Objective To investigate the effect of tissue engineering bone compounded in vitro by nanohydroxyapatite/collagen/ polylactic acid (nHAC/PLA) and recombinant human bone morphogenetic protein 2 (rhBMP-2) in repairing rabbit critical calvarial defects. Methods Forty eight New Zealand rabbits, weighting 2.0-2.5 kg, were made the models of critical cranial defects(15 mm in diameter) and divided into 4 groups randomly. Defects were repaired with autoflank bone in the positive control group; with no implant in the blank control group; with nHAC/PLA in the negative control; and with active nHAC/PLA(AnHAC/PLA) in the experimental group(the average quality of each AnHAC/PLA absorbed rhBMP-2 was 1.431 mg). The reapir results were observed through X-ray,HE dyeing and Masson’s trichrism dyeing after 8 and 16 weeks. Results The difference of bone formation was observed by X-ray block degree of skull defect area at 8 and 16 weeks. In the 8 th week and 16 th week, the radiopacities on cranial defect were 67.21%±2.06% and 86.48%±1.73% in the positive control group； 5.84%±1.92% and 9.48%±2.72% in the blank control group; 19.13%±2.51% and 35.67%±3.28% in the negative control group; and 58.84%±2.55% and 8561%±3.36% in the experimental group. There were significant differences between the negative control and the positive control group, and between the experimental group and the positive control group at 8 weeks(Plt;0.05) . There were significant differences between the negative control and blank group, and between the experiment and the blank group at 8 and 16 weeks(P＜0.05). The histology observation showed that the width of bone trabecula at 16 weeks was more than that at 8 weeks and bone defectwas full of bone tissue in positive control group. The bone defect was full of fibrous tissue at 8 and 16 weeks, and there was no new bone in the blank group. The bone defect was full of remnant material and fibrous tissue in the negative control group. The implanted area was replaced by the new bone at 8 weeks and the new bone was lamellar at 16 weeks in the experimental group; the residual material was less in defect area and there were more osteoblasts surrounding. Conclusion The nHAC/PLA is a good scaffoldmaterial of rhBMP-2 and AnHAC/PLA has agood ability in repairing bone defect. So it is hopeful to be applied in the clnical repair of large bone defect.
It is very difficult to repair large articular cartilage defect of the hip. From May 1990 to April 1994, 47 hips in 42 patients of large articuler cartilage defects were repaired by allograft of skull periosteum. Among them, 14 cases, whose femoral heads were grade. IV necrosis, were given deep iliac circumflex artery pedicled iliac bone graft simultaneously. The skull periosteum had been treated by low tempreturel (-40 degrees C) before and kept in Nitrogen (-196 degrees C) till use. During the operation, the skull periosteum was sutured tightly to the femoral head and sticked to the accetabulum by medical ZT glue. Thirty eight hips in 34 patients were followed up for 2-6 years with an average of 3.4 years. According to the hip postoperative criteria of Wu Zhi-kang, 25 cases were excellent, 5 cases very good, 3 cases good and 1 case fair. The mean score increased from 6.4 before operation to 15.8 after operation. The results showed, in compare with autograft of periosteum for biological resurface of large articular defect, this method is free of donor-site morbidity. Skull periosteum allograft was effective for the treatment of large articular cartilage defects in hip.
Craniofacial malformation caused by premature fusion of cranial suture of infants has a serious impact on their growth. The purpose of skull remodeling surgery for infants with craniosynostosis is to expand the skull and allow the brain to grow properly. There are no standardized treatments for skull remodeling surgery at the present, and the postoperative effect can be hardly assessed reasonably. Children with sagittal craniosynostosis were selected as the research objects. By analyzing the morphological characteristics of the patients, the point cloud registration of the skull distortion region with the ideal skull model was performed, and a plan of skull cutting and remodeling surgery was generated. A finite element model of the infant skull was used to predict the growth trend after remodeling surgery. Finally, an experimental study of surgery simulation was carried out with a child with a typical sagittal craniosynostosis. The evaluation results showed that the repositioning and stitching of bone plates effectively improved the morphology of the abnormal parts of the skull and had a normal growth trend. The child’s preoperative cephalic index was 65.31%, and became 71.50% after 9 months’ growth simulation. The simulation of the skull remodeling provides a reference for surgical plan design. The skull remodeling approach significantly improves postoperative effect, and it could be extended to the generation of cutting and remodeling plans and postoperative evaluations for treatment on other types of craniosynostosis.
