Autogenous bone graft: donor sites and techniques

Electrical Stimulation of Adipose-Derived Stem Cells in 3D Nanofibrillar Cellulose Increases Their Osteogenic Potential

Due to the ageing population, there is a steadily increasing incidence of osteoporosis and osteoporotic fractures. As conventional pharmacological therapy options for osteoporosis are often associated with severe side effects, bone grafts are still considered the clinical gold standard. However, the availability of viable, autologous bone grafts is limited making alternative cell-based strategies a promising therapeutic alternative. Adipose-derived stem cells (ASCs) are a readily available population of mesenchymal stem/stromal cells (MSCs) that can be isolated within minimally invasive surgery. This ease of availability and their ability to undergo osteogenic differentiation makes ASCs promising candidates for cell-based therapies for bone fractures. Recent studies have suggested that both exposure to electrical fields and cultivation in 3D can positively affect osteogenic potential of MSCs. To elucidate the osteoinductive potential of a combination of these biophysical cues on ASCs, cells were embedded within anionic nanofibrillar cellulose (aNFC) hydrogels and exposed to electrical stimulation (ES) for up to 21 days. ES was applied to ASCs in 2D and 3D at a voltage of 0.1 V/cm with a duration of 0.04 ms, and a frequency of 10 Hz for 30 min per day. Exposure of ASCs to ES in 3D resulted in high alkaline phosphatase (ALP) activity and in an increased mineralisation evidenced by Alizarin Red S staining. Moreover, ES in 3D aNFC led to an increased expression of the osteogenic markers osteopontin and osteocalcin and a rearrangement and alignment of the actin cytoskeleton. Taken together, our data suggest that a combination of ES with 3D cell culture can increase the osteogenic potential of ASCs. Thus, exposure of ASCs to these biophysical cues might improve the clinical outcomes of regenerative therapies in treatment of osteoporotic fractures.

Safety and Efficacy Results of BonoFill First-in-Human, Phase I/IIa Clinical Trial for the Maxillofacial Indication of Sinus Augmentation and Mandibular Bone Void Filling

PURPOSE

The gold standard for bone regeneration of bone deficiencies is still an autologous bone graft, which has considerable disadvantages; namely, the need for a second major surgery and the limited volume of bone available for harvesting. BonoFill (BF) is a novel, tissue-engineered, bone graft with intrinsic osteoinductive, osteoconductive, and osteogenic properties, consisting of the patient's own adipose tissue-derived mesenchymal stem cells, attached to hydroxyapatite particles. Here, we present the safety and efficacy results of BF first-in-human clinical study for maxillofacial bone tissue regeneration.

MATERIALS AND METHODS

Eleven eligible male and female subjects, aged 49-65 years, were enrolled into the clinical study in 2 clinical indications: Bone augmentation and bone void grafting in the jaws. Clinical follow-up was performed throughout a period of 6 months after BF treatment and included clinical examination, blood tests, CT scans, and biopsies collected from the transplantation site to assess chronic bone infection, changes in complete blood count, and adequate bone augmentation for implant placement.

RESULTS

The study results demonstrated that BF promoted adequate bone tissue regeneration without complications. Per our evaluation, there were no incidents of chronic bone infection, or significant changes in complete blood count, and the patients reported overall good health for the duration of the study. At trial end, in the sinus augmentation indication, the BF treated sites residual bone was augmented at an average of 6.36 mm (Δ new bone, n = 10) and the total bone height at the treated area was on average 11.44 mm (n = 10). In the indication of filling of bone voids, the patient's average residual bone height of 2.91 mm was 15.76 mm (n = 1) at trial end.

CONCLUSIONS

BF treatment was shown to be safe and resulted in newly generated bone, which provided adequate bone height for placement of dental implants. Thus, BF is a promising novel autologous bone graft for bone tissue repair.

Growth Factors, Carrier Materials, and Bone Repair

This chapter provides an overview of the growth factors active in bone regeneration and healing. Both normal and impaired bone healing are discussed, with a focus on the spatiotemporal activity of the various growth factors known to be involved in the healing response. The review highlights the activities of most important growth factors impacting bone regeneration, with a particular emphasis on those being pursued for clinical translation or which have already been marketed as components of bone regenerative materials. Current approaches the use of bone grafts in clinical settings of bone repair (including bone grafts) are summarized, and carrier systems (scaffolds) for bone tissue engineering via localized growth factor delivery are reviewed. The chapter concludes with a consideration of how bone repair might be improved in the future.

Radiographic and clinical assessment of unidirectional porous hydroxyapatite to treat benign bone tumors

Unidirectional porous hydroxyapatite (UDPHAp) was developed as an excellent scaffold with unidirectional pores oriented in the horizontal direction with interpore connections. The purpose of this study was to assess radiographic changes and clinical outcomes and complications following UDPHAp implantation to treat benign bone tumors. We retrospectively analyzed 44 patients treated with intralesional resection and UDPHAp implantation for benign bone tumors between 2010 and 2015. Clinical and radiographic findings were evaluated postoperatively at regular follow-up visits. The mean follow-up was 49 months. Radiographic changes were classified into five stages based on bone formation in the implanted UDPHAp according to Tamai’s classification. All patients showed excellent bone formation inside and around implanted UDPHAp. Absorption of UDPHAp and bone marrow cavity remodeling was identified in 20 patients at a mean of 17 months postoperatively, and was significantly more common in young patients. Preoperative cortical thinning was completely regenerated in 26 of 31 patients on average 10 months after surgery. There were no cases of delayed wound healing, postoperative infection, or allergic reaction related to implanted UDPHAp. UDPHAp is a useful bone-filling substitute for treating benign bone tumor, and the use of this material has a low complication rate.

Supramolecular self-assembling peptides to deliver bone morphogenetic proteins for skeletal regeneration

Recombinant human bone morphogenetic proteins (BMPs) have shown clinical success in promoting bone healing, but they are also associated with unwanted side effects. The development of improved BMP carriers that can retain BMP at the defect site and maximize its efficacy would decrease the therapeutic BMP dose and thus improve its safety profile. In this review, we discuss the advantages of using self-assembling peptides, a class of synthetic supramolecular biomaterials, to deliver recombinant BMPs. Peptide amphiphiles (PAs) are a broad class of self-assembling peptides, and the use of PAs for BMP delivery and bone regeneration has been explored extensively over the past decade. Like many self-assembling peptide systems, PAs can be designed to form nanofibrous supramolecular biomaterials in which molecules are held together by non-covalent bonds. Chemical and biological functionality can be added to PA nanofibers, through conjugation of chemical moieties or biological epitopes to PA molecules. For example, PA nanofibers have been designed to bind heparan sulfate, a natural polysaccharide that is known to bind BMPs and potentiate their signal. Alternatively, PA nanofibers have been designed to synthetically mimic the structure and function of heparan sulfate, or to directly bind BMP specifically. In small animal models, these bio-inspired PA materials have shown the capacity to promote bone regeneration using BMP at doses 10-100 times lower than established therapeutic doses. These promising results have motivated further evaluation of PAs in large animal models, where their safety and efficacy must be established before clinical translation. We conclude with a discussion on the possiblity of combining PAs with other materials used in orthopaedic surgery to maximize their utility for clinical translation.

Safety Profile Associated With Calcaneal Autograft Harvesting Using a Reaming Graft Harvester

BACKGROUND

Foot and ankle surgery often requires bone healing, whether in elective arthrodesis or trauma. While primary bone healing is possible, the rate of nonunion in foot and ankle surgery remains variable. The addition of autogenous bone graft can allow for higher union rates by adding to the biology at the site of bone healing. Harvesting autogenous bone graft from the calcaneus for foot and ankle surgery can be done quickly and efficiently and allow for an adequate amount of graft.

METHODS

A retrospective chart and radiographic review was performed for 1438 patients at a single center between August 1, 2015, and December 15, 2018, who underwent calcaneal autograft harvesting using a power-driven reaming graft harvester.

RESULTS

In total, 966 patients were included and evaluated for the safety and complication rate associated with the procedure. Only 1 patient (0.1%) had a major complication, and there were 14 minor complications (1.4%).

CONCLUSION

The safety profile and low complication rate of this case series demonstrate that this simple and efficient calcaneal autograft harvest technique can be considered when a small to moderate amount of autogenous bone graft is required to augment bone healing.

LEVEL OF EVIDENCE

Therapeutic level IV, case series.

