Time-course changes of intraosseous environment and shear resistance mechanical properties of jawbone in SD rats with fluorosis / 环境与职业医学

Background At present, a large number of reports focus on the bones of limbs and trunk, while there are few studies on the effect of fluorosis on jawbone which is the inevitable structural basis for the development and treatment of oral diseases. Objective To preliminarily investigate the effect of fluoride exposure on the mechanical properties of jawbone by observing the changes in the intraosseous environment and the maximum load against shearing force (LSFmax) of the jawbone in rats with chronic fluoride treatment. Methods Screening experiment: 48 SD male rats were randomly divided into a control group and three fluoride exposure groups (50, 150, and 250 mg·L−1 fluoride concentration), 12 rats in each group. The fluoride exposure groups were molded by feeding different concentrations of sodium fluoride solution, and the control group drank tap water from Guizhou area. Each group was further divided into 4 subgroups with 3 animals each according to observation time points after 0, 2, 4, and 6 months. The LSFmax of the jawbone was measured with an electronic universal ergometer, the expression of type I collagen (Col1) was shown by Sirius red staining, and the expression of runt-related transcription factor 2 (Runx2) was determined semi-quantitatively by immunohistochemistry at selected time points. Formal experiment: 12 male SD rats were randomly divided into a fluoride exposure group and a control group. The fluoride exposure group were fed with 150 mg·L−1 sodium fluoride solution, and the control group drank tap water from Guizhou. After feeding with fluoride for 5 months, the ergometer was used to measure the LSFmax of the jawbone. Osteoclasts were counted after tartrate resistant acid phosphatase (TRAP) staining. Col1, Runx2, bone morphogenetic protein 2 (BMP-2), alkaline phosphatase (ALP), and cathepsin K (Cath K) were detected semi-quantitatively by immunohistochemistry expression and Sirius red staining. Micro computed tomography (Micro CT) was used to observe the trabecular bone microstructure. Results Screening experiment: The LSFmax of the control group and the 50 mg·L−1 fluoride exposure group reached the peak value at the 2nd month, and the LSFmax of the 50 mg·L−1 fluoride exposure group reached the valley value at the 4th month. The LSFmax of the 150 mg·L−1 fluoride exposure group at the 4th month was higher than that at the 6th month (P<0.05). There was no significant difference in the LSFmax at each time point in the 250 mg·L−1 fluoride exposure group. At the same time point, there was no statistically significant difference in LSFmax among the groups. The Col1 levels of the 50 mg·L−1, 150 mg·L−1, and 250 mg·L−1 fluoride exposure groups were higher than the time point 0 from the 2nd month (P＜0.05). The Runx2 showed no statistically significant difference by concentration or time. Formal experiment: After feeding with 150 mg·L−1 fluoride for 5 months, the LSFmax of the fluoride exposure group was greater than that of the control group (P<0.05). The expressions of Col1, Runx2, BMP2, ALP, and Cath K in the fluorosis exposure group were higher than those in the control group (P<0.05). There were no statistically significant differences in osteoclast count or indicators of bone trabecular microstructure. Conclusion Chronic fluoride exposure may increase the shear strength of jaw bone.

Content of bone morphogenetic protein 2 in demineralized bone matrix prepared from different long bones and study of the osteogenic properties in vitro / 中国修复重建外科杂志

OBJECTIVE@#To measure the concentration of bone morphogenetic protein 2 (BMP-2) in demineralized bone matrix (DBM) prepared from different long bones and to evaluate the osteoinductivity of different DBM on MC3T3-E1 cells.@*METHODS@#Different bones from the same cadaver donor were used as the initial materials for making DBM, which were divided into ulna group (uDBM), humerus group (hDBM), tibia group (tDBM), and femur group (fDBM) according to the origins, and boiled DBM (cDBM) was taken as the control group. The proteins of DBM were extracted by guanidine hydrochloride, and the concentrations of BMP-2 were determined by ELISA assay. Then the DBM were co-cultured with MC3T3-E1 cells, the proliferation of MC3T3-E1 cells was observed by cell counting kit 8 (CCK-8) assay. The osteogenic differentiation ability of MC3T3-E1 cells was qualitatively observed by alizarin red, alkaline phosphatase (ALP), and Van Gieson staining, and the osteogenic differentiation ability of MC3T3-E1 cells was quantitatively analyzed by ALP content. Linear regression was used to analyze the effect of BMP-2 concentration in DBM on ALP synthesis.@*RESULTS@#There were significant differences in the concentration of BMP-2 among the DBM groups (P<0.05). The concentrations of BMP-2 in the lower limb long bone were higher than those in the upper limb long bone, and the concentration of BMP-2 in the fDBM group was about 35.5 times that in the uDBM group. CCK-8 assay showed that the cells in each group continued to proliferate within 5 days of co-culture, and the absorbance (A) values at different time points were in the order of cDBM group<uDBM group<hDBM group<tDBM group<fDBM group. After co-culture for 14 days, the expressions of ALP, calcified nodules, and collagen fibers in each group were consistent with the distribution of BMP-2 concentration in DBM. The order of ALP content from low to high was cDBM group<uDBM group<hDBM group<tDBM group<fDBM group, and the differences between the groups were significant (P<0.05). Linear regression analysis showed that y

