Allogeneic Bone Research Articles

Strategies To Enhance Biocompatibility of Bone Scaffold for Tissue Engineering Applications

Tissue engineering (TE) is a modern approach to improve or restore tissues that has been diseased or damaged by combining the factors in growth signaling and appropriate cells to form compatible biomaterial scaffold. Bone repair has been a major global health challenge in recent decades. Bone transplantation is widely used as an effective clinical treatment for this purpose. However, there are several serious issues with transplantation, including a shortage of autologous bone, immune rejection, the risk of virus transmission with allogeneic bone, and postoperative complications. In recent years, scaffolds for bone tissue engineering have emerged as a promising alternative for bone repair. These scaffolds have porous structures that mimic the extracellular matrix, which can enhance the migration, proliferation, and differentiation of osteoblasts. This process accelerates the repair of bone defects.The usage of bioactive materials has become important tool in tissue engineering and regenerative medicine application as they are to mimic tissues mechanically, chemically, and physically. Polymeric scaffold provides numerous advantageous for tissue engineering since the physicochemical properties such as porosity, pore size, solubility and biocompatibility can be controlled. Therefore, research works were carried out to explore the potential of various materials in producing bone scaffolds in tissue engineering technology. As for both newcomers and experts, this review paper will help them to find information on various types of biomaterials in imparting or enhancing their biological properties such as biocompatibility, bacterial inhibition, tissue regeneration and cell growth, bio inertness, bioactive and resorbability for bone scaffold tissue engineering application.

Alloplastic bone grafts in maxillofacial surgery – An overview

Bone grafting techniques have been used by medical practitioners for over a century. A few factors that influence how successfully a grafted material is assimilated are its mechanical strength, pore size, ability to stimulate bone growth, and type of the graft. The four properties that the bone transplant material should possess are osteogenesis, osteoinduction, osteoconduction, and osteointegration. Despite being the only material with all four qualities, autologous bone has limited applications because of morbidities at the donor site. Allogeneic bone, which is taken from a different person and is commonly processed by tissue banks, is an alternative to autogenous bone. It carries a danger of spreading illness and being antigenic. Over the past few decades, the development of synthetic bone substitutes has opened up a wide range of options and opportunities to solve these limitations. In bone grafting procedures, synthetic bone replacements and biological components are quickly taking the place of natural grafts. Considerations include the patient's characteristics, the location, the extent of the lesion, and the cost and availability of the graft materials. This review has covered a variety of commonly used alloplastic materials.

Subtuberosity anterior closing wedge osteotomy to correct the increased posterior slope of the tibial plateau

Reduction of increased reclination of the tibial plateau (posterior slope) to improve the anterior stability of the knee joint. Increased posterior reclination of the tibial plateau greater than 12° in combination with recurrent instability after anterior cruciate ligament (ACL) reconstruction. Hyperextension of more than 15° (relative). Anterior skin incision approximately 8-10 cm above the tibial tuberosity. Insertion of two converging guidewires directly below the patellar tendon ending obliquely in the area of the posterior cruciate ligament (PCL) insertion. Control of the wire position with the image intensifier core. Oscillating saw osteotomy. Removal of the wedge and closure of the osteotomy. Osteosynthesis with interfragmentary screw and medial angle-stable plate. Partial load with 10-20 kg for 2 weeks, then step by step increase in load. Mobility: free. To date we have operated on 36patients with recurrent instability after ACL reconstruction (20men, 16women, average age 34.4 years) in the manner described in this article. In 25cases, enlarged bone tunnels were filled with allogeneic bone at the same time. The posterior slope of the tibial plateau could be reduced from an average of 14.5° to8.8°. In 28cases another ACL reconstruction was performed after an interval of 4-12months. The Lysholm score significantly increased from 76.3 points to 89.2 points.