The platelet-rich plasma and mesenchymal stem cell milieu: A review of therapeutic effects on bone healing

Platelet-rich plasma is autologous plasma that contains concentrated platelets compared to whole blood. It is relatively inexpensive to produce, can be easily isolated from whole blood, and can be administered while the patient is in the operating room. Further, because platelet-rich plasma is an autologous therapy, there is minimal risk for adverse reactions to the patient. Platelet-rich plasma has been used to promote bone regeneration due to its abundance of concentrated growth factors that are essential to wound healing. In this review, we summarize the methods for producing platelet-rich plasma and the history of its use in bone regeneration. We also summarize the growth factor profiles derived from platelet-rich plasma, with emphasis on those factors that play a direct role in promoting bone repair within the local fracture environment. In addition, we discuss the potential advantages of combining platelet-rich plasma with mesenchymal stem cells, a multipotent cell type often obtained from bone marrow or fat, to improve craniofacial and long bone regeneration. We detail what is currently known about how platelet-rich plasma influences mesenchymal stem cells in vitro, and then highlight the clinical outcomes of administering platelet-rich plasma and mesenchymal stem cells as a combination therapy to promote bone regeneration in vivo.

Assessment of bone quality using buccal and palatal autogenous cortical shells harvested from two different mandibular donor sites for maxillary alveolar ridge augmentation: a histomorphometric randomized clinical trial

PURPOSE

This study aims to compare the quality of free autogenous bone grafts harvested from two different mandibular donor sites, used as onlay shells to augment horizontally and vertically deficient anterior maxillary alveolar ridges.

METHODS

Fourteen patients with edentulous and atrophic anterior maxillae are randomly allocated into two groups. Seven symphyseal chin (group I) and seven retromolar (group II) mandibular bone grafts were harvested and fashioned to construct buccal and palatal frameworks, fixed in place with mini-screws, followed by compacting the inter-positional gaps with an equal particulate mix of xenograft and autogenous cancellous particulates. Six months later, 42 core biopsies, three from each patient, 21 for each study group, were retrieved before the implants' insertion and subjected to histomorphometric bone area percent analysis.

RESULTS

The bone area percent of the newly formed bone augmented with the chin shells was 52.53 ± 1.68% versus 47.97 ± 1.83% for the retromolar grafts. The mean area percent difference between both groups was statistically significant (p = 0.0004).

CONCLUSION

A higher bone quality and more volumetric stability were associated with the symphyseal cortical shells.

CLINICAL TRIAL REGISTRATION

The study was registered on www.clinicaltrials.gov (#: NCT03607006) in July 2018 by Ola Alaa El Morsy.

DNA Hybridization-Based Differential Peptide Display Identified Potential Osteogenic Peptides

Abstract

A DNA hybridization-based differential peptide display (DPD) was developed for the screening of phage peptide library to find osteogenic peptides intended to bind to epigenetically induced osteogenic receptors on NIH/3T3 (3T3) cell surface. In the presence of DNA methylation inhibitor of 5-azacytidine (5AZC), an osteoblastic receptor of bone morphogenetic protein (BMP) receptor 1A (BMPR1A) was induced on the cell surface of NIH/3T3 fibroblasts. Cyclic heptamer-displaying phage library was screened against vehicle and 5AZC treated (Tx) 3T3 cells. Antisense oligo against library against library peptide coding DNA of control 3T3 cell bound phages were synthesized to subtract common binders from that of 5AZC-Tx 3T3 cell-bound phages that included 5AZC-induced receptor binders. The library peptide coding regions of conformational receptor binder-subtracted DPD were PCR-amplified and cloned into a plasmid vector specifically designed for short peptide expression. No unique binder was identified when 96 clones were randomly picked from the third round of panning against 5AZC-treated 3T3 cells, suggesting miscellaneous bindings to cell surface proteins. Unique binders showing homology to known function proteins were successfully identified when constitutive receptor binders were subtracted from 5AZC-induced protein binders. Some of identified peptides significantly increased alkaline phosphatase activity in 5AZC-Tx 3T3 cells. DPD can be a useful tool to screen functional peptide bindings to cell surface receptors.

Graphic Abstract

Osteogenic Properties of Novel Methylsulfonylmethane-Coated Hydroxyapatite Scaffold

Despite numerous advantages of using porous hydroxyapatite (HAp) scaffolds in bone regeneration, the material is limited in terms of osteoinduction. In this study, the porous scaffold made from nanosized HAp was coated with different concentrations of osteoinductive aqueous methylsulfonylmethane (MSM) solution (2.5, 5, 10, and 20%) and the corresponding MH scaffolds were referred to as MH2.5, MH5, MH10, and MH20, respectively. The results showed that all MH scaffolds resulted in burst release of MSM for up to 7 d. Cellular experiments were conducted using MC3T3-E1 preosteoblast cells, which showed no significant difference between the MH2.5 scaffold and the control with respect to the rate of cell proliferation (p > 0.05). There was no significant difference between each group at day 4 for alkaline phosphatase (ALP) activity, though the MH2.5 group showed higher level of activity than other groups at day 10. Calcium deposition, using alizarin red staining, showed that cell mineralization was significantly higher in the MH2.5 scaffold than that in the HAp scaffold (p < 0.0001). This study indicated that the MH2.5 scaffold has potential for both osteoinduction and osteoconduction in bone regeneration.

Hyaluronic acid as a bioactive component for bone tissue regeneration: Fabrication, modification, properties, and biological functions

Hyaluronic acid (HA) is widely distributed in the human body, and it is heavily involved in many physiological functions such as tissue hydration, wound repair, and cell migration. In recent years, HA and its derivatives have been widely used as advanced bioactive polymers for bone regeneration. Many medical products containing HA have been developed because this natural polymer has been proven to be nontoxic, noninflammatory, biodegradable, and biocompatible. Moreover, HA-based composite scaffolds have shown good potential for promoting osteogenesis and mineralization. Recently, many HA-based biomaterials have been fabricated for bone regeneration by combining with electrospinning and 3D printing technology. In this review, the polymer structures, processing, properties, and applications in bone tissue engineering are summarized. The challenges and prospects of HA polymers are also discussed.

Determination of the Optimal Location for Bone Graft Harvest in the Distal Radius

Background: The distal radius is commonly used as a bone graft donor site for surgery in the hand and wrist. The aim of this study was to evaluate the volume and relative density of cancellous bone in the distal radius. Methods: Thirty-four consecutive computed tomographic scans of the wrist in 33 patients without distal radius pathology were included. For each subject, 6 spherical regions of interest (ROIs) were identified within the distal radius. In each ROI, volumetric measurements and mean Hounsfield unit (HFU) values were recorded by 2 observers using a 3-dimensional imaging reconstruction software. Results: Compared with proximal bone, distal bone had larger volume (0.82 vs 0.27 cm³) and greater relative density (178 vs 152 HFU) on average. Among the 6 ROIs, the distal-central region had the largest average volume (1.20 cm³) and the distal-ulnar ROI had the greatest average relative density (193 HFU). Conclusion: Based on these results, we recommend performing cancellous autograft harvest relatively distal and ulnar within the distal radius.

Trephine biopsy versus conventional open surgical technique for bone graft harvesting from the olecranon: A retrospective comparison of perioperative outcomes

OBJECTIVE

This study aimed to compare the perioperative clinical outcomes of trephine biopsy (TB) with the conventional open surgical method (COSM) in bone graft harvesting from the olecranon.

METHODS

In this retrospective study, 130 patients who underwent bone graft harvesting from the olecranon using either TB or COSM were included. Patients were then divided into two groups: the COSM group (48 patients; 36 men and 12 women; mean age=32 years; age range=18-52) and the TB group (82 patients; 61 men and 21 women; mean age=34 years; age range=20-62). The mean follow-up was 30 months (range=17-57) in the COSM group and 26.8 months (range=6-48 months) in the TB groups. The two groups were compared in terms of pain intensity, operating time, complication rate, elbow range of motion, and the scar sensitivity of the graft donor site. Pain intensity was measured using the visual analogous scale (VAS) on postoperative days 1 and 15. Other outcome measures were evaluated at the final follow-up.

