-
Journal of the Mechanical Behavior of... Jul 2024The present study simulates the fracture behavior of diabetic cortical bone with high levels of advanced glycation end-products (AGEs) under dynamic loading. We consider...
The present study simulates the fracture behavior of diabetic cortical bone with high levels of advanced glycation end-products (AGEs) under dynamic loading. We consider that the increased AGEs in diabetic cortical bone degrade the materials heterogeneity of cortical bone through a reduction in critical energy release rates of the microstructural features. To simulate the initiation and propagation of cracks, we implement a phase field fracture framework on 2D models of human tibia cortical microstructure. The simulations show that the mismatch between the fracture properties (e.g., critical energy release rate) of osteons and interstitial tissue due to high AGEs contents can change crack growth trajectories. The results show crack branching in the cortical microstructure under dynamic loading is affected by the mismatches related to AGEs. In addition, we observe cortical features such as osteons and cement lines can prevent multiple cracking under dynamic loading even with changing the mismatches due to high AGEs. Furthermore, under dynamic loading, some toughening mechanisms can be activated and deactivated with different AGEs contents. In conclusion, the current findings present that the combination of the loading type and materials heterogeneity of microstructural features can change the fracture response of diabetic cortical bone and its fragility.
Topics: Humans; Cortical Bone; Glycation End Products, Advanced; Weight-Bearing; Biomechanical Phenomena; Fractures, Bone; Tibia; Finite Element Analysis; Stress, Mechanical
PubMed: 38759587
DOI: 10.1016/j.jmbbm.2024.106577 -
Medicine May 2024Gout is a chronic disease characterized by deposition of monosodium urate crystals. Tophi develop in some individuals with untreated or uncontrolled gout, which leads to...
INTRODUCTION
Gout is a chronic disease characterized by deposition of monosodium urate crystals. Tophi develop in some individuals with untreated or uncontrolled gout, which leads to ulcerations, cosmetic problems, mechanical obstruction of joint movement, joint damage and musculoskeletal disability. Currently, the treatment of gouty tophi is controversial and challenging. Both surgical and internal medical treatments have limitations and require further exploration in clinical practice.
PATIENT CONCERNS
In Case 1, we treated a patient with severe infection of diabetic foot ulcers with concomitant multiple gouty tophi in the same limb. A systematic management strategy was formulated to close the wound and save the limb. The ulcers healed successfully after half a year. In Case 2, a giant gouty tophi located in the first metatarsophalangeal joint of the left foot was removed by surgical treatment and vancomycin-loaded bone cement implantation. In Case 3, we present a case of gouty tophi that was resolved by standardized systemic medical management.
DIAGNOSIS
Three patients were all diagnosed with gout accompanied by gouty deposition, although there were other different comorbidities.
INTERVENTIONS
In case 1, we used debridement to gradually remove gouty tophi. In case 2, the giant gouty tophi was removed by surgical operation. In case 3, the gouty tophi disappeared after standardized treatment with medicine, diet and lifestyle management.
OUTCOMES
Three patients underwent different treatment therapies to remove gouty tophi based on their specific conditions.
LESSONS
We explored effective interventions for tophi in gout by surgical or other interventions in combination with pharmacotherapy.
Topics: Humans; Male; Gout; Aged; Limb Salvage; Middle Aged; Debridement; Metatarsophalangeal Joint; Anti-Bacterial Agents; Female; Vancomycin; Diabetic Foot
PubMed: 38758848
DOI: 10.1097/MD.0000000000038137 -
The Journal of Clinical Pediatric... May 2024To explore a new method to implant deciduous tooth pulp into the canal of young permanent teeth with necrotic pulps and apical periodontitis for the regenerative...
To explore a new method to implant deciduous tooth pulp into the canal of young permanent teeth with necrotic pulps and apical periodontitis for the regenerative endodontic treatment of tooth no: 41 in a 7-year-old male. Briefly, 1.5% Sodium Hypochlorite (NaOCl) irrigation and calcium hydroxide-iodoform paste were used as root canal disinfectant at the first visit. After 2 weeks, the intracanal medication was removed, and the root canal was slowly rinsed with 17% Ethylene Diamine Tetraacetic Acid (EDTA), followed by flushing with 20 mL saline and then drying with paper points. Tooth no: 72 was extracted, and its pulp was extracted and subsequently implanted into the disinfected root canal along with induced apical bleeding. Calcium hydroxide iodoform paste was gently placed over the bleeding clot, and after forming a mineral trioxide aggregate (MTA) coronal barrier, the accessed cavities were restored using Z350 resin composite. The root developments were evaluated radiographic imaging at 6 months, 1 year and 5 years after treatment. Imaging and clinical analysis showed closure of the apical foramen, thickening of the root canal wall, and satisfactory root length growth. Autologous transplantation might be useful to regenerate dental pulp in necrotic young permanent teeth.