Use of Circularly Polarized Light on the Evaluation of Injectable Platelet Rich Fibrin in the Early Formation of Woven and Lamellar Bone: A Specific Method in the Study of Osseous Tissue

Purpose: In bone grafting, the goal is the formation of 100% vital bone. The ideal graft material is osteogenic, osteoconductive and osteoinductive and can be evaluated by histology and histomorphometric methods to calculate percentages of vital bone formation, residual graft material and connective tissue. Bone graft substitute materials currently used include allogeneic, xenogeneic and alloplastic materials. The goal of this study is a histological evaluation of the early effects of the liquid (injectable) form of Platelet Rich Fibrin (i-PRF) on the formation of woven and lamellar bone using Circularly Polarized Light (CPL). Patients and Methods: This is a retrospective cohort study of forty-two patients from 2021 to 2022 who completed bone grafting after a non-restorable endodontically treated molar tooth was extracted in preparation for future implant surgery. Each bone graft was augmented with i-PRF. To process i-PRF, Relative Centrifugation Force (RCF) was reduced from 2,700 RPM to 700 RPM (60 g). Centrifugation time was reduced from 12 minutes to 3 minutes. After an average bone graft healing time of 8 to 12 weeks, bone core samples were obtained at the time of implant surgery for histological and histomorphometric analysis. Bone cores were stained with Stevenel’s blue and van Gieson’s picrofuchsin for histologic analysis by means of brightfield and circular polarized light microscopic evaluation to evaluate the early effects of the liquid form of PRF on formation of woven and lamellar bone using allogeneic bone. Results: Forty-two bone cores were harvested at the time of implant surgery for histological and histomorphometric analysis. The liquid form of PRF resulted in greater percentages of vital bone formation (average 87.4 %) compared to the existing published literature. CPL analysis of forty-two bone core specimens showed the positive effects of i-PRF on de novo bone formation. Conclusion: The results of this study using circularly polarized light demonstrate that the liquid form of PRF (i-PRF) resulted in greater percentages of early, new vital bone formation compared to the published literature. Circularly polarized light should be considered as an adjunctive method to determine bone maturity and structure.

Individualized surgical treatment of sarcomas of the extremities

Sarcomas of the extremities are rare entities, the treatment of which requires special expertise. Even if the treatment of patients is always interdisciplinary, the surgical R0 resection is the key point of each curatively intended treatment. In addition to resection in sano, the aim is to preserve the extremities and function, so that defect reconstruction after resection plays adecisive role. Due to the heterogeneity of tumors as well as their localization and extent, reconstruction is always an individually adapted treatment. Modular tumor endoprostheses are often used in this context, which can be constructed according to the size of the defect. The transplantation of autologous or allogeneic bone is also frequently used alone or as an additive procedure. Patient-specific (mega)prostheses are used particularly for pelvic tumors. Defect reconstruction using scaffold-based procedures from the field of tissue engineering is being tested as apromising procedure for the future. This article provides an overview of the treatment principles for sarcomas of the extremities and their individual reconstruction options.

Polydopamine-Functionalized Strontium Alginate/Hydroxyapatite Composite Microhydrogel Loaded with Vascular Endothelial Growth Factor Promotes Bone Formation and Angiogenesis.

Critical-size bone defects are a common and intractable clinical problem that typically requires filling in with surgical implants to facilitate bone regeneration. Considering the limitations of autologous bone and allogeneic bone in clinical applications, such as secondary damage or immunogenicity, injectable microhydrogels with osteogenic and angiogenic effects have received considerable attention. Herein, polydopamine (PDA)-functionalized strontium alginate/nanohydroxyapatite (Sr-Alg/nHA) composite microhydrogels loaded with vascular endothelial growth factor (VEGF) were prepared using microfluidic technology. This composite microhydrogel released strontium ions stably for at least 42 days to promote bone formation. The PDA coating can release VEGF in a controlled manner, effectively promote angiogenesis around bone defects, and provide nutritional support for new bone formation. In in vitro experiments, the composite microhydrogels had good biocompatibility. The PDA coating greatly improves cell adhesion on the composite microhydrogel and provides good controlled release of VEGF. Therefore, this composite microhydrogel effectively promotes osteogenic differentiation and vascularization. In in vivo experiments, composite microhydrogels were injected into critical-size bone defects in the skull of rats, and they were shown by microcomputed tomography and tissue sections to be effective in promoting bone regeneration. These findings demonstrated that this novel microhydrogel effectively promotes bone formation and angiogenesis at the site of bone defects.

