Objective To investigate the effectiveness of mosaicplasty in repair of large-sized osteochondral compound defects and the integrity of transplanted tissue with recipient sites so as to lay a foundation for clinical application. Methods Twenty-four adult goats were divided into 3 groups randomly. The diameters of defect were 6 mm for the medium-sized defects and 9 mm for the large-sized defects, which were created by a trepan. All of the defects were repaired with osteochondral plugs in diameters of 2 mm(the mediumsized defects) or 3 mm(the large-sized defects). The osteochondral plugs were harvested around the intercondylar fossa or intertrochlea groove, and pressed into the recipient sites by specialized instruments in a mosaic mode. No internal fixation was needed and the animal wereallowed to move freely after operation. From 4 to 24 weeks postoperatively, thespecimens were observed in gross and under electromicroscopy. X-ray detection and glycosaminoglycan(GAG) analysis were also performed to testify the healing processand the integrity of the cartilage and subchondral bone. Results The transplanted subchondral bone was integrated firmly with each other or with recipient sites in both mosaicplasty groups. But 24 weeks postoperatively, transplanted cartilage was not integrate with each other apparently. Obvious cleavage between cartilage plugs could be seen. But in the largesized defect groups, some of the osteochondral plugs were relapsed into the defects leaving the recipient sites some steps, leading to some degree of abrasion in the opposing articular cartilage. There was no significant difference in the GAG content between the transplanted cartilage and normal cartilage. X-ray analysis also demonstrated the healing process between the subchondral bone. Conclusion Mosaicplasty can repair the medium or small-sized osteochondral defects efficiently.
Objective To discuss the stabil ity and practical ity of temporomandibular joint replacement by establ ishing goats artificial temporomandibular joint replacement model. Methods Six healthy mature goats were selected, the male and female being half and weighing 35.3-37.0 kg. According to the parameters from X-ray films of goat’ s temporomandibular joint and the shape of the same kind goat’s skull, the total temporomandibular joint prosthesis was prepared. The one side temporomandibular joints of six goats were replaced by prosthesis randomly as the experimental group (n=6, fossa and condyle according to replacement location) and the other side by titanium plate as the control group (n=6). At 4,8, and 12 weeks, the histological observation, scanning electron microscope (SEM) observation were carried out for observing structural changes in the interface. The mechanical test and histochemistry test were used for observing the combination degree of interface and the alkal ine phosphatase (ALP) activity. Results All animals were al ive to the end of experiment with normal open mouth, good recovery of masticatory function, and normal eating. At 4, 8, and 12 weeks, implants were stable in 2 groups without loosening. The histological observation and SEM observation showed the amount of osteoblasts in interface increased over times. There were significant differences in the shearing force and the ALP activity between fossa in experimental group and control group at 4 weeks (P lt; 0.05), but there was no significant difference between other groups (P gt; 0.05). Conclusion The total temporomandibular prosthesis has good stabil ity in temporomandibular joint reconstruction of goat after replacement.
Objective To investigate the ability to repair goat tibia defect with marrow stromal stem cells (MSCs) and bio-derived bone, and the feasibility of the compounds as bone substitute material. Methods MSCs were cultured with the bioderived bone in vitro, and the 20 mm tibia defect of goat was made and fixedwith plate. Eighteen goats were divided into experimental group, control group and blankgroup. The defects were not filled with anything in blank group, with tissue engineering bone in experimental group and bio-derived bone in control group. Therepair capability was assessed by physical, X-ray and bone mineral density examinations8,12,16, and 24 weeks after operation. Results In experimental group, the defects were partially repaired 8 weeks, and completely repaired12 and 16 weeks; there was significant difference in bone density between experimental group and control group (P＜0.05) 8,12 and 16 weeks, but no significant difference 24 weeks. The defects of blank group were not repaired 24weeks. Conclusion The tissue engineering bone can efficiently repair bone defect, and its repair capability is better than that of bio-derived bone alone both in quantity and quality of boneformation.