Topics: Humans; Male; Child; Dental Pulp; Tooth, Deciduous; Incisor; Calcium Compounds; Aluminum Compounds; Oxides; Drug Combinations; Dental Pulp Necrosis; Silicates; Follow-Up Studies; Regenerative Endodontics; Mandible; Calcium Hydroxide; Neovascularization, Physiologic; Root Canal Therapy; Root Canal Irrigants; Root Canal Filling Materials; Periapical Periodontitis; Sodium Hypochlorite; Dental Pulp Cavity; Hydrocarbons, Iodinated
PubMed: 38755996
DOI: 10.22514/jocpd.2024.071 -
Annals of Anatomy = Anatomischer... May 2024When the natural process of bone remodeling is disturbed, the need arises for a stimulant material in order to enhance the formation of a new healthy and strong osseous... (Review)
Review
BACKGROUND
When the natural process of bone remodeling is disturbed, the need arises for a stimulant material in order to enhance the formation of a new healthy and strong osseous tissue to replace the damaged one. Recent studies have reported synthetic biomaterials to be a very good option for supporting bone regeneration.
STUDY DESIGN
Narrative review.
OBJECTIVE
This review aims to provide a brief presentation of two of the most recently developed synthetic biomaterials, i.e. calcium phosphate cements and synthetic composites, that are currently being used in bone regeneration with promising results.
METHODS
Literature searches using broad terms such as "bone regeneration," "biomaterials," "synthetic composites" and "calcium phosphate cements" were performed using PubMed. The osteal cells state of the art was explored by searching topic-specific full text keywords using Google Scholar.
CONCLUSIONS
Synthetic polymers such as PCL (poly-ε-caprolactone) and PLGA (poly lactic-co-glycolic acid) can improve the effectiveness of biomaterials like HA (hydroxyapatite) and BG (bioglass). Calcium phosphate, although being a suitable material for stimulating bone regeneration, needs an adjuvant in order to be effective in larger bone defects.
PubMed: 38754741
DOI: 10.1016/j.aanat.2024.152273 -
Journal of Cardiothoracic Surgery May 2024Deep sternal wound infection (DSWI) after midline sternotomy of cardiac surgery is a challenging complication that affects the outcome of surgery. This study aims to...
Antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management for sternal infection after midline sternotomy.
INTRODUCTION
Deep sternal wound infection (DSWI) after midline sternotomy of cardiac surgery is a challenging complication that affects the outcome of surgery. This study aims to assess the clinical effectiveness of the antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management in the treatment of DSWI.
METHODS
We retrospectively analyzed 5 patients with DSWI who underwent antibiotic-loaded bone cement combined with bilateral pectoralis major muscle flaps for chest wall reconstruction after sternotomy for cardiac surgery in a tertiary hospital in China from January 2020 to December 2021. The clinical and follow-up data were retrospectively analyzed.
RESULTS
All patients had no perioperative mortalities, no postoperative complications, 100% wound healing, and an average hospital stay length of 24 days. The follow-up periods were from 6 to 35 months (mean 19.6 months). None of the cases showed wound problems after initial reconstruction using antibiotic-loaded bone cement combined with bilateral pectoralis major muscle flaps.
CONCLUSIONS
We report our successful treatment of DSWI, using antibiotic-loaded bone cement fixation technique combined with bilateral pectoralis major muscle flaps tension-free management. The clinical and follow-up results are favorable.
