The aim of the present study was to investigate and compare the bone formation capacity with three different grafts. Four millimeter segmental defects were created in adult rat tibias and were either left empty （cont...The aim of the present study was to investigate and compare the bone formation capacity with three different grafts. Four millimeter segmental defects were created in adult rat tibias and were either left empty （control defects） or implanted with （1） nano-hydroxyapatite/collagen/PIA （nHAC/PIA） composite, （2） nHAC/ PIA composite added with bone marrow mesenchymal tem cells （ BMSCs ）, （ 3 ） nHAC/ PIA composite added with bone morphogenetic protein 2 （ BMP- 2）. Radiographs of the defects were taken weekly post-surgery. After 1 or 2 months, the rats were eathaaized. Histologic analyses were performed on the harvested tissue. nHAC/ PIA composite could enhance the repair of rat tibia segmental defects. Addition of BMSCs or BMP- 2 to nHAC/ PIA led to an increase in osteogenesis, nHAC/ PIA composite could be an Meal alternative bone-grafi material and it could also be used as an Meal carrier of BMSCs or BMP- 2.展开更多
BACKGROUND A 46-year-old male underwent ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection in 2016.However,an intraoperative stent-graft ...BACKGROUND A 46-year-old male underwent ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection in 2016.However,an intraoperative stent-graft was deployed in the false lumen inadvertently.This caused severe iatrogenic thoracic and abdominal aortic dissection,and the dissection involved many visceral arteries.CASE SUMMARY The patient had pain in the chest and back for 1 mo.A computed tomography scan showed that the patient had secondary thoracic and abdominal aortic dissection.The ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection were performed 2 years prior.An intraoperative stent-graft was deployed in the false lumen.Endovascular aneurysm repair was performed to address this intractable situation.An occluder was used to occlude the proximal end of the true lumen,and a covered stent was used to direct blood flow back to the true lumen.A three-dimensional printing technique was used in this operation to guide prefenestration.The computed tomography scan at the 1stmo after surgery showed that the thoracic and abdominal aortic dissection was repaired,with all visceral arteries remaining patent.The patient did not develop renal failure or neurological complications after surgery.CONCLUSION The total endovascular repair for false lumen stent-graft implantation was feasible and minimally invasive.Our procedures provided a new solution for stent-graft deployed in the false lumen,and other departments may be inspired by this case when they need to rescue a disastrous stent implantation.展开更多
BACKGROUND Severe horizontal bone deficiency of the maxillary anterior region is considered a major challenge in reconstruction and successful implant placement.Various approaches have been developed to augment bone v...BACKGROUND Severe horizontal bone deficiency of the maxillary anterior region is considered a major challenge in reconstruction and successful implant placement.Various approaches have been developed to augment bone volume.Of these approaches,onlay bone graft,alveolar bone splitting,and guided bone regeneration have been suggested.CASE SUMMARY A 22-year-old female patient,with no previous medical history,presented to the Department of Oral Implantology,Wuhan University due to a missing right maxillary incisor.The X-ray results showed severe horizontal bone deficiency,with an available bone width of 3.1-4.0 mm.The two bone blocks sandwich technique was performed to augment the bone volume.After 6 months healing,X-ray results showed that the newly formed alveolar ridge dimension increased to 4.7-9.5 mm horizontally.Implant insertion surgery was performed and allceramic restorations were fabricated.The implant was stable at the 1-year followup visit after restoration,and the X-ray showed a stable bone level around the dental implant.The scores for the pink esthetic score and white esthetic score were 12 and 8,respectively,and the patient was satisfied with the esthetic outcome.CONCLUSION The two bone blocks sandwich technique may be an alternative treatment option in augmenting severe horizontal bone deficiency of the anterior maxilla.展开更多