Biomechanical Environment Regulates Biomimetic Mineralization of Bone Matrix / 医用生物力学

Bone defects have always been an important cause of threat to human health, and artificial biomimetic bone repair replacement materials are currently one of the most effective and feasible solution approaches to treat bone damage. To develop artificial bone biomimetic materials, an in vitro biomimetic mineralization system must be constructed first to study in vitro biomimetic mineralization mechanism of natural bone matrix. Collagen is a template for mineralization, and its properties such as crosslinking degree, diameter, osmotic pressure, and surface charge can all directly affect mineralization progress. The biochemical and mechanical environments in which mineralization occurs are also quite distinct in their effects on mineralization process, particularly noncollagenous proteins and fluid shear stress (FSS). FSS is considered to be the main mechanical stimulation of bone tissues in micro-environment, which is of great significance to bone growth, repair and health maintenance. FSS at different levels and loading regimes has significant effects on transformation of amorphous calcium phosphate to bone apatite, self-assembly and directional alignment of collagen fibrils, and formation of hierarchical intrafibrillar mineralization. In this paper, the factors affecting collagen mineralization and their mechanism were summarized, with focus on regulation of FSS on collagen mineralization, and development direction in future was also prospected.

Regenerating effect of hyaluronic acid on circumferential bone defects in wistar albino rats / Efecto regenerador del ácido hialurónico en defectos óseos circunferenciales en ratas albinas wistar

Objective: To determine the regenerating effect of hyaluronic acid on circumferential bone defects in albino Wistar rats. Material and Methods: An experimental type study was designed and carried out with 15 albino male Wistar rats, 4 months old and weighing between 250 and 350 grams. Two circumferential bone defects 3mm in diameter and 0.8mm deep were created in the calvaria of the parietal bone (on both sides of the midline). One defect was filled with a demineralized bone matrix (control group); while the other defect was filled with the combination of a demineralized bone matrix plus hyaluronic acid (experimental group). Five experimental rats were euthanized at 30, 60 and 90 days after surgery and they were histologically evaluated following the parameters proposed by Heiple. Results: The experimental group presented a better degree of bone regeneration at 30 and 60 postoperative days. Conclusion: Hyaluronic acid is effective in bone regeneration of circumferential bone defects.

Objetivo: Determinar el efecto regenerador del ácido hialurónico en defectos óseos circunferenciales en ratas albinas Wista. Material y Métodos: Se diseñó un estudio de tipo experimental y se trabajó con 15 ratas albinas Wistar (todas macho) de 4 meses de edad y con un peso entre 250 a 350 gr. Se crearon en todas 2 defectos óseos circunferenciales de 3mm de diámetro y 0.8 mm de profundidad en la calota del hueso parietal (a ambos lados de la línea media). Un defecto fue rellenado con una matriz ósea desmineralizada (grupo control); mientras que el otro defecto fue rellenado con la combinación de una matriz ósea desmineralizada más el ácido hialurónico (grupo experimental). Se realizó la eutanasia a 05 ratas de experimentación a los 30, 60 y 90 días postquirúrgicos y se evaluaron histológicamente siguiendo los parámetros propuestos por Heiple. Resultados: El grupo experimental presentó un mejor grado de regeneración ósea en los 30 y 60 días postoperatorios. Conclusiones: El ácido hialurónico es eficaz en la regeneración ósea de defectos óseos circunferenciales.

Integration of heterologous bone matrix associated with polymethylmethacrylate in induced tibial bone defects. An experimental study in rabbits

ABSTRACT Purpose To analyze and compare the reactions at the interface between the composite, composed of fragmented heterologous mineralized bone matrix (MOMHF) and polymethylmethacrylate (PMMA), and the rabbit's tibias, through macroscopic evaluation and scanning electron microscopy (SEM) in different periods. Methods In this study, 12 New Zealand adult rabbits were used (E1: n = 3, E2: n = 3, E3: n = 3 and E4: n = 3). They had the right tibial defects filled with composite and were evaluated immediately after surgery and at 30, 60, 90, and 120 days. Results The composites were incorporated and integrated into the recipient beds in 100% of the cases, defined by the MOMHF osseointegration and the PMMA fibrointegration, with no sign of infection, migration, or rejection. Conclusions The behavior of the composites in the recipient beds demonstrates that these biomaterials have the potential to be used in bone defect repairs, offering, thus, better quality of life to the orthopedic patient.

