Criteria, Challenges, and Opportunities for Acellularized Allogeneic/Xenogeneic Bone Grafts in Bone Repairing.

As bone grafts become more commonly needed by patients and as donors become scarcer, acellularized bone grafts (ABGs) are becoming more popular for restorative purposes. While autogeneic grafts are reliable as a gold standard, allogeneic and xenogeneic ABGs have been shown to be of particular interest due to the limited availability of autogeneic resources and reduced patient well-being in long-term surgeries. Because of the complete similarity of their structures with native bone, excellent mechanical properties, high biocompatibility, and similarities of biological behaviors (osteoinductive and osteoconductive) with local bones, successful outcomes of allogeneic and xenogeneic ABGs in both in vitro and in vivo research have raised hopes of repairing patients' bone injuries in clinical applications. However, clinical trials have been delayed due to a lack of standardized protocols pertaining to acellularization, cell seeding, maintenance, and diversity of ABG evaluation criteria. This study sought to uncover these factors by exploring the bone structures, ossification properties of ABGs, sources, benefits, and challenges of acellularization approaches (physical, chemical, and enzymatic), cell loading, and type of cells used and effects of each of the above items on the regenerative technologies. To gain a perspective on the repair and commercialization of products before implementing new research activities, this study describes the differences between ABGs created by various techniques and methods applied to them. With a comprehensive understanding of ABG behavior, future research focused on treating bone defects could provide a better way to combine the treatment approaches needed to treat bone defects.

Variability in the reported surgical techniques and methods for intercalary reconstruction following tumor resection.

INTRODUCTION: There is currently no consensus regarding the best techniques or surgical strategies with which to maximize intercalary allograft reconstruction outcomes. The purpose of the current study was to assess which techniques and methods are being utilized by North American orthopaedic oncologists. METHODS: Members of the Musculoskeletal Tumor Society (MSTS) were invited to complete an anonymous online questionnaire. The survey presented participants with two clinical scenarios and interrogated them on their preferred type of allograft, method of compression and fixation, and additional techniques used. RESULTS: One hundred and twenty-six physicians completed the questionnaire. The majority studied in the United States (82%) and worked at an academic medical center (71%). Over half (54%) reported seeing over 10 primary bone tumors every year. Respondents were split between preferring a structural allograft alone or using a combined allograft-vascularized fibular graft. A majority indicated a preference for plate(s) and screw fixation but were divided between the use of two compression plates with a spanning plate, a single compression plate with a spanning plate, and two compression plates with an intramedullary nail. Screw fixation preferences were split between the use of unicortical locking only, bicortical locking only, and a combination of unicortical and bicortical locking. Almost equal percentages of respondents reported they would have used two, three, or four screws in both scenarios. Respondents were split between placing screws equidistantly and placing them peripherally within the allograft, adjacent to the allograft-host junction. DISCUSSION: There is no clear surgical preference for intercalary reconstruction following tumor extirpation within this sample of orthopaedic oncologists. The current survey demonstrates variability across nearly every aspect of allograft reconstruction, which may, in part, explain the wide spectrum of outcomes reported within the literature. Prospective studies are warranted to better evaluate technique-specific outcomes in an effort to maximize reconstructive longevity and minimize allograft related complications.

Load Sharing and Endplate Pressure Distribution in Anterior Interbody Fusion Influenced by Graft Choice.

BACKGROUND: Cage subsidence is a known complication of spinal fusion. Various aspects of cage design have been investigated for their influence on cage subsidence, whereas the potential contribution of graft material to load sharing is often overlooked. We aimed to determine whether graft in the aperture affects endplate pressure distribution. METHODS: The pressure distributions of a polyetheretherketone interbody cage with 3 different aperture graft conditions were evaluated: empty, demineralized bone matrix, and supercritical CO2-treated allograft bone crunch (SCCO2). RESULTS: Graft materials contributed as much as half the load transmission for SCCO2, whereas demineralized bone matrix contributed one third. Endplate areas in contact with the cage demonstrated decreased areas within the highest-pressure spectrum with SCCO2 graft materials compared with empty cages. CONCLUSIONS: Graft choice plays a role in reducing peak endplate pressures. This finding is relevant to implant subsidence, as well as graft loading and remodeling.

