Objective To review new progress of related research of bone tissue engineering in recent years. Methods Domestic and international l iterature concerning bone tissue engineering was reviewed and analyzed. Results In the recent years, great progression had been made in the research and development of bone tissue engineering, it had been used in more and more hospitals, and relevant national regulations and protocols had been set up. As to seed cells of bone tissue engineering, autologous and allogeneic stem cells had been widely used, while recently embryonic stem cells and induced pluri potent stem cells had attracted most attentions. In the field of scaffolds materials, significant improvementshad been made, from natural extractions to artificial polymers; from single construction to multiple compounds with surface modifications. As to the methods of construction, the static seeding approach had been widely accepted, and the appl ications of bioreactor had provided a stable and various micro-enviroment for the vitro-culture of different stem cells, which had beenregarded as an alternative way of vitro-culture and construction for bone tissue engineering. Conclusion With the tremendous help of the techniques and approaches above, we shall expect a promising future of a new generation bone tissue engineering based medical products in the years to come.
From 1976 to 1991, 34 cases of benign tumors of femoral neck were received in our department and 29 cases were treated surgically with either free bone graft (18 cases) or vascularized bone graft (11 cases). Fibrous dysplasia of bone and bone cyst had a high incidence in this group (75%)and most of the patients were over 30 years old. Because the femoral neck had its own anatomical characteristics and was biomechanically important and in order to accelerate. The graft healing and prevent the occurrence of pathological fracture, the choice of operations should depend on the extent of the lesion, the thickness of the cortical bone of the affected past,and the presence or absence of complications.
Objective To study the properties of the xenogeneic deproteinized cancellous bone used as a scaffold in the bone tissue engineering andits application to the spinal fusion of the lumbar intertransverse process in agoat. Methods The deproteinized bone was derived from an adult pig’s femoral cancellous bone through the physical and chemical treatments. Its morphological features, constituting components, and biomechanical properties were examined by the scanning electron microscopy, X-ray diffraction analysis, and mechanical experimental instrument. The cell-material complex was observed under the inverted phase contrast microscope to evaluate the adhesion and the growth of the osteoblasts. The experimental model of the spinal fusion of the lumbar intertransverse process was produced in 12 male goats aged 6-8 months, which were divided into two groups. In Group A, the tissue engineered bone constructed by thexenogeneic deproteinized cancellous bone, the recombinant human bone morphogenetic protein 2, and the mesenchymal stem cells was used for the spinal fusion; however, in Group B the autoilium was used. The samples were harvested at 4, 8 and 12 weeks postoperatively, and a series of examinations were performed, including the radiography and the histomorphological assay. Results The deproteinized cancellous bone had a natural pore network system, with an aperture ranging in size from 200 to 500 μm, containing a main organic material ofcollagen and the inorganic material of hydroxyapatite. So, the deproteinized cancellous bone had a good mechanical strength and a good histocompatibility. In Group A, the X-ray examination at different timepoints postoperatively showed that at 4 weeks,the bridging areas of all the fusion sites were not clear, especially on the internal side; at 8 weeks, the upper and lower bridged parts had a narrowed gap, with formation of much continuous bony callus; at 12 weeks, a complete fusion occurred. In the early stage, the material density was slightly lowerin Group A than in Group B, but at 12 weeks the density was almost the same in both the groups. Histological examination in the transplant area showed that at 4 weeks in Group A there was a new bone formation in a multipoint way; at 8 weeks, a “sandwichshaped” new bone wascrossed with the transplanting materials; and at 12 weeks, a medullary cavity was remodeled and a new cancellous bone was formed. The osteogenic process of thetissue engineered bone constructed by the xenogeneic deproteinized cancellous bone scaffold was almost the same as the autoilium osteogenesis. Conclusion The xenogeneic deproteinized cancellous bone is a good material in the bone tissue engineering, which can be used as an osteogenesis scaffold andprovide a stable environment for revascularization and osteoblastic differentiation.
