Reconstruction of isolated mandibular bone defects with non-vascularized corticocancellous bone autograft and graft viability

Evidence-Based Medicine for Ballistic Maxillofacial Trauma

Ballistic trauma is a serious health issue with significant costs to physical, psychosocial, economic, and societal well-being. It may be caused from firearms, explosive devices, or any other projectile forces, and is characterized by severe tissue loss and evolving tissue devitalization. This review covers mechanism, diagnosis, and management of ballistic maxillofacial trauma, specifically. Initial evaluation includes stabilization of airway, bleeding, and circulation, followed by assessment of other injuries. The overall degree of tissue damage is determined by intrinsic patient factors and extrinsic projectile factors. Management of ballistic injuries has shifted toward advocation for early operative repair with the advent of antibiotics and advanced techniques in maxillofacial reconstruction. Appropriate timing and method of reconstruction should be carefully selected on a case-by-case basis. While ballistic trauma research is limited to studies biased by institutional practices, areas for further study identified from current literature include guidelines directing timing of reconstructive surgery; thresholds for free tissue transfer; handling of retained projectiles; incidence of surgical complications; and clinical outcomes for computer-aided surgical repair of these highly destructive injuries.

An Analysis of the Viability of Nonvascular Iliac and Fibula Grafts in Mandibular Reconstruction in Patients with Circulatory Diseases: A Prospective Randomized Study

Vascularized bone grafts are considered as the gold standard for mandibular reconstruction. However, there are certain limitations of them, such as they are contraindicated in patients with circulatory disturbances. Therefore, Non-vascular bone grafts become the viable option for reconstruction. Our study aims to prospectively compare the long-term viability of avascular iliac and fibula bone grafts in the reconstruction of mandibular defects. Objectives were to evaluate the difficulty in swallowing, mastication, speech problems, infection, wound dehiscence, restricted limb movement, and altered gait among the iliac and fibula group. A total of 14 patients, planned for the reconstruction of mandibular defects from 2016 to 2018 were randomly allocated into two groups; nonvascular iliac and fibula graft groups. Clinical assessment for improvement in function, esthetics, wound healing, pain, and donor site morbidity was done and was followed up for one year. Digital orthopantomogram was taken for radiographic evaluation for up to one year. Difficulty in swallowing, mastication, speech, infection, restricted limb movement, and altered gait was statistically significant and was seen more in the fibula group. Wound dehiscence with graft exposure was found in one subject. The overall success rate was 100% in the iliac group and 85.7% in the fibula group. Considering the long-term complications and success rate, the nonvascular iliac graft was found to be superior and can be used as an alternative to a nonvascular fibula graft for a defect length up to 7 cm.

Utilization of non-vascularized bone graft with regional flap as an alternative for facial reconstruction

Mandibular resections decision is one of the most important steps in oral cavity malignant or nonmalignant lesions associated with the mandible. The role of mandibular reconstruction is not only for cosmesis, but it is also indicated for functional rehabilitation such as swallowing, phonetics, and for facial symmetrical. Even though the free tissue transfer is considered a gold standard for mandibular reconstruction, the importance of nonvascularized bone grafts (NVBGs) such as fibula, calvarium, rib, sternum, and iliac are still persisting in mandibulectomies condition like patient who have not taken radiotherapy or not willing to undergo radiotherapy or not fit for free tissue transfer and provides a good contour of mandibular replacement. The success rate of NVBG depends upon patient selection, preoperative planning, and meticulous nursing care. Addition to NVBG, regional flaps such as pectoralis major myocutaneous (PMMC) flap will help in soft-tissue replacement of the defect as well as it will help in the situation where primary closure and airtight closure is not possible. This case report will discuss in detail about the management of anterior segmental mandibulectomy due to oncological resection and reconstruction with NVBG with fibula and PMMC.