Evaluation of a cell-based osteogenic formulation compliant with good manufacturing practice for use in tissue engineering.

Proper bony tissue regeneration requires mechanical stabilization, an osteogenic biological activity and appropriate scaffolds. The latter two elements can be combined in a hydrogel format for effective delivery, so it can readily adapt to the architecture of the defect. We evaluated a Good Manufacturing Practice-compliant formulation composed of bone marrow-derived mesenchymal stromal cells in combination with bone particles (Ø = 0.25 to 1 µm) and fibrin, which can be readily translated into the clinical setting for the treatment of bone defects, as an alternative to bone tissue autografts. Remarkably, cells survived with unaltered phenotype (CD73+, CD90+, CD105+, CD31-, CD45-) and retained their osteogenic capacity up to 48 h after being combined with hydrogel and bone particles, thus demonstrating the stability of their identity and potency. Moreover, in a subchronic toxicity in vivo study, no toxicity was observed upon subcutaneous administration in athymic mice and signs of osteogenesis and vascularization were detected 2 months after administration. The preclinical data gathered in the present work, in compliance with current quality and regulatory requirements, demonstrated the feasibility of formulating an osteogenic cell-based tissue engineering product with a defined profile including identity, purity and potency (in vitro and in vivo), and the stability of these attributes, which complements the preclinical package required prior to move towards its use of prior to its clinical use.

Demographics and Distal Tibial Dimensions of Suitable Distal Tibial Allografts for Glenoid Reconstruction.

PURPOSE: To evaluate whether characteristics such as age, height, weight, sex, or body mass index affected the distal tibial dimensions and radius of curvature (ROC) of a potential donor for anterior glenoid augmentation. METHODS: A retrospective review of magnetic resonance imaging of ankles without bony trauma was performed, and the anteroposterior (AP) and medial-lateral (ML) distances and ROC of the tibial plafond articular surface were measured. Demographic characteristics, including age, sex, height, weight, and body mass index, were recorded. RESULTS: A total of 141 imaging studies were included (73 men and 68 women; average age, 38.2 ± 12.65 years). All potential specimens accommodated harvest of a 10 × 22-mm distal tibial allograft bone block. Men had greater ML (42.74 cm [95% confidence interval (CI), 42.09-43.39 cm] vs 38.01 cm [95% CI, 37.30-38.72 cm]; P < .001) and AP (38.16 cm [95% CI, 37.47-38.85 cm] vs 34.57 cm [95% CI, 33.97-35.17 cm]; P < .001) dimensions. Significant moderately positive correlations were found for AP dimensions with height (r = 0.584, P < .001) and weight (r = 0.383, P < .001) and for ML dimensions with height (r = 0.711, P < .001) and weight (r = 0.467, P < .001). ROC was positively correlated with height (r = 0.509, P < .001) and weight (r = 0.294, P < .001). Patient age was not related to either the AP or ML distal tibial dimensions or ROC. CONCLUSIONS: After magnetic resonance imaging analysis, all potential donors permitted harvest of a standard-sized distal tibial allograft irrespective of sex or common anthropometric measures, and 85.8% showed distal tibial morphology acceptable for glenoid augmentation. AP and ML graft dimensions and ROC correlated significantly with height and weight. LEVEL OF EVIDENCE: Level II, diagnostic study.

[Accuracy Verification of Robot-assisted Mandibular Reconstruction Surgery].

Mandible is an important bone of the head and neck. Mandibular defects not only affect patient's face, but also impede patient's daily functions, such as chewing, speech, and so on. Fibular transplantation for mandibular reconstruction is the common method, which requests high accuracy of bone positioning and posture adjustment. Therefore, a robotic system for mandibular reconstruction surgery with fibula flaps was designed to assist surgeons to hold and locate bones, and the model comparison experiments were conducted. The results showed that the robotic system can assist surgeons for mandibular reconstruction to improve quality of surgery.

Comparison of curettage and bone grafting combined with elastic intramedullary nailing vs curettage and bone grafting in the treatment of long bone cysts in children.

