Non-union Bone Fractures Research Articles

Electroceutical Technology: Anti-Inflammatory Effects Of 40-160 T/S Inductively Coupled Electrical Stimulation (ICES) In The Acute Inflammation Model

Electromagnetic therapies (sic: electroceuticals) have been studied and used for many years as a treatment for many ailments including chronic and acute pain, inflammation, muscle atrophy, non-union bone fractures, as well as peripheral and central neuropathies [1].
 Presently we seek to explore the realm of inductively coupled electrical stimulation (ICES) which is a subclass of pulsed electromagnetic field therapies (PEMFs) that uses rapidly changing electromagnetic fields to induce current flows in tissues. Such fields are hypothesized to act via various mechanisms. However, in the present we seek to clarify the often ambiguous and confusing literature regarding ICES mechanisms by conducting a scholarly review by which we then provide a dose reporting scheme for accurately describing the relevant parameters required to fully define ICES treatments. Based on our review and experience, we hypothesize that ICES requires very specific parameters to function appropriately. We seek to ascertain the efficacy of 40-160 Tesla/second (T/s) ICES stimulation as an anti-inflammatory therapy. A specific mechanism explored is the calcium/calmodulin (Ca/CaM) pathway implicated in the literature [2-9] . Our results bring into question the scientific methods of previously reported results by suggesting that nitric oxide levels in vitro fall below detection limits of commonly used methods for gauging Ca/CaM modulation by ICES. In an effort to elucidate the efficacy of ICES as an anti-inflammatory, we make use of the well-established carrageenan footpad edema (CFE) model in rats. The CFE model provides a spontaneously-resolving, acute inflammation model with a very well understood progression and biochemical mechanism. Our results indicate that 40-160 T/s ICES provides statistically significant, repeatable CFE reduction (P < 0.05) as measured by plethysmometry with no observed detrimental side-effects. Further work should focus on elucidating mechanism, evaluating safety, and exploring other potential applications—such as treating chronic conditions. The present studies support ICES as having the potential to provide life-changing therapy to individuals suffering from acute inflammation and pain.
 Given carefully conducted research in the future, we feel that ICES may revolutionize modern medicine not only from a treatment standpoint, but from the standpoint of understanding basic human electrophysiology and biochemistry.

Scaffolds and coatings for bone regeneration.

Bone tissue has an astonishing self-healing capacity yet only for non-critical size defects (<6 mm) and clinical intervention is needed for critical-size defects and beyond that along with non-union bone fractures and bone defects larger than critical size represent a major healthcare problem. Autografts are, still, being used as preferred to treat large bone defects. Mostly, due to the presence of living differentiated and progenitor cells, its osteogenic, osteoinductive and osteoconductive properties that allow osteogenesis, vascularization, and provide structural support. Bone tissue engineering strategies have been proposed to overcome the limited supply of grafts. Complete and successful bone regeneration can be influenced by several factors namely: the age of the patient, health, gender and is expected that the ideal scaffold for bone regeneration combines factors such as bioactivity and osteoinductivity. The commercially available products have as their main function the replacement of bone. Moreover, scaffolds still present limitations including poor osteointegration and limited vascularization. The introduction of pores in scaffolds are being used to promote the osteointegration as it allows cell and vessel infiltration. Moreover, combinations with growth factors or coatings have been explored as they can improve the osteoconductive and osteoinductive properties of the scaffold. This review focuses on the bone defects treatments and on the research of scaffolds for bone regeneration. Moreover, it summarizes the latest progress in the development of coatings used in bone tissue engineering. Despite the interesting advances which include the development of hybrid scaffolds, there are still important challenges that need to be addressed in order to fasten translation of scaffolds into the clinical scenario. Finally, we must reflect on the main challenges for bone tissue regeneration. There is a need to achieve a proper mechanical properties to bear the load of movements; have a scaffolds with a structure that fit the bone anatomy.

Reconstruction of Large Skeletal Defects: Current Clinical Therapeutic Strategies and Future Directions Using 3D Printing.