Objective To investigate the effectiveness of radical debridement, reconstruction with bone allograft, and pedicle screw-rod internal fixation via combined anterior and posterior approach in the treatment of lumbosacral tuberculosis. Methods Between January 2005 and May 2010, 16 patients with lumbosacral tuberculosis were treated. Radical debridement wasperformed via extraperitoneal approach, then tricortical il iac bone allograft was placed and pedicle screw-rod internal fixation was used to reconstruct the spinal column. There were 12 males and 4 females aged 38-65 years (mean, 48 years). The disease duration ranged from 6 to 24 months (mean, 10 months). The main cl inical symptom was persistent pain in lumbosacral area. The involved segments included L4, 5 (3 cases), L5, S1 (8 cases), and L4-S1 (5 cases). The lumbosacral angle was 18-32° (mean, 22°). The erythrocyte sedimentation rate (ESR) was 15-55 mm/1 hour (mean, 25 mm/1 hour). All the patients were given antituberculosis chemotherapy for 12 months after operation. Results The operation time was 120-240 minutes (mean, 180 minutes). The amount of bleeding was 300-600 mL (mean, 420 mL). All wounds healed by first intention, and no relative compl ication occurred. All 16 cases were followed up 12-24 months (mean, 16 months). No recurrence occurred and ESR recovered to normal. Persistent pain in lumbosacral area and radicular pain in lower extremities disappeared. The X-ray films demonstrated that bony fusion was obtained in all patients at 8-12 months postoperatively. The lumbosacral angle was 16-31° (mean, 21°) at last follow-up. Conclusion The extraperitoneal approach can provide direct and safe access to the lesion. The structural il iac bone allograft and posterior instrumentation could reconstruct effectively the stabil ity of the lumbosacral junction.
Objective To investigate the therapeutic effectof the modified anterior approach in treatment of the patients with cervicothoracic junction spinal lesions. Methods From September 2000 to January 2005, 23 patients (15 males, 8 females) with spinal lesions in the cervicothoracic junction underwent a standard cervical approach, which was combined with apartial median steotomy and transverse steotomy through the synostosis between the manubrium and body of the sternum to expose the lesion adequately. Among thepatients, 3 had fracture, 7 had dislocation, 6 had tuberculosis, and 7 had tumor. The pathologic change regions was as follows: 2 in the C6-T1 segment, 2in the C6-T2 segment, 3 in the C7-T1 segment, 3 in the T3 segment, 8 in the T1 segment, and 5 in the T2egment. The classification of Frankel were as follows: 2 at grade A, 4 at grade B, 7 at grade C, 4 at grade D, and 6 at grade E. All the patients underwent a radical excision of the affected spinal bone, were given a proper tricortical iliac crest and anterior instrumentation to reconstruct the anterior spinal column, followed by immobilization in a brace for 3-6 months. Results The mean followup period was 30 months (range, 1042 months). Bony fusion was obtained in all the patients.One patient died of pulmonary cancer metastasis 10 months after operation. The nerve function of the spinal cord recovered at different degrees (1 at grade A, None at grade B, 2 at grade C, 10 at grade D, 10 at grade E). Conclusion Ourmodified anterior approach can provide a direct and safe access to the lesions in the region.
Objective Tissue engineered bone (TEB) lacks of an effective and feasible method of storage and transportation. To evaluate the activity of osteogenesis and capabil ity of ectopic osteogenesis for TEB after freeze-dried treatment in vitro and in vivo and to explore a new method of preserving and transporting TEB. Methods Human bone marrow mesenchymal stem cells (hBMSCs) and decalcified bone matrix (DBM) were harvested from bone marrow and bone tissue of the healthy donators. TEB was fabricated with the 3rd passage hBMSCs and DBM, and they were frozen and dried at extremely low temperatures after 3, 5, 7, 9, 12, and 15 days of culture in vitro to obtain freeze-dried tissue engineered bone (FTEB). TEB and FTEB were observed by gross view and scanning electron microscope (SEM). Western blot was used to detect the changes of relative osteogenic cytokines, including bone morphogenetic protein 2 (BMP-2), transforming growth factor β1 (TGF-β1), and insul in-l ike growth factor 1 (IGF-1) between TEB and FTEB. The ectopic osteogenesis was evaluated by the methods of X-ray, CT score, and HE staining after TEB and FTEB were transplanted into hypodermatic space in athymic mouse. Results SEM showed that the cells had normal shape in TEB, and secretion of extracellular matrix increased with culture time; in FTEB, seeding cells were killed by the freeze-dried process, and considerable extracellular matrix were formed in the pore of DBM scaffold. The osteogenic cytokines (BMP-2, TGF-β1, and IGF-1) in TEB were not decreased after freeze-dried procedure, showing no significant difference between TEB and FTEB (P gt; 0.05) except TGF-β1 15 days after culture (P lt; 0.05). The ectopic osteogenesis was observed in TEB and FTEB groups 8 and 12 weeks after transplantation, there was no significant difference in the calcified level of grafts between TEB and FTEB groups by the analysis of X-ray and CT score. On the contrary, there was no ectopic osteogenesis in group DBM 12 weeks after operation. HE staining showed that DBM scaffold degraded and disappeared 12 weeks after operation. Conclusion The osteogenic activity of TEB and FTEB is similar, which provides a new strategy to preserve and transport TEB.