RESULTS

In the TB group, the mean VAS score was 4±1.62 on postoperative day 1 and 1.6±0.76 on postoperative day 15. In the COSM group, the mean VAS score was 7.2±1.38 on postoperative day 1 and 3.1±1.34 on postoperative day 15. The early VAS scores were significantly higher in the COSM group than in the TB group (p<0.05). The mean operating time was 7±1.99 minutes in the TB group and 20±4.51 minutes in the COSM group. Hematoma occurred in one patient from each group, with an incidence of 2.1% in the COSM group and 1.2% in the TB group. There was no significant difference between the two groups regarding elbow range of motion at final follow-up p>0.05). No patient in the TB group showed sensitivity of the scar region, while scar sensitivity occurred in 3 of 48 patients (0.6%) in the COSM group.

CONCLUSION

Compared with COSM, TB seems to be a safe technique with similar complication rates. TB can provide shorter operating time, less postoperative pain, and smaller and less sensitive scar compared with COSM.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Evaluation of Osteoconduction of a Synthetic Hydroxyapatite/β-Tricalcium Phosphate Block Fixed in Rabbit Mandibles

(1) Background: This study aimed to evaluate the incorporation of hydroxyapatite/β-tricalcium phosphate blocks grafted in rabbit mandibles. (2) Methods: Topographic characterization of biomaterial was performed through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX). Ten rabbits randomly received autogenous bone graft harvested from the tibia (Autogenous Group—AG) or synthetic biomaterial manufactured in β-tricalcium phosphate (Biomaterial Group—BG) at their right and left mandibular angles. Euthanasia was performed at 30 and 60 postoperative days; (3) Results: SEM-EDX showed a surface with the formation of crystals clusters. Histological analyses in BG at 30 days showed a slower process of incorporation than AG. At 60 days, BG showed remnants of biomaterial enveloped by bone tissue in the anabolic modeling phase. Histometric analysis showed that mean values of newly formed bone-like tissue in the AG (6.56%/9.70%) were statistically higher compared to BG (3.14%/6.43%) in both periods, respectively. Immunohistochemical analysis demonstrated early bone formation and maturation in the AG with more intense osteopontin and osteocalcin staining. (4) Conclusions: The biomaterial proved to be a possible bone substitute, being incorporated into the receiving bed; however, it showed delayed bone incorporation compared to autogenous bone.

Synergistic use of biomaterials and licensed therapeutics to manipulate bone remodelling and promote non-union fracture repair

Disrupted bone metabolism can lead to delayed fracture healing or non-union, often requiring intervention to correct. Although the current clinical gold standard bone graft implants and commercial bone graft substitutes are effective, they possess inherent drawbacks and are limited in their therapeutic capacity for delayed union and non-union repair. Research into advanced biomaterials and therapeutic biomolecules has shown great potential for driving bone regeneration, although few have achieved commercial success or clinical translation. There are a number of therapeutics, which influence bone remodelling, currently licensed for clinical use. Providing an alternative local delivery context for these therapies, can enhance their efficacy and is an emerging trend in bone regenerative therapeutic strategies. This review aims to provide an overview of how biomaterial design has advanced from currently available commercial bone graft substitutes to accommodate previously licensed therapeutics that target local bone restoration and healing in a synergistic manner, and the challenges faced in progressing this research towards clinical reality.

Autogenous bone ring for vertical bone augmentation procedure with simultaneous implant placement: A systematic review of histologic and histomorphometric outcomes in animal studies

STATEMENT OF PROBLEM

The performance of the autogenous bone ring (ABR) technique used for the vertical bone augmentation procedure has not yet been determined.

PURPOSE

The purpose of this systematic review was to investigate whether the ABR technique for the vertical bone augmentation procedure with simultaneous implant placement enhances the histologic and histomorphometric outcomes in surgically created bone defects in animal models.

MATERIAL AND METHODS

An electronic search of 3 databases, Medline/PubMed, Science Direct, Lilacs, and a manual search of a reference list of relevant studies were performed. Only animal studies regarding vertical bone augmentation by using the ABR technique with simultaneous implant placement in surgically created bone defects were included in the review. The SYstematic Review Center for Laboratory Animal Experimentation tool was used to determine the risk of bias assessment, and the quality of included studies was assessed by using the Animal Research: Reporting in Vivo Experiments guidelines.

RESULTS

Five studies were included in the qualitative analysis based on the inclusion and exclusion criteria. One study comparing the ABR technique with the bovine and biphasic ring reported a high percentage of bone area and bone implant contact of the ABR at 5 weeks of osseointegration. Similar histologic findings were reported in another study at 4 months of healing, but contrasting data were reported at 8 months. Another study reported an increase in the percentage of bone area and bone implant contact of the ABR technique from 3 months to 6 months of osseointegration. Two studies reported an increase in the percentage of bone area, and 1 study reported a decrease in the mean of bone implant contact, both with simultaneous and staged implant procedures.

CONCLUSION

Based on the limited available studies, the use of the ABR technique for the vertical bone augmentation procedure with simultaneous implant placement presented optimal histologic and histomorphometric outcomes in surgically created bone defects in animal models. However, the results of the current review are not sufficiently robust to support the use of the ABR technique for vertical bone augmentation in humans.

Three-Dimensional Printing for Craniofacial Bone Tissue Engineering

The basic concepts from the fields of biology and engineering are integrated into tissue engineering to develop constructs for the repair of damaged and/or absent tissues, respectively. The field has grown substantially over the past two decades, with particular interest in bone tissue engineering (BTE). Clinically, there are circumstances in which the quantity of bone that is necessary to restore form and function either exceeds the patient's healing capacity or bone's intrinsic regenerative capabilities. Vascularized osseous or osteocutaneous free flaps are the standard of care with autologous bone remaining the gold standard, but is commonly associated with donor site morbidity, graft resorption, increased operating time, and cost. Regardless of the size of a craniofacial defect, from trauma, pathology, and osteonecrosis, surgeons and engineers involved with reconstruction need to consider the complex three-dimensional (3D) geometry of the defect and its relationship to local structures. Three-dimensional printing has garnered significant attention and presents opportunities to use craniofacial BTE as a technology that offers a personalized approach to bony reconstruction. Clinicians and engineers are able to work together to produce patient-specific space-maintaining scaffolds tailored to site-specific defects, which are osteogenic, osseoconductive, osseoinductive, encourage angiogenesis/vasculogenesis, and mechanically stable upon implantation to prevent immediate failure. In this work, we review biological and engineering principles important in applying 3D printing technology to BTE for craniofacial reconstruction as well as present recent translational advancements in 3D printed bioactive ceramic scaffold technology.

Comparing the efficacy of syngeneic iliac and femoral allografts with iliac crest autograft in a rat model of lumbar spinal fusion

BACKGROUND

Despite widespread use of femoral-sourced allografts in clinical spinal fusion procedures and the increasing interest in using femoral reamer-irrigator-aspirator (RIA) autograft in clinical bone grafting, few studies have examined the efficacy of femoral grafts compared to iliac crest grafts in spinal fusion. The objective of this study was to directly compare the use of autologous iliac crest with syngeneic femoral and iliac allograft bone in the rat model of lumbar spinal fusion.

METHODS

Single-level bilateral posterolateral intertransverse process lumbar spinal fusion surgery was performed on Lewis rats divided into three experimental groups: iliac crest autograft, syngeneic iliac crest allograft, and syngeneic femoral allograft bone. Eight weeks postoperatively, fusion was evaluated via microCT analysis, manual palpation, and histology. In vitro analysis of the colony-forming and osteogenic capacity of bone marrow cells derived from rat femurs and hips was also performed to determine whether there was a correlation with the fusion efficacy of these graft sources.

RESULTS

Although no differences were observed between groups in CT fusion mass volumes, iliac allografts displayed an increased number of radiographically fused fusion masses and a higher rate of bilateral fusion via manual palpation. Histologically, hip-derived grafts showed better integration with host bone than femur derived ones, likely associated with the higher concentration of osteogenic progenitor cells observed in hip-derived bone marrow.

CONCLUSIONS

This study demonstrates the feasibility of using syngeneic allograft bone in place of autograft bone within inbred rat fusion models and highlights the need for further study of femoral-derived grafts in fusion.

Osteology of the ilium revised: illuminating the clinical relevance

BACKGROUND

Several studies on anterior and posterior pelvic ring fixation have identified a fragile monocortical area located at the iliac wing. However, there are no current studies regarding this structure's dimensions and relation to known anatomic structures.

METHODS

Eleven human ilia were dissected from 6 specimens. After debulking soft tissue, photoluminescence was used to indicate the fragile area. The size and thickness of the iliac wing were determined and mapped in relation to the anterior superior iliac spine (ASIS) and the posterior superior iliac spine (PSIS).