Osteogenic differentiation of bone marrow mesenchymal stem cells induced by demineralized bone matrix in vitro / 中国组织工程研究

BACKGROUND: Demineralized bone matrix contains many kinds of active factors such as bone morphogenetic protein 2, which can promote bone marrow mesenchymal stem cells to transform into chondrocytes and promote their proliferation under specific joint microenvironment. OBJECTIVE: To explore the osteogenic differentiation of bone marrow mesenchymal stem cells in vitro induced by demineralized bone matrix and its research value as cell carrier scaffold in the treatment of bone defect. METHODS: Rat femur bone marrow mesenchymal stem cells were isolated and adhered with whole bone marrow. Bone marrow mesenchymal stem cells at passage 3 were selected and cultured with complete medium and 50 mg/L demineralized bone matrix inducer. The proliferation and viability of bone marrow mesenchymal stem cells were determined by CCK-8 assay. Alkaline phosphatase activities were quantitatively measured by enzyme labeling at 7 and 14 days after culture. Calcium nodule formation was observed by alizarin red staining 21 days after culture. The expression of osteogenesis-related factors was detected by qRT-PCR 21 days after culture. Demineralized bone matrix and bone marrow mesenchymal stem cells were cultured for 21 days. The adhesion of them was observed by ordinary optical inverted phase contrast microscope and scanning electron microscope. RESULTS AND CONCLUSION: (1) The number of cells on days 5 and 6 in the demineralized bone matrix group was higher than that in the complete medium group (P < 0.05). (2) Alkaline phosphatase activities were significantly higher in the demineralized bone matrix group than in the complete medium group at 7 and 14 days (P < 0.05). (3) Calcium nodules were more in the demineralized bone matrix group than in the complete medium group. (4) The expression of RUNX2, ALP, OCN and OPN was significantly higher in the demineralized bone matrix group than in the complete medium group (P < 0.05). (5) The adherence of bone marrow mesenchymal stem cells was good on the demineralized bone matrix; cells were distributed in the space between scaffolds and crawled with each other. (6) The results showed that demineralized bone matrix could induce bone marrow mesenchymal stem cells to differentiate into osteoblasts, and the adhesion was good, which provided theoretical reference for the research of tissue engineering composite materials.

Lentivirus-mediated silencing of P75 neurotrophin receptor combined with nerve growth factor overexpression and transfection of bone marrow mesenchymal stem cells combined with demineralized bone matrix for heterotopic osteogenesis / 中国修复重建外科杂志

Objective: To investigate the effects of silencing P75 neurotrophin receptor (P75NTR) and nerve growth factor (NGF) overexpression on the proliferative activity and ectopic osteogenesis ability of bone marrow mesenchymal stem cells (BMSCs) combined with demineralized bone matrix for heterotopic osteogenesis. Methods: BMSCs of Sprague Dawley (SD) rats were cultured and passaged by adherent isolation method. The third generation BMSCs were transfected with lentivirus mediated P75NTR gene silencing (group B), NGF overexpression gene (group C), P75NTR silencing and NGF overexpression double genes (group D), respectively, and untransfected cells as control (group A). After 7 days of transfection, the expression of fluorescent protein of the target gene was observed by fluorescence microscope; cell counting kit 8 method was used to detect the cells activity for 8 days after transfection; the expressions of P75NTR and NGF proteins in each group were detected by Western blot. The adhesion of BMSCs to demineralized bone matrix (DBM) was observed by inverted phase contrast microscope and scanning electron microscope after transfection of p75NTR silencing and NGF overexpression double genes. After transfection, BMSCs and DBM were co-cultured to prepare 4 groups of tissue engineered bone, which were respectively placed in the dorsal subcutaneous tissue of 8-week-old SD rats to construct subcutaneous ectopic osteogenesis model ( n=6). HE staining was performed at 4 and 8 weeks after operation. ALP staining was used to observe the formation of calcium nodules at 8 weeks after operation. The expressions of Runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and osteocalcin (OCN) were detected by real-time fluorescent quantitative PCR. Results: At 7 days after transfection, there was no fluorescence expression in group A, red fluorescence expression was seen in group B, green fluorescence expression in group C, and red-green compound fluorescence expression in group D. The fluorescence expression rate of target gene was about 70%. Western blot detection showed that the relative expression of P75NTR protein in groups A and C was significantly higher than that in groups B and D, and the relative expression of NGF protein in groups C and D was significantly higher than that in groups A and B ( P<0.05). With the passage of time, the cell proliferation activity increased in all groups, especially in group D, which was significantly higher than that in group A at 3-8 days ( P<0.05). The results of inverted phase contrast microscope and scanning electron microscope showed that BMSCs could adhere well to DBM. In the subcutaneous ectopic osteogenesis experiment, HE staining showed that at 4 and 8 weeks after operation, the more bone tissue was formed in group D than in the other 3 groups. ALP staining showed that group D had the highest ALP activity and better osteogenic expression. Compared with group A, the relative expressions of Runx2, ALP, and OCN mRNAs in group D were significantly higher than those in group A ( P<0.05). Conclusion: Silencing P75NTR and NGF overexpression double genes co-transfected BMSCs with DBM to construct tissue engineered bone has good ectopic osteogenic ability. By increasing NGF level and closing P75NTR apoptosis channel, it can not only improve cell activity, but also promote bone tissue regeneration.