The healing of bone fractures is a well-orchestrated physiological process involving multiple cell types and signaling molecules interacting at the fracture site to replace and repair bone tissue without scar formation. However, when the lesion is too large, normal healing is compromised. These so-called non-union bone fractures, mostly arising due to trauma, tumor resection or disease, represent a major therapeutic challenge for orthopedic and reconstructive surgeons. In this review, we firstly present the current commonly employed surgical strategies comprising auto-, allo-, and xenograft transplantations, as well as synthetic biomaterials. Further to this, we discuss the multiple factors influencing the effectiveness of the reconstructive therapy. One essential parameter is adequate vascularization that ensures the vitality of the bone grafts thereby supporting the regeneration process, however deficient vascularization presents a frequently encountered problem in current management strategies. To address this challenge, vascularized bone grafts, including free or pedicled fibula flaps, or in situ approaches using the Masquelet induced membrane, or the patient’s body as a bioreactor, comprise feasible alternatives. Finally, we highlight future directions and novel strategies such as 3D printing and bioprinting which could overcome some of the current challenges in the field of bone defect reconstruction, with the benefit of fabricating personalized and vascularized scaffolds.

Validation of a long bone fracture non-union healing score after treatment with mesenchymal stromal cells combined to biomaterials

The available scores to clinically evaluate fracture consolidation encounter difficulties to interpret progression towards consolidation in long-bone non-union, particularly when incorporating biomaterials in the surgical treatment. The aims of this study were to validate the REBORNE bone healing scale in tibia, humerus and femur non-unions treated by a combination of mesenchymal stromal cells (MSCs) and biomaterials, through the interclass correlation (ICC) among raters, and to define reliability and concordance in anteroposterior and lateral radiographs, compared to computed tomography (CT). MethodsTwenty-six cases from the EudraCT 2011-005441-13 clinical trial underwent bone healing evaluation, if at least 3 out of 4 cortical views clearly identified. Three senior orthopaedic surgeons evaluated radiographs and CTs at 3 and 6 months FU. All cases included preoperative imaging and radiographs at 12 months. The 4-stage scale score was obtained from each cortical view in orthogonal radiographs or CTs. A score of 0.6875 (11/16) was set as a threshold for bone healing. Statistically, ICC evaluated agreement among raters. Cronbach's alpha coefficient tested reliability. Lin's concordance correlation coefficients (CCC) were estimated between mean CT scores and mean radiographic scores. Bland and Altman graphs provided the limits of agreement between both imaging techniques. Sensitivity and specificity were assessed in radiographs (against CT), and the Area Under the Receiver Operating Characteristics (ROC) Curve was estimated. The probability to predict bone consolidation with REBORNE scores obtained from radiographs was modelled. ResultsAn ICC of 0.88 and 0.91 (CT and radiographs) confirmed agreement in the REBORNE score for non-union bone healing, with an inter-rater reliability of 0.92 and 0.95. Scores through the radiographic evaluation were found equivalent to the CTs at 6 months FU. A CCC of 0.79 was detected against CT. The radiographic scores in the REBORNE bone healing scale correctly classified bone consolidation in 77%, with an accuracy of 83% based on ROC curves. ConclusionsThe REBORNE score measured with CT or radiographic images was reliable among raters at a follow-up time above 6 months for long bone non-union fractures. The REBORNE scale measured with radiographs proved valid to assess consolidation against CT measurements.

Scoring of radiographic cortical healing with the radiographic humerus union measurement predicts union in humeral shaft fractures.

The purpose of this study is to determine if the radiographic humerus union measurement (RHUM) is predictive of union in humeral shaft fractures treated nonoperatively. All patients with long bone fracture nonunion presenting to a single surgeon were enrolled in a prospective registry. This registry was queried to identify patients with humeral shaft fractures treated nonoperatively and developed nonunion. The nonunion cohort was matched to a three to one gender- and age-matched control group that were treated nonoperatively for a humeral shaft fracture and achieved union. Two fellowship-trained orthopedic traumatologists blinded to eventual union scored radiographs obtained 12weeks after injury using the RHUM. A binomial logistic regression determined the effect of the RHUM on the likelihood of developing union. Nine patients with humeral shaft fractures treated nonoperatively with radiographs 12weeks after injury that developed nonunion were identified. These patients were matched to 27 controls. Logistic regression demonstrated the RHUM was a significant predictor of healing 12weeks after humeral shaft fracture treated nonoperatively (p = 0.014, odds ratio 9.434, 95% CI for OR 1.586-56.098). All patients with RHUM below 7 went on to nonunion. All patients with RHUM above 8 healed. Three of seven patients (43%) with RHUM of 7 or 8 healed. The RHUM demonstrated an increased likelihood of achieving union 12weeks after injury. Orthopedic surgeons can counsel patients that fractures with RHUM scores of 6 or below are in danger of developing nonunion and can target interventions appropriately.

