Bone Chips Research Articles

A Successful Control of the Intraoperative Bleeding from McConnell's Artery during Fully Endoscopic Resection of Planum Sphenoidale Meningioma Using Bone Chip and Bioglue : A Case Report.

The endoscopic transsphenoidal approach is a common approach used in skull base neurosurgery to reach the sellar region. One of the intraoperative risks of this approach is intraoperative bleeding out of the carotid artery. Gentle drilling can prevent carotid artery injury. However, injury to smaller branches, such as the McConnell's capsular artery, which is located within the surgical corridor, is more difficult to prevent. If such an injury is within the junction to the main trunk of the carotid artery, there will be a small circular defect in this area. This can result in massive blood loss and should be closed surgically immediately. We describe a clinical case of intraoperative bleeding from the McConnell's artery originating from the carotid arterial segment (C4) in a 78-year-old female patient operated on for planum sphenoidale meningioma via endoscopic transsphenoidal approach, as well as provide a technical note on a possible technique for bleeding control in such cases. Pinpoint carotid bleeding as a result of intraoperative injury can be stopped by wedging a bone fragment in the carotid canal and fixing it in that position with histoacryl glue at the defect site.

From Waste to Innovation: A Circular Economy Approach for Tissue Engineering by Transforming Human Bone Waste into Novel Collagen Membranes.

The aim of the circular economy is to treat waste as a valuable raw material, reintegrating it into the industrial economy and extending the lifecycle of subsequent products. Efforts to reduce the production of hard-to-recycle waste are becoming increasingly important to manufacturers, not only of consumer goods but also of specialized items that are difficult to manufacture, such as medical supplies, which have now become a priority for the European Union. The purpose of the study is to manufacture a novel human-purified type I collagen membrane from bone remnants typically discarded during the processing of cortico-cancellous bones in tissue banks and to evaluate its mechanical properties and effectiveness in regenerating bone-critical mandibular defects in rabbits. To prepare the novel membrane, cortico-cancellous bone chip samples from a local tissue bank were processed to isolate collagen by demineralization under agitation in HCl, cast into a silicone mold, and air-dried at room temperature and UV irradiation. The average thickness of the four batches analyzed by SEM was 37.3 μm. The average value of Young's modulus and tensile strength obtained from the specimens was 2.56 GPa and 65.43 Mpa, respectively. The membrane's efficacy was tested by creating a critical bicortical and bilateral osteoperiosteal defect in rabbit mandibles. The right-side defects were covered with the collagen membrane, while the left-side defects were left untreated as a control. Nine weeks post-surgery, clinical, radiological, and histological analyses demonstrated new bone formation in the treated areas, whereas the control sites showed no bone regeneration. This innovative approach not only contributes to sustainability in healthcare by optimizing biological waste but also exemplifies efficient resource use in line with the circular economy, offering a cost-effective, biocompatible option that could benefit national health systems.

12 real forensic cases solved by the DNA STR-typing of skeletal remains exposed to extreme environment conditions, without the conventional bone pulverization step.

DNA identification of human skeletal remains play a valuable role in the forensic field, especially in missing persons and mass disasters investigation. Hard tissues, such as bones and teeth, represent a very common kind of samples analyzed in forensic laboratories because often they are the only biological materials remaining. However, the major limitation in using these compact samples rely on time consuming and labor-intensive treatment of grinding them into powder before proceeding with the conventional DNA purification and extraction step. In this context, a novel DNA extraction assay, called the TBone Ex kit (DNA Chip Research Inc.), was developed to digests bone chips without powdering "as reported by Kitayama (JAMA 12:84-89, 2010)." Here, we simultaneously analyzed bone and tooth samples obtained by our police laboratory that belonged to 15 different forensic cases from Sardinia (Italy). The total of 27 samples were recovered from different scenarios and were exposed to extreme environmental factors, including sunlight, seawater, soil, fauna, vegetation and high temperature and humidity. The TBone Ex kit was used prior to the EZ2 DNA extraction kit on the EZ2 Connect Fx instrument (Qiagen), and high quality autosomal and Y-chromosome STRs profiles were obtained for the 80% of the cases, in a relatively short time frame. This study provides additional support for the use of the TBone Ex kit for digesting bone fragments/whole teeth as an effective alternative to pulverization protocols. We empirically demonstrated the effectiveness of the kit in processing multiple bone samples simultaneously, largely simplifying the DNA extraction procedure, and the good yield of recovered DNA for downstream genetic typing in highly compromised forensic real specimens. In conclusion, the results of this study appear useful for forensic laboratories, to which the various actors of the criminal justice system - such as potential jury members, judges, defense attorneys and prosecutors - require immediate feedback.

