OBJECTIVE To investigate the feasibility of osteoid callus allograft as a kind of bone healing promoting materials. METHODS The osteoid callus was obtained at one week after bilateral femoral fracture of a SD rat, then was kept at -196 C for 2 weeks. The bone defect model which bone repair was in intra-membranous osteogenesis was made at bilateral tibial shaft in 5 rats, and filled with the osteoid callus in the left defect area, the right side was filled with allogenous cancellous as control group. The specimen were processed with undecalcified technique and the sections were staining with light blue and sofranin T. RESULTS After 2 weeks, there were cartilage and bone formation in the defect area of osteoid callus graft group(3/4), medullary cavity formation in bone tissue with cartilage arround it, fibrous tissues between new bone and host bone. While there were no cartilage or bone formation in the control group. CONCLUSION The allograft osteoid callus is not absorbed by immunological rejection, but changed into bone tissue through endochondral osteogenesis. It is inspiring to develop osteoid callus allograft as a kind of material for bone healing.
Objective To compare the healing process and clinical results of bioactive glass and allogenic bone in the repair of bone defects after benign bone tumor curettage. Methods Between November 2011 and December 2012, 20 patients with benign bone tumor received bioactive glass and allogenic bone for repair of bone defects after benign bone tumor curettage. There were 17 males and 3 females, aged 9-68 years (median, 18.5 years). The mean course of disease was 3.3 months (range, 1-9 months). Pathological examination revealed that there were 7 cases of chondroblastoma, 5 cases of bone cyst, 2 cases of non-ossifying fibroma, 2 cases of enchondroma, 1 case of vascular tumor of bone, 1 case of lipoma of bone, 1 case of osteoid osteoma, and 1 case of chondromyxoid fibroma. The lesion located at the femur in 5 cases, at the tibia in 11 cases, at the humerus in 1 case, at the calcaneus in 2 cases, and at the talus in 1 case. The bioactive glass and allogenic cancellous bone were implanted in the cavity at the same time. The Musculoskeletal Tumor Society (MSTS) function evaluation score was used for evaluation of postoperative limb function. According to the imaging and clinical benefit, the healing processes of two kinds of implants were evaluated. The healing rate and healing time were compared. The distribution of the bioactive glass was divided into two layers: the layer close to host bone and the layer close to allogenic bone. The bone ingrowth time and bone resorption time in different layers were evaluated and compared. Results All cases were followed up 12-42 months (mean, 34.5 months). All incisions healed by first intention. There were no complications of wound infection or deep infection, rejection, nonunion of bone, fracture at bone graft site, and collapsing of articular surface. There was no tumor recurrence during follow-up. The mean MSTS functional score was 29.5 (range, 28-30) at last follow-up. Complete healing was observed in 11 cases and healing in 9 cases. The healing rates of two kinds of implants were both 100%. The healing time of bioactive glass and allogenic bone was (4.7±1.3) months and (5.2±1.6) months, respectively, showing no significant difference (t=-1.240, P=0.244). The bone ingrowth time and the bone absorption time were (3.6±0.9) months and (3.7±1.0) months in the layer close to host bone and were (4.2±1.3) months and (4.2±1.3) months in the layer close to allogenic bone, all showing no significant difference (t=1.785, P=0.097; t=1.476, P=0.172). Conclusion For the repair of bone defects after benign bone tumor curettage, bioactive glass can achieve satisfactory healing result and has good safety.
