Cancellous Bone Research Articles

Clinical efficacy of open palmar approach combined with distal radial cancellous bone transplantation and internal fixation in the treatment of scaphoid nonunion

BackgroundTo investigate the clinical efficacy of the open palmar approach combined with distal radial cancellous bone transplantation and internal fixation in the treatment of scaphoid nonunion.MethodsFrom March 2019 to March 2022, our center conducted a clinical observation on 19 patients with scaphoid nonunion, including 14 males and 5 females, aged 18–63 years, with an average age of (43.5 ± 15.5) years. The surgical approach involved open palmar access combined with distal radial cancellous bone transplantation and internal fixation, followed by three months of immobilization with a splint. Postoperative x-ray examinations were performed at 6 months to observe bone graft healing and functional recovery.ResultsFollow-up of the 19 patients ranged from 6 to 24 months, with an average of 18 months. All patients achieved bony union, with an average healing time of 6 months. Postoperatively, wrist joint function was assessed using the modified Mayo wrist joint function scoring criteria: excellent in 15 cases, good in 2 cases; an excellent and good rate of 89.5%.ConclusionThe open palmar approach combined with distal radial cancellous bone transplantation and internal fixation is effective in treating scaphoid nonunion. The procedure is minimally invasive, allowing complete exposure of the fractured end of the scaphoid and the distal radius through the same incision. It facilitates easy cleaning of the fracture end, as well as convenient bone harvesting, grafting, and internal fixation. The postoperative efficacy is reliable, demonstrating significant advantages in the treatment of scaphoid nonunion.

Biocompatible nanocomposite hydroxyapatite-based granules with increased specific surface area and bioresorbability for bone regenerative medicine applications.

Hydroxyapatite (HA) granules are frequently used in orthopedics and maxillofacial surgeries to fill bone defects and stimulate the regeneration process. Optimal HA granules should have high biocompatibility, high microporosity and/or mesoporosity, and high specific surface area (SSA), which are essential for their bioabsorbability, high bioactivity (ability to form apatite layer on their surfaces) and good osseointegration with the host tissue. Commercially available HA granules that are sintered at high temperatures (≥ 900°C) are biocompatible but show low porosity and SSA (2-5 m2/g), reduced bioactivity, poor solubility and thereby, low bioabsorbability. HA granules of high microporosity and SSA can be produced by applying low sintering temperatures (below 900°C). Nevertheless, although HA sintered at low temperatures shows significantly higher SSA (10-60 m2/g) and improved bioabsorbability, it also exhibits high ion reactivity and cytotoxicity under in vitro conditions. The latter is due to the presence of reaction by-products. Thus, the aim of this study was to fabricate novel biomaterials in the form of granules, composed of hydroxyapatite nanopowder sintered at a high temperature (1100°C) and a biopolymer matrix: chitosan/agarose or chitosan/β-1,3-glucan (curdlan). It was hypothesized that appropriately selected ingredients would ensure high biocompatibility and microstructural properties comparable to HA sintered at low temperatures. Synthesized granules were subjected to the evaluation of their biological, microstructural, physicochemical, and mechanical properties. The obtained results showed that the developed nanocomposite granules were characterized by a lack of cytotoxicity towards both mouse preosteoblasts and normal human fetal osteoblasts, and supported cell adhesion to their surface. Moreover, produced biomaterials had the ability to induce precipitation of apatite crystals after immersion in simulated body fluid, which, combined with high biocompatibility, should ensure good osseointegration after implantation. Additionally, nanocomposite granules possessed microstructural parameters similar to HA sintered at a low temperature (porosity approx. 50%, SSA approx. 30m²/g), Young's modulus (5-8 GPa) comparable to cancellous bone, and high fluid absorption capacity. Moreover, the nanocomposites were prone to biodegradation under the influence of enzymatic solution and in an acidic environment. Additionally, it was noted that the hydroxyapatite nanoparticles remaining after the physicochemical dissolution of the biomaterial were easily phagocytosed by mouse macrophages, mouse preosteoblasts, and normal human fetal osteoblasts (in vitro studies). The obtained materials show great potential as bone tissue implantation biomaterials with improved bioresorbability. The obtained materials show great potential as bone tissue implantation biomaterials with improved bioresorbability.