RESULTS

This photoluminescent unicortical area measured 15.57 cm² with a mean minimal thickness of 1.37 mm at its thinnest part. Its average diameter was 41.15 mm horizontally and 37.45 mm vertically. In all cases, it was located at the middle third of the ilium with a mean distance of 64.58 mm to the AIIS and 62.73 mm to the PSIS. Trajectory angulation above 4.5° from the PSIS lead to violation of this area.

CONCLUSION

This study provides useful anatomical information regarding a thin unicortical area at the iliac wing that is relevant to anterior and posterior pelvic ring fixation and the potential complications that can arise from iatrogenic perforation of this area.

Nanovibrational Stimulation of Mesenchymal Stem Cells Induces Therapeutic Reactive Oxygen Species and Inflammation for Three-Dimensional Bone Tissue Engineering

There is a pressing clinical need to develop cell-based bone therapies due to a lack of viable, autologous bone grafts and a growing demand for bone grafts in musculoskeletal surgery. Such therapies can be tissue engineered and cellular, such as osteoblasts, combined with a material scaffold. Because mesenchymal stem cells (MSCs) are both available and fast growing compared to mature osteoblasts, therapies that utilize these progenitor cells are particularly promising. We have developed a nanovibrational bioreactor that can convert MSCs into bone-forming osteoblasts in two- and three-dimensional, but the mechanisms involved in this osteoinduction process remain unclear. Here, to elucidate this mechanism, we use increasing vibrational amplitude, from 30 nm (N30) to 90 nm (N90) amplitudes at 1000 Hz and assess MSC metabolite, gene, and protein changes. These approaches reveal that dose-dependent changes occur in MSCs' responses to increased vibrational amplitude, particularly in adhesion and mechanosensitive ion channel expression and that energetic metabolic pathways are activated, leading to low-level reactive oxygen species (ROS) production and to low-level inflammation as well as to ROS- and inflammation-balancing pathways. These events are analogous to those that occur in the natural bone-healing processes. We have also developed a tissue engineered MSC-laden scaffold designed using cells' mechanical memory, driven by the stronger N90 stimulation. These mechanistic insights and cell-scaffold design are underpinned by a process that is free of inductive chemicals.

The minimally effective dose of bone morphogenetic protein in posterior lumbar interbody fusion: a systematic review and meta-analysis

BACKGROUND CONTENT

The risks and benefits of recombinant human bone morphogenetic protein-2 (BMP) in posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) have been widely reported. However, the BMP dose associated with such reports varied widely. Additionally, data on the location of BMP placement on complications and fusion are lacking.

PURPOSE

To determine the minimally effective dose (MED) of BMP which results in optimal fusion rates while minimizing complications; to determine the effects of the location of BMP placement has on fusion rates and complications.

STUDY DESIGN

Systematic review and meta-analysis.

STUDY SAMPLE

Adult patients undergoing PLIF/TLIF for degenerative indications.

OUTCOME MEASURES

Rates of radiculitis, fusion, osteolysis, heterotopic bone formation, and new cancer diagnosis.

METHODS

PubMed, Embase, and Cochrane Database were used to identify studies published between January 1, 2011 and April 30, 2019 reporting BMP usage in adult patients who underwent PLIF/TLIF degenerative indications. A qualitative and quantitative synthesis was performed to evaluate the MED of BMP and the effect of location of BMP placement on fusion and complications. Complications were defined as osteolysis, heterotopic bone growth, radiculitis, and rate of new cancer diagnosis. Complications and fusion outcomes were each pooled according to commercially available BMP doses. Additionally, complications and fusion outcomes were pooled according to 4 location groups (interbody cage only, interbody cage + posterolateral gutter [PLG], cage + interspace, and interspace + PLG). Heterogeneity was assessed with Q and I² statistics.

RESULTS

Twenty-two articles, totaling 2,729 patients were included. Sixteen studies reported fusion and 15 reported complications. Among fusion studies, the mean BMP/level ranged from 1.28 to 12 mg/level. Among complication studies, the mean BMP/level ranged from 6.7 to 23.6 mg/level. The pooled overall fusion rate was 94.0% (91.4-95.8 confidence intervals). There was no significant difference in fusion and complication rates between different BMP doses. Thirteen studies included data on the location of BMP placement with 1,823 patients. At each BMP location, the fusion rate was not significantly different across the dose ranges (1.28-12 mg/level). We found the fusion rate to be marginally higher in the interspace + PLG group compared to the other groups. When BMP was placed in the interbody cage there was a mild increase in the rate of osteolysis compared to other placement locations.

CONCLUSIONS

Fusion and complication rates did not differ significantly between different doses of BMP with the lowest MED for fusion as low as 1.28 mg/level. The location of BMP placement does not significantly affect fusion or complication rates.

Highly impacted bone allograft may allow immediate weight bearing in tibial plateau fractures: A case report

Introduction

Proximal tibial fractures are common with an incidence of 10.2/100.000. Those displaced and involving the articular surface will often require surgical treatment. However, no consensus exists on whether to allow the patient early weight bearing or not. We developed a technique using structural bone chips, highly impacted under the articular surface, to permit immediate weight bearing after surgery.

Patient

The patient was a 44-year old male who suffered a lateral tibial plateau fracture (AO type 41B2).

Intervention

We used an anterolateral approach with an S-shaped incision. A small window in the tibia was made using an awl, and the articular surface was reduced under radiographic imaging. The bone allograft was prepared by splitting the frozen femoral head in quarters and then taking large pieces of bone with a bone rongeur forceps avoiding the cartilage. The large pieces of bone were gathered in a small tray and thereafter compressed into the drill guide insert. The drill guide filled with bone graft was then inserted into the tibia window and directed in the appropriate position guided by radiography. Hereafter, the bone graft was impacted under the articular surface with force using the appropriate trocar and a hammer, and the fracture was finally reduced. Finally, the fracture was fixated utilizing an angular stable plate.

Outcome

The patient was followed up one year postoperatively and allowed immediate weight bearing after surgery. No subsequent articular collapse occurred.

Discussion

In this case, we present a proximal tibial fracture with articular depression, which was surgically treated with a highly impacted bone allograft of large pieces and a locking plate. The patient was allowed immediate weight bearing and no subsequent articular collapse occurred.

Bone-Graft Resorption Reduced by the Induced Membrane Technique and Factors Affecting Volumetric Changes: An Analysis of 120 Serial Computed Tomographic Scans in 40 Patients

BACKGROUND

Little is known about the volumetric changes of grafted bone over time when using the induced membrane technique. This study investigates the volumetric changes of bone graft using serial computed tomographic (CT) scans following the induced membrane technique.

METHODS

Patients with critical-sized bone defects had serial CT scans after undergoing bone-grafting using the induced membrane technique. CT scans to evaluate the volume of bone graft were obtained immediately postoperatively and at 6 and 12 months. The change in the volume of bone graft was determined at 6 and 12 months postoperatively. Patient demographic characteristics, the location and composition of the bone graft, and the type of fixation construct were analyzed.

RESULTS

Forty patients met inclusion criteria. There were 27 tibiae and 13 femora with a mean size defect of 8.6 cm (range, 2.5 to 20.6 cm). Of these patients, 21 received autograft with cancellous bone graft and 19 received mixed autogenous bone with demineralized bone matrix (DBM) at a mean time of 17 weeks after the membrane formation. For the first 6 months, there was an overall osseous resorption of -9.9%. The overall graft volume from 6 to 12 months demonstrated an increase of osseous volume by +1.6%. For the entire 12-month period, there was a mean graft volume resorption of -8.3%. A correlation was found between the early volumetric changes of grafted bone and the percentage of DBM in the graft mixture. A correlation was also found between the late volumetric changes and the location of defect or the type of fixation.

CONCLUSIONS

At 1 year after use of the induced membrane technique for the treatment of a critical-sized bone defect, resorption of the grafted bone averaged -8.3%. The volumetric changes were influenced by the property of the grafted bone, the fixation construct, and the location of the defect.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Efficacy of a Standalone Microporous Ceramic Versus Autograft in Instrumented Posterolateral Spinal Fusion: A Multicenter, Randomized, Intrapatient Controlled, Noninferiority Trial

STUDY DESIGN

in the rest of the article written as patient- and observer-blinded, multicenter, randomized, intrapatient controlled, noninferiority trial.