Surgical outcome after autologous bone chips replacement in depressed skull fractures: a single center experience

BackgroundSurgery for depressed skull fractures (DSFs) is always faced by multiple challenges including ideal timing, defect reconstruction and complications. Few data are available regarding the aesthetic results and patients’ satisfaction following DSFs management.MethodsA prospective non-randomized study included 59 traumatic brain injury (TBI) patients surgically treated for DSFs. Depressed bone fragments were elevated and washed with diluted hydrogen peroxide for 15 min then replaced within a net made of vicryl 0 through edges of the galea. Our objective was to evaluate outcome and patients’ satisfaction of using autologous bone fragments for skull defect reconstruction.ResultsThe mean Glasgow Coma Scale (GCS) score on admission was 14.51 ± 1.237. The mean age was 16.505 ± 12.426 years. DSFs were of compound type in 81.4% with predominance towards the parietal region 54.2%. Associated intracranial pathologies were found in 39.0% of cases. Mean time to surgery was 5.79 ± 9.982 h. Dura was found torn in 19 cases (32.2%). Postoperative complications were encountered in 5 cases (8.5%). The mean hospital stay was 3.61 ± 3.157 days. 96.6% of cases had good discharge outcome. Factors with significant impact on outcome included; admission GCS score (P < 0.001), type of associated pathology (P = 0.006), and venous sinus involvement (P = 0.003). At the end of follow up, 46 patients (82.5%) were satisfied about the aesthetic results, while 10 patients (17.5%) were not satisfied and 9 of them underwent re-surgery for late cranioplasty.ConclusionsUsing autologous depressed bone chips for skull defect reconstruction can be a safe and feasible surgical technique for TBI patients suffering DSFs with good aesthetic results, high patient satisfaction, decreased need for later cranioplasty and consequently low overall management cost.

Comparison of Low-speed Drilling and Conventional Drilling in Implant Surgery: an Experimental Study.

To compare accuracy, duration of drilling and accumulation of bone chips between low-speed drilling and conventional drilling in freehand implant placement surgery. The implant surgery procedures were performed using identical drill bits on pig ribs in the low-speed drilling group and the conventional drilling group. CBCT images of the preoperative implant design and postoperative implant positions were compared by using the space vector formula to calculate the angular deviation of the implants between the two groups, as well as the horizontal and vertical deviations of the implant necks and roots. The duration of the procedure was recorded, and the bone chips were collected and compared using a screening method and scanning electron microscopy. There were no significant differences in any of the four primary outcome variables relating to accuracy between the low-speed and conventional drilling methods. However, the results revealed that the length of the procedure differed significantly between the two groups and more large bone fragments could be collected when performing low-speed drilling. Low-speed drilling does not affect the accuracy of implant nest preparation, but it can harvest large bone chips which may have better osteogenic activity. Low-speed drilling could be an alternative to conventional drilling.

Differences in Outcomes Based on the Degree to Which Bone Defects Are Filled with Cancellous Allochip Bone Grafts in Hand Enchondroma Patients.

