrying BMP-2 (Ad-BMP-2) gene transfected MSCs and gene modified tissue engineered bone was constructed. The 1.5 cm radial defect models were made on 60 rabbits, which were evenly divided into 4 groups randomly(n=15, 30 sides). Different materials were used in 4 groups: Ad-BMP-2 transfected MSCs plus PLA/PCL (group A), AdLacz transfected MSCs plus PLA/PCL (group B), MSCs plus PLA/PCL (group C) and only PLA/PCL scaffolds (group D). The X-ray, capillary vessel ink infusion, histology, TEM, VEGF expression and microvacular density counting(MVD) were made 4, 8, and 12 weeks after operation. Results In group A after 4 weeks, foliated formed bones image was observed in the transplanted bones, new vessels grew into the bones, the pores of scaffolds were filled with cartilage callus, osteoblasts with active function grew around the microvessels, and VEGF expression and the number of microvessels were significantly superior to those of other groups, showing statistically significant difference (Plt;0.01); after 8 weeks, increasingly more new bones grew in the transplanted bones, microvessels distended and connected with each other, cartilage callus changed into trabecular bones; after 12 weeks, lamellar bone became successive, marrow cavity recanalized, microvessels showed orderly longitudinal arrangement. In groups B and C, the capability of bone formation was weak, the regeneration of blood vessels was slow, after 12 weeks, defects were mostly repaired, microvessels grew among the new trabecular bones. In group D, few new vessels were observed at each time, after 12 weeks, broken ends became hardened, the defectedarea was filled with fibrous tissue. Conclusion BMP-2 gene therapy, by -upregulating VEGF expression, indirectly induces vascularization ofgrafts,promotes the living of seed cells, and thus accelerates new bone formation.
OBJECTIVE: To study the effect of platelet-rich plasma in the repair of bone defect. METHODS: Segmental bone defects of 1 cm were created in the mid-upper part of bilateral radius of 24 New Zealand white rabbits. One side was randomly chosen as the experimental side, which was filled with artificial bone with platelet-rich plasma (PRP). The other side filled with artificial bone without PRP as the control. After 2, 4, 8 and 12 weeks of implantation, the gross, radiological, histological observations, and computer graphic analysis were performed to investigate the bone healing of the defect in both sides. RESULTS: Two weeks after operation, new bone and fibrous tissue formation in both the experimental and the control sides were observed only in the areas adjacent to the cut ends of the host bone, but the amount of new tissue in the experimental side was much more than that in the control side. In the 4th and 8th weeks, the surface of the artificial bone was covered with a large amount of new bones, the artificial bone was bridged tightly with the host bone by callus in the experimental side, while new bone was limited mainly in the cut ends and was less mature in the control side. In the 12th weeks, bone defects were entirely healed in the experimental side, which were covered completely with cortical bone, while new bone formation was only observed in the ends of artificial bone and there were not continuous bone callus on the surface in the control side. CONCLUSION: Artificial bone with PRP is effective in the repair of segmental bone defects, and PRP could improve the healing of bone defect.
It is difficult to repair long defect of bone. Biological bone carrier (BBC) was one of the artifical bone substitutes. It was obtained from human or swine bone after a series of biochemical treatment. It had good histocompatibility. It had the same components and structure of bone, and its biological strength was samiliar to bone. In clinic, BBC was applied to repair of long defect of bone in two cases. The lengths of defect were 13 cm and 11 cm, respectively. After followed up for 2 to 3 years, it was found that the implanted BBC had been combined with the femur with new bone. It had the same metabolism and density as that of the normal bone.
OBJECTIVE: To investigate the feasibility of coralline hydroxyapatite (CHA) as scaffolds in bone tissue engineering. METHODS: The bone marrow stromal cells from 4-month New Zealand rabbits were harvested and cultured in vitro. After multiplied, dexamethasone was used to promote the osteoblastic phenotype of the cells. The cells were harvested and then seeded into CHA. By means of tissue engineering technique, osteoblastic cells/CHA complex were formed. The complex were implanted subcutaneously in nude mice. The CHA alone was implanted as control. Bone regeneration was assessed 6, 8 weeks after implantation by histological and roentgenographic analysis. RESULTS: After six weeks of implantation, x-ray film showed high-density signal, osteoid tissue formed under histological examination. Large amount of new bone were formed and connected to trabecularism 8 weeks after implantation in the experimental group. While in the control group, there were no new bone formation, but amount of fiber tissue grew into the pore of CHA 8 weeks after implantation. CONCLUSION: CHA may be used as a good scaffold material for bone tissue engineering.