A Finite Element Analysis of Peri-implant Stresses Surrounding Zirconium and Titanium Dental Implants

ABSTRACT Introduction: Stresses tend to vary depending on the kind of implant material (titanium or zirconium) because of differences in their mechanical and physical characteristics. Objectives: The current research was done to assess the peri-implant stresses around zirconium and titanium dental implants using finite element analysis. Materials and Method: Three distinct implant configurations were used to create three-dimensional finite element models (M1, M2, and M3) using ANSYS (11.0 Version) software, a P4 CPU running at 3 GHz, and hardware with three gigabytes of RAM. These configurations are typical for zirconium and titanium implants. Under 250 N of axial force and 50 N of nonaxial load, the stress surrounding the implants was examined. Result: When compared to titanium implants, zirconium implants displayed higher strains in cancellous bone and lower stresses in cortical bone. Overall, titanium implants caused larger stresses in the bone than zirconium implants. Conclusion: Compared to titanium implants, zirconium implants resulted in reduced peri-implant stresses.

Comparative Study of 3D Contact Area Percentage Between Zygomatic Implant and Bone in Different Surgical Approaches: Clinical and Biomechanical Perspectives.

Zygomatic implants, either alone or in combination with dental implant placement, have emerged as a viable surgical option for elderly patients with severe bone atrophy for occlusal restoration. This study aims to examine the biomechanical impact of the three-dimensional contact area between zygomatic implants and bone on biomechanics under different surgical methods. Using Cone Beam Computed Tomography (CBCT) images from 10 patients with severe bone atrophy, we reconstructed 3D maxillary bone models and created corresponding 3D zygomatic implant models. Two distinct surgical methods (extramaxillary or intrasinus approaches) were employed based on the position and angle of the zygomatic implant for each patient. The 3D bone-to-implant contact percentage (BIC%) was calculated, and finite element analysis with nonlinear contact was conducted to assess the relationship between 3D BIC% and surrounding bone stress for both surgical methods. The 3D BIC% of extramaxillary approach (57.63%) and intrasinus approach (56.49%) for total bone (including cortical and cancellous bone) was similar (P=0.425) in zygomatic implant surgery. In contrast, the intrasinus method exhibited higher 3D BIC% in cortical bone contact (28.08%) compared to the extramaxillary approach (21.92%) (P=0.011). The correlation between 3D BIC% and high bone stress was stronger in the intrasinus approach, likely due to increased contact area in cortical bone. The intrasinus approach led to lower bone stress and a more robust correlation between bone stress and 3D BIC%, particularly in cortical bone contact. Importantly, the coverage area of cortical bone surrounding the zygomatic implant significantly influenced biomechanical performance of the zygomatic implants.

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

Background/Objectives: 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. Methods: 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. Results: 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). Conclusions: 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.

Sex hormone deficiency in male and female mice expressing the Alzheimer’s disease-associated risk-factor TREM2 R47H variant impacts the musculoskeletal system in a sex- and genotype-dependent manner