Enchondroma, the most common benign cartilage tumor in the hand, often presents as pain, swelling, or pathological fractures. While curettage is the standard treatment preventing fractures, the optimal way of managing the bone cavity remains debated. In this study, we investigated the impact of a filled bone defect on radiologic and clinical outcomes among patients with enchondroma. We retrospectively reviewed patients with solitary enchondroma of the hand who underwent curettage followed by allogeneic cancellous bone chip impaction grafting. The patients were divided into two groups based on the extent to which their bone defects were filled post-curettage: Group 1 (complete filling) and Group 2 (incomplete filling, i.e., <50%). We reviewed demographic data, local recurrence data, complications, information on consolidation duration, data on range of motion (ROM), and functional scores. This study included 59 patients (25 males and 34 females; mean age, 30.4 ± 11.9 years, with a range of 8-78). Group 1 contained 35 patients, and Group 2 contained 24. No nonunion occurred following curettage and grafting. The mean radiological consolidation period was 6.4 weeks (range: 5-18). There was no significant difference in consolidation time between Group 1 (6.8 weeks) and Group 2 (6.9 weeks) (p = 0.166). The ROM and functional scores also showed no significant differences between the groups, with musculoskeletal society scores of 98.8 for Group 1 and 99.8 for Group 2 (p = 0.63). This study demonstrates that the use of the impaction technique combined with cancellous allochip bone grafting yields favorable results in the treatment of solitary hand enchondroma. The extent to which the bone defect was filled did not significantly impact the overall outcomes.

SURG-55. NOVEL IQ-DOME APPROACH FOR SUPERIOR SEMICIRCULAR CANAL DEHISCENCE REPAIR REDUCES REVISIONAL SURGERY RATE

Abstract Superior Semicircular Canal Dehiscence (SSCD) is characterized by a thinning of the bony ceiling of the superior semicircular canal, manifesting in auditory and vestibular deficits. Surgical repair is the standard treatment modality of SSCD, with conventional methods including plugging or recapping the defective canal with bone wax, bone chips, muscle, and others. Previous research has shown multiple complications with these conventional materials, including a high rate of failure of the primary repair and the need for revisional surgeries. To address this challenge, we investigated a novel surgical sealing technique using IQ-Dome, a titanium mesh plate overlying the arcuate eminence. We aim to assess the efficacy of IQ-Dome in the repair of SSCD compared to conventional material while evaluating outcome measures including postoperative symptom resolution, complication, and revisional surgery rates. We performed a retrospective analysis of patients undergoing SSCD repair via the middle cranial fossa approach at UCLA between 2017 and 2021. We compared demographics and post-operative outcomes between the application of IQ-Dome and conventional materials. A total of 160 patients undergoing SSCD repair were included in our study, with 80 patients receiving IQ-Dome and 80 patients receiving non-IQ-Dome approaches. 60% of patients in the IQ-Dome cohort and 66.7% of patients in the non-IQ-Dome cohort were female. The mean ages of patients were 45.7 years (range 13-78) in the IQ-Dome cohort and 48.9 years (range 17-69) in the non-IQ-Dome cohort. The surgical revision rates for the IQ-Dome and non-IQ-Dome cohorts were 5.7% and 8.5%, respectively. There was no significant difference in postoperative complications between groups. Thus, IQ-Dome is a safe approach for the surgical management of SSCD, decreasing failure and revision rate by nearly 3% in our patient population and offering an alternative surgical sealing repair intervention. Future studies with larger sample sizes are warranted to further assess the efficacy of IQ-Dome.

Treatment of adult spine deformity: A retrospective comparison of bone morphogenic protein and bone marrow aspirate with bone allograft.

This was a retrospective cohort study. ASD patients were stratified by use of intra-operative BMP (BMP +) or not (BMA + I) and surveyed for the development of complications and mechanical failure. Quality of life gained following the procedure was evaluated using quality-adjusted life years (QALYs). Cost was calculated using the PearlDiver database and CMS definitions. Multivariable analyses (ANCOVA) and logistic regression were used to adjust for confounding. 512 patients were included (60% BMP +). At baseline, BMP + patients were older (62.5 vs 60.8years, p < 0.010). Radiographic and quality-of-life metrics did not differ at follow up timepoints (all p > 0.05). BMP use was associated with higher supplemental rod use (OR: 7.0, 1.9 - 26.2, p = 0.004), greater number of levels fused (OR: 1.1, 1.03 - 1.17, p = 0.003) and greater neurological complications (OR: 5.0, 1.3 - 18.7, p = 0.017). Controlling for rod use and levels fused, BMP use was not associated with a lower risk of mechanical complications (OR 0.3, 95% CI: 0.2 - 3.0, p = 0.353), rod breakage (OR: 3.3, 0.6 - 18.7, p = 0.182) or implant failure (OR: 0.3, 0.04 - 1.51). At 2years, the BMP + cohort exhibited higher overall costs ($108,062 vs $95,144, p = 0.002), comparable QALYs (0.163 vs 0.171, p = 0.65) and higher cost per QALY (p = 0.001) at two years. In this analysis, BMP-2 application was not associated with superior outcomes when compared to a less costly biologic alternative (bone marrow aspirate + cancellous bone chips + i-Factor) following ASD surgery. The use of BMP-2 in ASD surgery appears to have reduced cost-efficacy at two years postoperatively.