Objective To investigate the method and effectiveness of coracoplasty with mini-incision for subcoracoid impingement syndrome. Methods Between May 2006 and September 2011, 4 patients with subcoracoid impingement syndrome were treated, including 3 cases of congenital dysplasia of the coracoid process and 1 case of anterior glenohumeral instability. There were 3 males and 1 female with an average age of 36 years (range, 20-56 years). The disease duration was 6-22 months (mean, 11.2 months). The patients had a history of chronic pain and click of the anterior should, which was aggravated in adduction, internal rotation, and flexion. The results of the coracoid impingement test were positive by Neer and Hawkins-Kennedy impingement sign. The axial CT in adduction position showed that the coracohumeral interval decreased and coracoid index increased. The 2 cm lateral coracoid incision was made and the 0.5-1.5 cm coracoid neck was revealed and cut by osteotomy. The coracoplasty was performed by amputating the conjoined tendon insertion of the short head of the biceps and the coracobrachialis muscle and suturing to proximal coracoid osteotomy surface. Shoulder was fixed with the external braces for 6 weeks. Results Healing of incision by first intention was observed in all cases without any complication. All the 4 patients were followed up from 8 months to 5 years. At last follow-up, pain and click disappeared. The mean visual analogue scale (VAS), University of California at Los Angeles (UCLA), Constant, and simple shoulder test (SST) scores were significantly improved from 7.75, 10.25, 65.50, and 9.75 at preoperation to 0.25, 34.25, 91.25, and 0.25 at last follow-up respectively. The axial CT in adduction position and MRI showed that long coracoid process was removed; the coracohumeral interval was increased to 13.38 mm from 4.16 mm at preoperation; and the coracoid index was decreased to 0.28 mm from 13.08 mm at preoperation. Conclusion Coracoplasty with mini-incision is an effective method to relieve clinical symptoms of subcoracoid impingement, which has less complications and faster recovery.
Objective The combined appl ication of green fluorescent protein (GFP) and confocal laser scanning microscope three-dimensional reconstruction (CLSM-3DR) were used to monitor the construction and in vivo transplantation of tissue engineered bone (TEB), to provide for technology in selection of scaffolds and three-dimensional constructional methods. Methods After bone marrow mesenchymal stem cells (BMSCs) were isolated from a 2-year-old green goat by a combination method of density gradient centrifugation and adherent culture, and the expressions of CD29, CD60L, CD45, and CD44 in BMSCs were detected by flow cytometry. Plasmid of pLEGFP-N1 was ampl ified, digested by enzymes (Hind III, BamH I, Sal I, and Bgl II), and identified. Transfection of pLEGFP-N1 into PT67 cells was performed under the help of l iposome. Positive PT67 cells were picked out with G418, and prol iferated for harvesting virus. Based on the titre of virus, after BMSCs were infected by virus containing pLEGFP-N1, GFP positive BMSCs were collected and prol iferated for seeding cells. TEB was fabricated by GFP positive BMSCs and decalcified bone matrix (DBM) and observed by CLSM-3DR for the evaluation of the distribution and prol iferation of seeding cells. After TEB was transplanted in the defect of goat femur, CLSM was used for observing the survival and distribution of GFP positive cells in the grafts. Results The isolated cells were fibroblast-l ike morphous, with the positive expression of CD29 and CD44, and negative expression of CD60L and CD45. The digested production of pLEGFP-N1 was collected for ionophoresis, whose results showed the correct fragment length (6 900 bp). The virus of pLEGFP-N1 was harvested by transfection of pLEGFP-N1 into PT67 cells and used for further infection to obtain GFP positive BMSCs. The prol iferated GFP positive BMSCs and DBM were used for fabrication of TEB. The distribution, prol iferation, and migration of BMSCs in TEB were observed by CLSM-3DR. GFP positive cells also were observed in images of TEB graft in goat femur 28 days after transplantation. Conclusion The BMSCs labeled by GFP in three-dimensional scaffold in vivo were monitored well by CLSM-3DR. It suggests a wide use potency in monitoring of three-dimensional cultured TEB.