OBJECTIVE

The aim of this study was to determine noninferiority of a biphasic calcium-phosphate (AttraX® Putty) as a bone graft substitute for autograft in instrumented posterolateral fusion (PLF).

SUMMARY OF BACKGROUND DATA

Spinal fusion with autologous bone graft is a frequently performed surgical treatment. Several drawbacks of autografting have driven the development of numerous alternatives including synthetic ceramics. However, clinical evidence for the standalone use of these materials is limited.

METHODS

This study included 100 nontraumatic adults who underwent a primary, single- or multilevel, thoracolumbar, instrumented PLF. After instrumentation and preparation for grafting, the randomized allocation side of AttraX® Putty was disclosed. Autograft was applied to the contralateral side of the fusion trajectory, so each patient served as his/her own control. For the primary efficacy outcome, PLF was assessed at 1-year follow-up on computed tomography scans. Each segment and side was scored as fused, doubtful fusion, or nonunion. After correction for multilevel fusions, resulting in a single score per side, the fusion performance of AttraX Putty was tested with a noninferiority margin of 15% using a 90% confidence interval (CI).

RESULTS

There were 49 males and 51 females with a mean age of 55.4 ± 12.0 (range 27-79) years. Two-third of the patients underwent a single-level fusion and 62% an additional interbody fusion procedure. The primary analysis was based on 87 patients, including 146 instrumented segments. The fusion rate of AttraX Putty was 55% versus 52% at the autograft side, with an overall fusion rate of 71%. The 90% CI around the difference in fusion performance excluded the noninferiority margin (difference = 2.3%, 90% CI = -9.1% to +13.7%).

CONCLUSION

The results of this noninferiority trial support the use of AttraX Putty as a standalone bone graft substitute for autograft in instrumented thoracolumbar PLF.

LEVEL OF EVIDENCE

1.

Comparative study of impact of animal source on physical, structural, and biological properties of bone xenograft

BACKGROUND

Due to the unique features of xenografts including large supply from donors, minimal risk of human disease transmission, and the lower cost of preparation and production compared to autografts and allografts, they are considered as attractive alternatives to traditional bone grafts. The animal source accessibility and production process have a direct correlation with the cost and quality of the final product. To evaluate whether the animal source of the bone has any effect on the physicochemical and histological properties of the final xenograft, three deproteinized bone grafts were prepared from sources that are easily available in Iran, including the bovine (DBB), camel (DCB), and ostrich (DOB).

METHODS

In the current study, three bone substitute materials intended to serve as bone xenografts were derived from the cow, camel, and ostrich using the thermochemical processing procedure. The physicochemical properties, in vitro cytocompatibility and in vivo bone regeneration capability of the prepared deproteinized bone grafts, were assessed and compared with OCS-B as an approved product in the global market.

RESULTS

The physical tests confirmed the hydroxyapatite nature of the final products. SEM and BET analysis showed morphological and structural differences between the products due to differences in the animal sources. In vitro studies showed the prepared deproteinized bone was free of processing chemicals and was biocompatible with mouse fibroblast and myoblast cell lines. In vivo studies revealed that the bone formation capability of the DBB, DCB, and DOB has no significant difference with one another and with OCS-B despite their structural differences. The DCB showed the highest graft residue after two month. No signs of immunogenicity were observed in the study groups compared to the blank group.

CONCLUSION

DBB, DCB, and DOB may offer a favorable cell response and bone regeneration similar to those of commercial bovine bone material.

[Acute appendicitis after bone grafting from the right anterior iliac crest-difficult differential diagnosis]

To fill bony defects, an iliac crest bone graft is often used. Typical complications are hematoma, nerve injuries, infection or donor site related pain. This article reports the case of a young patient with acute appendicitis after bone grafting from the right iliac crest. Because of the preceding operation, the correct diagnosis was difficult and was only possible by a differentiated clinical examination followed by machine-aided diagnosis.

Juvenile psammomatoid ossifying fibroma of the maxilla

Juvenile psammomatoid ossifying fibroma (JPOF) is a rare, benign, fibro-osseous variant of ossifying fibroma. It exhibits short-term rapid growth and has a high recurrence rate. Herein we describe a case of JPOF of the maxilla that was treated via complete excision utilizing an intraoral approach with immediate reconstruction using an iliac bone graft, in conjunction with a comprehensive review of the literature. A 20-year-old man presented with a mass on his right cheek that he reported had been growing over the last 10 months. In that cheek he had noticed fullness and experienced pressure, tenderness, and fluffiness, with no other ophthalmic or dental symptoms. After clinical, radiological, and histological examinations, the diagnosis was confirmed as JPOF. Surgical excision was performed, followed by immediate reconstruction with an autologous iliac cortical and cancellous bone graft harvested from the right iliac crest under general anesthesia. Good cicatrization of the intraoral surgical wounds and right iliac crest were evident. He was monitored for 6 months after the surgery and exhibited appropriate midfacial contour. There were no signs of recurrence or complications.

Bone Grafting Options

Union rates vary for arthrodesis sites and bone healing in foot and ankle surgery. The ultimate goal is to achieve complete bone healing within a reasonable time. There are many factors that surgeons cannot control, such as the patient's compliance and ability to heal. However, surgeons can control osseous preparation, stable fixation, preservation of soft tissue, and the osseous fusion initial healing environment. Modification of the healing environment can be achieved with the use of bone graft and orthobiologics. This article discusses the grafts and orthobiologics that can be used in bone healing for the foot and ankle.

In vivo effect of UV-photofunctionalization of CoCrMo in processes of guided bone regeneration and tissue engineering

Photofunctionalization of implant materials with ultraviolet (UV) radiation have been subject of study in the last two decades, and previous research on CoCrMo discs have showed good results in terms of bioactivity and the findings of apatite-like crystals in vitro. In the current study, CoCrMo domes were photofunctionalized with UV radiation of 254 nm on their internal faces during 24 hr; they were implanted in rabbit tibia and remained for 3, 4, and 6 weeks. The potential to induce bone formation beneath the dome-shaped membranes was evaluated through morphometric, histologic, and density measurements; and the results were compared with those obtained under control untreated domes. Higher density values were observed for irradiated domes at 3 weeks, whereas higher volumes were obtained under photofunctionalized domes for longer periods (4 and 6 weeks). Histologically, woven bone was formed by endochondral ossification in all cases; differences in the architecture and size of the trabeculae and in the number of osteoblasts were noted between irradiated and non-irradiated samples. The UV radiation of 254 nm generated a larger bone volume fraction compared to that found in the absence of UVC radiation and induced an increase of density in the early stages of healing, leading to a better initial bone quality and improved osseointegration.

Repair of Iliac Crest Defects with a Hydroxyapatite/Collagen Composite

Study Design

Retrospective study.

Purpose

This study aimed to assess the effect of refilling with hydroxyapatite/collagen (HAp/Col) composite on an iliac crest defect after spinal fusion.

Overview of Literature

The use of iliac crest bone graft has been the gold standard in spinal fusion for a long time because of its biological and non-immunologic properties. Few reports have addressed how bone defects recover after iliac crest bone harvest following spinal fusion.

Methods

Cancellous bone was collected from the anterior iliac crest during lateral interbody fusion (LIF), and the bone void of the ilium was refilled with a porous HAp/Col composite. We assessed bone recovery using computed tomography (CT). From the 74 patients who underwent LIF between January 2015 and December 2016, we included 49 patients whose iliac crest could be evaluated using CT at 3 months and 1 year after the surgery.

Results

Bone defects decreased in a time-dependent manner after the surgery. Cortical closure was observed in 28.5% of the cases 3 months after the surgery; at 1 year postoperatively, 95.9% of the patients had cortical closure. Complete repair of the cancellous bone was achieved in 57.1% of the patients at 3 months after the surgery and in 95.9% at 1 year after the surgery. There were no significant hematomas, infections, iliac crest fractures, or soft tissue herniation.

Conclusions

Radiographic recovery of cortical and cancellous bone defects was achieved with high probability via refilling with HAp/Col composite over the 1-year period.