Biological knee joint reconstruction using patella following giant cell tumor excision: a case report

A 20-year-old female patient presented to us with a large expansile swelling over right knee diagnosed clinically and confirmed histopathological and radiologically to be Giant Cell Tumor of upper end of Tibia involving both condyles with a breach in the posterior cortex. In this case report we tried to retain the joint function by biological reconstruction using the Patella after the wide excision of the tumor mass. A radical excision of the upper end of the Tibia was done. The Patella was used as an articular surface supported by ipsilateral Fibula and cortico-cancellous bone chips from the ipsilateral iliac crest as struts and complemented with synthetic bone graft pieces. Thus, the joint was reconstructed biologically. The case was followed for 1 year. The tumor was excised in toto, the knee joint was restored by the Patella and the bone graft struts. The results were discussed in detail.

Enhancement of a one-step membrane technique for the treatment of large bone defects by pre-seeding the membrane with CD8 lymphocyte depleted bone marrow mononuclear cells in a rat femoral defect model.

The one-step membrane technique, using a human acellular dermal matrix (hADM), is an experimental method for treating large bone defects. This eliminates the need for the Masquelet membrane induction step, shortening the procedure while maintaining effectiveness. However, previous studies showed that colonizing hADM with bone marrow mononuclear cells (BMC) worsens healing, likely due to the presence of CD8+ lymphocytes, which negatively affect bone regeneration. This study aims to investigate whether the negative impact of BMC on bone healing in this technique is due to the CD8+ cell population. A 5 mm femoral defect was created in 25 male Sprague-Dawley rats, divided into three groups (G1-G3). BMC were isolated from syngenic donor rats, with CD8+ lymphocytes removed magnetically from the BMC fraction in one group. The defects were filled with bone chips and wrapped with differently treated hADM: G1 received native hADM, G2 received hADM+BMC, and G3 received hADM+BMC-CD8. After 8 weeks, the femurs were evaluated through radiological, biomechanical, and histological examinations. Bone defects and bone mineral density (BMD) were significantly improved in G3 (hADM+BMC-CD8) compared to G2 (hADM+BMC). Bone volume, bone formation, and median bending stiffness were higher in G3. Immunohistological analysis showed a significant decrease in CD8 cell count in G3, with a lower percentage of IFNγ-producing cells compared to G2. Depleting CD8+ cells from BMC before colonizing hADM significantly improved bone healing, likely due to changes in the local mediator environment. This suggests that preoperative colonization with CD8+-depleted BMC could enhance the one-step membrane technique.

Bone allograft impregnated with tobramycin and vancomycin delivers antibiotics in high concentrations for prophylaxis against bacteria commonly associated with prosthetic joint infections.