Stanozolol promotes osteogenic gene expression and apposition of bone mineral in vitro

Abstract Stanozolol (ST) is a synthetic androgen with high anabolic potential. Although it is known that androgens play a positive role in bone metabolism, ST action on bone cells has not been sufficiently tested to support its clinical use for bone augmentation procedures. Objective: This study aimed to assess the effects of ST on osteogenic activity and gene expression in SaOS-2 cells. Material and Methods: SaOS-2 deposition of mineralizing matrix in response to increasing doses of ST (0-1000 nM) was evaluated through Alizarin Red S and Calcein Green staining techniques at 6, 12 and 24 days. Gene expression of runt-related transcription factor 2 (RUNX2), vitamin D receptor (VDR), osteopontin (SPP1) and osteonectin (ON) was analyzed by RT-PCR. Results: ST significantly influenced SaOS-2 osteogenic activity: stainings showed the presence of rounded calcified nodules, which increased both in number and in size over time and depending on ST dose. RT-PCR highlighted ST modulation of genes related to osteogenic differentiation. Conclusions: This study provided encouraging results, showing ST promoted the osteogenic commitment of SaOS-2 cells. Further studies are required to validate these data in primary osteoblasts and to investigate ST molecular pathway of action.

Comparison of Cortical Ring Allograft and Plate Fixation with Autologous Iliac Bone Graft for Anterior Cervical Discectomy and Fusion

STUDY DESIGN: A retrospective cohort study. PURPOSE: To compare the clinical and radiological outcomes of patients who underwent anterior cervical discectomy and fusion (ACDF) supplemented with plate fixation using allograft with those who underwent ACDF using tricortical iliac autograft. OVERVIEW OF LITERATURE: As plate fixation is becoming popular, it is reported that ACDF using allograft may have similar outcomes compared with ACDF using autograft. METHODS: Forty-one patients who underwent ACDF supplemented with plate fixation were included in this study. We evaluated 24 patients who used cortical ring allograft filled with demineralized bone matrix (DBM) (group A) and 17 patients who used tricortical iliac autograft (group B). In radiological evaluations, fusion rate, subsidence of grafted material, cervical lordosis, fused segmental lordosis, and radiological adjacent segment degeneration (ASD) were observed and analyzed with preoperative and postoperative plain radiographs. Clinical outcomes were evaluated using the Neck Disability Index score, Odom criteria, and Visual Analog Scale score of neck and upper extremity pain. Radiological union was determined by dynamic radiographs using cutoff values of 1 mm of interspinous motion as the indication of pseudarthrosis. RESULTS: There was no significant difference in the fusion rate, graft subsidence, cervical lordosis, fused segmental lordosis, and ASD incidence between the groups. Operative time was shorter in group A (136 min) than in group B (141 min), but it was not significant (p>0.05). Blood loss was greater in group B (325 mL) than in group A (210 mL, p=0.013). There was no difference in the clinical outcomes before and after surgery. CONCLUSIONS: In ACDF with plate fixation, cortical ring allograft filled with DBM group showed similar radiological and clinical outcomes compared with those of the autograft group. If the metal plate is reinforced, using cortical ring allograft could be a viable alternative to autograft.

Induction of Chondrogenic Differentiation in Human Mesenchymal Stem Cells Cultured on Human Demineralized Bone Matrix Scaffold under Hydrostatic Pressure

BACKGROUND: Articular cartilage damage is still a troublesome problem. Hence, several researches have been performed for cartilage repair. The aim of this study was to evaluate the chondrogenicity of demineralized bone matrix (DBM) scaffolds under cyclic hydrostatic pressure (CHP) in vitro. METHODS: In this study, CHP was applied to human bone marrow mesenchymal stem cells (hBMSCs) seeded on DBM scaffolds at a pressure of 5 MPa with a frequency of 0.5 Hz and 4 h per day for 1 week. Changes in chondrogenic and osteogenic gene expressions were analyzed by quantifying mRNA signal level of Sox9, collagen type I, collagen type II, aggrecan (ACAN), Osteocalcin, and Runx2. Histological analysis was carried out by hematoxylin and eosin, and Alcian blue staining. Moreover, DMMB and immunofluorescence staining were used for glycosaminoglycan (GAG) and collagen type II detection, respectively. RESULTS: Real-time PCR demonstrated that applying CHP to hBMSCs in DBM scaffolds increased mRNA levels by 1.3-fold, 1.2-fold, and 1.7-fold (p < 0.005) for Sox9, Col2, and ACAN, respectively by day 21, whereas it decreased mRNA levels by 0.7-fold and 0.8-fold (p < 0.05) for Runx2 and osteocalcin, respectively. Additionally, in the presence of TGF-β1 growth factor (10 ng/ml), CHP further increased mRNA levels for the mentioned genes (Sox9, Col2, and ACAN) by 1.4-fold, 1.3-fold and 2.5-fold (p < 0.005), respectively. Furthermore, in histological assessment, it was observed that the extracellular matrix contained GAG and type II collagen in scaffolds under CHP and CHP with TGF-β1, respectively. CONCLUSION: The osteo-inductive DBM scaffolds showed chondrogenic characteristics under hydrostatic pressure. Our study can be a fundamental study for the use of DBM in articular cartilage defects in vivo and lead to production of novel scaffolds with two different characteristics to regenerate both bone and cartilage simultaneously.