Objective To study the vascularization of the compositeof bio-derived bone and marrow stromal stem cells(MSCs) in repairing goat tibial shaft defect.Methods Bio-derived bone was processed as scaffold material. MSCs were harvested and cultured in vitro. The multiplied and induced cells were seeded onto the scaffold to construct tissue engineered bone. A 20 mm segmental bone defect inlength was made in the middle of the tibia shaft in 20 mature goats and fixed with plate. The right tibia defect was repaired by tissue engineered bone (experimental side), and the left one was repaired by scaffold material (control side).The vascularization and osteogenesis of the implants were evaluated by transparent thick slide, image analysis of the vessels, and histology with Chinese ink perfusion 2, 4, 6, and 8 weeks after operation.Results More new vessels were found in control side than in experimental side 2 and 4 weeks after implantation (Plt;0.05). After 8 weeks, there was no significant difference in number of vessels between two sides(Pgt;0.05), and the implants were vascularized completely. New bone tissue was formed gradually as the time and the scaffold material degraded quickly after 6 and 8 weeks in the experimental side. However, no new bone tissue was formed andthe scaffold degraded slowly in control side 8 weeks after operation.Conclusion Bio-derived bone has good quality of vascularization. The ability of tissue-engineered bone to repair bone defect is better than that of bio-derived bone alone.
Objective To establish a rapid, simple, and economic method to prepare osteoporosis (OP) in vitro model. Methods Eighty pairs of fresh goat femur were collected from 18-month-old female goats and were randomly divided into 4 groups (20 pairs in each group). The femur was immersed decalcifying solution (18% EDTA) for 1-5 days (group B), 6-10 days (group C), and 11-15 days (group D), while group A had no treatment as control. Four pairs of femur were taken out every day. Quantitative computed tomography was used to scan the medial and lateral femoral condyles, and the bone mineral density (BMD) was calculated. Electronic universal testing machine was used to do three-point bending test and compress and tensile ultimate strenght test, and the mechanical parameters for femur were calculated. Results With demineralized time passing, BMD of the medial and lateral femoral condyles were downtrend in groups A, B, C, and D, showing significant differences among 4 groups (P lt; 0.05); BMD of the lateral femoral condyle was significantly higher than that of the medial femoral condyle in each group (P lt; 0.05). The three-point bending test showed that broken load, ultimate strength, and elastic modulus of groups A and B were significantly higher than those of groups C and D (P lt; 0.05); but no significant difference was found between groups A and B, and between groups C and D (P gt; 0.05). Compress and tensile ultimate strength test showed that the compress and tensile ultimate strengths were significantly higher in group A than in groups C and D (P lt; 0.05), and in group B than in group D (P lt; 0.05), but no significant difference was found between groups A and B, between groups B and C, and between groups C and D (P gt; 0.05). Conclusion The 18% EDTA immersing for 6-15 days is a fast, simple, economical method to prepare an OP in vitro model of goat femur.
Objective To investigate the effect of hydrostatic pressure and insulin-like growth factor 1 (IGF-1) on the expression of filamentous actin (F-actin) of temporomandibular joint disc cells in goats, and to analyze the F-actin changes of temporomandibular joint disc cells in vitro under hydrostatic pressure and IGF-1 stimulation. Methods The bilateral temporomandibular joint discs were harvested from 4 1-month-old goats, and temporomandibular joint disc cells were isolated with collagenase. Immunohistochemical staining for collagen type I and collagen type II was performed for identification. The cells at passages 2-3 were used; the experiment was divided into 4 groups according to different interventions: the cells were cultivated with complete medium in group A as control; the cells were intervened by hydrostatic pressure (0.2 MPa and 1 Hz for 3 hours) in group B, by complete medium containing IGF-1 (10 ng/mL) in group C, and by a combination of hydrostatic pressure (0.2 MPa and 1 Hz for 3 hours) and complete medium containing IGF-1 (10 ng/mL) in group D. The changes of F-actin at 24 and 72 hours after cultivation were observed by immunofluorescence staining. The cell fluorescence intensity was measured. Results The cultivated cells were identified to be temporomandibular joint disc cells by morphological observation and immunohistochemical staining. At 24 hours, fluorescence intensity of groups A and C was b and clear, with normal morphology of temporomandibular joint disc cells; F-actin arranged in disorder in group B, and F-actin was thinner with arrangement disorder in group D. At 72 hours, the F-actin arranged regularly in groups A and C; however, some F-actin became blurry with irregular arrangement, breakage, and pseudopodia in group B; and F-actin was thinner and ruptured formed in group D. With time passing, the fluorescence intensity of F-actin in groups A, B, and D had an increasing trend, showing significant differences between 24 hours and 72 hours (P lt; 0.05); but there was no significant difference between 24 and 72 hours in group C (t=0.284, P=0.781). At 24 hours, fluorescence intensity of F-actin was highest in group C and was lowest in group B, showing significant difference when compared with groups A and D (P lt; 0.05). At 72 hours, fluorescence intensity in groups B and D was significantly lower than that in groups A and C (P lt; 0.05), but there was no significant difference between groups B and D, and between groups A and C (P gt; 0.05). Conclusion Hydrostatic pressure may cause the F-actin breakage and rearrangement of temporomandibular joint disc cells, and IGF-1 can up-regulate the F-actin expression. Such effects may be correlated with the biological behavior of the temporomandibular joint disc cells.