Objective:To report the clinical outcome of repairing massive bone defects biologically in limbs by homeochronous using structural bone allografts with intramedullary vascularized fibular autografts. Methods: From Jan...Objective:To report the clinical outcome of repairing massive bone defects biologically in limbs by homeochronous using structural bone allografts with intramedullary vascularized fibular autografts. Methods: From January 2001 to December 2005, large bone defects in 19 patients (11 men and 8 women, aged 6 to 35 years) were repaired by structural bone allografts with intramedullary vascularized fibular autografts in the homeochronous period. The range of the length of bone defects was 11 to 25 cm (mean 17.6 cm), length of vascularized free fibular was 15 to 29 cm (mean 19.2 cm), length of massive bone allografts was 11 to 24 cm (mean 17.1 cm). Location of massive bone defects was in humerus(n=1), in femur(n=9) and in tibia(n=9), respectively. Results: After 9 to 69 months (mean 38.2 months) follow-up, wounds of donor and recipient sites were healed inⅠstage, monitoring-flaps were alive, eject reaction of massive bone allografts were slight, no complications in donor limbs. Fifteen patients had the evidence of radiographic union 3 to 6 months after surgery, 3 cases united 8 months later, and the remained one case of malignant synovioma in distal femur recurred and amputated the leg 2.5 months, postoperatively. Five patients had been removed internal fixation, complete bone unions were found one year postoperatively. None of massive bone allografts were absorbed or collapsed at last follow-up. Conclusion: The homeochronous usage of structural bone allograft with an intramedullary vascularized fibular autograft can biologically obtain a structure with the immediate mechanical strength of the allograft, a potential result of revascularization through the vascularized fibula, and accelerate bone union not only between fibular autograft and the host but also between massive bone allograft and the host.展开更多
AIM:To investigate the osseointegration process of titanium implant and non-vascularized iliac bone grafts.METHODS:12 mongrel were divided into 4 groups randomly.Bone grafts were resected from iliac crest and then tra...AIM:To investigate the osseointegration process of titanium implant and non-vascularized iliac bone grafts.METHODS:12 mongrel were divided into 4 groups randomly.Bone grafts were resected from iliac crest and then transplanted to the other side.Animals were skilled in different time after surgery,X-ray pictures were taken,then histological observation were done.RESULTS:At 3rd week,bone grafts dissolved,resorbed or necrosis partly;At 6th week,new bone began to regenerated;At 9th week,the amount of new bone increased;At 12nd week,bone interface around implant formed,without soft tissue interrupt.CONCLUSION:Osseointegration can formed between non-vascularized iliac bone grafts and titanium implant.展开更多
BACKGROUND Leiomyosacromas in the Extremities are rare malignant smooth muscle tumors.Adjuvant radiation therapy, in combination with wide surgical excision allows the best chance of treatment. During the follow up pa...BACKGROUND Leiomyosacromas in the Extremities are rare malignant smooth muscle tumors.Adjuvant radiation therapy, in combination with wide surgical excision allows the best chance of treatment. During the follow up pathological fractures are common complications that can be accompanied by Implant failure and defect situations that are most challenging in their management.CASE SUMMARY We present a case of a 52-year-old female suffering from a pathological fracture of the humeral shaft 10 yr after resection of a Leiomyosarcoma and postoperative radiotherapy. She developed implant failure after retrograde nailing and another failure after revision to double plate fixation. In a two-stage revision, the implants were removed and the huge segmental defect created after debridement was bridged by a compound osteosynthesis with nancy nails and bone cement for formation of the induced membrane. Due to the previous radiotherapy treatment,20 cm of the humeral shaft were declared devascularized but were left in situ as a scaffold. In the second stage, a vascularized fibula graft was used in combination with a double plate fixation and autologous spongiosa grafts for final reconstruction.CONCLUSION This combinatory treatment approach led to a successful clinical outcome and can be considered in similar challenging cases.展开更多
Endovascular aneurysm repair is a new and minimally invasive repair for patients with abdominal aortic aneurysm (AAA). However, endotension is one of the post-operative compliances of endo-vascular aneurysm repair in ...Endovascular aneurysm repair is a new and minimally invasive repair for patients with abdominal aortic aneurysm (AAA). However, endotension is one of the post-operative compliances of endo-vascular aneurysm repair in abdominal aortic aneurysm. Typically, endotension is mainly a result of pressure transmitted to the aneurysm sac through endovascular implanted graft (EVG) by intermediary of the stagnant blood filled aneurysm cavity. Focusing on a representative AAA with an EVG, a fluid-structure interaction (FSI) solver has been employed to provide physical insight for evaluating the blood flow dynamics, maximum AAA-stresses and deformations. Although implanting an EVG can reduce the sac pressure, mechanical stress and wall deformation in AAAs significantly, they remain non-zero. These magnitudes depend on multi-factors including blood flow conditions such as velocity and