3D Bioprinting for Vascularized Tissue-Engineered Bone Fabrication

Vascularization in bone tissues is essential for the distribution of nutrients and oxygen, as well as the removal of waste products. Fabrication of tissue-engineered bone constructs with functional vascular networks has great potential for biomimicking nature bone tissue in vitro and enhancing bone regeneration in vivo. Over the past decades, many approaches have been applied to fabricate biomimetic vascularized tissue-engineered bone constructs. However, traditional tissue-engineered methods based on seeding cells into scaffolds are unable to control the spatial architecture and the encapsulated cell distribution precisely, which posed a significant challenge in constructing complex vascularized bone tissues with precise biomimetic properties. In recent years, as a pioneering technology, three-dimensional (3D) bioprinting technology has been applied to fabricate multiscale, biomimetic, multi-cellular tissues with a highly complex tissue microenvironment through layer-by-layer printing. This review discussed the application of 3D bioprinting technology in the vascularized tissue-engineered bone fabrication, where the current status and unique challenges were critically reviewed. Furthermore, the mechanisms of vascular formation, the process of 3D bioprinting, and the current development of bioink properties were also discussed.

A Preliminary Study on the Mechanical Reliability and Regeneration Capability of Artificial Bone Grafts in Oncologic Cases, With and Without Osteosynthesis

Several bone grafts are available for clinical use, each with their own peculiar biological and mechanical properties. A new bone graft was obtained by combining mineral structures from natural bovine bones with bioresorbable polymers and cellular nutrients. The study aims to evaluate the clinical, biological and structural properties of this bone graft and its reliability in orthopedic oncology. 23 adult patients (age range 18–85 years) were treated between October 2016 and December 2018; the oncologicdiagnoses were heterogeneous. After surgical curettage and bone grafting, a clinical-radiological follow up was conducted. Radiographs were used to evaluate graft integration according to the usual bone healing and oncologic follow up. Local complications (infection, local recurrence, wound dehiscence, fracture or early reabsorption) were evaluated. The mean followup was of 18.34 ± 4.83 months. No fracture or infection occurred. One case of patellar Giant Cell Tumor (GCT) and one of proximal tibia low-grade chondrosarcoma recurred after about one year. Two wound dehiscences occurred (one required a local flap). Follow-up X-rays showed good to excellent graft integration in most patients (20 out of 21). The investigated graft has a mechanical and structural function that can allow early weight-bearing and avoid a preventive bone fixation (only needed in four patients in this series). The graft blocks are different for shapes and dimensions, but they can be customized by the producer or sawcut by the surgeon in the operating theatre to fit the residual bone cavity. The complication rate was low, and a rapid integration was observed with no inflammatory reaction in the surrounding tissues. Further studies are mandatory to confirm these promising results.

Improved osteogenesis and angiogenesis of a novel copper ions doped calcium phosphate cement

Improving the angio1genesis potential of bone-repairing materials is vital for the repair of cancerous bone defects. It can further facilitate the delivery of active substances with osteogenesis and anti-tumor functions, ultimately promoting the formation of new bone tissues. Copper ions (Cu²⁺) have been proved to be beneficial to angiogenesis. This study developed a new type of Cu-containing calcium phosphate cement (Cu-CPC) by incorporating with copper phosphate (CuP) nanoparticles with a photothermal anti-tumor effect. The results revealed that the main phases of all hydrated CPCs were hydroxyapatite, unreacted tricalcium phosphate and calcium carbonate. But the hydration products of CPC became thinner after the incorporation of Cu²⁺. With the increase of CuP concentration, the setting time of CPC was prolonged while the injectability and the compressive strength were increased. The release concentration of Cu²⁺in vitro was among 0.01 to 0.74 mg/mL, which showed a positive relation with CuP content. Mouse bone marrow stromal cells (mBMSCs) displayed higher adhesion activity, proliferation performance and expression of osteogenic genes and proteins on CPC with 0.01 wt% CuP (0.01Cu-CPC) and 0.05 wt% CuP (0.05Cu-CPC). When human umbilical vein endothelial cells were co-cultured with 0.01Cu-CPC and 0.05Cu-CPC extracts, the proliferation and angiogenesis-related gene and protein expression were significantly increased, and the in vitro tube formation capacity was promoted. However, higher CuP content inhibited the proliferation of mBMSCs. In conclusion, CPC with 0.01 wt% and 0.05 wt% CuP nanoparticles has the potential to promote bone formation around cancerous bone defects, which would be promising for bone regeneration and treatment of bone tumors.

Burst, Short, and Sustained Vitamin D3 Applications Differentially Affect Osteogenic Differentiation of Human Adipose Stem Cells

Incorporation of 1,25(OH)₂ vitamin D₃ (vitD₃) into tissue-engineered scaffolds could aid the healing of critical-sized bone defects. We hypothesize that shorter applications of vitD₃ lead to more osteogenic differentiation of mesenchymal stem cells (MSCs) than a sustained application. To test this, release from a scaffold was mimicked by exposing MSCs to exactly controlled vitD₃ regimens. Human adipose stem cells (hASCs) were seeded onto calcium phosphate particles, cultured for 20 days, and treated with 124 ng vitD₃, either provided during 30 min before seeding ([200 nM]), during the first two days ([100 nM]), or during 20 days ([10 nM]). Alternatively, hASCs were treated for two days with 6.2 ng vitD₃ ([10 nM]). hASCs attached to the calcium phosphate particles and were viable (~75%). Cell number was not affected by the various vitD₃ applications. VitD₃ (124 ng) applied over 20 days increased cellular alkaline phosphatase activity at Days 7 and 20, reduced expression of the early osteogenic marker RUNX2 at Day 20, and strongly upregulated expression of the vitD₃ inactivating enzyme CYP24. VitD₃ (124 ng) also reduced RUNX2 and increased CYP24 applied at [100 nM] for two days, but not at [200 nM] for 30 min. These results show that 20-day application of vitD₃ has more effect on hASCs than the same total amount applied in a shorter time span.

Biologically Inspired Collagen/Apatite Composite Biomaterials for Potential Use in Bone Tissue Regeneration-A Review

Type I collagen and nanocrystalline-substituted hydroxyapatite are the major components of a natural composite—bone tissue. Both of these materials also play a significant role in orthopedic surgery and implantology; however, their separate uses are limited; apatite is quite fragile, while collagen’s mechanical strength is very poor. Therefore, in biomaterial engineering, a combination of collagen and hydroxyapatite is used, which provides good mechanical properties with high biocompatibility and osteoinduction. In addition, the porous structure of the composites enables their use not only as bone defect fillers, but also as a drug release system providing controlled release of drugs directly to the bone. This feature makes biomimetic collagen–apatite composites a subject of research in many scientific centers. The review focuses on summarizing studies on biological activity, tested in vitro and in vivo.

Bioactive Three-Dimensional Graphene Oxide Foam/Polydimethylsiloxane/Zinc Silicate Scaffolds with Enhanced Osteoinductivity for Bone Regeneration

Nanocomposite scaffold materials have shown great prospect in promoting bone integration and bone regeneration. A three-dimensional graphene oxide foam/polydimethylsiloxane/zinc silicate (GF/PDMS/ZS) scaffold for bone tissue engineering was synthesized via dip coating and hydrothermal synthesis processes, resulting in the interconnected macroporous structure. The scaffold was characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric (TG) analysis. The result showed that scaffolds exhibiting a porous characteristic had organic-inorganic components similar to natural bone tissue. Moreover, the scaffolds possessed suitable pore size, high porosity, and good mechanical properties. In vitro experiments with mouse bone marrow mesenchymal stem cells (mBMSCs) revealed that the composite scaffold not only has great biocompatibility but also has the ability to induce mBMSC proliferation and preferential osteogentic differentiation. Thereafter, the expression of critical genes, ALP, RUNX2, VEGFA, and OPN, was activated. In vivo analysis of critical bone defect in rabbits demonstrated superior bone formation in defect sites in the GF/PDMS/ZS scaffold group at 12 weeks of post implantation without no significant inflammatory response. All the results validated that the GF/PDMS/ZS scaffold is a promising alternative for applications in bone regeneration.

Surgical Treatment of Solitary Enchondromas of the Hand

Objective: The present retrospective study evaluated the clinical and radiologic results of patients who underwent complete curettage and autologous bone grafting for hand-located isolated enchondromas with a minimum follow-up period of one year.

Patients and Methods: Thirty-two patients with a follow-up period of at least 12 months who underwent operation between August 2010 and October 2018 due to the presence of solitary enchondroma of the hand were included in the study. All patients underwent complete curettage and filling of the defect via autologous bone grafting. Autologous bone graft was harvested from the iliac crest and distal radius in 24 and eight patients, respectively. The patients underwent radiography on the first postoperative visit and at six weeks, 12 weeks, and annually. The range of movement of the finger joint was evaluated by comparing it with the healthy contralateral side. Functional outcomes and radiologic outcomes were evaluated. The frequency of complications and recurrences were established.