Objective To investigate the diagnosis and effectiveness of surgical treatment for lumbar pyogenic spondyl itis. Methods Between February 2005 and June 2010, 15 cases of lumbar pyogenic spondyl itis were treated. There were 10 males and 5 females with an average age of 48.6 years (range, 26-72 years). Affected segments included L2, 3 in 3 cases,L3, 4 in 3 cases, L4, 5 in 8 cases, and L5, S1 in 1 case. All cases had cl inical manifestations of moderate or severe fever, local pain of lesion, and l imitation of the spinal movement; 10 patients had nerve root symptoms, and 8 patients had symptoms of lower limb paraplegia. Leukocyte, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) significantly increased in all cases. The preoperative X-ray and CT examinations showed no clear bone destruction; MRI showed decreased signal intensity on T1WI and increased signal intensity on T2WI, 7 cases had local ized abscess formation. The patients underwent focal cleaning and bone grafting and fusion combined with internal fixation, including anterior operation in 13 cases, posterior operation in 1 case, and combined anterior and posterior operation in 1 case. The results of bacterial culture were positive in 10 cases. According to the results of intraoperative bacterial cultures, sensitive antibiotics were selected. Results Healing of incision by first intention was achieved in 14 cases, healing by second intention in 1 case. After 2 weeks, 1 case recurred and symptoms was rel iefed after symptomatic treatment. Back pain and (or) lower limb pain were obviously improved in the other patients; body temperature recovered to normal after 3-4 days; leukocyte, ESR, and CRP significantly decreased. All the patients were followed up 12 to 70 months with an average of 35.4 months.The patients had no rejection, no fistula formation, no lumbar kyphosis, and no fixator loosening or breakage. The bony fusion time was 4-8 months. Conclusion Combination of cl inical manifestations, laboratory tests, and MRI can diagnose lumbar pyogenic spondyl itis, of which CRP is an important indicator to determine progression of the disease, and MRI is important for diagnosis. Debridement combined with interbody fusion and internal fixation is a safe and effective treatment method.
OBJECTIVE: To investigate the effects of bone morphogenetic protein (BMP) on the proliferation and collagen synthesis of skeletal muscle satellite cells. METHODS: Skeletal muscle satellite cells were harvested and cultured in vitro. The 0 ng/ml, 50 ng/ml, 100 ng/ml, 500 ng/ml, and 1000 ng/ml BMP were used to induce skeletal muscle satellite cells for 48 hours. Cell proliferation, rate of myotube formation and collagen-1 synthesis were measured. RESULTS: BMP promoted cell proliferation and reduced the rate of myotube formation. Collagen synthesis increased when skeletal muscle satellite cells were induced with more than 500 ng/ml BMP. And the higher the concentration of BMP was, the ber this effect became. CONCLUSION: BMP can enhance the proliferation of skeletal muscle satellite cells and change their differentiation from myoblasts to osteoblasts.
Objective To study the effect of direct bone morphogenetic protein 2 (BMP-2) gene therapy mediated by adenovirus on repairing bone defect. Methods The radial defect models were made on 60 rabbits, which were evenly divided into 4 groups randomly. The 4 groups were treated with different materials: group A, adenovirus carrying BMP-2 gene (AdBMP-2) plus bovine cancellous bone (BCB); group B, reconstructed BMP-2 plus BCB; group C, AdLacz plus BCB; and group D, only BCB scaffolds. The X-ray, histological examination, biomechanics analysis, and immunohistochemical staining were made 4, 8, and 12 weeks after the operation. Results Group A gained better effect in the volume of new bones, the anti-bending intensity of the healing bone, and the expression of BMP-2 than those of group B. The defect in group A was healed. No new bones were observed in group C and group D. Conclusion Direct BMP-2 gene therapy is easy to perform and has veryb osteoinduction ability. It is a good method to repair segmental bone defects.
It is one of the difficult clinical problems to repair the large bone defect created by excision of benign tumors and to rebuilt the bone shelf. On the basis of the animal experiment, we excised thoroughly the effected bone subperiosteally and repaired the bone defect by fibula without its periosteum of other materials. The bone framework was successfully reconstracted. From Jan. 1984 to Dec. 1992, a series of seven cases were treated accordingly. The patients were followed up for 1 to 9 years. The skeletal framework in each was rebuilt rigidly. There was no recurrence and the functions of the extremity was recovered. In part of thesubperiosteum of fibula supplier bave regeneration of a new fibula with normal size at the site where the fibula was excised subperiosteally.
OBJECTIVE: To explore the anatomic feature and clinical application of the bone (periosteum) flap pedicled with upper muscular branches of lateral femoral muscle. METHODS: The anatomic features and distribution of upper muscular branches of lateral femoral muscle were observed in the lower extremities of 40 adult cadavers. From February 1989 to February 1999, 7 cases with bone defect or nonunion of upper part of femur were treated with transfer of bone (periosteum) flap pedicled with upper muscular branches of lateral femoral muscle. RESULTS: The upper muscular branches of lateral femoral muscle originated from the transversal branch of lateral circumflex femoral artery. The musculoperiosteal branch and periosteal branch were originated at 16.8 +/- 3.0 cm below the greater trochanter. The diameter and length of musculoperiosteal branch were 1.4 to 1.7 mm and 2.7 to 5.6 cm, those of the periosteal branch were 0.4 to 0.6 mm and 1.2 to 1.5 cm respectively. Bone union achieved in 10 to 18 weeks after operation in all 7 cases after 18 to 42 months follow-up. The motion of hip joint reached 180 degrees in 4 cases, 120 degrees in 2 cases and 65 degrees in 1 case. The donor area recovered well. CONCLUSION: The bone (periosteum) flap pedicled with upper muscular branches of lateral femoral muscle is an effective alternative for repairing the bone defect or nonunion of the upper or middle part of femur.
Since 1979, 13 different types of vascularized bone or periosteal flaps were used to repair bone defects following resection of skeletal neoplasms in 109 cases. The result was satisfactory. In this article, the main points in discussion werethe operative indication, how to design the flap and the technique used to repair the defect.