Use of anterior ramus bone graft for mandibular reconstruction in elderly patients

In this study, we investigated the feasibility of using a geometrically designed anterior ramus graft to reconstruct lateral mandibular defects. This was achieved by assessing the anatomical dimensions of the mandibular ramus on computed-tomographies. The design sequence and application of the graft was also demonstrated using one of our cases. The following dimensions were measured; a and b - horizontal length from mid-ramus to the posterior and anterior ramus border respectively, c - longest length of the graft, Mp - width at the centre of the ramus, h - vertical length of the angle at its cross-section, w - horizontal length of the angle at its cross-section, x - cross-sectional area along the mandible angle. A total of 80 mandibular rami were examined. The mean length of a, b, c were 17.3 ± 1.8 mm, 15.9 ± 1.2 mm, 54.6 ± 3.8 mm, respectively. The mean width of Mp was 9.8 ± 1.1 mm. The mean cross section area of Eo-Md (x) was 326.7 ± 67.8 mm². The average length of h and w were 26.5 ± 3.2 and 15.6 ± 2.1 mm, respectively. The use of virtual surgical planning (VSP) to geometrically design the graft was also described. Together with VSP, the anterior ramus bone graft will allow for reconstruction of the mandible with greater surgical efficiency, reduced complexity and without the need for extra-oral bone harvest. This may be an useful alternative in situations where simpler reconstructive procedures are preferred.

Salvage mandibular reconstruction: multi-institutional analysis of 17 patients

Unsuccessful mandibular reconstruction occasionally occurs, leaving the patient with undesirable function and contours. In such cases, second- or third-time corrective operations are challenging. However, published studies on the complicated retreatment of such patients are scarce. A retrospective analysis covering the years 2015-2019 was conducted in three centers. All 17 patients included had undergone prior failed mandibular reconstructions in other institutions. Salvage secondary or tertiary reconstructive surgeries were attempted and the results are presented. Major factors for these failed reconstructions included exposed non-vascularized bone grafts (n = 7, 41.2%), flap loss (n = 4, 23.5%), exposed artificial joint (n = 3, 17.6%), skewed occlusion with deformity (n = 1, 5.9%), non-union (n = 1, 5.9%), and recurrence (n = 1, 5.9%). Fibula flaps were transferred in 15 patients, while iliac flaps were used in two patients for mandibular re-do reconstructions. Virtual surgical designs were conducted in nine (52.9%) patients, with navigation-guided approaches performed in three cases. Postoperative functions were relatively favorable in these complicated mandibular re-do reconstruction cases. Mandibular symmetry (mandibular length and height; P = 0.002) and condylar position (P < 0.001) were regained after these re-do attempts. Secondary or tertiary mandibular re-do reconstruction can still achieve good functional outcomes with appropriate preoperative selection and well-conceived designs, especially with the aid of virtual surgery and navigation.

Computer-assisted planning with 3D printing for mandibular reconstruction caused by a mandibular fracture with secondary osteomyelitis: A Case Report

Mandibular reconstructions are complex clinical pictures that require careful planning for functional and aesthetic outcomes. Virtual surgical planning and 3D printing are ideal to achieve a predictable result. Through "hybrid techniques" (prebending plates with 3D-models) and free software, this goal is within reach for clinics with limited financial resources.

Bone Fragment Co-transplantation Alongside Bone Marrow Aspirate Infusion Protects Kidney Transplant Recipients

Integration of non-vascularized bone grafting and bone marrow aspirate infusion in transplantation may provide clinical benefit. Here we have incorporated bone fragment co-transplantation and bone marrow aspirate infusion (BF-BM) into living kidney transplantation (LKT). Twenty LKT recipients receiving bone fragments and bone marrow aspirates donated from their corresponding donors were enrolled into a retrospective study. A contemporaneous control group was formed of 38 out of 128 conventional LKT recipients, selected using propensity score matching by a 1:2 Greedy algorithm. Ultrasonography, contrast-enhanced ultrasonography (US/CEUS) and SPECT/CT showed that the co-transplanted bone fragments remained viable for 6 months, subsequently shrank, and finally degenerated 10 months post-transplantation. BF-BM resulted in earlier kidney recovery and more robust long-term kidney function. Throughout 5 years of follow-up, BF-BM had regulatory effects on dendritic cells (DCs), T helper (Th1/Th2) cells and regulatory T cells (Tregs). Both alloantigen-specific lymphocyte proliferation and panel reactive antibody levels were negative in all recipients with or without BF-BM. In addition, the BF-BM group experienced few complications during the 5-year follow-up (as did the donors)—this was not different from the controls. In conclusion, BF-BM is safe and benefits recipients by protecting the kidney and regulating the immune response.