Effects of concurrent training associated with N-acetylcysteine on bone density of spontaneously hypertensive rats

Abstract Aim: The present study aimed to analyze the effects of N-acetylcysteine supplementation associated with concurrent training on the bone mineral density of spontaneously hypertensive elderly rats. Methods: For the present study, 28 male spontaneously hypertensive rats, six months old, were distributed in the following groups: control (C, n=7); control + N-acetylcysteine (CNAC, n=7); concurrent training (T, n=7); and concurrent training+N-acetylcysteine (TNAC, n=7). The concurrent training was composed of aerobic training on a treadmill and resistance training in the same training session, three times a week. Animals of the NAC groups received a dose equivalent to 120 mg/kg/day orally for eight weeks. The animals in the trained groups underwent training for eight weeks. The animals were evaluated at the beginning and end of the experiment. After euthanasia, the tibias and femurs were submitted to bone densitometry analysis in an X-ray dual emission device. Results: Lower weight variation was observed in the trained animals and a reduction in pressure values in all groups, but without a statistical difference (p> 0.05). The animals in the T and TNAC groups presented a better performance in the physical tests (p <0.05). In relation to bone, the NAC groups demonstrated a decrease in femoral bone density when compared to groups C and T. Finally, all experimental groups demonstrated an increase in tibial bone density, but with no statistical difference (p>0.05). Conclusion: The animals in group T demonstrated better performance in the physical tests. In addition, the NAC caused a reduction in the bone mineral density of the femur.

The cortical matrix of femur in adult-aged Wistar rats is critically affected by maternal malnutrition during lactation period / La matriz cortical del fémur en ratas Wistar de edad adulta se ve críticamente afectada por la malnutrición materna durante el período de lactancia

Osteoporosis is associated with poor dietary habits. Malnutrition is characterized as a deficit on the intake of necessary nutrients that are essential for optimal health maintenance. It is known that malnutrition during the lactation period can affect the offspring. The present study aims to evaluate the chronic effects caused by maternal energy-protein restriction during lactation period in the offspring. At parturition, Wistar rat dams were divided in three groups: (1) Control group (C) - which received a 23 % protein diet without restrictions; (2) Protein-Energy restriction group (PER)- which received a 8 % protein diet; (3) Energy restriction group (ER) which received a 23 % protein diet in limited amounts, according to the ingestion of the second group. Each group had 12 pups. After weaning, all pups received free access to a 23 % protein diet until 180 days and then were euthanized. Their femur was excised, decalcified, histologically processed and analyzed under a microscope. The measurements of the osteon lacunae on the C, ER and PER groups were, respectively: 2.1 µm, 10.9 µm and 14.7 µm (p<0.05). A poor ingestion of proteins and calories during lactation period provoked critical and permanent changes on the bone matrix of the femur, which simulated osteoporosis.

La osteoporosis se asocia con malos hábitos alimenticios. La desnutrición se caracteriza como un déficit en la ingesta de los nutrientes necesarios que son esenciales para un mantenimiento óptimo de la salud. Se sabe que la malnutrición durante el período de lactancia puede afectar a la descendencia. El presente estudio tiene como objetivo evaluar los efectos crónicos causados por la restricción energética-proteína materna durante el período de lactancia en la descendencia. En el parto, las hijas de rata Wistar se dividieron en tres grupos: (1) grupo control (C) - que recibió una dieta con 23 % de proteína sin restricciones; (2) Grupo restricción de energía de proteína (PER) - que recibió una dieta con 8 % de proteína; (3) Grupo restricción de energía (ER) - que recibió una dieta de 23 % de proteína en cantidades limitadas, de acuerdo con la ingestión del segundo grupo. Cada grupo tenía 12 crías. Después del destete, todas las crías recibieron acceso libre a una dieta con 23 % de proteína hasta 180 días y luego fueron sacrificadas. Su fémur fue extirpado, descalcificado, procesado histológicamente y analizado bajo un microscopio. Las mediciones de las lagunas de osteón en los grupos C, ER y PER fueron, respectivamente: 2,1 mm, 10,9 mm y 14,7 mm (p <0,05). Una mala ingesta de proteínas y calorías durante el período de lactancia provocó cambios críticos y permanentes en la matriz ósea del fémur, que simulaba osteoporosis.

