In order to observe the histological changes of the autogenous perichondrium graft from rib in the repair of injured articular cartilage of the condylar process of mandible, 50 rabbits were used, in which 15 were served as control. The articular cartilage with its subchondral bone were resected and an autogenous graft of costal perichondrium was sutured onto the raw surface of the condylar process, and in the controls, only the articular portion of the condylar process was resected without the application of autogenous costal perichondrium graft. The morphological changes of the newly formed cartilage during the process of its development were investigated by hiostological and autoradiog aphic techniques. The result revealed that 10 days after operation, the graft had increased in thickness and was richly populated form the proliferation of mesenchyme-like cells. Twenty to thirty days later, the chondrocytes were matured and the newly formed cartilage had covered the bony surface of mandibular condyle. At 60 days, the newly formed cartilagenous joint surface became glossy, and the morphology and arrangement of cells tended to be regular simulating the morphology of normal articular cartilage. From the experiment, it could be concluded that (1) The autogenous perichondrium graft placed on the condylar surface of mandible could form new articular cartilage which was similar in tissue morphology to the normal condylar cartilage. (2) The process of development of newly formed cartilage was similar to that of the normal cartilage. (3) The motion and loading on the joint could promote the formation of new cartilage and undergo biological reformation, gradually resulting in normal joint morphology. On this basis, the clinical application of autogenous perichondrium graft to repair injured cartilage of the condylar process of the mandible was feasible.
In order to investigate the effect of motion on repairing articular cartilage defect following autogenous periosteal graft, sixty adult rabbits were divided randomly into three groups: out-cage motion (OCM), in-cage motion (ICM) and immobilization (IMM). A defect of the articular cartilage, 1 cm x 0.5 cm in size, was made in the patellar-groove of femur of each hind limb. Free autogenous periosteal graft from the proximal tibia was sutured on the base of the left defect, while the right limb was served as control. The animals were sacrificed at 4, 8 and 12 weeks, respectively, after operation. The regeneration of the cartilage implanted was observed through gross, histology, histochemical assay and electronic microscope. The influence of different amount of motion on the chondrogenesis from the periosteal implant was also compared. The result showed that the hyaline cartilage produced from periosteal implant could be capable to repair full-thickness of articular cartilage. From statistical study, there was significant difference between OCM and ICM groups (P lt; 0.05), ICM and IMM (P lt; 0.05) as well as OCM and IMM (P lt; 0.01). It was suggested that the periosteal graft was effective in repair of defect of articular cartilage and the amount of motion was important for chondrogenesis.
To investigate the feasibility of using the pedicled patella for repaire of the superior articular surface of the medial tibial condyle, 37 lower limbs were studied by perfusion. In this series, there were 34 obsolete specimens and 3 fresh specimens of lower legs. Firstly, the vessels which supply to patella were observed by the methods of anatomy, section and casting mould. Then, the form and area of the patellar and tibial medial conylar articular surface were measured in 30 cases. The results showed: (1) the arteries supplied to patella formed a prepatellar arterial ring around patella, and the ring gave branches to patella; (2) medial inferior genicular artery and inferior patellar branches of the descending genicular arterial articular branch merge and acceed++ to prepatellar ring at inferior medial part of patella; (3) the articular surface of patella is similar to the superior articular surface of the tibial medial condyle on shape and area. It was concluded that the pedicled patella can be transposed to medial tibial condyle for repaire of the defect of the superior articular surface. The function of the knee can be reserved by this method.
ObjectiveTo evaluate the effect of bone cement filling on articular cartilage injury after curettage of giant cell tumor around the knee. MethodsFifty-three patients with giant cell tumor who accorded with the inclusion criteria were treated between January 2000 and December 2011, and the cl inical data were retrospectively analyzed. There were 30 males and 23 females, aged 16-69 years (mean, 34.2 years). The lesion located at the distal femur in 28 cases and at the proximal tibia in 25 cases. According to Campanacci grade, there were 6 patients at grade I, 38 at grade Ⅱ, and 9 at grade Ⅲ. Of 53 patients, 42 underwent curettage followed by bone cement fill ing, and 11 received curettage followed by bone grafts in the subchondral bony area and bone cement fill ing. Two groups were divided according to whether secondary osteoarthritis occurred or not during postoperative follow-up. The gender, age, lesion site, the subchondral residual bone thickness, tumor cross section, preoperative Campanacci grade, subchondral bone graft, and Enneking function score were compared between 2 groups, and multivariate logistic regression analysis was done. ResultsAll incisions healed by first intention. The average follow-up time was 65 months (range, 23-158 months). Of 53 cases, 37 (69.8%) had no osteoarthritis, and 16 (30.2%) had secondary osteoarthritis. Three cases (5.7%) recurred during the follow-up period. Univariate logistic regression analysis showed no significant difference in gender, age, lesion site, and Campanacci grade between 2 groups (P>0.1); difference was significant in the subchondral residual bone thickness, tumor cross section, Enneking function score, and subchondral bone graft (P<0.1). The multivariate logistic regression analysis showed that the decreased subchondral residual bone thickness, the increased tumor cross section, and no subchondral bone graft are the risk factors of postoperative secondary osteoarthritis (P<0.05). ConclusionCurettage of giant cell tumor around the knee followed by bone cement filling can increase the damage of cartilage, and subchondral bone graft can delay or reduce cartilage injury.