Degradation, Bone Regeneration and Tissue Response of an Innovative Volume Stable Magnesium-Supported GBR/GTR Barrier Membrane

Introduction: Bioresorbable collagenous barrier membranes are used to prevent premature soft tissue ingrowth and to allow bone regeneration. For volume stable indications, only non-absorbable synthetic materials are available. This study investigates a new bioresorbable hydrofluoric acid (HF)-treated magnesium (Mg) mesh in a native collagen membrane for volume stable situations. Materials and Methods: HF-treated and untreated Mg were compared in direct and indirect cytocompatibility assays. In vivo, 18 New Zealand White Rabbits received each four 8 mm calvarial defects and were divided into four groups: (a) HF-treated Mg mesh/collagen membrane, (b) untreated Mg mesh/collagen membrane (c) collagen membrane and (d) sham operation. After 6, 12 and 18 weeks, Mg degradation and bone regeneration was measured using radiological and histological methods. Results: In vitro, HF-treated Mg showed higher cytocompatibility. Histopathologically, HF-Mg prevented gas cavities and was degraded by mononuclear cells via phagocytosis up to 12 weeks. Untreated Mg showed partially significant more gas cavities and a fibrous tissue reaction. Bone regeneration was not significantly different between all groups. Discussion and Conclusions: HF-Mg meshes embedded in native collagen membranes represent a volume stable and biocompatible alternative to the non-absorbable synthetic materials. HF-Mg shows less corrosion and is degraded by phagocytosis. However, the application of membranes did not result in higher bone regeneration.

Nonvascularized Iliac Bone Reconstruction for the Mandible Without Maxillofacial Skin Scarring

PURPOSE

There are many methods to reconstruct the mandible, but they are often accompanied by trauma, which can lead to scarring of the maxillofacial skin. The purpose of this study was to show the utility of a minimally invasive method for reconstruction of the mandible with nonvascularized iliac bone grafts without a skin scar, as well as to evaluate the success rate and complications.

PATIENTS AND METHODS

This was a retrospective case series. We retrospectively analyzed patients who underwent transoral resection of benign mandibular pathologies, followed by nonvascularized iliac bone graft reconstruction. The primary outcome variable was the success rate of the bone grafts. Secondary outcome variables were postoperative complications at the grafted bone recipient and donor sites, the long-term absorptivity of grafted bone, and the type of mandibular defect. We computed descriptive statistics or performed the χ² test for each variable.

RESULTS

Overall, 54 patients were included in the study, including 21 male and 33 female patients, with an age range of 10 to 65 years. The complete survival rate was 87.0% (47 of 54 patients), and the partial survival rate was 98.1% (53 of 54). The average bone absorption rate 3 years after surgery was 1.8 to 30.7%. We propose a new classification method for mandibular defects based on the extent of the tumor, location of the osteotomy, and degree of surgical difficulty.

CONCLUSIONS

Intraoral nonvascularized iliac bone grafting is a highly successful minimally invasive method for mandibular reconstruction. It is also one of the best methods for mandibular reconstruction in patients with benign mandibular tumors without soft tissue involvement.

Three-Dimensionally Printed Hyperelastic Bone Scaffolds Accelerate Bone Regeneration in Critical-Size Calvarial Bone Defects

BACKGROUND

Autologous bone grafts remain the gold standard for craniofacial reconstruction despite limitations of donor-site availability and morbidity. A myriad of commercial bone substitutes and allografts are available, yet no product has gained widespread use because of inferior clinical outcomes. The ideal bone substitute is both osteoconductive and osteoinductive. Craniofacial reconstruction often involves irregular three-dimensional defects, which may benefit from malleable or customizable substrates. "Hyperelastic Bone" is a three-dimensionally printed synthetic scaffold, composed of 90% by weight hydroxyapatite and 10% by weight poly(lactic-co-glycolic acid), with inherent bioactivity and porosity to allow for tissue integration. This study examines the capacity of Hyperelastic Bone for bone regeneration in a critical-size calvarial defect.

METHODS

Eight-millimeter calvarial defects in adult male Sprague-Dawley rats were treated with three-dimensionally printed Hyperelastic Bone, three-dimensionally printed Fluffy-poly(lactic-co-glycolic acid) without hydroxyapatite, autologous bone (positive control), or left untreated (negative control). Animals were euthanized at 8 or 12 weeks postoperatively and specimens were analyzed for new bone formation by cone beam computed tomography, micro-computed tomography, and histology.

RESULTS

The mineralized bone volume-to-total tissue volume fractions for the Hyperelastic Bone cohort at 8 and 12 weeks were 74.2 percent and 64.5 percent of positive control bone volume/total tissue, respectively (p = 0.04). Fluffy-poly(lactic-co-glycolic acid) demonstrated little bone formation, similar to the negative control. Histologic analysis of Hyperelastic Bone scaffolds revealed fibrous tissue at 8 weeks, and new bone formation surrounding the scaffold struts by 12 weeks.