Demineralized bone matrix and calcium-phosphate cement in bone regeneration in rats

Abstract Purpose: To compare bone regeneration in critical-sized defects in rat calvarium using demineralized bone matrix and calcium phosphate cement. Methods: Thirty Wistar rats were divided into 3 groups of 10 animals each. Two defects of 5-mm were made in the parietal bones of each animal. Group I had calcium phosphate cement placed in the experimental defect, Group II had filled with demineralized bone matrix and Group III had with the combination of the matrix and cement in equal parts. All animals had one defect left unfilled to serve as controls. Five animals in each group were sacrificed at 4 and 8 weeks. Histomorphometric analysis was used to quantify the amount of new bone within the defects. Results: The results showed that demineralized bone matrix-treated defects had significantly more new bone at 4 weeks compared to calcium phosphate cement-treated defects (p=0.03) and also had significantly more new bone at 8 weeks compared to unfilled defects (p=0.04). Conclusions: The demineralized bone matrix was superior to calcium phosphate cement in bone regeneration. It seems that calcium phosphate cement acted by inhibiting the osteogenesis when associated with a demineralized bone matrix and this combination should not be recommended.

Outcomes of Anterior Cervical Fusion Using Polyetheretherketone Cage with Demineralized Bone Matrix and Plate for Management of Subaxial Cervical Spine Injuries / 대한신경손상학회지

OBJECTIVE: We evaluated the usefulness of a polyetheretherketone (PEEK) cage filled with demineralized bone matrix (DBM) and plate fixation in anterior interbody fusions for subaxial cervical spine injuries. METHODS: A retrospective review of 98 patients (58 women, 40 men; mean age, 49.7 years; range, 17–78 years) who underwent single-level anterior cervical discectomy and fusion (ACDF) using a PEEK cage filled with DBM and plate fixation for subaxial cervical spine injuries from March 2005 to June 2018 was conducted. Bone fusion, interbody height (IBH), segmental lordosis, and adjacent segment degeneration (ASD) development were assessed with plain radiographs and computed tomography. Clinical outcomes were assessed using a visual analog scale (VAS) for pain and the Frankel grade for neurologic function. RESULTS: The mean follow-up period was 27.6 months (range, 6–142 months). Twenty-one patients (21.4%) had an improvement of at least one Frankel grade. The mean preoperative and final follow-up neck pain VAS scores were 8.3±0.9 and 2.6±1.5 (p < 0.05). All patients showed solid fusion at the final follow-up. The mean preoperative and final Cobb's angles were −3.7±7.9° and 1.9±5.1° (p < 0.05). The mean preoperative and final IBHs were 36.9±1.7 mm and 38.2±1.8 mm (p < 0.05). Five patients (5%) showed ASD. CONCLUSION: ACDF using a PEEK cage filled with DBM and plate fixation yielded high fusion rates and satisfactory clinical outcomes without donor-site morbidity. This procedure is safe and effective for single-level subaxial cervical spine injuries.

Clinical analysis of acellular dermal matrix and acellular bone matrix in oro-antral fistula repair / 华西口腔医学杂志

OBJECTIVE@#This study aimed to investigate the application of acellular dermal matrix and acellular bone matrix in the management of oro-antral fistula.@*METHODS@#Nine patients with oro-antral fistula (with defect greater than 5 mm×5 mm) after maxillary cyst resection or maxillary molar extraction were selected. The defects were repaired by the simultaneous implantation of acellular dermal matrix and acellular bone matrix.@*RESULTS@#The incisions of nine patients were all primary healing. After 6 months of follow-up, the oro-antral communication healed well, and no symptom such as nasal congestion or runny nose was observed. The clinical and CT examinations confirmed wound healing.@*CONCLUSIONS@#The usage of acellular dermal matrix and acellular bone matrix is a reliable repairing method for ora-antral fistula.

Use of Allogenic Mesenchymal Cellular Bone Matrix in Anterior and Posterior Cervical Spinal Fusion: A Case Series of 21 Patients

STUDY DESIGN: Retrospective case series. PURPOSE: To report our early experience using allogenic mesenchymal cellular bone matrix (CBM) products in cervical spine fusion. OVERVIEW OF LITERATURE: Multi-level cervical fusions have historically yielded lower fusion rates than single level fusions, especially in patients with high risk medical comorbidities. At this time, significant literature in cervical fusion outcomes with this cellular allograft technology is lacking. METHODS: Twenty-one patients underwent either multilevel (3 or 4 level) anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion, or posterior cervical fusion. ViviGen (DePuy Synthes Spine, Raynham, MA, USA), an allogenic bone matrix product, was used in addition to standard instrumentation. Radiographic evaluation was performed at 2 weeks, 12 weeks, 24 weeks and 1 year postoperative. Visual analog scale (VAS) and neck disability index (NDI) scores along with return to work and leisure activity were recorded. RESULTS: At 6 months postoperative, all patients had radiographic evidence of bone fusion regardless of age or medical comorbidities. All patients reported subjective improvement with a mean decrease in VAS from 8.3 to 1.5 and a mean decrease in NDI from 40.3% to 6.0% at 1 year. All patients also returned to work and/or regular leisure activity within 3 months. CONCLUSIONS: Twenty-one patients undergoing high-risk anterior and posterior cervical spine fusion, with the use of a commercially available mesenchymal CBM product, went on to radiographic fusion and all had improvement in subjective outcomes. While further effort and research is needed to validate its widespread use, this study shows favorable use of CBM in cervical fusion for high-risk cases.