ObjectiveTo review the current treatment status of osteochondral defects (OCD) of the knee joint. MethodsRecent literature concerning treatment of OCD of the knee joint was extensively reviewed and summarized. ResultsOCD affect both the articular cartilage and the underlying subchondral bone, whereas OCD caused by different etiologies require various treatments. OCD repair is available by conventional clinical methods or the advanced tissue engineering strategies. Current clinical treatment outcomes remain uncertain; tissue engineering has emerged as a potential option as it can be efficiently applied to regenerate bone, cartilage, and the bone-cartilage interface, as well as effectively restore normal function and mechanical properties of the cartilage and subchondral bone. ConclusionOCD management and repair remain a great challenge in orthopedic surgery, thus cartilage and subchondral bone should be promoted as an interdependent functional unit considering treatment strategies to provide the best solution for the treatment of osteochondral defects.
The repair of defects of articular cartilage has continued to be a difficult problem. This article provided a collective review from literature pertaining to the advances gained in the repair of cartilaginous defects. In the spontaneous repair, if the defect of the cartilage was less than 3 mm, might result in complete or partial repair, but in those the diameter was more than 3 mm, the defect could not be repaired by normal cartilage. Although the cartilaginous autograft could give good result, but it could not be widely applied because short of supply of the autogenous cartilage. Cartilagious allograft could not be taken to repair cartilaginous defect because of reaction from tissue rejection. The transplantation of periosteal or perichondral graft had been tried but was eventually abandoned because of poor long-term result. The transplantation of free chondrocytes might be a method of hope. In general, transplantation of free chondrocytes into the cartilaginous defect will be lost. The supply of autogenous chondrocytes was very limited, and the heterogenous chondrocytes would inflict immunoreaction after being transplanted. In late of 1980, a new concept of tissue engineering was proposed. The problem that a scaffold of appropriate material which could hold the free chondrocytes in place from being lost might undergo proliferation and differentiation into new cartilage was far from being solved. Although tissue engineering still had various problems needed further investigation, but it will probably be the main direction of development in this field.
Objective Toreview theresearch progress of nucleus pulposus cells phenot ypic markers. Methods The domestic and international l iterature about nucleus pulposus cells phenotypic markers was reviewed extensively and summarized. Results Due to different biomechanical properties，nucleus pulposus cells and articular chondrocytes have differences in morphology and extracellular components such as the ratio of aggrecan to collagen type II α1. Nucleus pulposus cells can be identified by surface marker (CD24), gene markers (hypoxia inducible factor 1α, glucosetransporter protein 1, matrix metalloproteinase 2, vascular endothel ial growth factor A, etc), and various markers (keratin 19 and glypican 3，paired box 1, forkhead box F1 and integrin-binding sialoprotein, etc). Conclusion Nucleus pulposus cells and articular chondrocytes have different phenotypic markers, but nucleus pulposus cells are still lack of specific markers.