Effect of Pulsed Electromagnetic Fields on Human Mesenchymal Stem Cells Using 3D Magnetic Scaffolds.

Alternative bone regeneration strategies that do not rely on harvested tissue or exogenous growth factors are needed. One of the major challenges in tissue reconstruction is recreating the bone tissue microenvironment using the appropriate combination of cells, scaffold, and stimulation to direct differentiation. This study presents a bone regeneration formulation that involves the use of human adipose‐derived mesenchymal stem cells (hASCs) and a three‐dimensional (3D) hydrogel scaffold based on self‐assembled RADA16 peptides containing superparamagnetic iron oxide nanoparticles (NPs). Although superparamagnetic NPs could be used as stimulus to manipulate the cell proliferation and differentiation, in this paper their use is explored for assisting osteogenic differentiation of hASCs in conjunction with direct stimulation by extremely low‐frequency pulsed electromagnetic fields (pEMFs). Cellular morphology, proliferation, and viability, as well as alkaline phosphatase activity, calcium deposition, and osteogenic capacity were monitored for cells cultured up to 21 days in the 3D construct. The results show that the pEMFs and NPs do not have any negative effect on cell viability, but instead distinctly induced early differentiation of hASCs to an osteoblastic phenotype, when compared with cells without biophysical stimulation. This effect is attributed to synergy between the pEMFs and NPs, which may have stimulated mechanotransduction pathways, which, in turn activated biochemical signals between cells to differentiate or proliferate. This approach may offer a safe and effective option for the treatment of non‐union bone fractures. Bioelectromagnetics. © 2020 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.

Surgical angiogenesis for scaphoid non-union: a literature review

&nbsp; Non-union of scaphoid bone fractures, though an uncommon occurance, are a signficant cause of morbidity in young patients. This review outlines the current understanding of vascularised bone grafts and non-union, and examines the most current clinical literature regarding the role of these procedures in modern orthopaedic practice. Composite evidence from level III studies would support using osseous grafts on a vascular pedicle for patients with non-union of the proximal end of the scaphoid with associated avascular necrosis and in cases of revision surgery where a previous non-vascularised graft has failed to achieve bony union. &nbsp

Preclinical biological and physicochemical evaluation of two-photon engineered 3D biomimetic copolymer scaffolds for bone healing.

A major challenge in orthopedics is the repair of large non-union bone fractures. A promising therapy for this indication is the use of biodegradable bioinspired biomaterials that stabilize the fracture site, relieve pain and initiate bone formation and healing. This study uses a multidisciplinary evaluation strategy to assess immunogenicity, allergenicity, bone responses and physicochemical properties of a novel biomaterial scaffold. Two-photon stereolithography generated personalized custom-built scaffolds with a repeating 3D structure of Schwarz Primitive minimal surface unit cell with a specific pore size of ∼400 μm from three different methacrylated poly(d,l-lactide-co-ε-caprolactone) copolymers with lactide to caprolactone monomer ratios of 16 : 4, 18 : 2 and 9 : 1. Using in vitro and in vivo assays for bone responses, immunological reactions and degradation dynamics, we found that copolymer composition influenced the scaffold physicochemical and biological properties. The scaffolds with the fastest degradation rate correlated with adverse cellular effects and mechanical stiffness correlated with in vitro osteoblast mineralization. The physicochemical properties also correlated with in vivo bone healing and immune responses. Overall these observations provide compelling support for these scaffolds for bone repair and illustrate the effectiveness of a promising multidisciplinary strategy with great potential for the preclinical evaluation of biomaterials.

Osteogenesis and bone remodeling: A focus on growth factors and bioactive peptides.