Local delivery of antibiotics as prophylaxis for prosthetic joint infections (PJIs) is frequently used during total hip replacement surgery. Morselized bone allograft impregnated with vancomycin and tobramycin (TobraVanc) could provide effective prophylaxis against bacteria commonly associated with PJIs. In this study, the concentrations of antibiotics released by bone allograft impregnated with TobraVanc were determined by using an in vitro bioassay system entailing measuring inhibition zone diameters caused by antibiotic-impregnated bone chips cast in agar against standard curves. The concentrations were determined in samples of TobraVanc-impregnated bone graft taken before and after the application of the bone graft in the patients undergoing acetabular revision surgery. Antibiotic-impregnated bone grafts, sampled prior to application in the patient, delivered antibiotics in the concentration ranges of 730-9,800 mg/L for tobramycin and 1,300-11,000 mg/L for vancomycin. Samples taken after application in the patient released lower concentrations of tobramycin (490-1,900 mg/L; P < 0.01) and vancomycin (3,000-5,100 mg/L; P < 0.05); however, these concentrations remained well above the tobramycin minimum inhibitory concentrations (MICs) for investigated, highly tobramycin-resistant Staphylococcus epidermidis strains (MICs > 256 mg/L). At the tested concentrations, bone graft material mixed with TobraVanc delivered antibiotics in potent concentrations above the MICs for bacteria causing PJIs. Clinical trials are needed to evaluate the efficacy and risk of TobraVanc-impregnated bone graft as a prophylactic agent for patients undergoing hip replacement surgery.IMPORTANCEAntibiotic prophylaxis is the cornerstone of successful joint replacement surgery, reducing the risk for the dreaded complication of prosthetic joint infection (PJI) to roughly 0.5%-2% in standard total hip replacement (THR). In addition to systemic antibiotics, antibiotics added locally have the potential to reduce the PJI risk even further, because of the high concentrations that can be achieved in the joint with limited risk for systemic toxicity. The results in the current study show that bone chips impregnated with a combination of tobramycin and vancomycin (TobraVanc) release antibiotics in concentrations that are potent against common bacteria causing PJIs. Especially in high-risk patients, our results support the prophylactic use of TobraVanc in hip replacement surgery requiring the use of a bone graft. A clinical study testing the efficacy of TobraVanc-impregnated bone graft in reducing the incidence of PJI in hip replacement surgery is currently ongoing (EudraCT: 2021-001708-14).

Microarchitectural properties of compacted cancellous bone allografts: A morphology micro-computed tomography analysis

Massive bone loss poses a significant challenge in defect reconstruction. The use of compacted allografts is a valuable technique to reconstruct bone stock. This study aimed to assess the impact of compression on the microstructure of native cancellous bone chips with a micro-CT analysis.Bone samples were harvested from 15 femoral heads donated by patients who underwent total hip arthroplasty. Bone chips were prepared using a bone mill. All samples with the same weight were compressed by 25% and 50% of their original volume and subsequently scanned with a micro-CT scanner to determine the microarchitectural morphology of the bone chips. Uniaxial compression test was carried out before and after a standardized compaction procedure.Comparing the samples without compaction to 50%, the number of trabeculae doubled, the volume ratio doubled, and the trabeculae spacing was reduced, showing voids of 800 μm on average. The number of interlocking possibilities tripled, while no differences were seen in the trabeculae morphology. Uniaxial compression test showed a yield limit after compaction of 0.125 MPa.Interlocking might occur three times more with a denser material than in a non-compacted sample. The increase in density comparable to manual intraoperative compaction did not lead to significant fragmentation of the allograft material. The assessed microarchitecture should, therefore, reassemble the intraoperative situation during a manual bone impaction procedure.

Clinical and Micro-CT analyses of Vertical Guided Bone Regeneration of Mandible using a d-PTFE Membrane, Autogenous Bone, and High-Temperature Processed Xenograft- A Case Series Study.

Purpose: To evaluate the efficacy of vertical guided bone regeneration (GBR) in the mandible utilizing a non-resorbable membrane and a bone graft combination of autogenous bone chips, and high-temperature processed (HTP) xenograft, through CT scans and microCT analysis. Materials and Methods: Patients underwent vertical ridge augmentation procedures prior to implant placement. The surgical procedure included flap elevation and placement of a bone graft comprising a 1:1 combination of autogenous posterior mandible-derived bone chips, and HTP xenograft graft particles covered with a d-PTFE membrane trimmed to suit the 3D shape of the bone defect. This was fastened securely with titanium screws and pins, and a layer of native collagen membrane. Post-operative complications and ridge measurements were assessed. Pre bone augmentation and pre implant placement bone parameters were obtained from CT scans. Biopsy specimens collected during implantation were examined by microCT. Results: All 13 study procedures were successful without any complications. The results revealed average vertical and horizontal bone gains of 3.35 mm and 5.15 mm respectively. A total of 33 implants were successfully placed in the augmented areas, without the need for further bone augmentation. MicroCT analysis revealed 48% bone, 15% filler material, and 37% non-calcified tissue in the augmented region compared to 65% bone, 3% filler material, and 32% non-calcified tissue in the pristine bone. Conclusions: A mixture of autogenous bone and HTP xenograft, covered with a d-PTFE membrane and a layer of native collagen membrane is effective for vertical GBR.