Comparison of Clinical and Radiological Outcomes of Lumbar Interbody Fusion Using a Combination of Hydroxyapatite and Demineralized Bone Matrix and Autografts for Lumbar Degenerative Spondylolisthesis

STUDY DESIGN: Prospective, cohort, non-inferiority study. PURPOSE: This study evaluated the clinical and radiological outcomes of interbody fusion using a combination of demineralized bone matrix (DBM) and hydroxyapatite (HA). OVERVIEW OF LITERATURE: The use of autografts remains a gold standard in lumbar interbody fusion, but the limited availability and donor site morbidity encourages the use of bone substitutes. In addition to autografts, a combination of HA and DBM is being increasingly use for lumbar interbody fusion. However, there are no data on the clinical and radiological outcomes of this procedure. METHODS: We examined 35 patients with lumbar degenerative spondylolisthesis who underwent transforaminal interbody fusion. Autografts were used in 18 patients, and 17 patients received a combination of HA and DBM. Clinical outcomes were evaluated using the visual analog scale (VAS) for back and leg pain, Oswestry disability index (ODI), and Japanese Orthopaedic Association (JOA) scores at 3, 6, and 12 months postoperatively. Fusion was evaluated using computed tomography images obtained at 12 months postoperatively. RESULTS: The mean ODI, JOA, and back and leg pain VAS scores increased significantly in both groups. However, the VAS, JOA, and ODI scores did not differ significantly between the two groups (p=0.599, p=0.543, and p=0.780, respectively). The fusion rates at 1 year postoperatively were 77.8% and 76.5% in the autograft and HA+DBM groups, respectively (p=0.99). CONCLUSIONS: The clinical and radiological outcomes of using a combination of HA and DBM in lumbar interbody fusion were not inferior to those of using autografts. A combination of HA and DBM can be considered as an alternative in patients with lumbar degenerative spondylolisthesis requiring surgery.

Avaliação das citocinas TNF-α, RANKL e OPG e do número de osteoclastos no reparo de defeito ósseo em calvária de ratos diabéticos tratados com matriz óssea desmineralizada / Evaluation of cytokines TNF-α, RANKL and OPG and the number of osteoclasts on repair of bone defects in skulls of diabetic rats treated with demineralized bone matrix

Neste trabalho, foi avaliado a participação dos osteoclastos bem como a ação das citocinas RANKL, OPG e TNF-α durante a formação e remodelação óssea em defeitos ósseos de tamanho crítico em ratos normoglicêmicos e diabéticos tratados ou não com a MAOD. Para isso, foram utilizados 250 ratos machos Wistar. Trinta ratos foram utilizados para coleta dos fêmures e tíbias, os quais foram processados para obtenção da MAOD. Os demais 220 ratos foram divididos em Grupo Não Diabétido (CTL, n=110) e Grupo Diabético (DIAB, n= 110) induzido pela aplicação de uma dose única de 47 mg/Kg de massa corporal de estreptozotocina. Um defeito transósseo de 8 mm de diâmetro foi realizado nos ossos parietais dos ratos, sendo que, nos subgrupos CTL MAOD e DIAB MAOD, os defeitos foram preenchidos com MAOD e nos grupos CTL COAG e DIAB COAG apenas com coágulo sanguíneo. Após 0, 7, 14, 21 e 42 dias, as calotas cranianas foram coletadas para determinação da densidade de volume, número de osteoclastos/mm2 na área do defeito, quantificação por imunoistoquimica e expressão do RNAm para as proteínas RANKL, OPG e TNF-α. Os resultados para volume do tecido ósseo neoformado foi maior nos grupos CTL COAG e CTL MAOD, bem como no grupo DIAB MAOD quando comparado com DIAB COAG (CTL MAOD > CTL COAG e DIAB MAOD > DIAB COAG). O número de osteoclastos nos grupos CTL aumentaram significantemente (3,69 osteoclasto/mm2), enquanto que nos grupos MAOD aumentaram gradualmente até os 42 dias (2,8 osteoclasto/mm2). Os resultados para imunomarcação mostraram que a MAOD promove 1,28 vezes maior expressão de OPG, bem como de TNF-α tanto no grupo CTL (1,59 vezes) como no DIAB (1,76 vezes). Os resultados para expressão do RNAm para OPG mostrou que a média dos valores do grupo COAG comparado com a do grupo MAOD foi 1,91 vezes maior no grupo COAG. Já os valores para expressão de RANKL permaneceram constantes no grupo DIAB MAOD, com aumento significativo de 2,57 vezes aos 42 dias, sendo 4,3 vezes maior, quando comparado com a média dos outros grupos no mesmo período. Conclui-se que nos animais normoglicemicos, o tratamento com a MAOD aumenta a expressão de OPG, RANKL e TNF-α, assim como a atividade osteoclástica, promovendo reabsorção da MAOD e formação de tecido ósseo, enquanto que nos animais diabéticos, a atividade osteoclástica foi reduzida, sem alteração nos níveis de OPG e RANKL, reduzindo a reabsorção da MAOD e consequentemente da formação óssea.(AU)