Abstract The R47H variant of the Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) is a risk factor for Alzheimer’s disease in humans and leads to lower bone mass accrual in female but not male 12-month-old mice. To determine whether, as with aging, gonadectomy results in sex-specific musculoskeletal effects, gonad removal or SHAM surgery were performed in 4-month-old TREM2R47H/+ mice and wild type (WT) male and female littermates (n = 10-12/group), with sexes analyzed separately. Body weight was lower in males, but higher in females after gonadectomy, independently of their genotype. Gonadectomy also lead to decreased BMD in males at all sites and in whole body (total) and spine in female mice for both genotypes. Total and femur BMD was lower in gonadectomized male mice 6-weeks post-surgery, independently of the genotype. On the other hand, BMD was only lower in ovariectomized WT but not TREM2R47H/+ mice in all sites measured at this time point. Bone formation and resorption markers levels were not affected by orchiectomy, whereas CTX was higher 3 weeks after surgery and P1NP showed a tendency towards lower values at the 6 weeks timepoint only in ovariectomized WT mice. μCT analyses showed no differences resulting from gonadectomy in structural parameters in femoral cortical bone for either sex, but lower tissue mineral density in males of either genotype 6 weeks post-surgery. Nevertheless, biomechanical properties were overall lower in gonadectomized males of either genotype, and only for WT ovariectomized mice. Distal femur cancellous bone structure was also affected by gonadectomy in a genotype- and sex-dependent manner, with genotype-independent changes in males, and only in WT female mice. Thus, expression of the TREM2 R47H variant minimally alters the impact of gonadectomy in the musculoskeletal system in males, whereas it partially ameliorates the consequences of ovariectomy in female mice.

Determining the Permeability of Porous Bioceramic Scaffolds: Significance, Overview of Current Methods and Challenges Ahead

The “architectural suitability” of scaffolds for bone tissue engineering is commonly evaluated by assessing the pore volume and the mean pore size (or pore size distribution, if possible) and comparing these values with the reference ranges of human cancellous bone. However, these two parameters cannot precisely describe the complex architecture of bone scaffolds and just provide a preliminary comparative criterion. Permeability is suggested as a more comprehensive and significant parameter to characterize scaffold architecture and mass transport capability, being also related to bone in-growth and, thus, functional properties. However, assessing the permeability of bioactive ceramics and glass scaffolds is a complex task from both methodological and experimental viewpoints. After providing an overview of the fundamentals about porosity in scaffolds, this review explores the different experimental and numerical approaches used to determine the permeability of porous bioceramics, describing the methodologies used (pump-based, gravity-based, acoustic and computational methods) and highlighting advantages and limitations to overcome (e.g., reliability issues and need for better standardization of the experimental procedures).

Biomechanical Effects of Different Spacing Distributions Between the Cemented Superior Boundary and Surgical Vertebral Superior Endplates After Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures: A Three-Dimensional Finite Element Analysis.

Patients with osteoporotic vertebral compression fractures (OVCF) treated with vertebroplasty (PVP) are experiencing an increasing number of problems such as pain recurrence, mainly due to recompression fractures of the operated vertebral body within a certain period of time after the operation, which is closely related to the distribution of intraoperative bone cement. The aim of this study is to investigate the effect of different spacing distributions between the upper boundary of the cement and the upper endplate of the operated vertebra on the biomechanics of the operated vertebra after percutaneous vertebroplasty for OVCF using finite element analysis (FEA). One patient with L1 vertebral body OVCF was selected, and computed tomography (CT) of the thoracolumbar segment was performed. The CT data were extracted to establish an FEA model of the T12-L2 vertebral bodies. Bone cement was injected into the L1 vertebral body. Based on the spacing between the upper boundary of the bone cement and the vertebral body's upper endplates, the model vertebrae were divided into 0, 2, 4, and 6 mm spacing groups, and the human body's upright, flexion-extension, lateral flexion, and rotational positions were simulated. The biomechanical effects of different spacing distributions on the postoperative L1 vertebral body and the injected bone cement were evaluated. In this paper, we found that the Von Mises stress of the L1 vertebrae was the smallest when the spacing between the upper boundary of the bone cement and the vertebral body's upper endplates was 0 mm. The larger the spacing in a certain range between the upper boundary of the bone cement and the vertebral body's upper endplates, the greater the Von Mises stress of the L1 vertebrae. However, in the stress comparison of the injected bone cement, the Von Mises stress of the bone cement was greatest when the spacing between the upper boundary of the bone cement and the upper endplate of the vertebral body was 0 mm; the larger the spacing, the smaller the Von Mises stress. When the contact spacing between the upper boundary of the bone cement and the upper endplate of the vertebral body is 0 mm, it can effectively eliminate and transfer the pressure caused by the load, thus reducing the stress on the cancellous bone and further reducing the risk of vertebral refracture after surgery.