To compare the efficacy of curettage and bone grafting combined with elastic intramedullary nailing (EIN) vs curettage and bone grafting in the treatment of long bone cysts in children and to clarify the necessity of using EIN in the treatment of bone cysts.Sixty-two patients were involved in this study from Jan. 2009 to Sept. 2017 (43 males, 19 females; 27 humeri, 35 femurs); the patients were assigned to an EIN group, comprising 30 patients who underwent curettage and bone grafting combined with EIN, or to a non-elastic intramedullary nailing (NEIN) group, comprising 32 patients who underwent curettage and bone grafting alone. The prognosis of the 2 groups was assessed with reference to the standard of Capanna.No statistically significant differences in sex, age, location, activity, pathological fracture, cyst volume, operative time and intraoperative blood loss were found between the 2 groups (P > .05). The effective rate was 90.0% in the EIN group and 68.8% in the NEIN group, and the difference was statistically significant (P < .05).Compared to simple curettage and bone grafting, curettage and bone grafting combined with EIN treatment can significantly improve the prognosis of children with bone cysts. It is recommended that EIN be added to bone cyst curettage and bone grafting.

Successful management of lower limb nonunion using locking plates and bone graft with retention of intramedullary nail.

This study aims to investigate the clinical effect of the combined an additional locking plate with bone graft based on retaining the original intramedullary nail for the treatment of lower limb nonunion.From June 2008 to December 2012, 39 patients were admitted and treated, who developed non-infectious bone nonunion after intramedullary nail fixation for long bone fracture in the lower limb. Additional locking plate and autogenous iliac bone grafting were performed for these patients, in which the original intramedullary nail was retained. Follow-ups were performed once at postoperative months 1, 2, 3, 6, and 12, and every year onwards. During these follow-ups, imaging and clinical function examinations were performed, in order to observe callus growth and the fractured limb functions.All patients have been followed-up, in which the duration of these follow-ups ranged between 8 and 24 months. All patients gained bony union within 6 to 11 months, and the healing rate was 100%. Radiographic healing time ranged between 8 and 15 months. Full weight-bearing time ranged between 2 and 10 months. According to Harris hip scores and Hospital for Special Surgery (HSS) Knee joint scores, 17 cases were excellent, 2 cases were good, and 1 case was acceptable; with an excellent and good rate of 95.00%. According to HHS score for the knee, 15 cases were excellent, 3 cases were good, and 1 case was acceptable; with an excellent and good rate of 94.74%.The combined treatment of the additional blocking plate with bone grafting based on retaining the original intramedullary nail for bone nonunion could effectively eliminate lateral and rotatory instability of the fractured ends. This surgical method had a short operation time, high healing rate and other advantages.

Comparison of synthetic bone graft ABM/P-15 and allograft on uninstrumented posterior lumbar spine fusion in sheep.

BACKGROUND: Spinal fusion is a commonly used procedure in spinal surgery. To ensure stable fusion, bone graft materials are used. ABM/P-15 (commercial name i-Factor™ Flex) is an available synthetic bone graft material that has CE approval in Europe. This peptide has been shown to improve bone formation when used in devices with fixation or on bone defects. However, the lack of external stability and large graft size make posterolateral lumbar fusion (PLF) a most challenging grafting procedure. This prospective randomized study was designed to evaluate early spinal fusion rates using an anorganic bovine-derived hydroxyapatite matrix (ABM) combined with a synthetic 15 amino acid sequence (P-15)-ABM/P-15 bone graft, and compared with allograft in an uninstrumented PLF model in sheep. The objective of this study was to assess fusion rates when using ABM/P-15 in uninstrumented posterolateral fusion in sheep. METHODS: Twelve Texas/Gotland mixed breed sheep underwent open PLF at 2 levels L2/L3 and L4/L5 without fixation instruments. The levels were randomized so that sheep received an ABM graft either with or without P15 coating. Sheep were euthanized after 4.5 months and levels were harvested and evaluated with a micro-CT scanner and qualitative histology. Fusion rates were assessed by 2D sections and 3D reconstruction images and fusion was defined as intertransverse bridging. RESULTS: There was 68% fusion rate in the allograft group and an extensive migration of graft material was noticed with a fusion rate of just 37% in the ABM/P-15 group. Qualitative histology showed positive osteointegration of the material and good correlation to scanning results. CONCLUSIONS: In this PLF fusion model, ABM/P15 demonstrated the ability to migrate when lacking external stability. Due to this migration, reported fusion rates were significantly lower than in the allograft group. The use of ABM/P15 as i-Factor™ Flex may be limited to devices with fixation and bone defects.