CONCLUSION

Findings from our study suggest that Hyperelastic Bone grafts are effective for bone regeneration, with significant potential for clinical translation.

Acceleration of Bone Regeneration in Critical-Size Defect Using BMP-9-Loaded nHA/ColI/MWCNTs Scaffolds Seeded with Bone Marrow Mesenchymal Stem Cells

Biocompatible scaffolding materials play an important role in bone tissue engineering. This study sought to develop and characterize a nano-hydroxyapatite (nHA)/collagen I (ColI)/multi-walled carbon nanotube (MWCNT) composite scaffold loaded with recombinant bone morphogenetic protein-9 (BMP-9) for bone tissue engineering by in vitro and in vivo experiments. The composite nHA/ColI/MWCNT scaffolds were fabricated at various concentrations of MWCNTs (0.5, 1, and 1.5% wt) by blending and freeze drying. The porosity, swelling rate, water absorption rate, mechanical properties, and biocompatibility of scaffolds were measured. After loading with BMP-9, bone marrow mesenchymal stem cells (BMMSCs) were seeded to evaluate their characteristics in vitro and in a critical sized defect in Sprague-Dawley rats in vivo. It was shown that the 1% MWCNT group was the most suitable for bone tissue engineering. Our results demonstrated that scaffolds loaded with BMP-9 promoted differentiation of BMMSCs into osteoblasts in vitro and induced more bone formation in vivo. To conclude, nHA/ColI/MWCNT scaffolds loaded with BMP-9 possess high biocompatibility and osteogenesis and are a good candidate for use in bone tissue engineering.

Antibiotic-loaded bone cement spacer usage combined with membrane induction in infected gap non-unions: A case series

Objective:

To explore the clinical effects upon gap nonunion of antibiotic-loaded bone cement spacer combined with membrane induction on infected bone defects.

Methods:

The data of 16 patients with infected bone defects admitted in General Hospital of Shenyang Military Area Command from January 2009 to January 2011 were analyzed retrospectively. There were 12 males and 4 females aged between 24-63 years age (average 43.1 ± 9.7) who had received antibiotic laiden bone cement spacer treatment. Stage-1, debridement and anti-biotic treatment with intraoperative preparation of customized bone cement spacers (antibiotics and bone cement spacer) with or without internal or external fixation Stage-2, removal of spacer and repair of bone defects using membrane-induced technique and internal fixation at bone defects site.

Results:

Sixteen patients were followed up for 39-98 months, (67.2 ± 20.4) on average. All patients with infected bone defects were healed. X-ray showed that fractures had healed and the new bone formed at graft site was more radio opaque than that of adjacent bone segments. The healing time was 6 to 10 months, (7.4 ± 1.1) on average. There was no recurrence of infection or deformity.

Conclusion:

The antibiotic-loaded cement spacer can control the local infection while maintaining the limb length and increasing the stability, reducing the contracture of bone and soft tissue, creating conditions for subsequent repair and reducing the infection rate of bone defects.

Non-vascularised fibular bone graft after vascular crisis: compensation for the failure of vascularised fibular free flaps

After reconstruction of a segmental mandibular defect with a fibular free flap, a vascular crisis can be detected clinically and a "no-flow" phenomenon found during re-exploration. Traditional methods used to solve this include removal of the failed flap and delayed mandibular reconstruction, or restoration of the defect with a functional reconstruction plate or contralateral fibular free flap. Our aim therefore was to investigate under what circumstances it is feasible to use a non-vascularised fibular bone graft (NVFB) as a free bone graft after the failure of a vascularised fibular free flap. From 1 January 2010-31 December 2014, 10 patients who had NVFB after failure of a fibular free flap were included in the study. All patients were treated at the Peking University School and Hospital of Stomatology. NVFB were preserved successfully without infection in all 10 cases, and follow-up imaging showed that it had incorporated well with the residual mandible, the basic function and facial aesthetics of which were maintained. In conclusion we have identified that by precise selection of patients, detailed preoperative planning, and meticulous postoperative care, NVFB can be used as a "rescue" technique after failure of a fibular free flap, and can successfully restore the segmental mandibular defect and facial contour.