Bone is one of the most frequently transplanted tissues. The bone structure and its physiological function and stem cells biology were known to be closely related to each other for many years. Bone is considered a home to the well-known systems of postnatal mesenchymal stem cells (MSCs). These bone resident MSCs provide a range of growth factors (GF) and cytokines to support cell growth following injury. These GFs include a group of proteins and peptides produced by different cells which are regulators of important cell functions such as division, migration, and differentiation. GF signaling controls the formation and development of the MSCs condensation and plays a critical role in regulating osteogenesis, chondrogenesis, and bone/mineral homeostasis. Thus, a combination of both MSCs and GFs receives high expectations in regenerative medicine, particularly in bone repair applications. It is known that the delivery of exogenous GFs to the non-union bone fracture site remarkably improves healing results. Here we present updated information on bone tissue engineering with a specific focus on GF characteristics and their application in cellular functions and tissue healing. Moreover, the interrelation of GFs with the damaged bone microenvironment and their mechanistic functions are discussed.

Translational Insights into Extremely Low Frequency Pulsed Electromagnetic Fields (ELF-PEMFs) for Bone Regeneration after Trauma and Orthopedic Surgery.

The finding that alterations in electrical potential play an important role in the mechanical stimulation of the bone provoked hype that noninvasive extremely low frequency pulsed electromagnetic fields (ELF-PEMF) can be used to support healing of bone and osteochondral defects. This resulted in the development of many ELF-PEMF devices for clinical use. Due to the resulting diversity of the ELF-PEMF characteristics regarding treatment regimen, and reported results, exposure to ELF-PEMFs is generally not among the guidelines to treat bone and osteochondral defects. Notwithstanding, here we show that there is strong evidence for ELF-PEMF treatment. We give a short, confined overview of in vitro studies investigating effects of ELF-PEMF treatment on bone cells, highlighting likely mechanisms. Subsequently, we summarize prospective and blinded studies, investigating the effect of ELF-PEMF treatment on acute bone fractures and bone fracture non-unions, osteotomies, spinal fusion, osteoporosis, and osteoarthritis. Although these studies favor the use of ELF-PEMF treatment, they likewise demonstrate the need for more defined and better controlled/monitored treatment modalities. However, to establish indication-oriented treatment regimen, profound knowledge of the underlying mechanisms in the sense of cellular pathways/events triggered is required, highlighting the need for more systematic studies to unravel optimal treatment conditions.

The use of regional anaesthesia for surgical intervention has minimal effect on functional outcomes following fracture nonunion repair

PurposeThe purpose of this study was to determine the effect of regional anaesthesia as compared to general anaesthesia on clinical, functional, and radiographic outcomes following long bone fracture nonunion repair. Methods262 patients who underwent operative repair of a long bone fracture nonunion and had at least 12 months of post-operative follow up were included in this study. Functional outcomes were assessed prospectively using the Short Musculoskeletal Function Assessment (SMFA) and Visual Analog Scale (VAS) pain scores prior to nonunion repair and at routine intervals post-operatively. Patients were divided into two matched groups based upon the type of anaesthetic method used in surgery. The regional anaesthesia cohort was composed of all patients who received regional anaesthesia (spinal anaesthesia or peripheral nerve block) alone or in addition to general anaesthesia, while patients who received general anaesthesia alone made up the general anaesthesia cohort. Univariate and multivariate analyses were performed to examine the effect of anaesthesia type on functional outcome scores, post-operative pain, bony healing, and complication rate. ResultsThe regional anaesthesia and general anaesthesia cohorts each consisted of 131 patients. Multiple linear regression demonstrated there to be no significant association between anaesthetic method and total SMFA scores at all post-operative time points. Additionally, anaesthetic method was not associated with post-operative VAS pain scores, time to union, or the rate of post-operative complications. ConclusionIn this cohort, the use of regional anaesthesia during operative repair of long bone fracture nonunion was associated with no significant difference in functional outcome scores or pain levels at all post-operative time points. Furthermore, the use of regional anaesthesia had no effect on the rate of post-operative complications. Either type of anaesthetic appears to be safe and effective in performing these surgeries.

Biological Compatibility Profile on Biomaterials for Bone Regeneration.

