Objective To develop a new method, the bone marrow stromal cells (BMSCs)-mediated tissue engineering technique combined with mosaicplasty, for repair of osteochondral defects and integration of gaps. Methods BMSCs from 12 Chinese goats were cultured and proliferated in vitro. Prior to the BMSCs harvest, osteochondral defects, 5 mm in diameter and 3 mm in depth, were created in the femoral medial condyles of both the goat's hind limbs. When the mosaicplasty (osteochondral autograft transplantation) was performed, the BMSCs, which had been harvested and compounded with hyaluronic acid, were injected into the gaps between the osteochondral autografts in the left hind limb. The right hind limb which only received osteochondral autograft transplantation without BMSCs served as a control. At four, eight and 16 weeks post-operatively, samples of the repaired defects were harvested and assessed by histological evaluation, immunohistochemical analysis and glycosaminoglycan (GAG) quantification. In both groups 16 weeks post-operatively, the GAG quantification was analyzed by one-way ANOVA and least significant difference (LSD) method. Results At all the time points, the cartilage autografts in both groups survived as hyaline cartilage and presented no significant difference from the surrounding native cartilage. In the group filled with BMSCs compound, the gaps were replaced by regenerated hyaline cartilage and disappeared; however, in the control group, the osteochondral autografts were still distinct from the surrounding normal cartilage, though the gaps were replaced by fibrous tissue or fibrous cartilage. Immunohistochemical analysis of typeⅡcollagen showed positive staining in the matrix of transplanted and regenerated cartilage. The Alcian blue method also confirmed a significantly less GAG content in the regenerated tissue in gaps in the control group than in the treatment group and in the normal cartilage. Conclusion Since tissue engineering combined with mosaicplasty can promote gap integration and cartilage healing, the method can be an ideal way for osteochondral defect repair.

Objective To qualitatively analyze the expressions of key marker genes involved in osteogenic differentiation of bone marrow stromal cells (BMSCs) of mice at defined stages in vitro using real-time RT-PCR. Methods The BMSCs of mice were cultured in vitro and induced to osteoblasts for 7, 14, and 21 days. The total RNA was extracted from the cultured cells and the gene expression levels of collagenⅠ, bone alkaline phosphatase (APL), osteopontin (OPN) and bone sialoprotein (BSP) in the osteoblasts at the defined stages were determined by real-time RT-PCR. Results The ColⅠmRNA levels in 14 and 21 days were (0. 75?0. 04) and (0. 34?0. 03) times respectively of that in 7 days. ALP, OPN and BSP mRNA levels in 21 days were (19. 70?2. 36), (150. 12?9. 31) and (7. 73?0. 58) times of those in 7 days respectively. Conclusions ColⅠexpression levels tend to gradually decline while ALP, OPN and BSP levels gradually increase along with the culture time. Real-time RT-PCR is a reliable method for investigation of gene expressions in BMSCs cultured in vitro.

Objective To construct vectors based on adeno-associated virus type 2 (rAAV2) carrying bone morphogenetic protein-7 (BMP-7) and observe their expression in adipose-derived adult stem cells, which can be served as a new gene therapy method and cell source for bone tissue engineering. Methods The coding sequence (1. 3 kb) of BMP-7 was amplified by PCR from the pcDNAl. 1 ( + ) plasmid containing the human BMP-7 cDNA. After purified, the gene fragments were cloned into a plasmid pUC18 and termed plasmid pUC18-hBMP7. The recombinant pUC18-hBMP7 was digested and further ligated to the pSNAV by T4DNA ligase and termed plasmid pSNAV-hBMP7. BHK-21 cells were transfected with the purified pSNAV-BMP7 plasmid according to a standard calcium phosphate precipitation method. The cells were isolated and the integrity of hBMP7 gene was determined by polymerase chain reaction (PCR) using the above PCR primers. To package the virus, stably transfected BHK-21 cells were subsequently infected with recombinant herpes simplex virus type 1 (rHSV-1). The collected cells were processed by chloroform treatment, PEG8000/NaCl precipitation and chloroform extraction for purification. The tiler was determined using quantitative DNA dot blots and the purity was examined by sodium dodecyl sulphatepolyacrylamide gel electrophoresis. Following infection with rAAV2-BMP7 at multiplicities of infection of 1?105 vector genomes per cell and subsequent culture, adipose-derived adult stem cells were assessed qualitatively for BMP7 production. Results The recombinant plasmid pSNAV-hBMP7 was identified by PCR and digested with restriction enzyme. Transfection showed an efficiency of 90 % in ADAS cells. BMP-7 expression in ADAS cells was identified by Western blot. Conclusions The hBMP-7 recombinant adeno-associated virus vectors can be successfully constructed in vitro and rAAV2-hBMP7 can infect ADAS cells.

Objective To investigate the effect of osteoinductive calcium phosphate ceramics (OICPC) on tendon healing in bone tunnels. Methods Anterior cruciate ligament reconstruction with semitendonous tendon was performed in the knee joints of 30 New Zealand rabbits by suspended fixation. OICPC grains were implanted into the bone tunnel of 15 rabbits which were the experimental group and the other 15 rabbits without OICPC implants severed as the control group. Specimens were collected four weeks, eight weeks and 12 weeks after surgery. Sections were stained with H. E., Sirius Red and Masson. Histological changes in the interface tissue between the bone tunnel and the tendon graft were observed, and the morphology of interface tissue was classified according to Yamakado method. Histomorphometry was done on Masson stain sections to measure new bone formation around the grafted tendon. Results In OICPC group, histological sections obtained four and eight weeks after surgery showed statistically greater new bone formation than those in the control group. Abundant penetrating Sharpey fibers appeared at eight weeks and direct connection was found at 12 weeks in the experimental group. On the other hand, Sharpey fibers appeared only at 12 weeks in the control group. Conclusion OICPC has a capability of enhancing biological fixation of a tendon to the bone tunnel.