pressure, as well as EVG and aneurysm geometries. In this study, it was found that blood flow velocity deceleration occurs on the graft due to the curvature of its neck, so greater curvature of the graft neck can contribute to vortex formation in this area and exert load on the graft wall. In the iliac bifurcation region, divaricating of the flow leads to a large net flow momentum change. It results in additional stress on the implant graft and may lead to graft migration. One of the peak wall stress points is in the neck region where the stent-graft is in contact with the aneurysm wall. This necessitates considering adequate graft fixation to withstand the stresses of blood flow through the implanted graft. Also, maximum deformation of sac wall occurs in around the large diameter of the sac, and deformation during the systole phase is higher than that during the diastole phase.展开更多
Tissue engineering aims to offer large-scale replacement of damaged organs using implants with the com-bination of cells,growth factors and scaffolds.However,the intra/peri-implant region is exposed to se-vere hypoxic...Tissue engineering aims to offer large-scale replacement of damaged organs using implants with the com-bination of cells,growth factors and scaffolds.However,the intra/peri-implant region is exposed to se-vere hypoxic stress and oxidative stress during the early stage of implantation with bone graft materials,which endangers the survival,proliferation and differentiation of seed cells within the implants as well as the host cells surrounding the implants.If the bone graft material could spontaneously and intelligently regulate the hypoxic stress and oxidative stress to a moderate level,it will facilitate the vascularization of the implants and the rapid regeneration of the bone tissue.In this review,we will first introduce the signaling pathways of cellular response under hypoxic stress and oxidative stress,then present the clas-sical material designs and examples in response to hypoxic stress and oxidative stress.And finally,we will address the important role of epigenetic mechanisms in the regulation of hypoxic stress and oxida-tive stress and describe the potential applications and prospective smart bone graft materials based on novel epigenetic factors against hypoxic stress and oxidative stress in bone repair.The main content of this review is summarized in the following graphical abstract.展开更多
文摘The aim of the present study was to investigate and compare the bone formation capacity with three different grafts. Four millimeter segmental defects were created in adult rat tibias and were either left empty （control defects） or implanted with （1） nano-hydroxyapatite/collagen/PIA （nHAC/PIA） composite, （2） nHAC/ PIA composite added with bone marrow mesenchymal tem cells （ BMSCs ）, （ 3 ） nHAC/ PIA composite added with bone morphogenetic protein 2 （ BMP- 2）. Radiographs of the defects were taken weekly post-surgery. After 1 or 2 months, the rats were eathaaized. Histologic analyses were performed on the harvested tissue. nHAC/ PIA composite could enhance the repair of rat tibia segmental defects. Addition of BMSCs or BMP- 2 to nHAC/ PIA led to an increase in osteogenesis, nHAC/ PIA composite could be an Meal alternative bone-grafi material and it could also be used as an Meal carrier of BMSCs or BMP- 2.
基金Supported by National Natural Science Foundation of China,No.81600375
文摘BACKGROUND A 46-year-old male underwent ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection in 2016.However,an intraoperative stent-graft was deployed in the false lumen inadvertently.This caused severe iatrogenic thoracic and abdominal aortic dissection,and the dissection involved many visceral arteries.CASE SUMMARY The patient had pain in the chest and back for 1 mo.A computed tomography scan showed that the patient had secondary thoracic and abdominal aortic dissection.The ascending aortic replacement,total arch replacement,and descending aortic stent implantation for Stanford type A aortic dissection were performed 2 years prior.An intraoperative stent-graft was deployed in the false lumen.Endovascular aneurysm repair was performed to address this intractable situation.An occluder was used to occlude the proximal end of the true lumen,and a covered stent was used to direct blood flow back to the true lumen.A three-dimensional printing technique was used in this operation to guide prefenestration.The computed tomography scan at the 1stmo after surgery showed that the thoracic and abdominal aortic dissection was repaired,with all visceral arteries remaining patent.The patient did not develop renal failure or neurological complications after surgery.CONCLUSION The total endovascular repair for false lumen stent-graft implantation was feasible and minimally invasive.Our procedures provided a new solution for stent-graft deployed in the false lumen,and other departments may be inspired by this case when they need to rescue a disastrous stent implantation.