Allogeneic versus autogenous shell technique augmentation procedures: a prospective-observational clinical trial comparing surgical time and complication rates

ObjectivesAutogenous and allogeneic blocks for shell augmentation of the jaw have shown comparable results. This observational clinical study aimed to compare both materials for shell augmentation concerning surgery time and intra- and postoperative complications.Material and methodsBone augmentation with the shell technique using autogenous or allogenous bone was performed in 117 patients with segmental jaw atrophy. The primary study parameter was the surgical time, comparing both materials. Subsequently, intra- and postoperative complications were recorded.ResultsAllogeneic (n = 60), autogenous (n = 52), or both materials (n = 5) were used. The use of allogeneic material led to a significantly shorter operation time (p < 0.001). A more experienced surgeon needed significantly less time than a less experienced surgeon (p < 0.001). An increasing number of bone shells (p < 0.001), an additional sinus floor elevation, and intraoperative complications also significantly increased the operation time (p = 0.001). Combining allogeneic and autogenous shells (p = 0.02) and simultaneous sinus floor elevation (p = 0.043) significantly impacted intraoperative complications. No correlations were found between the included variables for postoperative complications (all p > 0.05). In total, 229 implants were inserted after a healing time of 4–6 months, with a survival of 99.6% after a mean follow-up duration of 9 months.ConclusionsCompared to the autogenous technique, allogeneic shell augmentation has a shorter surgical time and a similar rate of intra- and postoperative complications as autogenous bone. Together with its promising clinical results, this technique can be recommended.Graphical

Three-dimensional digital technology-assisted precise tumor resection and reconstruction of the femoral trochanter and postoperative functional recovery: a retrospective study

BackgroundThe trochanter of the femur is a common site for bone tumors. However, locating the specific boundary of bone tumor infiltration and determining the surgical method can be challenging. The objective of this study was to review the diagnosis, treatment, and surgical outcomes of patients with tumors or tumor-like changes in the femoral trochanter after computer-assisted precise tumor resection and hip-preserving reconstruction of the trochanter. MethodsFrom January 2005 to September 2020, 11 patients with trochanteric tumors (aged: 18–53 years; six males and five females) were treated in Guangzhou First People's Hospital. The cases included aneurysmal bone cyst (n = 1), giant cell tumor of bone (n = 2), fibrous histiocytoma of bone (n = 1), endochondroma (n = 1), and fibrous dysplasia of bone (n = 6). For patients with trochanteric tumors, computed tomography and magnetic resonance imaging scanning were performed before operation to obtain two-dimensional image data of the lesion. A three-dimensional digital model of bilateral lower limbs was reconstructed by computer technology, the boundary of tumor growth was determined by computer simulation, the process of tumor resection and reconstruction was simulated, and the personalized guide template was designed. During the operation, the personalized guide plate guided the precise resection of the tumor, and the allogeneic bone was trimmed to match the shape of the bone defect. ResultsAll 11 patients underwent accurate resection of the tumor or tumor-like lesion and reconstruction of the hip. In eight cases, the lesion was confined to the trochanter, which was fixed with large segment allogeneic bone, autologous iliac bone, and proximal femoral anatomic plate. In three cases, allogeneic bone, autologous iliac bone, and femoral reconstruction nail were used to fix the tumor under the trochanter. Postoperative X-ray examination showed that the repair and reconstruction of the bone defect was effective, and callus bridging between the allogenic bone and autogenous bone was observed 6 months after operation. All patients recovered their walking function 3–6 months after operation. The duration of the follow-up period ranged from 6 months to 6 years. A patient experienced recurrence of endochondroma; pathological examination revealed chondrocytic sarcoma. The remaining 10 patients were treated with segmental resection and reconstruction. The operation time ranged 2.5–4.5 h (average: 3.2 h). Intraoperative blood loss ranged from 300 to 500 ml (average: 368 ml). The local recurrence rate was 9.1%, and the overall survival rate was 100%. The average Musculoskeletal Tumor Society score was 27 (excellent and good for eight and three patients, respectively). ConclusionsThree-dimensional computer skeleton modeling and simulation-assisted resection and reconstruction of femoral trochanteric tumor is a new surgical technique, which might markedly improve the surgical effect, shorten the surgical time, increase the overall survival rate of patients with tumors, reduce the local recurrence rate, assist in the digitization and programming of femoral trochanteric tumor surgery, and improve surgical accuracy.