Results: Twelve patients were male and 20 were female. The average age was 34 (range: 16-56) years. The most common digit involved was the little finger (nine cases, 28.125%); the proximal phalanx was the most common location (17 cases, 53.125%). Control radiography in the sixth week revealed graft consolidation in all patients. No case of nonunion or recurrence was detected clinically or radiologically, with a mean follow-up period of 54 (range: 12-96) months. Functional outcomes were classified as excellent in 28 patients and as good in four patients. The final radiographic appearances included Tordai’s group 1 in 28 bones and group 2 in four bones. 

Conclusion: Curettage and autologous bone grafting are safe, costless, and effective treatment options for hand enchondroma, with satisfactory functional and radiographic outcomes. Harvesting bone graft from the distal radius provides a shorter length of hospital stay and lower complication rates compared to obtaining the graft from the iliac crest.

Reconstruction of a Traumatic Partial First-Ray Amputation with the Use of an Induced Pseudosynovial Membrane and Corticocancellous Autograft

Reconstruction of large bone defects of the metatarsals, whether resulting from trauma, infection, or a neoplastic process, can be especially challenging when attempting to maintain an anatomical parabola and basic biomechanical stability of the forefoot. We present the case of a 42-year-old man with no significant medical history who presented to the emergency department following a severe lawnmower injury to the left forefoot resulting in a large degloving type injury along the medial aspect of the left first ray extending to the level of the medial malleolus. The patient underwent emergent debridement with application of antibiotic bone cement, external fixation, and a negative-pressure dressing. He was subsequently treated with split-thickness skin graft and iliac crest tricortical autograft using a locking plate construct for reconstruction of the distal first ray. Although the patient failed to advance to radiographic osseous union, clinically there was no motion at the attempted fusion site and no pain with ambulation, suggestive of a pseudoarthrosis. The patient has since progressed to full nonpainful weightbearing in regular shoes and has returned to normal activities of daily living. The patient returned to his preinjury level of work and has had complete resolution of all wounds including his split-thickness skin graft donor site. This case shows the potential efficacy of the Masquelet technique for spanning significant traumatic bone defects of the metatarsals involving complete loss of the metatarsophalangeal joint.

Fibular-Lengthening Osteotomy in Patient with Progressive Valgus Deformity After an Ankle Fracture

Patient: Male, 23-year-old

Final Diagnosis: Malunion fracture of the fibula

Symptoms: Pain and limited movement in the right ankle

Medication:—

Clinical Procedure: Fibular-lengthening osteotomy

Specialty: Orthopedics and Traumatology

Iliac Crest Bone Grafting for the Management of Anterior Shoulder Instability in Patients with Glenoid Bone Loss: a Systematic Review of Contemporary Literature

BACKGROUND

A number of clinical trials have been published assessing the role of iliac crest bone grafting for the management of recurrent anterior instability with glenoid bone loss in contemporary practice. We therefore performed a systematic review of contemporary literature to examine the effect of iliac crest bone grafting on postoperative outcomes of these patients. Our hypothesis is that contemporary iliac crest bone block techniques are associated with low reoperation and complication rates combined with satisfactory functional results.

METHODS

The US National Library of Medicine (PubMed/MEDLINE), the Cochrane Database of Systematic Reviews, and EMBASE were searched between January 2008 and December 2019 for relevant publications.

RESULTS

Following the application of the inclusion-exclusion criteria, nine articles were found eligible for our analysis. In total, 261 patients (mean age range, 25.5-37.5 years; mean follow-up range, 20.6-42 months) were included in the studies of the current review. The mean modified Coleman score was 48.6 (range 37-65), indicating an overall low-to-moderate methodological quality. In the short term, the overall all-cause reoperation rate was 6.1%, while the rate of recurrent instability was 4.8%. The graft non-union rate was 2.2%, while the rate of osteolysis, graft fracture, and infection was 0.4%, 0.9%, and 1.7%, respectively. Finally, hardware-related complications, such as screw breakage or symptomatic mechanical irritation around the screw insertion, occurred in 3.9% of the patients.

CONCLUSIONS

Iliac crest bone block techniques in contemporary practice are safe and effective in the short-term (< 4 years) follow-up for the management of anterior shoulder instability with substantial glenoid bone deficiency. However, further studies of higher quality and longer follow-up are required to establish the therapeutic value of these techniques as well as to clarify whether there are differences in the outcomes of arthroscopic and open iliac crest bone block procedures.

Autologous Iliac Bone Graft Compared with Biphasic Hydroxyapatite and Calcium Sulfate Cement for the Treatment of Bone Defects in Tibial Plateau Fractures: A Prospective, Randomized, Open-Label, Multicenter Study

BACKGROUND

Bone-graft substitutes are commonly used for the augmentation of traumatic bone defects in tibial plateau fractures. However, their clinical performance compared with that of autologous bone-grafting, the gold standard in bone defect reconstruction, still remains under debate. This study investigates the differences in quality of life, pain, and radiographic outcomes in the treatment of tibial plateau fracture-associated bone defects with either autologous bone grafts or a bioresorbable hydroxyapatite and calcium sulfate cement (CERAMENT BONE VOID FILLER [CBVF]; BONESUPPORT).

METHODS

In this study, 135 patients with acute depression and split-depression fractures of the proximal part of the tibia (OTA/AO types 41-B2 and 41-B3) were enrolled in a prospective, controlled, randomized, multicenter trial including 20 hospitals in Germany. Patients were randomized to receive either autologous iliac bone graft or CBVF for reconstruction of the bone defect. The primary outcome measures were the Short Form (SF)-12 version 2 Physical Component Summary (PCS) score at week 26 (the study was designed to show noninferiority of the CBVF with regard to the PCS with a prespecified margin of -5 points) and the pain level at 26 weeks postoperatively measured by a visual analog scale (VAS). The secondary outcomes were the SF-12 version 2 Mental Component Summary (MCS) and SF-12 PCS scores at weeks 1, 6, and 12 and bone-healing on radiographs.

RESULTS

Age, sex, fixation methods, and fracture pattern were comparable in both groups. There were no significant differences (p > 0.05) in the SF-12 PCS or VAS scores at postoperative week 26. There was a significant reduction of blood loss (p = 0.007) and pain levels (p = 0.008) at postoperative day 1 in the CBVF group. The rates of fracture-healing, defect remodeling, and articular subsidence were not significantly different (p > 0.05) in both groups.

CONCLUSIONS

Bioresorbable CBVF was noninferior to autologous bone graft with regard to both patient-reported and radiographic outcomes in tibial plateau fractures of OTA/AO types 41-B2 and 41-B3.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Immobilization of nanocarriers within a porous chitosan scaffold for the sustained delivery of growth factors in bone tissue engineering applications

To guide the natural bone regeneration process, bone tissue engineering strategies rely on the development of a scaffold architecture that mimics the extracellular matrix and incorporates important extracellular signaling molecules, which promote fracture healing and bone formation pathways. Incorporation of growth factors into particles embedded within the scaffold can offer both protection of protein bioactivity and a sustained release profile. In this work, a novel method to immobilize carrier nanoparticles within scaffold pores is proposed. A biodegradable, osteoconductive, porous chitosan scaffold was fabricated via the "freeze-drying method," leading to scaffolds with a storage modulus of 8.5 kPa and 300 μm pores, in line with existing bone scaffold properties. Next, poly(methyl methacrylate-co-methacrylic acid) nanoparticles were synthesized and immobilized to the scaffold via carbodiimide-crosslinker chemistry. A fluorescent imaging study confirmed that the conventional methods of protein and nanocarrier incorporation into scaffolds can lead to over 60% diffusion out of the scaffold within the first 5 min of implantation, and total disappearance within 4 weeks. The novel method of nanocarrier immobilization to the scaffold backbone via carbodiimide-crosslinker chemistry allows full retention of particles for up to 4 weeks within the scaffold bulk, with no negative effects on the viability and proliferation of human umbilical vein endothelial cells.