Objective To observe the effect of vascular endothelial growth factor (VEGF) in fracture healing and to investigate the influence of VEGF and VEGF antibody in fracture healing. Methods One hundred and five rabbits were used tomake fracture model in the left radius and randomly divided into control group,VEGF group and VEGF antibody group. VEGF and VEGF antibody were used in the VEGF group and VEGF antibody group respectively, then the blood flow of the fracture ends was measured by single photon emission computed tomography (SPECT) 8,24 , 72 hours, 1, 3, 5 and 8 weeks after fracture, the X-ray films of the fracture sites were taken after 1, 3, 5 and 8 weeks to observe the fracture healing. Results The blood flow of the fracture ends in the VEGF groupincreased during aperiod from 8h to 3wk after fraction when compared with that of the control group, and no obvious difference was seen on the X-ray films between the two groups. In the VEGF antibody group, the blood flow of the fracture ends decreased obviously when compared with that of the control group. The fracture healing processwas interfered seriously and nonunion change was seen in the fracture site. Conclusion The lack of VEGF will interfere with the fracture healing process and result in nonunion in the fracture site. Administration of ectogenous VEGF may promote fracture healing by increasing the blood flow of the fracture ends.
ObjectiveTo assess the effect of microfracture and biomimetic hydrogel scaffold on tendon-to-bone healing in a rabbit rotator cuff tear model.MethodsGelatin and methacrylic anhydride were used to synthesize gelatin methacryloyl (GelMA). Then the GelMA were treated with ultraviolet rays and vacuum freeze-drying method to obtain a biomimetic hydrogel scaffold. The morphology of the scaffold was observed by gross observation and scanning electron microscope. Degradation of the scaffold was determined at different time points. Twenty-four adult New Zealand rabbits, weighting 2.8-3.5 kg and male or female, were surgically created the bilateral acute rotator cuff tear models. One shoulder was treated with microfractures on the footprint and transosseous suture (control group, n=24). The other shoulder was treated with the same way, except for putting the scaffold on the footprint before transosseous suture (experimental group, n=24). The general conditions of rabbits were observed postoperatively. Tendon-to-bone healing was evaluated by gross observation, Micro-CT, HE staining, and bio-mechanical testing at 4 and 8 weeks after operation.ResultsThe scaffold was white and has a porous structure with pore size of 31.7-89.9 μm, which degraded slowly in PBS solution. The degradation rate was about 95% at 18 days. All the rabbits survived to the completion of the experiment. Micro-CT showed that there was no obvious defect and re-tear at the tendon-to-bone interface in both groups. No difference was found in bone mineral density (BMD), tissue mineral density (TMD), and bone volume/total volume (BV/TV) between the two groups at 4 and 8 weeks postoperatively (P>0.05). HE staining showed that the fibrous scar tissue was the main component at the tendon-to-bone interface in the control group at 4 and 8 weeks postoperatively; the disorderly arranged mineralized cartilage and fibrocartilage formation were observed at the tendon-to-bone interface in the experimental group at 4 weeks, and the orderly arranged cartilage formation was observed at 8 weeks. Besides, the tendon maturation scores of the experimental group were significantly higher than those of the control group at 4 and 8 weeks (P<0.05). There was no significant difference in the ultimate load to failure and stiffness between the two groups at 4 weeks (P>0.05); the ultimate load to failure at 8 weeks was significantly higher in the experiment group than in the control group (t=4.162, P=0.009), and no significant difference was found in stiffness between the two groups at 8 weeks (t=2.286, P=0.071).ConclusionCompared with microfracture alone, microfracture combined with biomimetic hydrogel scaffold can enhance tendon-to-bone healing and improve the ultimate load to failure in rabbits.
Abstract There have been many types of bone-grafting operation dealing with the congenital pseudarthrosis of the tibia (CPAT), but the failure rate is fairly high. Since 1990, 2 children with CPAT, who had received repeated bone-grafting operation in failure, were treatedaccordingto the Ilizarovs theory and its related technique. The essentials of the operation were: (1) Thorough resection of abnormal bone tissues at pseudarthrosis might freshen the ends of the bone and facilitate bone union. (2) The firm fixation and constant compression force to the bone ends might promote bone healing. (3) The tibial lengthening was performed by osteotomy at the upper tibia. The pseudarthrosis was united in 2～3 months after operation. The patients were followed up from 1 to 3 years, and it was found that the remodelling of thebone was good, no recurrence occured. The advantages were: (1) The bone grafting was no longer necessary. (2) It could give a chance to equalizethe limb length. (3) It could enable early weight bearing and functional exercise.