Changes in DOPAC, 3-MT, DOPAC/DA, HVA/DA, 3-MT/DA in the Hippocampus After Simulated Septoplasty and Maxillary Sinusotomy

Objective: to evaluate changes in DOPAC, 3-MT, DOPAC/DA, HVA/DA, 3-MT/DA in the hippocampus after simulation of septoplasty and maxillofacial surgery in rats. Materials and methods. Simulation of operations was carried out on male Wistar rats under general anesthesia with Zoletil 100 solution. In group 1, septoplasty (n=10) was simulated by the standard method by zigzag scarification of the nasal mucosa. In group 2 (n=10), dental implantation with a titanium implant was performed after the implant bed was formed using drill. In group 3 (n=10), only implant bed was made in the alveolar ridge of the upper jaw without subsequent manipulations. In group 4, 10 rats underwent sinus lifting with bone chips with immediate implantation of a titanium implant. In group 5 (n=10)– with the help of a micro drill through a pre-formed implant bed in the alveolar ridge of the upper jaw, a maxillary sinusotomy was performed with damage to the mucous membrane of the ipsilateral maxillary sinus. Liquid chromatography with electrochemical detection was used to determine the concentration of dopamine (DA), homovanilic acid (HVA), 3,4-dihydroxyphenylacetic acid (DOPAC), 3- methoxytiramine (3-MT) in the hippocampal formation. DOPAC/DA, HVA/DA, 3-MT/DA were also determined. Results. The concentration of dopamine in the hippocampus, compared with the control, was significantly higher in group 5 and lower in group 4. The HVA concentration was significantly higher in group 2, group 5 (p&lt;0.01) and group 1 (p&lt;0.05). An intergroup comparison determined that the concentration of HVA was significantly higher in group 2, compared with the rest of the experimental groups (p&lt;0.001). In groups 1, 3 and 4, this indicator was significantly lower compared to group 5 (p&lt;0.01). The DOPAC level was significantly higher (p&lt;0.01) compared to the control data. The concentration of 3-MT was significantly higher in groups 4 and 5 (p&lt;0.001), as well as in group 1 (p&lt;0.05) and in group 3 (p&lt;0.01). Conclusion. After simulating sinus lifting with immediate implantation and dental implantation complicated by maxillary sinusotomy, there is an increase in the concentration of dopamine metabolites 3-MT, HVA and DOPAC, but at the same time a decrease in dopaminergic activity of the hippocampal formation, compared with simulation of septoplasty and simple damage to the alveolar ridge of the upper jaw. Such changes are markers of disruption of adaptation processes after surgery in the head and neck.

Development and verification of a novel bone collector with automatic size separating function for orthopedics surgery

ABSTRACT Background Autologous bone dust can be filled in bone defects to promote effective bone healing but typically it is lost when using suction during surgery. The aim of this study was to develop a novel bone collector that can be used to collect bone chips/dust of varying sizes without changing current surgical procedures. Research design and methods This collector was designed to connect to a surgical continuous suction system and comprised a plate filter with a 3 mm hole and featured a taper filter with a mesh size of 0.27 mm for the separation and collection of both coarse and fine bone chips/dust. The bone collector was manufactured using nylon 3D printing and plastic injection with biocompatible materials. Results The bone collector functional test revealed high bone chip collection efficiency (93%) with automatic size separation function. Low (3.42%) filtration errors showed that most of the water can be drained smoothly from the bone collector. In clinical usability testing, bone collectors can provide functions demonstrated in in vivo spinal fusion and femoral fracture surgeries with different bone grafting size requirements. Conclusions The novel bone collector has been validated as a viable and effective surgical device, offering surgeons an additional option to enhance patient outcomes.

NOISe: Nuclei-Aware Osteoclast Instance Segmentation for Mouse-to-Human Domain Transfer.