Large non-union bone fractures are a significant challenge in orthopedic surgery. Although auto- and allogeneic bone grafts are excellent for healing such lesions, there are potential complications with their use. Thus, material scientists are developing synthetic, biocompatible biomaterials to overcome these problems. In this study, we present a multidisciplinary platform for evaluating biomaterials for bone repair. We combined expertise from bone biology and immunology to develop a platform including in vitro osteoclast (OC) and osteoblast (OB) assays and in vivo mouse models of bone repair, immunogenicity, and allergenicity. We demonstrate how to perform the experiments, summarize the results, and report on biomaterial biocompatibility. In particular, we tested OB viability, differentiation, and mineralization and OC viability and differentiation in the context of β-tricalcium phosphate (β-TCP) disks. We also tested a β-TCP/Collagen (β-TCP/C) foam which is a commercially available material used clinically for bone repair in a critical-sized calvarial bone defect mouse model to determine the effects on the early phase of bone healing. In parallel experiments, we evaluated immune and allergic responses in mice. Our approach generates a biological compatibility profile of a bone biomaterial with a range of parameters necessary for predicting the biocompatibility of biomaterials used for bone healing and repair in patients.

Application of mesenchymal stem cells to enhance non-union bone fracture healing.

ECM components include a number of osteoinductive and osteoconductive factors, which are involved in bone fracture healing. In this study, a combination of adipose derived mesenchymal stem cells (Ad-MSCs), cancellous bone graft (CBG), and chitosan hydrogel (CHI) was applied to the non-union bone fracture and healing effects were evaluated for the first time. After creation of animal models with non-union fracture in rats, they were randomly classified into seven groups. Radiography at 0, 2, 4, and 8 weeks after surgery, indicated the positive effects of Ad-MSCs + CBG + CHI and Ad-MSCs + CBG in treatment of bone fractures as early as 2 weeks after the surgery. These data were confirmed with both biomechanical and histological studies. Gene expression analyses of Vegf and Bmp2 showed a positive effect of Ad-MSCs on vascularization and osteogenic differentiation in all groups receiving Ad-MSCs, as shown by real-time PCR. Immunofluorescence analysis and RT-PCR results indicated existence of human Ad-MSCs in the fractured region 8 weeks post-surgery. In conclusion, we suggest that application of Ad-MSCs, CBG, and CHI, could be a suitable combination for osteoinduction and osteoconduction to improve non-union bone fracture healing. Further investigations are required to determine the exact mechanisms involved in this process before moving to clinical studies. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 301-311, 2019.

Risk factors for nonunion of bone fracture in pediatric patients: An inception cohort study of 237,033 fractures.

Adult fracture nonunion risk is related to injury severity and surgical technique, yet nonunion is not fully explained by these risk factors alone; biological risk factors are also important. We test a hypothesis that risk factors associated with pediatric fracture nonunion are similar to adult nonunion risk factors.Inception cohort study in a large payer database of pediatric fracture patients (0–17 years) in the United States in calendar year 2011. Continuous enrollment in the database was required for 12 months, to allow time to capture a nonunion diagnosis. The final database collated demographic descriptors, treatment procedures as per Current Procedural Terminology (CPT) codes, comorbidities as per International Statistical Classification of Diseases and Related Health Problems (ICD-9) codes, and drug prescriptions as per National Drug Code Directory (Red Book) codes. Logistic regression was used to calculate odds ratios (ORs) for variables associated with nonunion.Among 237,033 pediatric fractures in 18 bones, the nonunion rate was 0.85%. Increased nonunion risk was associated with increasing age, male gender, high body-mass index, severe fracture (e.g., open fracture, multiple fractures), and tobacco smoking (all, P < .0001). Nonunion rate varied with fracture location; scaphoid, neck of femur, and tibia/fibula were most likely to go to nonunion. Nonunion ORs were significantly increased for risk factors including; surgical procedure, cardiovascular disease, Vitamin D deficiency, osteoarthritis, osteoporosis, and opioid prescription (all, multivariable P < .001).Nonunion is rare in pediatric patients, but nonunion risk increases with increasing age. We confirm a hypothesis that risk factors for pediatric nonunion are similar to adult nonunion risk factors. Scaphoid fractures in adolescents have nearly the same risk of nonunion as in adults. Opioids should be used cautiously in pediatric patients, as they are associated with a significant and substantial elevation of nonunion risk.Level of Evidence: Prognostic study, Retrospective, Level II.

Prospective study of managing long bone fracture nonunion: is bone graft needed in every case?