Revision Anterior Cruciate Ligament Reconstruction: Current Approaches to Preoperative Planning (Systematic Review)

Background. The number of primary anterior cruciate ligament (ACL) reconstructions increases every year, which causes an increase in revision interventions due to ACL graft failure. When studying the literature, we identify many factors that together influence the outcome of revision ACL reconstruction, but are not always taken into account by surgeons.&#x0D; Aim of the review — is to perform a systematic review of studies that evaluated the outcomes of revision anterior cruciate ligament reconstructions and to identify optimal solutions to the most common problems encountered in preoperative planning.&#x0D; Methods. Information search was performed in the eLIBRARY, PubMed, and Scopus databases for the period from 2013 to 2022. Studies describing the main aspects of revision ACL reconstruction were selected for analysis. Inclusion criteria were the following: mean patient follow-up period of no less than 12 months, number of observations of no less than 10 cases. After evaluation of 898 articles, 22 articles were included in the systematic review.&#x0D; Results. Five main factors that should be taken into account in preoperative planning of revision ACL reconstruction have been identified: choice of the graft, necessity of reconstruction of the anterolateral complex, correction of tibial plateau deformity in the sagittal plane, determination of indications for one- or two-stage intervention, method of bone defect replacement in two-stage surgical treatment.&#x0D; Conclusion. The patient’s autogenous tissues should be preferred when choosing a graft. Correction of excessive anteroposterior tibial plateau inclination angle is performed only at the second revision intervention if the inclination angle exceeds 12º. Reconstruction of the anterolateral complex should be performed in young, active patients who are involved in pivot sports and in case of severe anterior instability. When determining the possibility of performing revision ACL reconstruction in one or two stages, the canal diameter is not a crucial parameter, as it is necessary to take into account the possibility of fusion of the canals from the previous surgery with the newly created ones. If the canals have correct entry points, one-stage revision reconstruction can be performed with the canal width not exceeding 10 mm and depending on the expected diameter and type of the prepared tendon graft. Bone grafting of the secondary dilated canals in two-stage intervention can be carried out using any material, but allogenous bone or synthetic grafts have certain advantages.

Efficacy of positive space acquiring membrane and antimicrobial membrane combined with granular bone substitute implantation in guiding oral bone regeneration.

Augmentation of the alveolar bone is important before oral implantation. For large bone defects, it becomes necessary to apply guided bone regeneration (GBR) materials, accompanied by filling defect sites with autologous or allogeneic bone, or bone substitutes such as acellular bone powder. In this study, we tested a granular bone substitute and GBR membrane combination therapy in treating MC3T3-E1 and L929 cells in vitro and rat calvarial and alveolar defects in vivo. The recovery conditions of bone defects were monitored by micro-CT, and 3D reconstruction of the CT images was applied to evaluate the bone augmentation semi-quantitatively. Test GBR materials could support the proliferation of MC3T3-E1 cells, poly (p-dioxanone-co-L-phenylalanine) (PDPA)-based membrane could induce apoptosis of L929 cells. Among GBR membranes applied groups, the regeneration condition of defected calvarial defects of PDPA based membrane applied group was the best and this may be caused by its excellent positive space acquiring effect. However, in a complex bacteriogenic environment, the oral bone regeneration-guided efficacy of the PDPA membrane decreased in the post-repair stage with the aggravation of infections. By contrast, the antimicrobial membrane combined with the PDPA membrane exhibited continually increasing GBR efficacy at the later stage of repair owing to its multifunctional properties, which are infection-inhibiting and positive space acquiring. Therefore, multifunctional GBR membranes are preferable for GBR in complex oral environments, and further research should be conducted to determine their efficacy in other models.

Posterior instrumented correction and fusion of adolescent idiopathic scoliosis

Balanced frontal curve correction with horizontal shoulder levels, restoration of sagittal plane and vertebral derotation with afusion length as short as possible. Curves larger than 40-50° Cobb angle; furthermore age, location, degree of rotation, and sagittal plane deviation have to be considered. Posteriorly, segmental pedicle screw instrumentation with ahigh screw density (80%) and both titanium alloy and cobalt chrome rods. Freehand screw placement under consideration of both natural and deformity-induced pedicle morphology. Correction via reduction screws or instruments. Combined correction technique with rod rotation, segmental screw approximation to the generally concave rod and segmental correction of vertebral translation. Moderate concave distraction and convex compression. If needed, final in situ bending of the rods. Schwab typeI osteotomies; in rigid curves typeII osteotomies. Fusion with local bone, allogenic bone and/or bone substitutes (i.e.,tricalcium phosphate). Intraoperative placement of athoracic epidural catheter for postoperative pain control. Neurological monitoring throughout the procedure. Mobilization on postoperative day1 with focus on pain management and nutrition. Return to school after 4weeks. Physiotherapy after 3months, cycling after 3-6months, and full sport activities after 1year. Frontal curve correction of 60-80%, sufficient sagittal plane correction. Correction of rib hump 40%. Patient satisfaction is high at 95% and long-term revision rates of < 10%.