Topics: Humans; Male; Sternotomy; Anti-Bacterial Agents; Retrospective Studies; Bone Cements; Pectoralis Muscles; Middle Aged; Surgical Wound Infection; Female; Surgical Flaps; Aged; Cardiac Surgical Procedures; Sternum; Plastic Surgery Procedures
PubMed: 38745239
DOI: 10.1186/s13019-024-02749-0 -
International Journal of Molecular... Apr 2024The use of temporary resin for provisional restorations is a fundamental step to maintain the position of prepared teeth, to protect the pulpal vitality and the... (Comparative Study)
Comparative Study
The use of temporary resin for provisional restorations is a fundamental step to maintain the position of prepared teeth, to protect the pulpal vitality and the periodontal health as well as the occlusion. The present study aimed at evaluating the biological effects of two resins used in dentistry for temporary restorations, Coldpac (Yates Motloid) and ProTemp 4™ (3M ESPE ™), and their eluates, in an in vitro model of human gingival fibroblasts (hGFs). The activation of the inflammatory pathway NFκB p65/NLRP3/IL-1β induced by the self-curing resin disks was evaluated by real-time PCR, Western blotting and immunofluorescence analysis. The hGFs adhesion on resin disks was investigated by means of inverted light microscopy and scanning electron microscopy (SEM). Our results suggest that hGF cells cultured in adhesion and with eluate derived from ProTemp 4™ (3M ESPE ™) resin evidenced a downregulation in the expression of the inflammatory mediators such as NFκB p65, NLRP3 and IL-1β compared to the cells cultured with Coldpac (Yates Motloid) after 24 h and 1 week of culture. Furthermore, the cells cultured with ProTemp 4™ (3M ESPE ™) after 24 h and 1 week of culture reported a higher cell viability compared to the cells cultured with Coldpac (Yates Motloid), established by MTS cell analysis. Similar results were obtained when hGFs were placed in culture with the eluate derived from ProTemp 4™ (3M ESPE ™) resin which showed a higher cell viability compared to the cells cultured with eluate derived from Coldpac (Yates Motloid). These results highlighted the lower pro-inflammatory action and improved cell biocompatibility of ProTemp 4™ (3M ESPE ™), suggesting a better performance in terms of cells-material interaction.
Topics: Humans; Fibroblasts; Gingiva; Composite Resins; Polymethyl Methacrylate; Interleukin-1beta; NLR Family, Pyrin Domain-Containing 3 Protein; Cells, Cultured; Transcription Factor RelA; Cell Adhesion
PubMed: 38732100
DOI: 10.3390/ijms25094880 -
Materials (Basel, Switzerland) May 2024Bone substitutes are ideally biocompatible, osteoconductive, degradable and defect-specific and provide mechanical stability. Magnesium phosphate cements (MPCs) offer...
Bone substitutes are ideally biocompatible, osteoconductive, degradable and defect-specific and provide mechanical stability. Magnesium phosphate cements (MPCs) offer high initial stability and faster degradation compared to the well-researched calcium phosphate cements (CPCs). Calcium magnesium phosphate cements (CMPCs) should combine the properties of both and have so far shown promising results. The present study aimed to investigate and compare the degradation and osseointegration behavior of 3D powder-printed wedges of CMPC and MPC in vivo. The wedges were post-treated with phosphoric acid (CMPC) and diammonium hydrogen phosphate (MPC) and implanted in a partially loaded defect model in the proximal rabbit tibia. The evaluation included clinical, in vivo µ-CT and X-ray examinations, histology, energy dispersive X-ray analysis (EDX) and scanning electron microscopy (SEM) for up to 30 weeks. SEM analysis revealed a zone of unreacted material in the MPC, indicating the need to optimize the manufacturing and post-treatment process. However, all materials showed excellent biocompatibility and mechanical stability. After 24 weeks, they were almost completely degraded. The slower degradation rate of the CMPC corresponded more favorably to the bone growth rate compared to the MPC. Due to the promising results of the CMPC in this study, it should be further investigated, for example in defect models with higher load.
PubMed: 38730942
DOI: 10.3390/ma17092136 -
BMC Musculoskeletal Disorders May 2024This systemic review and meta-analysis aimed to evaluate the clinical outcomes of proximal humeral fracture in elderly patient fixation using locked plate with or... (Meta-Analysis)
Meta-Analysis
BACKGROUND
This systemic review and meta-analysis aimed to evaluate the clinical outcomes of proximal humeral fracture in elderly patient fixation using locked plate with or without cement augmentation.
METHODS
The databases of PubMed, Embase, and Cochrane Library were searched in August 2023 for literature comparing the clinical outcomes of patients with PHFs treated with locked plate alone and locked plate augmented with cement. Data describing study design; level of evidence; inclusion criteria; demographic information; final follow-up; revision rate; implant failure rate; avascular necrosis rate; total complication rate; constant score; and disability of arm, shoulder, and hand (DASH) score were collected.
RESULTS
Eight studies (one randomized-controlled trial and seven observational studies), involving 664 patients, were identified. Compared with locked plates alone, using cement-augmented locked plates reduced the implant failure rate (odds ratio (OR) = 0.19; 95% confidence interval (CI) 0.10-0.39; P < 0.0001) and total complication rate (OR = 0.45; 95% CI 0.29-0.69; P = 0.0002) and improved DASH scores (mean difference (MD) = 2.99; 95% CI 1.00-4.98; P = 0.003). However, there was no significant difference in clinical outcomes, including revision rate, avascular necrosis rate, and constant score.