Objective To investigate the effect of Kartogenin (KGN) combined with adipose-derived stem cells (ADSCs) on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction in rabbits. Methods After the primary ADSCs were cultured by passaging, the 3rd generation cells were cultured with 10 μmol/L KGN solution for 72 hours. The supernatant of KGN-ADSCs was harvested and mixed with fibrin glue at a ratio of 1∶1; the 3rd generation ADSCs were mixed with fibrin glue as a control. Eighty adult New Zealand white rabbits were taken and randomly divided into 4 groups: saline group (group A), ADSCs group (group B), KGN-ADSCs group (group C), and sham-operated group (group D). After the ACL reconstruction model was prepared in groups A-C, the saline, the mixture of ADSCs and fibrin glue, and the mixture of supernatant of KGN-ADSCs and fibrin glue were injected into the tendon-bone interface and tendon gap, respectively. ACL was only exposed without other treatment in group D. The general conditions of the animals were observed after operation. At 6 and 12 weeks, the tendon-bone interface tissues and ACL specimens were taken and the tendon-bone healing was observed by HE staining, c-Jun N-terminal kinase (JNK) immunohistochemical staining, and TUNEL apoptosis assay. The fibroblasts were counted, and the positive expression rate of JNK protein and apoptosis index (AI) were measured. At the same time point, the tensile strength test was performed to measure the maximum load and the maximum tensile distance to observe the biomechanical properties. Results Twenty-eight rabbits were excluded from the study due to incision infection or death, and finally 12, 12, 12, and 16 rabbits in groups A-D were included in the study, respectively. After operation, the tendon-bone interface of groups A and B healed poorly, while group C healed well. At 6 and 12 weeks, the number of fibroblasts and positive expression rate of JNK protein in group C were significantly higher than those of groups A, B, and D (P<0.05). Compared with 6 weeks, the number of fibroblasts gradually decreased and the positive expression rate of JNK protein and AI decreased in group C at 12 weeks after operation, with significant differences (P<0.05). Biomechanical tests showed that the maximum loads at 6 and 12 weeks after operation in group C were higher than in groups A and B, but lower than those in group D, while the maximum tensile distance results were opposite, but the differences between groups were significant (P<0.05). Conclusion After ACL reconstruction, local injection of a mixture of KGN-ADSCs and fibrin glue can promote the tendon-bone healing and enhance the mechanical strength and tensile resistance of the tendon-bone interface.
To investigate the cl inical results and the mechanism of bone heal ing for the repair of bone defects following tumor resection with novel interporous TCP bone graft, and to test the hypothesis of “structural transplantation”. Methods From January 2003 to December 2005, 61 cases of various bone defects following the curettage of the benign bone tumors were treated with interporous TCP, with 33 males and 28 females, including bone fibrous dysplasiain 8 cases, bone cyst in 23 cases, eosinophil ic granuloma in 12 cases, enchondroma in 13 cases, non-ossifying fibroma in 2 cases, and osteoblastoma in 3 cases. Tumor sizes varied from 1.5 cm × 1.0 cm to 7.0 cm × 5.0 cm. The plain X-ray, single photon emission computed tomography (SPECT) and histology examination were obtained at various time points after operation. The in vivo biodegradation rate of the implanted TCP was evaluated based on a semi-quantitive radiographic analyzing method. Histopathology examination was performed in 1 revision case. Results All the patients were followed up for 5 to 24 months after operation. They all had good wound heal ing and bone regeneration. There was neither significant reverse reaction to the transplanted material nor locally inflammatory reaction in all of the cases. The bone defects were repaired gradually from 1 to 6 