In order to repair cartilage defect in joint with transplantation of cryopreserved homologous embryonic periosteum, 30 rabbits were used and divided into two groups. A 4 mm x 7 mm whole thickness cartilage defect was made in the patellar groove of femur of each rabbit. The homologous embryonic rabbit skull periosteum (ERSP), preserved in two-step freezing schedule, was transplanted onto the cartilage defect of joints of one group and autogenous periosteal graft was done in the joint defect of the other group. The knees were not immobilized, following operation and 16 weeks later, the newly formed tissue in the defects were assessed by gross observation, histochemical examination and biochemical analysis. The results showed that new hyaline-like cartilage was formed in the cryopreserved ERSP grafted knee, and had no significant difference from that of the knee receiving autogenous periosteal graft, but had significant difference from that of the fresh ERSP grafted knee and the non-grafted knee. Furthermore, the new hyaline-like cartilage had the biochemical characteristics of a fibrous cartilage. The conclusion was that this method might be feasible to repair articular cartilage defects.
Cranial defects may result from clinical brain tumor surgery or accidental trauma. The defect skulls require hand-designed skull implants to repair. The edge of the skull implant needs to be accurately matched to the boundary of the skull wound with various defects. For the manual design of cranial implants, it is time-consuming and technically demanding, and the accuracy is low. Therefore, an informer residual attention U-Net (IRA-Unet) for the automatic design of three-dimensional (3D) skull implants was proposed in this paper. Informer was applied from the field of natural language processing to the field of computer vision for attention extraction. Informer attention can extract attention and make the model focus more on the location of the skull defect. Informer attention can also reduce the computation and parameter count from N2 to log(N). Furthermore,the informer residual attention is constructed. The informer attention and the residual are combined and placed in the position of the model close to the output layer. Thus, the model can select and synthesize the global receptive field and local information to improve the model accuracy and speed up the model convergence. In this paper, the open data set of the AutoImplant 2020 was used for training and testing, and the effects of direct and indirect acquisition of skull implants on the results were compared and analyzed in the experimental part. The experimental results show that the performance of the model is robust on the test set of 110 cases fromAutoImplant 2020. The Dice coefficient and Hausdorff distance are 0.940 4 and 3.686 6, respectively. The proposed model reduces the resources required to run the model while maintaining the accuracy of the cranial implant shape, and effectively assists the surgeon in automating the design of efficient cranial repair, thereby improving the quality of the patient’s postoperative recovery.
摘要:目的:进行深低温贮存回植自体颅骨瓣的临床应用效果研究。方法:将74例患者术后骨瓣深低温(零下80℃)贮存,2～12月后予以原位回植,术中取骨标本病检,随诊1～36月。结果:74例中72例伤口Ⅰ期愈合,颅骨复位良好。病检示回植骨有正常骨细胞,与新鲜颅骨对照无骨母细胞。2例患者回植骨吸收明显,失去支撑作用而再次行修补钛网,2例感染,余下70例患者2～4月后骨缝不同程度增宽1～2 mm,6月后骨缝不再增宽,12～36月后骨缝部分变窄,达骨性愈合,而颅骨钻孔处及颞下骨缝较宽区未见骨性结构,为纤维疤痕愈合。结论:深低温贮存的自体颅骨部分骨细胞能长时间存活,回植后无免疫排异性。回植手术简便,患者容易接受,临床应用效果较好。
Objective To summarize the treatment of chronic osteomyel itis of the skull and its effectiveness. Methods Between January 2004 and February 2009, 24 patients with chronic osteomyel itis of skull were diagnosed and treated, including 16 males and 8 females with an average age of 45.6 years (range, 18-56 years). The mean disease duration was 5.8 years (range, 3-11 years). The causes included infection after craniotomy in 3 cases, burn in 15 cases, and electrical injury in 6 cases, and the leision was located at the frontal and parietal of the skull in 10 cases, at the temporal and parietal of skull in 8 cases, and at the occipital of the skull in 6 cases. The soft tissue defects ranged from 7 cm × 6 cm to 19 cm × 12 cm, and the skull defects ranged from 5 cm × 4 cm to 10 cm × 7 