Evaluation of long-term functional donor-site morbidity after deep circumflex iliac crest artery bone flap harvest.

PURPOSE: Free flap surgery can be associated with donor-site morbidity. The purpose of this study was to analyze long-term functional outcomes at the donor site after deep circumflex iliac artery (DCIA) bone flap harvesting. METHODS: Fourteen patients (8 men and 6 women, mean age 53.9 years; range 22-87 years) with mandible resection (8 carcinomas, 4 ameloblastomas, 1 osteonecrosis, and 1 myxofibroma) and DCIA flap reconstruction were included in an observational study. Ranges of motion in the hip and lumbar spine, Harris hip score (HHS), jumping mechanography, chair rising, and balance testing were performed on a ground force reaction plate (Leonardo Mechanograph, Novotec Medical GmbH, Germany). The primary outcome was the Esslinger fitness index (EFI, maximum peak power in W/kg normalized to age and gender). RESULTS: Functional assessment was performed preoperatively and 29.0 months postoperatively (range 12-51 months). Mean DCIA flap length was 6.3 cm (range 3.3-10.1 cm). Jaw reconstruction was successful in all cases. HHS (99.2 vs. 97.7 points, P = .004) and all ranges of motion in the lumbar spine and hip joint except for dorsal extension were significantly reduced postoperatively (range -4° to -11.0°). There was no significant difference between pre- and postoperative EFI (77.9% vs. 74.28%, P = .591) and body sway (1.25 cm2 vs. 2.01 cm2 , P = .806). Sensory deficits (n = 5), load dependent pain (n = 3), and limitations of daily activities (n = 3) were subjective complaints. CONCLUSION: Functional donor site morbidity after DCIA harvesting can be expected to be low in the long-term.

Back to Basics: Autologous Tissue: 1.5 www.aornjournal.org/content/cme.

Perioperative personnel manage autologous tissue when they care for patients undergoing procedures requiring the use of bone, soft tissue, or other autologous tissue to repair or replace defects. Use of autologous tissue can minimize the risk of rejection, disease transfer, and infection compared with the use of artificial materials. There are important steps to follow when handling autologous tissue to ensure it is safe for replantation and does not become contaminated. This Back to Basics article provides strategies for managing some types of autologous tissue, including bone flaps, parathyroid tissue, skin grafts, and veins. Tissue management strategies include creating strict documentation policies, standardizing processes and communication, and implementing routine audits to assess compliance.

Bone augmentation using autogenous bone versus biomaterial in the posterior region of atrophic mandibles: A systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to answer the PICO question: "Do patients who have received bone grafts with bone substitute (biomaterials) present bone gain (before implant installation), complications, and implant survival rates similar to autogenous grafts when used in the posterior mandible region?". DATA: This review followed the PRISMA statement and has been registered at PROSPERO (CRD42016048471). Studies published in English, randomized controlled and/or prospective clinical trials with at least 10 patients, and studies that compared grafts with bone substitutes to autogenous bone grafts (split-mouth design) were included. SOURCES: An electronic search and a manual search were conducted in PubMed/MEDLINE, Scopus, and Cochrane databases up to April 2018. STUDY SELECTION: Our initial search yielded 640 articles; we selected four articles that met the inclusion criteria. All selected studies used a split-mouth design. RESULTS: Our analysis revealed no significant difference between the biomaterial and autogenous groups in terms of bone gain (P = 0.11; mean difference [MD]: 0.59; 95% confidence interval [CI]: -0.13-1.31) or complication rate (P = 0.72; risk ratio [RR]: 1.25; 95% CI: 0.37-4.23). Sixty-six implants were installed in the biomaterial group and 63 in the autogenous group; these showed no significant difference in implant survival rate (P = 0.50; RR: 1.57; 95% CI: 0.43-5.81). CONCLUSION: We conclude that biomaterials or autogenous bone are indicated for the reconstruction of the posterior mandibular atrophic region, without lowering implant survival.