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Increased road traffic accidents lead to increased incidence of fracture of long bones. It has a tendency of non-union. Infection is very common in these cases which are an important cause of nonunion of long bone fractures. The objective of the study was to study the incidence and patterns of non-union of long bone fracture.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Hospital based prospective study was carried out at Department of Orthopedics, from June 2017 to March 2018. Patients admitted to wards of Department of Orthopedics with nonunion of long bones were included. During the study period a total of 20 cases were eligible for the present study as per the inclusion and exclusion criteria.&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Results:&lt;/strong&gt; Males were more affected than females. Most commonly affected age group was 41-50 years and 61-70 years (25% each). Most commonly affected long bone was femur in 35% of the cases. Most common type of non-union was hypertrophic (50%). Most common cause of non-union was broken implant in 35% of the cases. Maximum number of patients had union in 4-6 months in 60% of the cases after surgery of previous non-union of long bones. Only four patients developed complications like shortening of the limb or persistent non-union.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; Hypertrophic non unions doesn’t require bone graft, they require only stable fixation. For removal of broken implant in hypertrophic non-union if we open the fracture site, then even the gap after debridement of fracture site shows partial segmental defect it doesn’t require bone grafting.&lt;/p&gt;

Nonunion fractures, mesenchymal stem cells and bone tissue engineering.

Depending on the duration of healing process, 5-10% of bone fractures may result in either nonunion or delayed union. Because nonunions remain a clinically important problem, there is interest in the utilization of tissue engineering strategies to augment bone fracture repair. Three basic biologic elements that are required for bone regeneration include cells, extracellular matrix scaffolds and biological adjuvants for growth, differentiation and angiogenesis. Mesenchymal stem cells (MSCs) are capable to differentiate into various types of the cells including chondrocytes, myoblasts, osteoblasts, and adipocytes. Due to their potential for multilineage differentiation, MSCs are considered important contributors in bone tissue engineering research. In this review we highlight the progress in the application of biomaterials, stem cells and tissue engineering in promoting nonunion bone fracture healing. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A:2551-2561, 2018.

237 - Bone healing of critical size calvarial defects in rabbits with collagen sponge reinforced poly glycolic acid

Objective: Nowadays composite scaffolds based on synthetic and natural biomaterials have attracted attention in healing of non-union bone fractures. We evaluated the capability of collagen/poly glycolic acid (PGA) scaffolds to regenerate bone in a critical-sized defect (CSD) rabbit calvarial. The bone defect healing process and inflammatory reactions were evaluated histologically, computed tomography (CT) scan and real time polymerase chain reaction (RT-PCR) (with bone specific primers: sialoprotein and alkaline phosphatase) at 4, 8 and 12 weeks postoperatively.

17β-estradiol improves the efficacy of exploited autologous bone marrow-derived mesenchymal stem cells in non-union radial defect healing: A rabbit model