Osteoclast cell image analysis plays a key role in osteoporosis research, but it typically involves extensive manual image processing and hand annotations by a trained expert. In the last few years, a handful of machine learning approaches for osteoclast image analysis have been developed, but none have addressed the full instance segmentation task required to produce the same output as that of the human expert led process. Furthermore, none of the prior, fully automated algorithms have publicly available code, pretrained models, or annotated datasets, inhibiting reproduction and extension of their work. We present a new dataset with ~2 × 105 expert annotated mouse osteoclast masks, together with a deep learning instance segmentation method which works for both in vitro mouse osteoclast cells on plastic tissue culture plates and human osteoclast cells on bone chips. To our knowledge, this is the first work to automate the full osteoclast instance segmentation task. Our method achieves a performance of 0.82 mAP0.5 (mean average precision at intersection-over-union threshold of 0.5) in cross validation for mouse osteoclasts. We present a novel nuclei-aware osteoclast instance segmentation training strategy (NOISe) based on the unique biology of osteoclasts, to improve the model's generalizability and boost the mAP0.5 from 0.60 to 0.82 on human osteoclasts. We publish our annotated mouse osteoclast image dataset, instance segmentation models, and code at github.com/michaelwwan/noise to enable reproducibility and to provide a public tool to accelerate osteoporosis research.

Histological Evaluation of Alveolar Ridge Preservation Using Different Bone Grafts: Clinical Study Analysis Part II.

To compare histologically the percentage of bone formation 12-20 weeks after ridge augmentation using 2 different techniques. Tooth loss is associated with 3-dimensional bone remodeling and ridge atrophy. Ridge preservation procedures can prevent alveolar bone volume loss. Different techniques and materials are used to preserve the alveolar ridge. Computer-generated randomization software was used to assign 2 ridge preservation techniques for 11 extraction sites. In group I, type I bovine Achilles tendon collagen plugs with bioactive resorbable calcium apatite crystals (CPCAC) were placed, and in group II, cortico-cancellous bone chips (CCBC) mix and an expanded polytetrafluoroethylene (ePTFE) barrier membrane were placed. The histomorphometric studies were performed using a computer-based image analysis system (ImageJ 1.4, National Institute of Health, Bethesda, Md) to calculate the pixel area of bone tissue and the remaining bone graft material. The histomorphometric data were analyzed using a Student t test to compare the measurements between the 2 experimental groups. This parametric statistical test was employed to determine if there were any statistically significant differences in the quantitative histological parameters between the groups. The sockets that received CPCAC showed a lower (31.89%) percentage of native bone surface area compared with the CCBC group (43.87%). However, the difference was not statistically significant (P < .05). In addition, the CPCAC group showed evidence of foreign-body reaction. The CCBC graft covered with an ePTFE barrier may induce more bone formation with minimal inflammation in an extraction socket compared with a collagen plug with calcium apatite crystals. In addition, histological analysis of the CPCAC graft showed evidence of foreign-body reaction, which indicates a negative clinical impact.

Autologous bone harvested during implant bed preparation: A randomized clinical trial comparing high-speed drilling with irrigation versus low-speed drilling without irrigation.

To compare collected bone weight and the frequency of autologous bone harvesting from the flutes of surgical drills used for implant bed preparation using two different drilling techniques. A comparative evaluation of radiographic bone density and bone quality was also made. A randomized clinical trial was made of 66 dental implants in patients with a single posterior edentulous site. The compared drilling techniques were high-speed drilling with irrigation (control group) and low-speed drilling without irrigation (test group). The bone collected in both groups was dried and weighed with a precise electronic balance. The frequency of harvesting was calculated. The median radiographic bone density of each implant site was measured using cone-beam computed tomography (CBCT) pixel values. Patient sex, age, implant position and dimensions, as well as the last drill diameter were analyzed as independent variables. The level of significance was 5%. The harvesting of bone chips from drill flutes proved possible in 51.5% of the procedures in the control group and in 100% in the test group (p < 0.001). There were also statistically significant differences in bone weight between the control group (6.7 ± 10.6 mg) and the test group (41.9 ± 30.3 mg) (p < 0.001). The CBCT pixel values were directly correlated with the collected bone weight in both groups. The median radiographic bone density, arch and last drill diameter were significantly associated with harvesting bone frequency and collected bone weight (p < 0.05). Our findings suggest that the frequency and weight of autologous bone harvested from drills are greater with low-speed drilling without irrigation than with high-speed drilling with irrigation. Radiographic bone density, arch and last drill diameter also significantly influenced the harvesting outcomes.