CONCLUSION
In this review and meta-analysis, fixation of the PHFs in elderly patients using locked plates with or without cement augmentation has no significant difference in revision rate, but the implant failure and total complication rates may be lesser on using the cement-augmented locked plate for fixation than on using a locked plate alone. Good results are expected for most patients treated with this technique.
TRIAL REGISTRATION
The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)21 guidelines were followed to conduct this systematic review and meta-analysis and was registered as a protocol in PROSPERO (CRD42022318798).
Topics: Humans; Bone Plates; Shoulder Fractures; Fracture Fixation, Internal; Bone Cements; Aged; Treatment Outcome; Aged, 80 and over; Postoperative Complications; Reoperation
PubMed: 38730497
DOI: 10.1186/s12891-024-07502-1 -
Joint Diseases and Related Surgery Apr 2024This study aimed to review a 35-year experience with chondromyxoid fibroma at our institution.
OBJECTIVES
This study aimed to review a 35-year experience with chondromyxoid fibroma at our institution.
PATIENTS AND METHODS
The study retrospectively analyzed the records of 31 consecutive patients (17 males, 14 females; mean age: 30.5±15.7 years; range, 6 to 63 years) with chondromyxoid fibroma who were treated between January 1988 and December 2021. The clinical and radiological characteristics of lesions, tumor volume, and recurrence rates were assessed using the tumor archive of the hospital.
RESULTS
The mean follow-up duration was 65.9±42.0 months. Pelvis, proximal tibia, and distal femur were the most common sites of localization. The initial surgical treatment was performed on 27 patients at our clinic, while four patients were referred to the clinic after recurrence. The overall recurrence rate was 16.1%. Intralesional curettage was applied to 21 (77.8%) out of 27 patients. The cavity created after curettage was filled with bone graft (autograft or allograft) in 15 (55.5%) cases. Bone cement was applied in four (14.8%) cases. Resection was applied to five (18.5%) patients. In two (7.4%) cases, intralesional curettage alone was performed. One of these two patients experienced recurrence, resulting in a recurrence rate of 50% in this patient group. No recurrence was observed in other treatment groups.
CONCLUSION
Intralesional curettage and filling the defect with bone graft or cement were effective for local control in most cases. Curettage alone was associated with high recurrence rates.
Topics: Humans; Male; Female; Retrospective Studies; Adult; Adolescent; Middle Aged; Bone Neoplasms; Young Adult; Child; Fibroma; Curettage; Neoplasm Recurrence, Local; Bone Transplantation; Bone Cements
PubMed: 38727118
DOI: 10.52312/jdrs.2024.1620 -
Effects of hexagonal boron nitride on mechanical properties of bone cement (Polymethylmethacrylate).Joint Diseases and Related Surgery Feb 2024The aim of this study was to investigate the effects of adding hexagonal boron nitride at four different concentrations to polymethylmethacrylate (PMMA) bone cement,...
OBJECTIVES
The aim of this study was to investigate the effects of adding hexagonal boron nitride at four different concentrations to polymethylmethacrylate (PMMA) bone cement, which is commonly used in orthopedic surgeries, on the mechanical properties and microarchitecture of the bone cement.
MATERIALS AND METHODS
The study included an unaltered control group and groups containing four different concentrations (40 g of bone cement with 0.5 g, 1 g, 1.5 g, 2 g) of hexagonal boron nitride. The samples used for mechanical tests were prepared at 20±2ºC in operating room conditions, using molds in accordance with the test standards. As a result of the tests, the pressure values at which the samples deformed were determined from the load-deformation graphs, and the megapascal (MPa) values at which the samples exhibited strength were calculated.
RESULTS
The samples with 0.5 g boron added to the bone cement had significantly increased mechanical strength, particularly in the compression test. In the group where 2 g boron was added, it was noted that, compared to the other groups, the strength pressure decreased and the porosity increased. The porosity did not change particularly in the group where 0.5 g boron was added.
CONCLUSION
Our study results demonstrate that adding hexagonal boron nitride (HBN) to bone cement at a low concentration (0.5 g / 40 g PPMA) significantly increases the mechanical strength in terms of MPa (compression forces) without adversely affecting porosity. However, the incorporation of HBN at higher concentrations increases porosity, thereby compromising the biomechanical properties of the bone cement, as evidenced by the negative impact on compression and four-point bending tests. Boron-based products have gained increased utilization in the medical field, and HBN is emerging as a promising chemical compound, steadily growing in significance.
Topics: Boron Compounds; Polymethyl Methacrylate; Bone Cements; Materials Testing; Porosity; Compressive Strength; Stress, Mechanical
PubMed: 38727113
DOI: 10.52312/jdrs.2024.1513