Exploiting mesenchymal stem cells (MSCs) appears to be an appealing alternative to the traditional clinical approach in the treatment of non-union bone defects. It has been shown that 17β-estradiol improves the osteogenesis and proliferation potential of the MSCs via estrogen receptors. We investigated the effect of 17β-estradiol on exploiting autologous BMSCs (bone marrow-derived MSCs) for the purpose of healing of radial non-union segmental defect in rabbit. Twenty rabbits were divided into 4 experimental groups: 1. Control group; 2. MSC treatment group; 3. 17β-estradiol (E2) treatment group; and 4. E2+MSC treatment group. Isolated BMSCs were seeded in a critical-sized defect on radial mid-diaphysis that was filled with autologous fibrin clot differently in 4 groups: 1. intact fibrin clot (control); 2. Fibrin clot containing MSCs; 3. Estradiol; and 4. E2 and MSCs. Defect healing was assessed by radiological (week 0, 2, 4, 6, 8 and 10) and histopathological evaluation (week 10). Radiological evaluation data demonstrated that quantities for the E2+MSC group were significantly the greatest in comparison with the other groups at week 4 to 10 inclusive. Moreover, Histopathological evaluation indicated that the E2+MSC group had the highest score which was significantly greater than the E2 group and the control group (P<0.05). In-vivo application of in situ 17β-estradiol provides the seeded BMSCs with improved osteogenic capacity in tandem with an accelerated rate of bone healing. This obviously more qualified approach that yields in a shorter time appears to be promising for the future cell-based clinical treatments of the non-union bone fractures.Exploiting mesenchymal stem cells (MSCs) appears to be an appealing alternative to the traditional clinical approach in the treatment of non-union bone defects. It has been shown that 17β-estradiol improves the osteogenesis and proliferation potential of the MSCs via estrogen receptors. We investigated the effect of 17β-estradiol on exploiting autologous BMSCs (bone marrow-derived MSCs) for the purpose of healing of radial non-union segmental defect in rabbit. Twenty rabbits were divided into 4 experimental groups: 1. Control group; 2. MSC treatment group; 3. 17β-estradiol (E2) treatment group; and 4. E2+MSC treatment group. Isolated BMSCs were seeded in a critical-sized defect on the radial mid-diaphysis that was filled with autologous fibrin clot differently in 4 groups: 1. intact fibrin clot (control); 2. Fibrin clot containing MSCs; 3. Estradiol; and 4. E2 and MSCs. Defect healing was assessed by radiological (week 0, 2, 4, 6, 8 and 10) and histopathological evaluation (week 10). Radiological evaluation data demonstrated that quantities for the E2+MSC group were significantly the greatest in comparison with the other groups at week 4 to 10 inclusive. Moreover, Histopathological evaluation indicated that the E2+MSC group had the highest score which was significantly greater than the E2 group and the control group (P<0.05). In-vivo application of in situ 17β-estradiol provides the seeded BMSCs with improved osteogenic capacity in tandem with an accelerated rate of bone healing. This obviously more efficient approach that yields in a shorter time appears to be promising for future cell-based clinical treatments of the non-union bone fractures.

Pulsed Electromagnetic Fields and Tissue Engineering of the Joints

Bone and joint formation, maintenance, and regeneration are regulated by both chemical and physical signals. Among the physical signals there is an increasing realization of the role of pulsed electromagnetic fields (PEMF) in the treatment of nonunions of bone fractures. The discovery of the piezoelectric properties of bone by Fukada and Yasuda in 1953 in Japan established the foundation of this field. Pioneering research by Bassett and Brighton and their teams resulted in the approval by the Food and Drug Administration (FDA) of the use of PEMF in the treatment of fracture healing. Although PEMF has potential applications in joint regeneration in osteoarthritis (OA), this evolving field is still in its infancy and offers novel opportunities. We have systematically reviewed the literature on the influence of PEMF in joints, including articular cartilage, tendons, and ligaments, of publications from 2000 to 2016. PEMF stimulated chondrocyte proliferation, differentiation, and extracellular matrix synthesis by release of anabolic morphogens such as bone morphogenetic proteins and anti-inflammatory cytokines by adenosine receptors A2A and A3 in both in vitro and in vivo investigations. It is noteworthy that in clinical translational investigations a beneficial effect was observed on improving function in OA knees. However, additional systematic studies on the mechanisms of action of PEMF on joints and tissues therein, articular cartilage, tendons, and ligaments are required.

Long bone mesenchymal stem cells (Lb-MSCs): clinically reliable cells for osteo-diseases.

Mesenchymal stem cells (MSCs) have been designated as the most reliable cells in clinics to treat osteo-diseases because of their versatile nature. MSCs, isolated from long bone (Lb-MSCs) are rarely reported and named as RIA-MSCs because of the reamer-irrigator-aspirator (RIA) device. The potential of these cells in the treatment of non-union bone fractures made them the ideal candidates to be studied for clinical practices. In this work, effect of cryopreservation on the proliferation and differentiation capabilities of long bone MSCs (Lb-MSCs) has been studied. For this purpose, Lb-MSCs were isolated via RIA device and characterized using flow cytometry and differentiation assays. Cells were cryopreserved for 3, 6 and 12months and thereafter were characterized using differentiation assays and genetic markers specific for osteogenic, chondrogenic, and adipogenic potential quantitatively by qRT-PCR. Lb-MSCs were found expressing MSC characteristic markers defining their identity. The population doubling time (PDT) was about 2.5±0.5days and colonies appeared after 7-10days. Differentiation potential and gene expression of 3, 6 and 12months cryopreserved Lb-MSCs were unaltered. The results show that cryopreservation did not have an effect on the differentiation potential of human Lb-MSCs. Therefore, our work offers Lb-MSCs as clinically cells for treating osteo-diseases.