A posterior versus anterior debridement in combination with bone graft and internal fixation for lumbar and thoracic tuberculosis.

BACKGROUND: Surgery treatment is usually required for spinal tuberculosis. The aim of this study was to compare the clinical efficacy and outcomes of anterior and posterior surgical approach in combination with debridement, bone grafting, and internal fixation. METHODS: All patients with thoracic and lumbar tuberculosis who underwent either the anterior or posterior surgery in combination with debridement, bone grafting, and internal fixation from August 2009 to August 2016 were reviewed retrospectively. RESULTS: A total of 186 patients were recruited in the analyses, 37 of whom received the anterior approach and 149 treated with the posterior approach. In the entire study population, there was no statistically significant difference between the groups in terms of kyphosis Cobb's angle, VAS pain score, neurological status, operation duration, perioperative blood loss, and hospitalization days (p > 0.05). Good clinical outcomes were achieved in both treatment groups. In lumbar vertebra-affected patients, the average preoperative kyphosis Cobb's angle was 8.7 ± 16.6° and - 5.6 ± 16.0° for the anterior and posterior groups, respectively, which were corrected to - 3.3 ± 13.2° and - 10.1 ± 13.8° after surgery. For thoracic vertebra-affected patients, the corrected kyphosis Cobb's angle was 8.1 ± 9.7° and 10.3 ± 6.5°, respectively. After surgery, 32.4% of patients in the anterior group and 48.3% of patients in the posterior group claimed no pain (p = 0.24), while 83.8 and 85.9% recovered to Frankel grade E, respectively (p = 0.85). CONCLUSIONS: The posterior debridement joint bone graft and internal fixation is an alternative procedure to treat lumbar and thoracic tuberculosis compared to the traditional anterior approach with similar clinical efficacy in terms of pain control, Cobb's angle, and neurological function. The posterior approach is sufficient for lesion debridement.

Intraoperative culture positive allograft bone and subsequent postoperative infections: a retrospective review.

BACKGROUND: Obtaining intraoperative cultures of allograft bone just before use in orthopedic procedures is standard practice in many centres; however, the association between positive cultures and subsequent surgical infections is unknown. Our study had 3 goals: to determine the prevalence of positive intraoperative allograft culture and subsequent infection; to determine if, in cases of subsequent infection, organisms isolated at reoperation were the same as those cultured from the allograft at the time of the index procedure; and to assess the costs associated with performing intraoperative allograft cultures. METHODS: In this retrospective case series, we obtained data on patients receiving allograft bone between 2009 and 2012. Patients receiving allograft with positive cultures were reviewed to identify cases of significant infection. Organisms isolated at reoperation were compared with the allograft culture taken at the time of implantation, and we performed a cost assessment. RESULTS: Of the 996 allograft bone grafts used, 43 (4.3%) had positive intraoperative cultures and significant postoperative infections developed in 2, requiring reoperation. Antibiotics based on culture results were prescribed in 24% of cases. Organisms cultured at the time of reoperation differed from those isolated initially. The cost of performing 996 allograft cultures was $169 320. CONCLUSION: This series suggests that rates of positive intraoperative bone allograft culture are low, and subsequent infection is rare. In cases of postoperative infection, primary allograft culture and secondary tissue cultures isolated different organisms. Costs associated with performing cultures are high. Eliminating initial culture testing could save $42 500 per year in our health region.