Repair of critical sized cranial defects with BMP9-transduced calvarial cells delivered in a thermoresponsive scaffold

Large skeletal defects caused by trauma, congenital malformations, and post-oncologic resections of the calvarium present major challenges to the reconstructive surgeon. We previously identified BMP-9 as the most osteogenic BMP in vitro and in vivo. Here we sought to investigate the bone regenerative capacity of murine-derived calvarial mesenchymal progenitor cells (iCALs) transduced by BMP-9 in the context of healing critical-sized calvarial defects. To accomplish this, the transduced cells were delivered to the defect site within a thermoresponsive biodegradable scaffold consisting of poly(polyethylene glycol citrate-co-N-isopropylacrylamide mixed with gelatin (PPCN-g). A total of three treatment arms were evaluated: PPCN-g alone, PPCN-g seeded with iCALs expressing GFP, and PPCN-g seeded with iCALs expressing BMP-9. Defects treated only with PPCN-g scaffold did not statistically change in size when evaluated at eight weeks postoperatively (p = 0.72). Conversely, both animal groups treated with iCALs showed significant reductions in defect size after 12 weeks of follow-up (BMP9-treated: p = 0.0025; GFP-treated: p = 0.0042). However, H&E and trichrome staining revealed more complete osseointegration and mature bone formation only in the BMP9-treated group. These results suggest that BMP9-transduced iCALs seeded in a PPCN-g thermoresponsive scaffold is capable of inducing bone formation in vivo and is an effective means of creating tissue engineered bone for critical sized defects.

Reconstruct the proximal radius with iliac graft and elastic intramedullary nail fixation after tumor resection

Background

This study aims to introduce a novel technique in treating benign bone tumors of the proximal radius by elastic intramedullary nail fixation and iliac graft after tumor resection.

Method

In this retrospective case series, the treatment outcomes of 17 patients with benign bone tumor involving the proximal radius were reported from January 2010 to August 2014. All the patients received reconstruction surgery with iliac graft and elastic intramedullary nail fixation after tumor resection. Pain scoring was assessed using the 0 to 10 numerical rating scale. The quality of life scoring was assessed using the SF-30 scoring system. In addition, functional outcome was assessed with the Musculoskeletal Tumor Society score and the Disabilities of the Arm, Shoulder, and Hand score.

Results

The mean follow-up was 16 months (range, 10–22). The average bone consolidate time was 19.2 weeks (range, 16–24 weeks). The pre- and postoperative pain scores were 5.47 ± 1.58 and 1.18 ± 0.39, respectively. The pain symptom was significantly ameliorated after the operation (t = 13.50, p < 0.01). The pre- and postoperative and the quality of life scores were 48.29 ± 6.58 and 77.47 ± 5.89, respectively; the quality of life score was dramatically improved (t = −20.11, p < 0.01). The mean Musculoskeletal Tumor Society score was 83.41 % (range, 63–93 %) and the mean Disabilities of the Arm, Shoulder, and Hand score was 14.1 (range, 5.8–38.3).

Conclusion

Taken together, the application of iliac graft and elastic intramedullary nail fixation after excision of lesions might be associated to a significant reduction of the pain and improvement of QOL (quality of life) and limb function of patients with benign bone tumors of proximal radius.

Autogenous non-vascularized bone graft in segmental mandibular reconstruction: a systematic review

The restoration of mandibular bone defects with non-vascularized bone grafts depends on the diagnosis, anatomical site, extent of the defect, and the patient's age, as well as the surgeon's experience. The aim of this study was to perform a systematic literature review on mandibular reconstruction for segmental mandibular bone defects using non-vascularized bone grafts to answer the following question: Is there scientific evidence to support the use of this technique? The initial literature search in PubMed, Scopus, and Cochrane databases identified 862 articles. Of these, 25 were included in the final review. These articles encompassed 926 procedures with non-vascularized bone grafts; 76.1% were from the iliac crest. Benign tumours were the major cause of these defects (56.8%), and 44.7% of defects were located in the lateral mandibular area. Although this technique showed a high occurrence of complications (290 in 873 patients, some with more than one complication), these did not account for treatment failure. The restoration of bone defects due to malignant tumours treated with radiation therapy had lower success rates, and these appear to be a contraindication for the technique. Although standardized randomized controlled clinical studies are needed to obtain better clinical evidence for treatment choices in general, the use of non-vascularized bone grafts for mandibular reconstruction showed an 87.6% success rate in this review.