Analysis of risk factors for non-fusion of bone graft in anterior cervical discectomy and fusion: A clinical retrospective study

BackgroundBone graft fusion is a major concern among surgeons after Anterior Cervical Discectomy and Fusion (ACDF) surgery as non-fusion may lead to further physical and drug therapies. MethodsThe related risk elements of non-fusion of bone graft in ACDF surgery were retrospectively assessed. Patients receiving ACDF operation in our hospital from January 2015 to December 2019 were retrospectively analyzed. According to the criteria, 107 study subjects were recruited with a total of 164 surgical segments. The general information of patients, bone graft materials, imaging parameters, and clinical efficacy was recorded. T-test, chi-square test and binary logistic regression evaluation were employed to explore the risk factors of bone graft nonunion. ResultsLow housefield unit (HU) value, diabetes, allogeneic bone, and hydroxyapatite (HA) artificial bone could be risk factors for bone graft fusion in ACDF surgery. Further multivariate analysis was performed and confirmed those related factors of bone graft non-fusion including low HU value (non-fusion rate: 32.53% [27/83], OR = 5.024, p = 0.025), diabetes (non-fusion rate: 53.33% [8/15], OR = 4.776, p = 0.031), allogeneic bone (18.57% [13/70], OR = 3.964, p = 0.046), and artificial bone (68.29% [28/41], OR = 50.550, p < 0.01). ConclusionBy looking at bone graft fusion, selecting autologous iliac bone is an ideal selection to avoid non-fusion of bone graft in ACDF. Diabetes was more important predictor of bone graft nonunion than low HU value. Larger sample size and longer follow-up are required to further confirm these findings in the future.

Clinical Evaluation of the Combination of rhPDGF-BB and Xenogeneic Bone Substitutes for Treatment of Severe Periodontal Intrabony Defects: A Case Series.

Growth factors are considered an important component for periodontal wound healing and a key element in the periodontal regeneration triad. Randomized controlled clinical trials have demonstrated that purified recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in combination with bone graft materials is effective in treating intrabony periodontal defects. Many clinicians are currently using rhPDGF-BB in combination with xenogeneic or allogeneic bone. Therefore, the purpose of this case series was to assess the clinical effectiveness of combining rhPDGF-BB with xenogeneic bone substitutes to treat severe intrabony periodontal defects. Three patients with challenging deep and wide intrabony defects were treated using a combination of rhPDGF-BB and xenogeneic graft matrix. Probing depth (PD) reduction, bleeding on probing (BOP), mobility reduction, and radiographic bone fill (RBF) were observed for 12 to 18 months. PD decreased from 9 mm to 4 mm, BOP was eliminated, mobility decreased, and RBF ranged from 85% to 95% over the postsurgical observation period. These results indicate that combination of rhPDGF-BB with xenogeneic bone substitutes is a safe and effective graft that leads to favorable clinical and radiographic outcomes for treating severe intrabony periodontal defects. Larger case series or randomized studies will further elucidate the clinical predictability of this treatment protocol. Int J Periodontics Restorative Dent 2023;43:193-200. doi: 1011607/prd.6313.

Simple curettage and allogeneic cancellous bone chip impaction grafting in solitary enchondroma of the short tubular bones of the hand

Enchondroma is the most common bone tumor in the hand. While standard surgical procedure is intra-lesional excision and bone grafting, there is a dispute between allogeneic bone, autogenous bone, and synthetic bone substitute grafting. Diverse adjuvant treatments have been introduced to reduce recurrence, but results are mixed with controversies. Meanwhile, whether existing descriptive classification could predict treatment outcome remains unclear. Thus, we reviewed patients with solitary enchondroma of the hand who underwent simple curettage followed by allogeneic cancellous bone chip impaction grafting. Eighty-eight patients with more than 5 years of follow-up were enrolled. Demographic data, local recurrence, and complications were reviewed. Duration of consolidation and the difference according to Takigawa classification were assessed. Range of motion (ROM), and functional scores were also evaluated. There were 51 women and 37 men, with a mean age of 37.9 years. Mean follow-up was 10.2 years. Recurrence occurred only in one patient. There was no complication. Mean postoperative total active motions of fingers and thumb were 239° and 132.9°. Mean modified Disabilities of the Arm, Shoulder, Hand score, and Musculoskeletal Tumor Society Score were 1.63, and 99.2 at the last follow-up. Consolidation, ROM, and functional scores according to Takigawa classification showed no significant differences. This study suggests that simple curettage with impaction grafting of allogeneic cancellous bone chip is a feasible method for treating solitary enchondromas involving short tubular bone of the hand with good long-term outcomes. Postoperative recurrence and complication rates were very low. Radiographic and clinical results were good regardless of the previous radiological classification.