Objective To evaluate the feasibil ity of intrauterine abdominal wall defect repair of fetal lamb at late pregnancy. Methods Eight healthy pregnant ewes at 110-115 days of gestation (weighing 14-22 kg) were randomly divided into 2 groups. In group A (n=3), the abdominal wall defect of 5 cm × 1 cm was made in the fetal lambs, then was closed by strengthening suture; in group B (n=5), the abdominal wall defect of 5 cm × 2 cm was made in the fetal lambs, then was repairedby 2 layers of biological patches. After the lambs del ivered naturally, the lambs and their wounds were observed; at 10th day after birth, the scars were harvested for biomechanical and histological observations. Results One ewe of group A and 2 ewes of group B aborted, while the others were successfully del ivered. In group A, the abdominal incisions of 2 lambs healed well with a l ine-l ike scar and mild intra-abdominal adhesion, and the scar thickness was 4-5 mm. In group B, the abdominal incisions of 3 lambs did not heal completely with minor intra-abdominal adhesions, and the scar thickness was 3-4 mm. The wound breaking strength was 16, 20 N in group A and 10, 14, and 18 N in group B, respectively. A sl ight scar was seen in group A; skin ulcer and underlying fibrous connective tissue with inflammatory cell infiltration were seen in group B. Conclusion It was feasible to repair the abdominal wall defect of fetal lamb at late pregnancy in uterine. Small abdominal wall defect can be sutured directly; biological patch can be used to repair larger abdominal wall defect.
Objective To investigate the effect of cleft palate on the development of the mid-part of the face so as to provide an optimum animal model for the fetal cleft repair. Methods Twenty female Boer hybrid goats were selected, aging from 8 to 12 months and weighing from 35 to 55 kg. The mating day was identified as 0 day of pregnancy. The goats werediagnosed with pregnancy by the B-ultrasound examination at 30 days, and were allocated into experimental group (n=14) and control group (n=6). In experimental group, uterine cavitory operation was performed at 65 days of pregnancy to form cleft palate which was a fissure between oral and nasal cavity; no treatment was given as the control group. At 120 days of pregnancy, and after 1 month and 3 months of birth, the gross observation and 3-dimensional skull CT reconstruction were performed; and the maxillary bone width named as PPMM and the maxillary bone length named as APMM were measured. Results After operation, 2 goats died of infection, miscarriage occurred in 3 goats; 9 goats were included into the experiment. The operation success rate was 64.3%. In experimental group, maxillary dysplasia occurred in all the fetal goats at 120 days of pregnancy, and more obvious maxillary dysplasia was observed at 1 month and 3 months after birth; no maxillary dysplasia occurred in control group. There were significant differences in PPMM and APMM between 2 groups at different time points (P lt; 0.05). In experimental group, the lambs had poor chewing function, and died of pulmonary infection after aspiration at 1-4 months after birth. Conclusion The surgical procedure for partial ablation of secondary primitive palate in the midl ine could make the model of cleft palate.