cm. After wide thorough debridement of necrotic tissue, soft tissue defects were repaired with adjacent scalp flap in 12 cases, trapezius myocutaneous flap in 6 cases, and free anterolateral thigh flap in 6 cases; the flap size ranged from 8 cm × 7cm to 20 cm × 13 cm. The donor sites were sutured directly or covered with spl itthickness skin. Results All pathological examinations showed pyogenic osteomyel itis of the skull, and local ized squamous carcinoma was found in 1 case. One patient had sub-flap infection at 2 weeks after operation, and heal ing was achieved after surgical removal of residual tissue; the remaining flaps survived, and incision healed by first intention. All patients were followed up 10 months to 4 years with an average of 2 years after operation. The color and texture of the flaps were good. No recurrence of osteomyel itis happened during follow-up. The patient diagnosed as having local ized squamous carcinoma was followed up 4 years without recurrence. At 3 to 6 months after operation, 8 patients had headache or felt dizzy, and the skull was reconstructed by the titanium meshes. Conclusion In patients with chronic osteomyel itis of skull, the infected foci should be cleaned out thoroughly as early as possible, and the skin flap or myocutaneous flap is used to repair the wounds, thus the good results can be achieved.
ObjectiveTo evaluate the physical and chemical properties, immunogenicity, and osteogenesis of two antigen-extracted xenogeneic bone scaffolds—decalcified bone matrix (DBM) and calcined bone.MethodsBy removing the inorganic and organic components of adult pig femus, xenogeneic DBM and calcined bone were prepared respectively. The density and pH value of the two materials were measured and calculated, the material morphology and pore diameter were observed by scanning electron microscope, and the surface contact angle was measured by automatic contact angle measuring instrument. The safety, osteogenic activity, and immunogenicity of the two materials were evaluated by cytotoxicity test, osteoblast proliferation test, DNA residue test, and human peripheral blood lymphocyte proliferation test. The two materials were implanted into the 5 mm full-thickness skull defect of 6-week-old male Sprague Dawley rats (the blank control group was not implanted with materials). The materials were taken at 4 and 8 weeks after operation, the repair effect of the materials on the rat skull was observed and evaluated by gross observation, Micro-CT scanning, and HE staining observation.ResultsCompared with calcined bone, DBM has lower density and poor hydrophilicity; the pH value of the two materials was 5.5-6.1, and the pore diameter was 160-800 μm. The two materials were non-cytotoxic and could promote the proliferation of osteoblasts. The absorbance (A) values of osteoblast proliferation at 1, 4, and 7 days in the DBM group were significantly higher than those in the calcined bone group (P<0.05). The DNA residues of the two materials were much lower than 50 ng/mg dry weight, and neither of them could stimulate the proliferation and differentiation of human peripheral blood lymphocytes. The results of animal experiments in vivo showed that the bone volume/total volume (BV/TV) in DBM group and calcined bone group were significantly higher than that in blank control group at 4 weeks after operation (P<0.05), and that in calcined bone group was significantly higher than that in DBM group (P<0.05); at 8 weeks after operation, there was no significant difference in BV/TV between groups (P>0.05). HE staining showed that at 4 and 8 weeks after operation, the defect in the blank control group was filled with fibrous connective tissue, the defect was obvious, and no bone growth was found; the defect in DBM group and calcined bone group had been repaired to varying degrees, and a large number of new bone formation could be seen. The material degradability of DBM group was better than that of calcined bone group.ConclusionThe physical and chemical properties and degradability of the two kinds of xenogeneic bone scaffolds were slightly different, both of them have no immunogenicity and can promote the repair and reconstruction of skull defects in rats.