Clinical effects of early debridement, internal fixation, and Masquelet technique for childhood chronic haematogenous osteomyelitis of long bones

BackgroundChildhood chronic haematogenous osteomyelitis (CCHOM) is a severe condition in paediatric patients. The optimal timing of debridement and the subsequent method of bone reconstruction in CCHOM patients remain controversial. The purpose of this study was to assess the treatment efficacy of Masquelet technique with early debridement and internal fixation in CCHOM of long bones.MethodsBetween January 2016 and January 2021, a total of 21 patients (18 males, 3 females) with CCHOM of long bone were included. The mean age was 10.4 years (range, 2–18 years). All cases were treated by a two-stage surgical protocol of Masquelet technique. In the first stage, aggressive debridement, sequestrectomy, and inducing membrane by bone cement spacer were performed after definite diagnosis. In the second stage, cement spacer was removed, and autologous and allogeneic bone was grafted. Internal fixation was used for the first and/or second stage depending on stability requirements. The patients’ clinical and imaging results were retrospectively analysed.ResultsThe mean follow-up was 31.7 months (range, 21–61 months). None of the patients experienced recurrence of infection. Radiographic bone union time was 4.3 months (range, 2.5–11 months). Five cases underwent re-operation due to complications such as bone resorption or refracture. By the last follow-up visit, bones had healed and all of the patients had resumed daily living and sports activities.ConclusionThe Masquelet technique with early debridement and internal fixation is a viable surgical method for the management of large long bone defects of CCHOM patients.

A modified surgical method for the treatment of ONFH: quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery

BackgroundOsteonecrosis of the femoral head (ONFH) can lead to pain and loss of function of the hip joint, which places a great burden on patients and society. Surgery is the main treatment for osteonecrosis of the femoral head, and quadratus femoris muscle pedicle bone grafting has a definite therapeutic effect as one method of surgery for the treatment of ONFH. However, the posterior superior retinacular artery is often injured during quadratus femoris muscle pedicle bone graft surgery. There is evidence that this artery is extremely important to the femoral head, as injury to this artery will seriously affect the blood supply of the femoral head. Therefore, this situation restricts the clinical application of quadratus femoris muscle pedicle bone grafts. We aimed to explore a new surgical method of quadratus femoris muscle pedicle bone grafting that can preserve the integrity of the posterior superior retinacular artery.MethodsWe modified the traditional quadratus femoris muscle pedicle bone graft and preserved the integrity of the posterior superior retinacular artery. To explore the safety and feasibility of the operation, we simulated the operation on 6 fresh frozen cadavers (12 hips) and measured the related data. We also tried this modified surgical method in the clinic and collected detailed data from the patients.ResultsBy simulating the modified quadratus femoris muscle pedicle bone graft on the hip joints of fresh frozen cadavers, we found that the posterior superior retinacular artery existed in all cadaver specimens and that the sources may be different (MFCA or IGA). In the modified operation, the joint capsule did not need to be cut during the operation; therefore, the integrity of the posterior superior retinacular artery was preserved. The quadratus femoris muscle was exposed via the posterior approach of the hip joint, and then the quadratus femoris muscle pedicle bone flap was chiseled. After the pedicle of the quadratus femoris muscle was loosened properly, the migration distance of the quadratus femoris muscle pedicle bone flap reached 5.89 ± 0.45 (χ ± s) cm. The bone flap was trimmed properly and placed on one side. Next, we drilled a bone tunnel from the external intertrochanteric aspect of the capsule of the hip joint, and the bone tunnel broke through the sclerosing zone and proceeded straight to the necrotic area of the femoral head. Next, the necrotic bone was removed with a ring saw and arc bone knife, autogenous bone or allogeneic bone was filled into the bone groove according to the situation, and the cancellous bone in the bone groove was tamped by percussion. Then, the bone flap was inserted into the bone groove, and appropriate pressurization was performed. The depth of the bone groove was determined by the location of ONFH. We found that the furthest distance between the bone groove and the femoral head was 4.76 ± 0.07 (χ ± s) cm and that the length of the bone flap was (4.91 ± 0.23) (χ ± s) cm. This means that when the depth of the bone groove reached the area of ONFH, the quadratus femoris muscle pedicle bone flap had a sufficient length and migration distance to be embedded in the area of ONFH and firmly fixed, and the quadratus femoris did not have much tension. The closest distance between the posterior superior retinacular artery and the bone groove was (1.11 ± 0.96) (χ ± s) cm. When the bone groove was created in this area, the edge of the bone groove had a safe distance of at least 1 cm from the posterior superior retinacular artery of the femoral head. We attempted to implement this modified operation clinically. During the procedure, the quadratus femoris muscle pedicle bone flap was embedded into the drilled bone groove and fixed with a magnesium nail. There was no sliding of the bone flap after the operation, and the posterior superior retinacular artery was intact. We followed the patient for 3 months and found that the patient recovered well with no weight-bearing by the affected limb. The duration of the modified operation was shorter than that of the traditional quadratus femoris muscle pedicle bone graft, the amount of bleeding was significantly reduced, the postoperative pain was lessened, and no special discomfort was reported. Postoperative imaging examination showed that the collapse of the femoral head had been partially corrected and that the bone flap had gradually fused with the surrounding bone.ConclusionsThrough this experimental study, we confirmed the feasibility of the modified method for quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery. This modified operation not only retains the integrity of the posterior superior retinacular artery of the femoral head but also reduces the difficulty of the operation and shortens the surgical time, which is of great clinical significance.