Objective To investigate effects of the autologous bone mesenchymal stem cells (MSCs) enriched by the small intestinal submucosa (SIS) film implantation on the myocardial structure, cardiac function, and compensator y circulation after myocardial infarction in the goats. Methods Sixteen black goats were selected and divided randomly into the control group (n=8)and the experimental group (n=8). The chronic myocardial infarction models were made by the ligation of the far end of the left anterior desc ending coronary artery. At the same time, MSCs were aspired from the thigh bone of the goats in the experimental group. MSCs were isolated by the centrifu gation through a percoll step gradient and purified by the plating culture and depletion of the non-adherent cells. Primary MSCs were cultured in the DMEM me dium supplemented with the fetal bovine serum in vitro. After that, the cultures were labeled by 5- BrdU. The active cells were transplanted into the SIS film. Six weeks after the ligation, the MSCs-SIS film was implanted by its being sutured onto the infarction area; whereas, the control group underwent a shamoperation. In both groups, echocardiographic measurements were performed before infarction, 6 weeks after infarction and 6 weeks after the MSC-collagen mplantion, respectively, to assess the myocardial structure and ca rdiac function. The left coronary artery angiography was performed with the digi tal subtraction angiography. Results In an assessment of the left ventricular function, at 6 weeks after operation, t he stroke volume and the ejection fraction of the control group and the experim ental group were 42.81±4.91, 37.06±4.75 ml and 59.20%±5.41%, 44.56%±4.23%, respectively (Plt;0.05). The enddisatolic volume and the endsystolic volume of the control group and the experimental group were 72.55±8.13, 83.31±8.61 ml and 29.75±5.98, 46.25±6.68 ml, respectively (Plt;0.05). The maximal velocity of peak E of contral group and experimental group were 54.8 5±6.35 cm/s and 43.14±4.81cm/s (Plt;0.01); and the maximal velocity of peak A o f control group and experimental grouop were 52.33±6.65 cm/s and 56.91±6.34 cm/s (Pgt;0.05). Echocowdiogr aphy sho wing a distinctly dilatation of left ventricle with the ventricular dyskinesia i n contral group, but without the ventricular dyskinesia in experimental group. T he selective-coronary evngiography revealed that the obvious compensatory circu l ation established between the anterior descending branch and the left circumflex branch in the experimental group. Conclusion Implantation of the autologus MSCs enriched by the SIS film can prevent dilatation of the left ventricular chamber and can improve the contractile ability of the myocardium, cardiac function, and collateral perfusion.
ObjectiveTo evaluate the performance, safety, and precision of the Yuanhua robotic-assisted total knee arthroplasty system (YUANHUA-TKA) through animal experiments, which will provide reference data for human clinical trials.MethodsSix 18-month-old goats, weighing 30-35 kg, were used in this study. The experimental study was divided into two parts: the preoperative planning and intraoperative bone resection. CT scans of the goats’ lower extremities were firstly performed before the experiments. Then the CT scans were segmented to generate the femoral and tibial three-dimensional (3D) models in the YUANHUA-TKA system. The volumes and angles of each resection plane on the femur and tibia were planned. The bone resection was finally implemented under the assistance of the YUANHUA-TKA system. After completing all bone resections, the lower extremities of each goat were taken to have CT scans. By comparing the femoral and tibial 3D models before and after the experiments, the actual bone resection volumes and angles were calculated and compared with the preoperative values.ResultsDuring the experiments, no abnormal bleeding was found; the YUANHUA-TKA system ran smoothly and stably and was able to stop moving and keep the osteotomy in the safe zone all the time. After the experiment, the resection planes were observed immediately and found to be quite flat. There was no significant difference between the planned and actual osteotomy thickness and osteotomy angle (P>0.05); the error of the osteotomy thickness was less than 1 mm, and the error of the osteotomy angle was less than 2°.ConclusionThe YUANHUA-TKA system can assist the surgeons to perform osteotomy following the planned thickness and angle values. It is expected to assist surgeons to implement more accurate and efficient osteotomy in the future clinical applications.