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.

A novel personalized homogenous finite element model to predict the pull-out strength of cancellous bone screws

BackgroundOrthopedic surgeries often involve the insertion of bone screws for various fixation systems. The risk of postoperative screw loosening is usually assessed through experimental or finite element (FE) evaluations of the screw pull-out strength. FE simulations are based on either personalized complex but accurate heterogeneous modeling or non-personalized simple but relatively less accurate homogeneous modeling. This study aimed to develop and validate a novel personalized computed tomography (CT)-based homogeneous FE simulation approach to predict the pull-out force of cancellous bone screws.MethodsTwenty FE simulations of L1-L5 vertebral screw pull-out tests were conducted, i.e., 10 heterogeneous and 10 homogenous models. Screws were inserted into the lower-middle region of vertebrae. In our novel homogeneous model, the region around approximately twice the diameter of the screw was used as a bone material reference volume. Subsequently, the overall material property of this region was homogeneously attributed to the entire vertebra, and pull-out simulations were conducted.ResultsThe mean error of the predicted pull-out forces by our novel homogenous simulations was ~ 7.9% with respect to our heterogeneous model. When solely the cancellous bone was involved during the pull-out process (i.e., for L1, L2, and L3 vertebral bodies whose cortical bone in the inferior region is thin), the novel homogenous model yielded small mean error of < 6.0%. This error, however, increased to ~ 11% when the screw got involved to the cortical bone (for L4 and L5 vertebrae whose cortical bone in the inferior region is thick).ConclusionThe proposed personalized CT-based homogenous model was highly accurate in estimating the pull-out force especially when only the cancellous bone was involved with the screw.

Anti-Inflammatory and Osteogenic Effects of Vitamin K from Sargassum fulvellum Fermented by Lactococcus lactis KCCM12759P and Leuconostoc mesenteroides KCCM12756P

Vitamin K (VitK) is a vital nutrient that is newly recognized to support bone and cardiovascular health. As a nutraceutical, VitK is produced via plant extraction and bacterial fermentation. This study examined the potential anti-inflammatory and osteogenic benefits of VitK, i.e., VitK1 (phylloquinone; PK) and VitK2 (menaquinone; MKs), derived from Sargassum fulvellum fermented by Lactococcus lactis and Leuconostoc mesenteroides (SfLlLm) using lipopolysaccharide (LPS)-induced Raw264.7, MC3T3-E1 cells, and ovariectomized (OVX) mice. MK4, MK7, and MK9, as well as PK, were effectively acquired from SfLlLm and analyzed. SfLlLm_VitK reduced levels of proinflammatory cytokine in LPS-induced Raw264.7 cells and induced an osteogenesis regulating factor in MC3T3-E1 cells. In OVX mice, SfLlLm feeding reduced plasma levels of alkaline phosphatase, phosphate, and the pro-collagen type I alpha 2 gene (pro-Col1a2) while elevating cancellous bone volume and trabecular numbers. Accordingly, SfLlLm, comprising MKs, may be a candidate for preventing and treating immune and bone diseases.