Characterization of bioactive substances involved in the induction of bone augmentation using demineralized bone sheets

PurposeTo investigate the bone augmentation ability of demineralized bone sheets mixed with allogeneic bone with protein fractions containing bioactive substances and the interaction between coexisting bioactive substances and proteins.MethodsFour types of demineralized bone sheets mixed with allogeneic bone in the presence or absence of bone proteins were created. Transplantation experiments using each demineralized bone sheet were performed in rats, and their ability to induce bone augmentation was analysed by microcomputed tomography images. Bioactive substances in bone proteins were isolated by heparin affinity chromatography and detected by the measurement of alkaline phosphatase activity in human periodontal ligament cells and dual luciferase assays. Noncollagenous proteins (NCPs) coexisting with the bioactive substances were identified by mass spectrometry, and their interaction with bioactive substances was investigated by in vitro binding experiments.ResultsDemineralized bone sheets containing bone proteins possessed the ability to induce bone augmentation. Bone proteins were isolated into five fractions by heparin affinity chromatography, and transforming growth factor-beta (TGF-β) was detected in the third fraction (Hep-c). Dentin matrix protein 1 (DMP1), matrix extracellular phosphoglycoprotein (MEPE), and biglycan (BGN) also coexisted in Hep-c, and the binding of these proteins to TGF-β increased TGF-β activity by approximately 14.7% to 32.7%.ConclusionsDemineralized bone sheets are capable of inducing bone augmentation, and this ability is mainly due to TGF-β in the bone protein mixed with the sheets. The activity of TGF-β is maintained when binding to bone NCPs such as DMP1, MEPE, and BGN in the sheets.

Comparing Bone Graft Techniques for Interbody Fusion through a Posterior Approach for Treating Mid-Thoracic Spinal Tuberculosis: A Retrospective Analysis.