Modified and alternative bone cements can improve the induced membrane: Critical size bone defect model in rat femur

BackgroundAs a two-stage surgical procedure, Masquelet's technique has been used to care for critical-size bone defects (CSD). We aimed to determine the effects of modified and altered bone cement with biological or chemical enriching agents on the progression of Masquelet's induced membrane (IM) applied to a rat femur CSD model, and to compare the histopathological, biochemical, and immunohistochemical findings of these cements to enhance IM capacity. MethodsThirty-five male rats were included in five groups: plain polymethyl methacrylate (PMMA), estrogen-impregnated PMMA (E+PMMA), bone chip added PMMA (BC+PMMA), hydroxyapatite-coated PMMA (HA) and calcium phosphate cement (CPC). The levels of bone alkaline phosphatase (BALP), osteocalcin (OC), and tumor necrosis factor-alpha (TNF-α) were analyzed in intracardiac blood samples collected at the end of 4 weeks of the right femur CSD intervention. All IMs collected were fixed and prepared for histopathological scoring. The tissue levels of rat-specific Transforming Growth Factor-Beta (TGF-β), Runt-related Transcription Factor 2 (Runx2), and Vascular Endothelial Growth Factor (VEGF) were analyzed immunohistochemically. ResultsSerum levels of BALP and OC were significantly higher in E+PMMA and BC+PMMA groups than those of other groups (P = 0.0061 and 0.0019, respectively). In contrast, TNF-α levels of all groups with alternative bone cement significantly decreased compared to bare PMMA (P = 0.0116). Histopathological scores of E+PMMA, BC+PMMA, and CPC groups were 6.86 ± 1.57, 4.71 ± 0.76, and 6.57 ± 1.51, respectively, which were considerably higher than those of PMMA and HA groups (3.14 ± 0.70 and 1.86 ± 0.69, respectively) (P < 0.0001). Significant increases in TGF-β and VEGF expressions were observed in E+PMMA and CPC groups (P = 0.0001 and <0.0001, respectively) whereas Runx2 expression significantly increased only in the HA group compared to other groups (P < 0.0001). ConclusionsThe modified PMMA with E and BC, and CPC as an alternative spacer resulted in a well-differentiated IM and increased IM progression by elevating BALP and OC levels in serum and by mediating expressions of TGF-β and VEGF at the tissue level. Estrogen-supplemented cement spacer has yielded promising findings between modified and alternative bone cement.

The influence of connective tissue grafting on the reconstruction of a missing facial bone wall using immediate implant placement and simultaneous bone reconstruction: a retrospective long-term cohort study

PurposeThis retrospective cohort study evaluates the influence of connective tissue grafts (CTG) on bone regeneration at implant sites with total loss of the buccal bone wall treated with flapless immediate implant placement (IIP) and reconstruction with autogenous bone chips (AB) within a follow-up of up to 13 years.MethodsSixty implants were inserted in 55 patients in sites with total loss of the buccal bone wall between 2008 and 2021. The implants were inserted and the buccal gaps were grafted by AB. A subgroup of 34 sites was grafted additionally with CTG using tunnel technique. Primary outcome was the vertical bone regeneration in height and thickness. Secondary outcome parameters were interproximal marginal bone level, recession, soft tissue esthetics (PES), width of keratinized mucosa (KMW) and probing depths (PPD).ResultsMean follow-up period was 60.8 months. In 55 sites a complete vertical bone regeneration was documented. The mean buccal bone level increased by 10.6 mm significantly. The thickness of the buccal bone wall ranged between 1.7 and 1.9 mm, and was significantly thicker in sites without CTG. Interproximal marginal bone level was at implant shoulder level. The mean recession improved significantly by 1.2 mm. In sites with CTG, recessions and PES improved significantly more.ConclusionsAdditional CTG in extraction sites with total buccal bone loss followed by IIP with simultaneous AB grafting led to improved PES and recession, but also to a thinner buccal bone wall compared to sites grafted just with AB.Graphical