Study on antibacterial properties and cytocompatibility of EPL coated 3D printed PCL/HA composite scaffolds

Biomaterial scaffolds play a critical role in bone tissue engineering. Moreover, 3D printing technology has enormous advantage in the manufacture of bioengineering scaffolds for patient-specific bone defect treatments. In order to provide an aseptic environment for bone regeneration, ε-poly-l-lysine (EPL), an antimicrobic cationic polypeptide, was used for surface modification of 3D printed polycaprolactone/hydroxyapatite (PCL/HA) scaffolds which were fabricated by fused deposition modeling (FDM) technology. The scaffold morphology and micro-structure were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transform infrared spectroscopy (FT-IR). The release profile surface roughness, open porosity, and mechanical properties of the scaffolds were evaluated. Cell adhesion, proliferation, differentiation potential and antibacterial properties were also examined. As a result, 3D printed PCL/HA scaffolds with interconnected pores showed a slightly rough surface and improved mechanical properties due to adding hydroxyapatite (HA) particles. After being modified by EPL, favorable biocompatibility and osteoconductivity of ε-poly-l-lysine/polycaprolactone/hydroxyapatite (EPL/PCL/HA) scaffolds were observed. Moreover, antibacterial activity of the EPL/PCL/HA scaffolds was apparent. As a consequence, the EPL/PCL/HA scaffolds had great potential for bone regeneration and prevention of infections. This would yield a patient-specific bioactive and antibacterial composite scaffold for advanced bone tissue engineering applications.

A sericin/ graphene oxide composite scaffold as a biomimetic extracellular matrix for structural and functional repair of calvarial bone

Bone defects affect millions of people worldwide each year, leading to severe disabilities. Biomimetic scaffolds mediated tissue regeneration represents a promising alternative for bone repair. However, the major problem associated with most currently clinical available artificial bone substitutes (scaffolds) is that they mainly possess filling function but lack of osteo-induction abilities. Therefore, development of biomaterials with osteo-induction property for effective bone regeneration is highly desired. Methods: We report the design and fabrication of a photo-crosslinked sericin methacryloyl (SerMA)/ graphene oxide (GO) hydrogel (SMH/GO) as a biomimetic scaffold for the functional repair of the bone. The mechanical strength, degradation and biocompatibility behavior of SMH/GO hydrogel were measured in vitro. The effect of SMH/GO hydrogel on BMSCs proliferation, migration, osteogenesis differentiation was assessed. After that, SMH/GO-2 was used as an artificial bone substitute for bone regeneration after calvarial defects and effect on bone repair was evaluated by histological, X-Ray and microCT analysis. Furthermore, the potential mechanism of SMH/GO hydrogel regulating BMSCs migration and differentiation was investigated by RNA sequencing. Results: This scaffold has good biocompatibility, cell adhesive property, proliferation- and migration-promoting effects, and osteogenic induction property. After being implanted in a rat calvarial defect model, this SMH/GO scaffold effectively promotes new bone regeneration and achieves structural and functional repair within 12 weeks by inducing autologous bone marrow-derived mesenchymal stem cells (BMSCs) differentiation. By utilizing cell-biological assays and RNA sequencing, we reveal its possible regeneration mechanisms: the SMH/GO hydrogel regulates BMSCs migration and osteo-differentiation via activating MAPK, TNF, and chemokine signaling for bone regeneration. Conclusion: Aiming to meet clinical demands and overcome current limitations of existing artificial bones, we have developed a new type of sericin/ graphene oxide composite scaffold and provided histological, functional, and molecular evidence demonstrating that it is capable of effectively repairing defective bones by inducing autologous BMSCs directional migration and osteogenic differentiation.

Enchondromas of the Hand: A 20-year Experience

Objective  Enchondromas are the commonest tumors of the bones of the hand. Treatment approaches vary. The present article presents the characteristics of the tumors, diagnostic methods, and treatments.

Methods  We discuss the approach used in our institution, where we have treated 48 patients with enchondromas of the hand between 1996 and 2016. Our technique of treatment, which has remained the same over 2 decades, comprises the use of curettage, high-speed burr, and autologous bone graft (harvested with a minimally invasive technique, using a Craig biopsy needle).

Results  Pain and fractures were the most common symptoms leading the patients to consultation, at frequencies of 33.3% and 31.3%, respectively. A total of 27.1% of the cases were asymptomatic, and their lesions were discovered incidentally. The mean age was 34.4 years (SD = 12.9 years). Tumors were more frequently presented in the ulnar side of the hand, in the fifth ray (41.5%) and in the proximal bones (in the proximal phalanges [43.8%], and in the metacarpal [33.3%]). The size of the tumors ranged from 0.2 cm ² to 5.7 cm ² , with a mean of 1.7 cm ² (standard deviation [SD] = 1.0 cm ² ) and were not associated with fracture ( p  = 0.291). Fracture was also not associated with any of the symptoms, neither with the age of the patients ( p  = 0.964). After the treatment, most patients achieved full range of motion (91.7%), with good integration of the bone graft. Three patients presented deficit in range of motion (6.3%) and the incidence of complications was also 6.3% (3 patients). At the end, after the needed surgical revisions, these three patients also recovered full function. They achieved full bone graft integration, regained full range of motion and returned to work. There was no tumor recurrence case during the follow-up period evaluated. For all cases, no donor site complications occurred.

Conclusion  Our method of treatment has consistently provided good outcomes, with only a few minor complications. Therapeutic level of evidence: IV.

Efficacy and safety of bone substitutes in lumbar spinal fusion: a systematic review and network meta-analysis of randomized controlled trials

PURPOSE

A variety of alternative grafts to autologous iliac crest bone (ICBG) have been developed for lumbar spondylodesis, due to frequent complications following ICBG harvest. The optimal alternative graft to ICBG, however, remains elusive till now. The purpose of this study was to compare the efficacy and safety of fusion materials in lumbar degeneration diseases and to provide a ranking spectrum of the grafts.

METHODS

Randomized controlled trials (RCTs) comparing different bone grafts in lumbar arthrodesis were eligible for inclusion. A network meta-analysis was performed for endpoints including fusion rate and incidence of adverse events.

RESULTS

Twenty-seven RCTs involving 2488 patients and 13 available interventions were included. rhBMP-2 provided the highest fusion rate, being significantly superior to that of ICBG (OR = 0.21, p < 0.001), autograft local bone (ALB) (OR = 0.18, p = 0.022), rhBMP-7 (OR = 0.15, p < 0.001), allograft (OR = 0.13, p = 0.009), and DBM + ALB (OR = 0.07, p = 0.048). The treatment efficacy of allograft could be significantly enhanced by bone marrow concentrate (BMC) supplying (OR = 0.16, p = 0.010). ICBG ranks second on the frequency of complications, which is significantly higher than that of allograft (OR = 0.14, p = 0.041) and ALB (OR = 0.14, p = 0.030). All of the other comparisons showed similar efficacy and safety profiles between groups.

CONCLUSION

Ranking spectrums of the efficacy and safety for various bone grafts were provided graphically. Though rhBMP-2 was of the highest success rate, the application should be taken with proper caution because of the widely proposed life-threatening adverse events. ALB, ALB plus synthetic ceramic materials and allograft mixed with BMC were also proved to be potentially effective alternative graft to ICBG. These slides can be retrieved under Electronic Supplementary Material.

Eight to eleven-year follow-up of immediately loaded implants placed in edentulous maxillae with compromised bone volume and poor bone quality: A prospective cohort study

BACKGROUND

There is a lack of long-term evaluations of immediately loaded implants in patients with compromised maxillary bone.

PURPOSE

To evaluate long-term survival and success of immediately loaded implants in subjects with poor maxillary bone quality and volume.

MATERIAL AND METHODS

Follow-up was performed on subjects who received six implants loaded within 24 hours with screw-retained fixed prostheses. Twenty-five subjects with limited bone (Lekholm and Zarb, quantity 3 and 4, and quality C and D) were included in the study. Nineteen participated in the radiographic examination and of these 17 participated in the clinical examination at the last visit. Evaluations of marginal bone loss were performed at 1, 3, 5, and 8-11 years. The last clinical examination included removal of the prosthesis followed by registration of: plaque, pus, pocket depth, bleeding upon probing, mobility, and percussion testing.

RESULTS

The mean follow-up was 9 years and 2 months (101-131 months) after surgery and showed a cumulative implant survival rate of 81.9% and success rate of 74.7%. Mean marginal bone loss was 1.29 mm (SD 2.47 mm range 0-11 mm) with a mean pocket depth of 3.1 mm (SD 2.4 mm, range 1.5-13.5 mm). 42.5% of the implants showed plaque retention and 72.2% showed bleeding on probing.

CONCLUSION

This nonaugmenting immediate loaded implant protocol for maxillary edentulous patients is a satisfactory solution for selected patients.