CONTEXTE: L'obtention de cultures d'allogreffes osseuses peropératoires juste avant une intervention orthopédique est une pratique standard dans de nombreux centres. Or, on ignore s'il y a un lien entre des résultats de cultures positifs et les infections chirurgicales subséquentes. Notre étude avait 3 objectifs : déterminer la prévalence des cultures d'allogreffes peropératoires positives et des infections subséquentes; déterminer si, dans les cas d'infections subséquentes, les agents pathogènes isolés lors d'une réintervention étaient les mêmes que dans les spécimens prélevés sur les allogreffes au moment des interventions initiales; évaluer les coûts associés à l'obtention des cultures d'allogreffes peropératoires. MÉTHODES: Dans cette série de cas rétrospectifs, nous avons réuni des données sur des patients receveurs d'allogreffes osseuses entre 2009 et 2012. Nous avons passé en revue les cas d'allogreffes dont les résultats de culture étaient positifs pour recenser ceux qui étaient porteurs d'une infection significative. Nous avons comparé les agents pathogènes isolés lors de la réintervention à ceux de la culture de l'allogreffe effectuée lors de l'implantation, et nous avons procédé à une évaluation des coûts. RÉSULTATS: Parmi les 996 allogreffes osseuses effectuées, 43 (4,3 %) avaient des résultats positifs aux cultures peropératoires; des infections postopératoires significatives se sont déclarées dans 2 de ces cas et ont nécessité une réintervention. Des antibiotiques ont été prescrits en fonction des résultats des cultures dans 24 % des cas. Les agents pathogènes isolés en culture au moment de la réintervention étaient différents de ceux qui avaient été initialement isolés. Le coût des 996 cultures d'allogreffes s'est élevé à 169 320 $. CONCLUSION: Cette série donne à penser que les taux de résultats de cultures d'allogreffes osseuses peropératoires positifs sont bas et que les infections subséquentes sont rares. Dans les cas d'infections postopératoires, les cultures des allogreffes primaires et les cultures tissulaires secondaires ont révélé la présence d'organismes pathogènes différents. Les coûts associés à la réalisation des cultures sont élevés. Éliminer les cultures initiales permettrait à notre région de santé d'économiser 42 500 $ par année.

[Treatment of Osteochondral Lesions in the Ankle: A Guideline from the Group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU)]. / Behandlung osteochondraler Läsionen des Sprunggelenks: Empfehlungen der Arbeitsgemeinschaft Klinische Geweberegeneration der DGOU.

Background: Osteochondral lesions (OCL) of the ankle are a common cause of ankle pain. Although the precise pathophysiology has not been fully elucidated, it can be assumed that a variety of factors are responsible, mainly including traumatic events such as ankle sprains. Advances in arthroscopy and imaging techniques, in particular magnetic resonance imaging (MRI), have improved the possibilities for the diagnosis of OCLs of the ankle. Moreover, these technologies aim at developing new classification systems and modern treatment strategies. Material and Methods: This article is a review of the literature. Recommendations of the group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU) for the treatment of OCLs of the ankle are presented. The review gives a concise overview on the results of clinical studies and discusses advantages and disadvantages of different treatment strategies. Results: Non-operative treatment shows good results for selected indications in children and adolescents, especially in early stages of osteochondritis dissecans (OCD). However, surgical treatment is usually indicated in OCLs in adolescents and adults, depending on the size and location of the lesion. Various arthroscopic and open procedures are frequently employed, including reattachment of the fragment, local debridement of the lesion with fragment removal and curettage of the lesion, bone marrow-stimulation by microfracture or microdrilling (antegrade or retrograde), and autologous matrix-induced chondrogenesis (AMIC®) - with or without reconstruction of a subchondral bone defect or cyst by autologous cancellous bone grafting. Isolated subchondral cysts with an intact cartilage surface can be treated by retrograde drilling and possibly additional retrograde bone grafting. For larger defects or as salvage procedure, osteochondral cylinder transplantation (OATS® or Mosaicplasty®) or matrix-induced autologous chondrocyte transplantation (MACT) are recommended. Transplantation of so-called (osteochondral) mega grafts, such as autologous bone grafts or allografts, are used for very large osteochondral defects that cannot be reconstructed otherwise. Implantation of the so-called "small metal implants" - such as HemiCAP Talus® - is reserved for selected cases after failed primary reconstruction. Corrective osteotomies are indicated in accompanying axial malalignments. Conclusions: There are several different treatment strategies for OCLs, but clinical studies are rare and evidence is limited. Therefore, interventional studies, e.g. randomised controlled trials (RCTs), but also observational studies, e.g. based on data of the Cartilage Registry of the German Society of Orthopaedics and Traumatology (www.knorpelregister-dgou.de), are needed and are recommended by the authors.