文摘BACKGROUND Severe horizontal bone deficiency of the maxillary anterior region is considered a major challenge in reconstruction and successful implant placement.Various approaches have been developed to augment bone volume.Of these approaches,onlay bone graft,alveolar bone splitting,and guided bone regeneration have been suggested.CASE SUMMARY A 22-year-old female patient,with no previous medical history,presented to the Department of Oral Implantology,Wuhan University due to a missing right maxillary incisor.The X-ray results showed severe horizontal bone deficiency,with an available bone width of 3.1-4.0 mm.The two bone blocks sandwich technique was performed to augment the bone volume.After 6 months healing,X-ray results showed that the newly formed alveolar ridge dimension increased to 4.7-9.5 mm horizontally.Implant insertion surgery was performed and allceramic restorations were fabricated.The implant was stable at the 1-year followup visit after restoration,and the X-ray showed a stable bone level around the dental implant.The scores for the pink esthetic score and white esthetic score were 12 and 8,respectively,and the patient was satisfied with the esthetic outcome.CONCLUSION The two bone blocks sandwich technique may be an alternative treatment option in augmenting severe horizontal bone deficiency of the anterior maxilla.
文摘Objective:To report the clinical outcome of repairing massive bone defects biologically in limbs by homeochronous using structural bone allografts with intramedullary vascularized fibular autografts. Methods: From January 2001 to December 2005, large bone defects in 19 patients (11 men and 8 women, aged 6 to 35 years) were repaired by structural bone allografts with intramedullary vascularized fibular autografts in the homeochronous period. The range of the length of bone defects was 11 to 25 cm (mean 17.6 cm), length of vascularized free fibular was 15 to 29 cm (mean 19.2 cm), length of massive bone allografts was 11 to 24 cm (mean 17.1 cm). Location of massive bone defects was in humerus(n=1), in femur(n=9) and in tibia(n=9), respectively. Results: After 9 to 69 months (mean 38.2 months) follow-up, wounds of donor and recipient sites were healed inⅠstage, monitoring-flaps were alive, eject reaction of massive bone allografts were slight, no complications in donor limbs. Fifteen patients had the evidence of radiographic union 3 to 6 months after surgery, 3 cases united 8 months later, and the remained one case of malignant synovioma in distal femur recurred and amputated the leg 2.5 months, postoperatively. Five patients had been removed internal fixation, complete bone unions were found one year postoperatively. None of massive bone allografts were absorbed or collapsed at last follow-up. Conclusion: The homeochronous usage of structural bone allograft with an intramedullary vascularized fibular autograft can biologically obtain a structure with the immediate mechanical strength of the allograft, a potential result of revascularization through the vascularized fibula, and accelerate bone union not only between fibular autograft and the host but also between massive bone allograft and the host.
基金Supported by "Ninth Five"Tackle Key Problems Topic of General Rear-servine Department of PLA(No.96Z049)
文摘AIM:To investigate the osseointegration process of titanium implant and non-vascularized iliac bone grafts.METHODS:12 mongrel were divided into 4 groups randomly.Bone grafts were resected from iliac crest and then transplanted to the other side.Animals were skilled in different time after surgery,X-ray pictures were taken,then histological observation were done.RESULTS:At 3rd week,bone grafts dissolved,resorbed or necrosis partly;At 6th week,new bone began to regenerated;At 9th week,the amount of new bone increased;At 12nd week,bone interface around implant formed,without soft tissue interrupt.CONCLUSION:Osseointegration can formed between non-vascularized iliac bone grafts and titanium implant.