Participation of osteoclasts was evaluated in reabsorption process of demineralized allogenic bone matrix (DABM) as well as the activity of cytokines RANKL, OPG and TNF- α during formation and bone remodeling in critial size defect of normoglycemic and diabetic rats treated or not with DABM. Therefore, 250 male Wistar rats were used. Thirty rats had femurs and tibias collected and processed to obtain DABM. 220 rats were divided into control group (CTL, n=110) and diabetic group (DIAB, n= 110) injected by a single dose of 47 mg/Kg of body weight streptozotocin. Were made 8mm bone defect on skulls of rats, in subgroups CTL DABM and DIAB DABM, defects were filled with DABM and subgroups CTL CLOT and DIAB CLOT were filled with blood clot. After 0, 7, 14, 21 and 42 days, the skulls were collected to determine the volume density, number of osteoclasts/mm2 into defects area, quantification by immunohistochemistry and RNAm expression of RANKL, OPG and TNF-α cytokines. The results of volume density of newly formed bone was higher in CTL CLOT and CTL DABM, as well as in DIAB DABM compared to DIAB CLOT (CTL DABM > CTL CLOT and DIAB DABM > DIAB CLOT). The number of osteoclasts in CTL groups increased to 3,69 osteoclasts/mm2, while in subgroups treated with DABM gradually increased up until 42 days (2,8 osteoclasts/mm2). Immunohistochemistry showed that DABM promotes an increase of 1.28-fold of OPG expression, as well as TNF-a expression in CTL group (1.59-fold) and DIAB group (1.76-fold). The results of RNAm expression of OPG showed that the average values of the CLOT subgroup compared to the average values of DABM subgroup was 1.91- fold higher in CLOT subgroup. The values of RANKL RNAm expression increase 2.57-fold at 42 days, being 4.3-fold higher than the average os the other groups in the same period. In conclusion, in the normoglicemic animals (CTL group), the treatment with DABM increase the expression of OPG, RANKL and TNF-α as the activity of osteoclasts, leading to DABM resorption and bone tissue formation, while in diabetic animals, the osteoclast activity was reduced, without changes in the leves of OPG and RANKL, decreasing DABM resorption and bone formation.(AU)

Effect of dietary n-3 Polyunsaturated Fatty Acids on Bony Remodeling during Eruptive Tooth Movement

The aim of this study was to investigate the effect of n-3 polyunsaturated fatty acids (PUFAs) on eruptive movement during tooth development. Sprague-Dawley (SD) rat pups were randomly divided into two groups; control group and experimental group. The experimental group was administered daily with n-3 PUFA by intraperitoneal (IP) injection. After 10 days postpartum, rat pups were sacrificed to evaluate the effect of n-3 PUFA on eruptive tooth movement. Histological analyses were by hematoxylin-eosin (H&E) staining. Tartrate-resistant acid phosphatase (TRAP) assay was performed to compare the osteoclast distribution in the bone matrix above the developing molar teeth. Incisor teeth eruptions were noticeably observed in IP group, as compared to control group. Rat pups in IP group showed faster tooth eruption on day 8 after birth. Through histological analyses, IP group showed thinner bone matrix and more osteoclasts above the 1st molar teeth, as compared to control group. TRAP assay showed significantly stronger stained pattern that the osteoclast above the 1st molar teeth in IP group, as compared to control group. The results suggested that n-3 PUFA could affect osteoclastic activity involved in bony remodeling during eruptive tooth movement.

Bone Union Rate Following Instrumented Posterolateral Lumbar Fusion: Comparison between Demineralized Bone Matrix versus Hydroxyapatite

STUDY DESIGN: Retrospective study. PURPOSE: To compare the union rate of posterolateral lumbar fusion (PLF) using demineralized bone matrix (DBM) versus hydroxyapatite (HA) as bone graft extender. OVERVIEW OF LITERATURE: To our knowledge, there has been no clinical trial to compare the outcomes of DBM versus HA as a graft material for PLF. METHODS: We analyzed prospectively collected data from consecutive 79 patients who underwent instrumented PLF. Patients who received DBM were assigned to group B (n=38), and patients who received HA were assigned into group C (n=41). The primary study outcome was fusion rate assessed with radiographs. The secondary outcomes included pain intensity using a visual analogue scale, functional outcome using Oswestry disability index score, laboratory tests of inflammatory profiles and infection rate. RESULTS: One year postoperatively, bone fusion was achieved in 73% in group B and 58% in group C without significant difference between the groups (p=0.15). There were no differences between the groups with respect to secondary outcomes. CONCLUSIONS: DBM would provide noninferior outcomes compared to the HA as a fusion material for PLF, and could be a notable alternative.