ObjectiveTo investigate the effects of micro-fracture and insul in-l ike growth factor 1 (IGF-1) in treatment of articular cartilage defect in rabbits. MethodsTwenty-four New Zealand white rabbits (aged, 4-6 months; weighing, 2.5-3.5 kg) were randomly divided into 4 groups (n=6):micro-fractures and recombinant human IGF-1 (rhIGF-1) treatment group (group A), micro-fracture control group (group B), rhIGF-1 treatment control group (group C), and blank control group (group D). Full thickness articular cartilage defects of 8 mm×6 mm in size were created in the bilateral femoral condyles of all rabbits. The micro-fracture surgery was performed in groups A and B. The 0.1 mL rhIGF-1 (0.01 μg/μL) was injected into the knee cavity in groups A and C at 3 times a week for 4 weeks after operation, while 0.1 mL sal ine was injected in groups B and D at the same time points. At 4, 12, and 24 weeks, the gross, histological, and immunohistochemical observations were performed, and histological score also was processed according to Wakitani's score criteria. The collagen contents in the repair tissues and normal patellofemoral cartilage were detected by the improved hydroxyproline (HPR) method at 24 weeks. Electron microscope was used to observe repair tissues of groups A and B at 24 weeks. Results All animals were survival at the end of experiment. At 24 weeks after operation, defect was repaired with time, and the repair tissue was similar to normal cartilage in group A; the repair tissue was even without boundary with normal cartilage in group B; and the repair tissue was uneven with clear boundary with normal cartilage in groups C and D. Histological staining showed that the repair tissues had no difference with normal cartilage in group A; many oval chondrocytes-l ike cells and l ight-colored matrix were seen in the repair tissues of group B; only a few small spindle-shaped fibroblasts were seen in groups C and D. Moreover, histological scores of group A were significantly better than those of groups B, C, and D (P<0.05) at 4, 12, and 24 weeks. Electron microscope observation showed that a large number of lacuna were seen on the surface of repair tissue in group A, and chondrocytes contained glycogen granules were located in lacunae, and were surrounded with the collagen fibers, which was better than that in group B. Collagen content of the repair tissue in group A was significantly higher than that in groups B, C, and D (P<0.05), but it was significantly lower than that of normal cartilage (P<0.05). Conclusion Combination of micro-fracture and rhIGF-1 for the treatment of full thickness articular cartilage defects could promote the repair of defects by hyaline cartilage.
Objective To examine the biological characteristic changes in thededifferenciated human articular chondrocytes by the bioreactor culturing in vitvo.Methods The cartilage tissue was obtained from the joints of the adult human. The chondrocytes were isolated from the cartilage tissue with the type Ⅱ collagenase digestion（0.2%, 37℃, 3 h）and were cultured in DMEMF12 supplemented with 20% fetal bovine serum (FBS) with 1 ng/ml of TGF-β1and 5 ng/mlof FGF-2. After about 20 passages by the monolayer culture，the cells were then transferred to the bioreactor culturing of the rotational cell culture system (RCCS) for a 3-week sequence culture. The cell counting was performed with the platelet counter, and the doubling time for each passage of thecells was determined. The frozen section was stained with HE. The differentiated phenotype was evaluated by histochemistry or immunohistochemistry. Results When the monolayer culture was performed without any growth factors, the chondrocytes were rapidly proliferated within 3 passages (average doubling time, 59 h),but at the same time, dedifferentiation was also progressing rapidly. After the4th passage, most of the cells were dedifferenciated and the proliferation was decreased. With the growth factors (TGF-β1/FGF-2), the speed of the expansion was accelerated (average doubling time, 47 h), but the speed of the dedifferentiation was slowed down. After 20 passages were performed with the monolayer culture, the dedifferentiated chondrocytes could be redifferentiated when they were cultured for 3 weeks with RCCS. Then, the Safranine-O staining was bly positive for the cells, positive for aggrecan and collagen Ⅱ, but negative for collagen Ⅰ, with a wellregained phenotype. Conclusion The bioreactor culturing of the dedifferenciated human articular condrocytes can regain the differentiated phenotype and it is a useful method of obtaining the human articular chondrocytes in large amounts and in a differentiated phenotype in vitro.
OBJECTIVE To investigate the feasibility of repairing the whole layer defects of tibial plateau by implanting tissue-engineering cartilage. METHODS: The chondrocytes of 2-week-old rabbits were cultured and transferred to the 3rd generation, and mixed with human placenta collagen-sponge. The whole layer defects of tibial plateau in adult rabbits were repaired by the tissue-engineering cartilage in the experimental group; the defects were left un-repaired in control group. The repair results of defects were observed after 4, 12 and 24 weeks. RESULTS: In experimental group, no obvious new cartilage formation was seen 4 weeks after operation; some new cartilage formation was found after 12 weeks. Histological observation showed that chondrocytes had irregular edge, honeycombing structure and that cartilage cavities formed around the chondrocytes. After 24 weeks, obvious new cartilage formation was found with smooth surface, and linked with the tissues around it, but the defect was not repaired completely; histological results showed that cartilage cavities formed and that cartilage matrix was stained positively for toluidine blue. In control group, the defect was not repaired. CONCLUSION: The tissue-engineering cartilage can repair the defects of the whole layer cartilage of tibial plateau in rabbits, it is feasible to repair the whole layer cartilage defects of tibial plateau by this method.