文摘BACKGROUND Leiomyosacromas in the Extremities are rare malignant smooth muscle tumors.Adjuvant radiation therapy, in combination with wide surgical excision allows the best chance of treatment. During the follow up pathological fractures are common complications that can be accompanied by Implant failure and defect situations that are most challenging in their management.CASE SUMMARY We present a case of a 52-year-old female suffering from a pathological fracture of the humeral shaft 10 yr after resection of a Leiomyosarcoma and postoperative radiotherapy. She developed implant failure after retrograde nailing and another failure after revision to double plate fixation. In a two-stage revision, the implants were removed and the huge segmental defect created after debridement was bridged by a compound osteosynthesis with nancy nails and bone cement for formation of the induced membrane. Due to the previous radiotherapy treatment,20 cm of the humeral shaft were declared devascularized but were left in situ as a scaffold. In the second stage, a vascularized fibula graft was used in combination with a double plate fixation and autologous spongiosa grafts for final reconstruction.CONCLUSION This combinatory treatment approach led to a successful clinical outcome and can be considered in similar challenging cases.
文摘Endovascular aneurysm repair is a new and minimally invasive repair for patients with abdominal aortic aneurysm (AAA). However, endotension is one of the post-operative compliances of endo-vascular aneurysm repair in abdominal aortic aneurysm. Typically, endotension is mainly a result of pressure transmitted to the aneurysm sac through endovascular implanted graft (EVG) by intermediary of the stagnant blood filled aneurysm cavity. Focusing on a representative AAA with an EVG, a fluid-structure interaction (FSI) solver has been employed to provide physical insight for evaluating the blood flow dynamics, maximum AAA-stresses and deformations. Although implanting an EVG can reduce the sac pressure, mechanical stress and wall deformation in AAAs significantly, they remain non-zero. These magnitudes depend on multi-factors including blood flow conditions such as velocity and pressure, as well as EVG and aneurysm geometries. In this study, it was found that blood flow velocity deceleration occurs on the graft due to the curvature of its neck, so greater curvature of the graft neck can contribute to vortex formation in this area and exert load on the graft wall. In the iliac bifurcation region, divaricating of the flow leads to a large net flow momentum change. It results in additional stress on the implant graft and may lead to graft migration. One of the peak wall stress points is in the neck region where the stent-graft is in contact with the aneurysm wall. This necessitates considering adequate graft fixation to withstand the stresses of blood flow through the implanted graft. Also, maximum deformation of sac wall occurs in around the large diameter of the sac, and deformation during the systole phase is higher than that during the diastole phase.
基金financially supported by the National Nat-ural Science Foundation of China(Nos.32071341,82202741,52003302,31430030,51973021,32201111,and 52202358)the Chinese Postdoctoral Science Foundation(Nos.2021M703710 and 2021M691464)+1 种基金the Guangdong Basic and Applied Basic Re-search Foundation(Nos.2021A1515111040,2019A1515110841 and 2019A1515011935)the Beijing Municipal Health Commis-sion(Nos.BMHC-20216 and PXM 2020_026275_000002)。
文摘Tissue engineering aims to offer large-scale replacement of damaged organs using implants with the com-bination of cells,growth factors and scaffolds.However,the intra/peri-implant region is exposed to se-vere hypoxic stress and oxidative stress during the early stage of implantation with bone graft materials,which endangers the survival,proliferation and differentiation of seed cells within the implants as well as the host cells surrounding the implants.If the bone graft material could spontaneously and intelligently regulate the hypoxic stress and oxidative stress to a moderate level,it will facilitate the vascularization of the implants and the rapid regeneration of the bone tissue.In this review,we will first introduce the signaling pathways of cellular response under hypoxic stress and oxidative stress,then present the clas-sical material designs and examples in response to hypoxic stress and oxidative stress.And finally,we will address the important role of epigenetic mechanisms in the regulation of hypoxic stress and oxida-tive stress and describe the potential applications and prospective smart bone graft materials based on novel epigenetic factors against hypoxic stress and oxidative stress in bone repair.The main content of this review is summarized in the following graphical abstract.