Enxerto ósseo em bloco autógeno na maxila: relato de caso clínico / Autogenous block bone graft in the upper jaw: report of case

A instalação de implantes em áreas com perda óssea pode estar associada a uma relação coroa-implante desfavorável, resultado estético insatisfatório e dificuldades de higienização, prejudicando o prognóstico do tratamento. O enxerto ósseo possibilita a instalação de implantes em uma posição tridimensional favorável. Alguns métodos têm sido estudados e propostos para a reconstrução do osso alveolar perdido: enxertos ósseos autógenos, homógenos, substitutos ósseos alógenos, xenógenos e aloplásticos. Ainda existe a regeneração óssea guiada, distração osteogênica, fatores de crescimento e as combinações destas referidas metodologias. Dentre os materiais disponíveis, o osso autógeno é tido como primeira opção para a reconstrução óssea,tido como padrão ouro em enxertia óssea, pois fornece as condições mais favoráveis de reparo pós-cirúrgico, por apresentar as propriedades de osteocondução, osteoindução e osteogênese,auxiliando na correção de defeitos de espessura, desde que haja um bom suprimento vascular no local. Neste trabalho é demonstrada uma técnica de enxertia óssea em bloco autógeno, através da realização de um caso clínico, para a reconstrução de maxila atrófica, visando o aumento do volume ósseo disponível para a instalação de implantes dentais.

The installation of implants in areas of bone loss may be associated with an unfavorable ratiocrown-implant, unsatisfactory aesthetic result and cleaning difficulties, impairing treatment prognosis. The bone graft allows the installation of implants in a favorable three-dimensional position. Some methods have been studied and proposed for the reconstruction of lost alveolar bone: autogenous bone grafts, homogeneous bone, allogenic, xenogenous and alloplasticbone substitutes. There is still the guided bone regeneration, distraction osteogenesis, growth factors and combinations of these referred methodologies. Among the materials available, the autogenous bone is considered as the first option for bone reconstruction, considered the gold standard in bone grafting because it provides the most favorable conditions for post-surgical repair, presenting the properties of osteoconductive, osteoinductive and osteogenesis, helping the correction of the defects of thickness, since there is a good blood supply in the area. Thiswork shows a bone grafting technique in autogenous block by performing a case for the reconstruction of atrophic maxilla, in order to increase bone volume available for the installation of dental implants.

The Autoclaving of Autologous Bone is a Risk Factor for Surgical Site Infection After Cranioplasty.

BACKGROUND: This retrospective study was designed to evaluate the effectiveness of autoclaving for the prevention of surgical site infection (SSI) after cranioplasty. METHODS: Patients who underwent cranioplasty with autologous bone were enrolled. SSI was defined as an infection requiring bone flap removal. Risk factors of SSI, as reported by other researchers, and microbiologic features of SSI were analyzed. All bone flaps were preserved in a deep freezer (-70°C). Autoclaving of the preserved autologous bone flap before cranioplasty was performed for 5 minutes at 135°C in the 26 patients. RESULTS: Eighty patients were enrolled. The mean age was 53.3 years and the male/female ratio was 3:2. Causes of craniectomy included trauma (n = 37) and nontrauma (n = 43). The mean time interval between craniectomy and cranioplasty was 49.7 days. The SSI rate after cranioplasty with autologous bone was 17.5% (n = 14). In univariate analysis, the cranioplasty operation time (P = 0.09) and the use of autoclaved bone (P = 0.00) were supposed to be risk factors for SSI. The use of autoclaved autologous bone was found to be the only risk factor of SSI (P = 0.01; hazard ratio = 8.88) in binary logistic regression analysis. Non-methicillin-resistant Staphylococcus aureus (MRSA) causes were more frequent in the autoclaved group (MRSA, 30%; non-MRSA, 70%) compared with the nonautoclaved group (MRSA, 100%) (P = 0.07). A microscopic examination showed that autoclaving after long-term cryopreservation may result in a loss of bone viability. CONCLUSIONS: Autoclaving of autologous bone causes SSI after cranioplasty and it seems to increase the risk of non-MRSA infection by normal skin flora.

Efficacy of i-Factor Bone Graft versus Autograft in Anterior Cervical Discectomy and Fusion: Results of the Prospective, Randomized, Single-blinded Food and Drug Administration Investigational Device Exemption Study.