months after operation (bone heal ing at average 2.6 months after surgery) with a bone heal ing rate up to 96.7%. There was only 1 recurrence case (eosinophil ic granuloma in ischium) 3 months after operation. Given revision operation, this case gained bone heal ing. Radiographically, the interface between the implanted bone and host bone became fuzzy 1 month after implantation, indicating the beginning of new bone formation. Three months later, the absorption of the interporous TCP was noticed from peripheral to the center of the implanted bone evidenced by the vague or fuzzy realm. New bone formation could be seen both in peri pheral and central areas. Six months later, implanted bone and host bone merged together and the bone defect was totally repaired, with 78.9% degradation rate of the implanted TCP. Twelve months later, the majority of the implanted bone was absorbed and bone remodel ing was establ ished. In the cases that were followed up for 24 months, the function of affectedextremity was excellent with good bone remodel ing without recurrence. In 2 cases, SPECT showed that nucl ide uptake could be observed in implanted site and the metabol ic activity was high both in the central as well as the peripheral areas of the graft 1 month after implantation, which was an evidence of osteogenesis. Pathologically, the interporous TCP closely contacted the host bone inside the humerus 1 month after grafting. The interface between the implanted bone and host bone became fuzzy, and vascularized tissue began growing inside the implanted graft as a “l ining” structure. Conclusion The interporous TCP proves to be effective for cl inical reparation of bone defects following tumor resection. The inside three-dimensional porous structure simulates the natural bionic bone structure which is suitable for recruitment related cells in-growth into the scaffold, colonizing and prol iferation companied with the process of vascularize, finally with the new bone formation. The novel interporous TCP may boast both bone conductive and bone inductive activities, as an appeal ing “structural transplantation” bone graft.
ObjectiveTo investigate the effect of hamstring tendon transfected with adenovirus-mediated transforming growth factor β1 (AdTGF-β1) genes on the histomorphology of tendon-bone interface healing after anterior cruciate ligament (ACL) reconstruction in rabbits. MethodsAdTGF-β1 and AdGFP were diluted to 5×108 PFU/mL with DMEM. Forty-eight New Zealand white rabbits were divided into 3 groups randomly (n=16), weighing 1.6-2.5 kg for ACL reconstruction with hamstring tendon autograft. Hamstring tendon was cultured and transfected with AdTGF-β1 (group A) and AdGFP (group B) for 12 hours before ACL reconstruction, and was cultured with DMEM in group C. After 12 hours of transfection, the expression of green fluorescence was observed in groups A and B under fluorescence microscopy; TGF-β1 protein level was detected by ELISA in group A. At 2, 4, 8, and 12 weeks after operation, the specimens were harvested for HE and Masson staining; the number of fibroblasts was counted, and the Buark grading was used to evaluate tendon-bone interface healing. ResultsGreen fluorescence was observed after 12 hours of transfection in groups A and B. TGF-β1 protein level reached (221.0±12.2) ng/mL at 12 hours in group A. The histological observation showed that few fibroblasts and collagen fibers were found, and Sharpey fibers appeared in group A; regular Sharpey fibers were seen in the interface, and integrity interface in some areas at 12 weeks. But fibroblasts of groups B and C were less than those of group A, with loose tendon-bone interface; no integrity interface was observed at 12 weeks. The number of fibroblasts and Buark grading of group A were significantly higher than those of groups B and C (P<0.05), but no significant difference was found between groups B and C (P>0.05). ConclusionHamstring tendon transfected with AdTGF-β1 gene can promote the healing of tendon-bone interface after ACL reconstruction.