Objective To study the feasibility of applying nanometer ceramics artificial bone in clinical repair of bone defects. Methods The animal models of bone defect was made on the unilateral radius of 45 New Zealand white rabbits, which were divided into experimental group(repair with nanometer ceramics artificial bone), control group (repair with ceramics artificial bone) and blank group (unrepaired) randomly. The reconstructive effect in each group was evaluated by gross observation, alkaline phosphatase(ALP) detection of blood serum, histopathological observation, X-ray examination and SEM detection at 4th, 8th and 12th weeks postoperatively. Results In the experimental group there was more bone formation than in the control and the blank groups. The differences in reconstructive effect were statistically significant ( P

Objective To explore the characteristics of chondrocyte apoptosis following acute osteochondral injury and the effect of intra-articular sodium hyaluronate injection in prevention of chondrocyte apoptosig. Methods Acute osteochondral injuries were created by drilling holes in knees at both sides of 28 rabbits according to Costouros' method. The experimental and control sides were randomized in each animal. Another four rabbits served as a normal control which received dissection of knee joint capsule without osteochondral injury. The experimental knee was injected with 1 % sodium hyaluronate at the end of the operation and then every week postoperatively. TUNEL and fluorescence-activated cell sorter (FACS) were applied to study the injured femoral condyles obtained at different intervals following the drilling injury. Results From day 4 after injury, the injured cartilage specimens displayed a statistically significant increase in overall level of apoptosis. Chondrocyte apoptosis was significantly reduced in the experiment knees compared with the injured ones. Conclusions Chondrocyte apoptosis may contribute to the subsequent development of post-traumatic arthritis. Intra-articular sodium hyaluronate injection just after acute osteochondral injury can suppress chondrocyte apoptosis, and thus help prevent the knee from post-traumatic arthritis.

Objective To study the feasibility and clinical results of C2, 3 pedicle-lateral mass plate fixation in the treatment of unstable Hangman's fractures. Methods From March 1999 to July 2005, 25 cases of unstable Hangman's fracture were treated surgically using the C2, 3 pedicle-lateral mass plate. All the cases were followed up for the healing of bone and function of the cervical vertebrate. Results The average follow-up period was 38 months. Twenty-three cases had a perfect reduction. Three cases had kyphosis deformity. There were no other complications related to the operation. AH the cases had a perfect early fusion of the C2 pedicle isthmus and long-term stability of C2, 3 intervertebral space. The clinic results were good. Conclusion Since the C2, 3 pedicle-lateral mass fixation can provide immediate reduction and satisfactory biomechanical stability, it is a good device for unstable Hangman s fractures.

Objective To discuss the design of arthroscopic reconstruction of posterior cruciate ligament (PCL) with quadriceps tendon fixed by a patellar block and an allograft bone plug, and its clinical outcome. Methods Thirteen patients suffering from PCL injury were treated by the technique mentioned above. The connection between quadriceps tendon and superior patellar pole was preserved in the harvest process of quadriceps tendon. The femoral tunnel was made like a bottle neck, which was clogged with the patellar bone block. The quadriceps tendon strip was fixed by an allograft bone plug pressed into the tibial tunnel. Their functional recovery was evaluated by Lysholm scoring and IKDC(International Knee Documentation Committee) criteria. Results In the average follow-up period of 19 months, there were not any severe nerve or blood vessel lesions, or failures of transplanted ligament None of the patient complained of knee instability after the operation. The pain was relieved in most patients, but three complained of pain after knee movement A little calcification was found in the quadriceps tendon at the superior patellar pole one year after the operation in the X-ray of a patient There was significant difference in Lysholm scale between pre-operation and post-operation (P

Objective To introduce a new technique in reconstruction of anterior cruciate ligament (ACL) by transplantation of autogenous hamstring and fixation with double crossbar (Rigidfix) under arthroscopy. Methods From July 2003 to Spetember 2005, 32 patients with ACL injury were treated with ACL reconstruction. Autogenous semitendinous and gracilis tendons were transplanted, fixed by double crossbar at the femoral end and an Intrafix screw in the tibial tunnel. Knee joint function and stability before and after operation as well as X-ray radiographs were evaluated according to the Lysholm scoring scale and International Knee Documentation Committee (IKDC) rating scale. The reliability of the fixation and its short term effect were analyzed. Results Twenty-eight patients were available for follow-up with duration from 6 to 28 months. The function of knee joint improved greatly. Four cases had unconscious positive findings in physical examination. The average Lysholm scores before and after opration were 53. 0?6. 3 and 90. 0?5. 2, respectively ( P

Objective To compare traditional arthroscopic reconstruction of anterior cruciate ligament (ACL) and the arthroscopic ACL reconstruction assisted by fluoroscopy-based navigation system in accuracy and reproducibility of the tunnel placement. Methods Fluoroscopy-based navigation system was used in 40 cases of arthroscopic ACL reconstruction from December 2005 to March 2006. Another 40 cases of traditional arthroscopic ACL reconstruction performed between June 2005 and March 2006 were used as control. The positions of the femoral and tibial tunnels were measured on their radiograms and compared statistically. Results The femoral tunnel position measurements averaged 62. 3%?5. 6% (52% - 73% ) in navigation-assisted ACL reconstruction, and 56. 6%?7. 3% (46% - 77% ) in the traditional arthroscopic operation. The tibial tunnel position measurements averaged 45.4%?3. 8% (37%-53% ) in the navigation-assisted ACL reconstruction, and 41. 1%?6. 0% (25% - 54% ) in the traditional arthroscopic operation. The differences were statistically significant ( P