STUDY DESIGN: A prospective, randomized, controlled, parallel, single-blinded noninferiority multicenter pivotal FDA IDE trial. OBJECTIVE: The objective of this study was to investigate efficacy and safety of i-Factor Bone Graft (i-Factor) compared with local autograft in single-level anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy. SUMMARY OF BACKGROUND DATA: i-Factor is a composite bone substitute material consisting of the P-15 synthetic collagen fragment adsorbed onto anorganic bone mineral and suspended in an inert biocompatible hydrogel carrier. P-15 has demonstrated bone healing efficacy in dental, orthopedic, and nonhuman applications. METHODS: Patients randomly received either autograft (N = 154) or i-Factor (N = 165) in a cortical ring allograft. Study success was defined as noninferiority in fusion, Neck Disability Index (NDI), and Neurological Success endpoints, and similar adverse events profile at 12 months. RESULTS: At 12 months (follow-up rate 87%), both i-Factor and autograft subjects demonstrated a high fusion rate (88.97% and 85.82%, respectively, noninferiority P = 0.0004), significant improvements in NDI (28.75 and 27.40, respectively, noninferiority P < 0.0001), and high Neurological Success rate (93.71% and 93.01%, respectively, noninferiority P < 0.0001). There was no difference in the rate of adverse events (83.64% and 82.47% in the i-Factor and autograft groups, respectively, P = 0.8814). Overall success rate consisting of fusion, NDI, Neurological Success and Safety Success was higher in i-Factor subjects than in autograft subjects (68.75% and 56.94%, respectively, P = 0.0382). Improvements in VAS pain and SF-36v2 scores were clinically relevant and similar between the groups. A high proportion of patients reported good or excellent Odom outcomes (81.4% in both groups). CONCLUSION: i-Factor has met all four FDA mandated noninferiority success criteria and has demonstrated safety and efficacy in single-level ACDF for cervical radiculopathy. i-Factor and autograft groups demonstrated significant postsurgical improvement and high fusion rates. LEVEL OF EVIDENCE: 1.

The need for structural allograft biomechanical guidelines.

Because of their osteoconductive properties, structural bone allografts retain a theoretic advantage in biologic performance compared with artificial interbody fusion devices and endoprostheses. Current regulations have addressed the risks of disease transmission and tissue contamination, but comparatively few guidelines exist regarding donor eligibility and bone processing issues with a potential effect on the mechanical integrity of structural allograft bone. The lack of guidelines appears to have led to variation among allograft providers in terms of processing and donor screening regarding issues with recognized mechanical effects. Given the relative lack of data on which to base reasonable screening standards, a basic biomechanical evaluation was performed on one source of structural bone allograft, the femoral ring. Of the tested parameters, the minimum and maximum cortical wall thicknesses of femoral ring allograft were most strongly correlated with the axial compressive load to failure of the graft, suggesting that cortical wall thickness may be a useful screening tool for compressive resistance expected from fresh cortical bone allograft. Development of further biomechanical and clinical data to direct standard development appears warranted.

A retrospective study on annual evaluation of radiation processing for frozen bone allografts complying to quality system requirements.

Bone allografts have been used widely to fill up essential void in orthopaedic surgeries. The benefit of using allografts to replace and reconstruct musculoskeletal injuries, fractures or disease has obtained overwhelming acceptance from orthopaedic surgeons worldwide. However, bacterial infection and disease transmission through bone allograft transplantation have always been a significant issue. Sterilization by radiation is an effective method to eliminate unwanted microorganisms thus assist in preventing life threatening allograft associated infections. Femoral heads procured from living donors and long bones (femur and tibia) procured from cadaveric donors were sterilized at 25 kGy in compliance with international standard ISO 11137. According to quality requirements, all records of bone banking were evaluated annually. This retrospective study was carried out on annual evaluation of radiation records from 1998 until 2012. The minimum doses absorbed by the bones were ranging from 25.3 to 38.2 kGy while the absorbed maximum doses were from 25.4 to 42.3 kGy. All the bones supplied by our UMMC Bone Bank were sterile at the required minimum dose of 25 kGy. Our analysis on dose variation showed that the dose uniformity ratios in 37 irradiated boxes of 31 radiation batches were in the range of 1.003-1.251, which indicated the doses were well distributed.