Mid-thoracic spinal tuberculosis is prone to kyphotic deformities and neurologic impairment. Posterior approach can effectively restore the spinal stability by reconstructing the anterior and middle spinal columns. Titanium mesh cages (TMC), allogeneic bone (ALB), and autogenous bone (AUB) are three main bone graft struts. We aimed to compare the therapeutic efficacy of three bone graft struts, for anterior and middle column reconstruction through a posterior approach in cases of mid-thoracic spinal tuberculosis. Hundred and thirty seven patients with thoracic spinal tuberculosis who had undergone a posterior approach from June 2010 to December 2018 were enrolled. Of them, 46 patients were treated using a titanium mesh cage (TMC group), 44 with allogenic bone grafts (ALB group), and 47 using autogenous bone grafts (AUB group). The following were analyzed to evaluate clinical efficacy: visual analogue scale (VAS) values, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, kyphotic Cobb's angle, operation duration, intraoperative blood loss, improvement in American Spinal Injury Association (ASIA) grade and in the mental component summary (MCS) and physical component summary (PCS) of Short Form-36 (SF-36), duration of bone graft fusion. The data of the three groups were compared by way of variance analysis, followed by the LSD⁃t test to compare each group. A repeated measures ANOVA was used to analyze the dates of pre-, postoperative and final follow-up. The follow-up duration was at least 3 years. All patients achieved a complete cure for spinal TB. Neurological performance and quality of life were remarkably improved at the final follow-up. The intraoperative blood loss, operation time and VAS values 1 day postoperatively for TMC group and ALB group were significantly lower than those in AUB group (P < 0.05). The duration of bone graft fusion in ALB group (18.1 ± 3.7 months) was longer than that in TMC group and AUB group (9.5 ± 2.8 and 9.2 ± 1.9 months) (P < 0.05). No significant intergroup differences were observed in terms of age or preoperative, 3-months postoperative, and final follow-up indices of ESR and CRP among the three groups (P > 0.05). At the final follow-up, the correction loss was mild (2.1 ± 0.9, 2.2 ± 1.0, 2.1 ± 0.8) and Cobb's angles of the three groups were 20.1 ± 2.9, 20.5 ± 3.2, 20.9 ± 3.4, respectively, which were remarkably rectified in comparison with the preoperative measurements (P < 0.05). In terms of postoperative recovery and successful fusion rate of bone graft, it seems that posterior instrumentation, debridement, and interbody fusion with titanium mesh cages are more effective and appropriate surgical methods for mid-thoracic spinal tuberculosis.

Novel method for the treatment of congenital pseudarthrosis of the tibia using the gastrocnemius flap: A preliminary study.

Purpose:Congenital pseudarthrosis of the tibia is a rare disease that is particularly difficult to treat; the most difficult complications include nonunion of the tibia, refracture, and failed surgery. This study aimed to evaluate the efficiency of transposing gastrocnemius flaps for the treatment of congenital pseudarthrosis of the tibia.Methods:Nine patients (aged 6.2 ± 3.6 years) diagnosed with congenital pseudarthrosis of the tibia in our hospital between March 2013 and March 2018 were enrolled. The tibial pseudarthrosis and thickened periosteum were completely removed, and intramedullary nails were used to fix the tibia. Bone harvest from the iliac, mixed with allogenic bone, was filled in the gap created by excision of the pseudarthrosis site and the surrounding periosteum; the gastrocnemius flap was then used to wrap the pseudoarthrosis site. The plaster cast was fixed postoperatively. The tibial union was evaluated via radiograph, and the plaster cast was removed after 12–24 weeks. Patients began walking approximately 12–14 weeks postoperatively.Results:Anatomical reduction was achieved in all the patients; the mean bone healing time was 10.1 ± 2.1 months. Bone nonunion was observed in one patient, and no neurovascular injury or wound infection occurred. Limb length discrepancy was in the range 3.2 ± 1.8 cm at 1 year and 4.7 ± 2.7 cm at 2 years after surgery. Two patients underwent replacement of the intramedullary nail, and eight patients exhibited good functional and radiographic outcomes.Conclusion:This preliminary study proved that using the gastrocnemius muscle flap to cover the pseudarthrosis site was an effective method to promote the tibial union and treat congenital pseudarthrosis of the tibia.

Allograft Transplantation and Reconstruction of Bones after Malignant Tumor Resections.

Reconstruction surgery after the excision of musculoskeletal tumors has advanced greatly in the last few decades. After resection of a large piece of bone, limb reconstruction (when is necessary) can be easily achieved with mechanical reconstruction with metallic prosthesis, or biological reconstruction with bone. The use of bone in reconstructive orthopedic surgery is to repair skeletal defects and accelerate bone healing. Bone grafts can be used to achieve this. Those can be allografts and autografts.&#x0D; The standard in bone grafting consists of tissue harvested from the patient, autograft, usually from the iliac crest or distal femur and tibia. Allografts are taken from donors or cadavers and they serve as alternatives to autograft in bone reconstruction. In our case, the patients were treated with wide resection of the bone segment. The defect was reconstructed with intercalary bone and osteosynthesis was made with locking plates. A cadaveric graft was used. Autogenous bone is generally used as an optimal graft because it integrates faster and with fewer complications. Allogenous bone can carry the risk of viral infection for the recipient. Anyhow, allografts can serve as the only therapeutic options, besides endoprosthesis devices for large size reconstruction.