ObjectiveTo observe the effect and significance of autologous fibrin clot on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction.MethodsBetween October 2014 and January 2016, 34 patients (34 knees) with ACL injury were enrolled in the study. During ACL reconstruction, autologous fibrin clot was used in 17 cases (trial group) and was not used in 17 cases (control group). The anterior drawer test, Lachman test, and axial displa-cement test were positive in 2 groups before operation. There was no significant difference in gender, age, causes of injury, injury side, disease cause, and preoperative knee joint activity, Lysholm score, and American Hospital for Special Surgery (HSS) score between 2 groups (P>0.05), with comparable. The results of anterior drawer test, Lachman test, and axial displacement test were recorded and compared between 2 groups after operation. The knee joint activity, Lysholm score, and HSS score were used to evaluate the knee function recovery at 6, 24, and 48 weeks after operation; the graft signal intensity, graft signal to noise ratio, bone tunnel expansion, and graft tendon-bone node T2 value were measured.ResultsAll patients were followed up 48 weeks. Surgical incision healed at stage I. No joint infection and joint adhesion occurred. The drawer test, Lachman test, and axial shift test were negative in 2 groups. At 6, 24, and 48 weeks after operation, the Lysholm score of trial group was significantly higher than that of control group (P<0.05); there was no significant difference in knee joint activity between 2 groups (P>0.05). The HSS score of trial group was significantly higher than that of control group at 24 and 48 weeks (P<0.05), but no significant difference was found at 6 weeks (P>0.05). MRI measu-rement showed that there was significant difference in graft signal intensity, bone tunnel expansion, and graft signal to noise ratio between 2 groups at 6, 24, and 48 weeks after operation (P<0.05). There was no significant difference in graft tendon-bone node T2 value between 2 groups (P>0.05) at 48 weeks after operation, but difference was significant at 6 and 24 weeks (P<0.05).ConclusionAutologous fibrin clot can effectively enhance graft revascularization, and accelerate the process of tendon-bone healing after ACL reconstruction.
Objective To explore the situation of tendon-bone heal ing when allogenic tendon graft is wrapped with autologous periosteum around the tendon in rabbits. Methods Twenty healthy New Zealand white rabbits with the age of 4-5 months were used in the experiment, weighing 2.5-3.0 kg. One-side posterior l imb was selected randomly as the test, and thecontralateral l imb was served as the control at the same time. The allogenic tendon graft was designed as a tendon-bone model in the proximal tibial metaphysis of rabbits. The portion of tendon in the bone tunnel was wrapped with autologous periosteal graft in which the cambium layer was facing the bone tunnel in the experimental group, while the portion of tendon in the bone tunnel was not wrapped with autologous periosteal graft in the control group. The histologic examination of the tendon-bone interface (n=2) and the biomechanical test for maximal pullout load (n=8) were conducted 4 and 8 weeks after operation, respec tively. Results All specimens were observed with naked eyes 4 and 8 weeks after the operation. Many new bones around bone tunnel outlet were seen in the experimental group, while a few or few new bones were seen in the control group. Four weeks after operation, histological observation showed there were a lot of prol iferative mesenchymal cells in the periosteal germinal layer in the experimental group and conspicuous membrane bone formation was obvious. The arrangement of massive osteoblasts around newborn bone trabecula was similar to pal isade. The newborn bone trabecula was l inked with the periosteum. Some loose connective tissues and few newborn bones between the tendon graft and the bone tunnel were seen in the control group, and the connection of them was loose. Eight weeks after operation, the connection between the tendon graft and the bone tunnel was tight and no gap existed in the experimental group. The number of newborn bones was large and their arrangement was relatively regular. The tidemark l ine was seen between the tendon graft and the bone tunnel, which was similar to normal tendon-bone interface. The prol iferation of fibroblast was active in the periosteum, and there were many fibrous joints betweenthe periosteum and the tendon graft. Partial bone formation was seen between the tendon graft and the bone tunnel in thecontrol group, with disorderly arrangement, and there were many collagen fibrous joints between the tendon graft and the bone tunnel. Four and 8 weeks after operation, the pullout or pull and break loads of the experimental group were (35.03 ± 1.21) N/ cm and (42.36 ± 1.31) N/cm, respectively, and those of the control group were (26.14 ± 6.13) N/cm and (31.63 ± 6.87) N/ cm, respectively. There was significant difference between the two groups (P lt; 0.05). Conclusion The transplantation of autologous periosteum graft wrapping around allogenic tendon graft may shorten the time of osteochondral ossification between the tendon graft and the bone tunnel, improve heal ing strength and promote tendon-bone heal ing in the bone tunnel in rabbits.