A Two-Stage Approach to Alveolar Clefts Repair with Combined Cortical and Cancellous Bone Grafting

Background: Achieving optimal efficacy in secondary alveolar bone grafting (SABG) poses a considerable challenge for patients with alveolar clefts post-canine eruption. This study introduces a novel technique called the "two-stage SABG" to improve the treatment outcomes for patients who have missed the optimal timing for bone grafting. Methods: Patients aged 12 and above, presenting with unilateral, complete alveolar clefts after canine eruption, were divided into two cohorts: conventional and two-stage groups. The two-stage group underwent oronasal fistula closure and mucoperiosteal sealing during the initial stage, followed by particulate cancellous bone marrow (PCBM) and mandibular cortical bone grafting in the second stage after a three-month interval. Six months after surgery, the SABG was evaluated quantitatively and qualitatively using computed tomography (CT). Results: A total of 81 patients (median age: 14 years; male/female: 49/32) were included in the conventional group, while the two-stage group consisted of 33 patients (19 years; 20/13). The two-stage group exhibited significantly superior outcomes (P &lt; 0.01) in terms of radiographic healing rate (&gt; 4 points) (96.97% vs. 55.56%), bone bridge height (12.17mm, IQRs=4.26mm), bone bridge width (9.09mm, IQRs=2.74mm), bone formation rate (69.73%, IQRs=22.73%), and bone resorption rate (48.85%, IQRs=22.57%). Additionally, the average three-dimensional deviations greater than 3.5mm at the affected piriform aperture margin. Conclusions: The novel two-stage SABG approach demonstrates significant benefits in the repair of alveolar clefts and pyriform foramen deformities through combined cortical and cancellous bone grafting.

Relationship between bone union and degree of bone marrow fibrosis at resection margins of advanced mandibular ORN

BackgroundThe pathological evaluation of cancellous bone at resection margins of mandibular osteoradionecrosis (ORN) has not been well elucidated. Here, we developed a unique classification system for evaluating the degree of bone marrow fibrosis, one of most common pathological features, in patients with mandibular ORN, based on which we investigated its relationship with treatment outcome.MethodsThis study included 15 patients who underwent mandibulectomy and free fibula osteocutaneous flap reconstruction. The extent of mandibulectomy was determined, with safety margins of approximately 10 mm from the apparent osteolytic areas on preoperative computed tomography image. Special staining was performed on thin sections from center of the osteolytic areas (medial area) and bilateral resection margins, and the degree of bone marrow fibrosis was evaluated and investigated its relationship with presence of bone union as a treatment outcome.ResultsThe degree of bone marrow fibrosis of medial area was significantly higher than those of resection margins. Although most resection margins had collagen fibers which indicate severe fibrosis, all transferred fibula flaps achieved bone union.ConclusionWhen mandibulectomy is performed with safety margins of approximately 10 mm from the apparent osteolytic areas, all transferred fibula flaps achieved bone union regardless of the degree of bone marrow fibrosis at resection margin. In other words, the association between severe bone marrow fibrosis at resection margins and treatment outcome was not seen.Clinical RelevanceSetting safety margins of approximately 10 mm may achieve bone union, but further study is needed.

Demineralized cancellous bone scaffolds as reinforcement for degradable magnesium biocomposite

AbstractThis study investigates demineralized bone matrix (DBM) combined with magnesium (Mg) to create degradable composite materials. Two types of DBM were utilized: carbon-coated (H.A.) and non-carbon-coated (HA-HT). An advanced liquid metal infiltration method prevented the structural collapse of the scaffold due to capillary forces. Both composites exhibited an interphase layer primarily composed of MgO, differing in thickness by 50%, attributed to the reaction between H.A. and Mg. The Mg/H.A. composite demonstrated a compressive yield strength 1.7 times higher than Mg/HA-HT, resembling Mg’s mechanical behavior but with a lower metal phase fraction than other composites. Compared to pure Mg, the composites generated less hydrogen (45–54 ml cm−2), reducing the corrosion rate (~ 0.1181 mm year−1) under simulated conditions (90 ml cm−2 and 4.2 mm year−1 for Mg). A localized phenomenon was identified mainly at the interphase of both composites but specifically in the Mg/H.A., where the scaffold structure was kept over extended exposure periods. These materials hold promise for temporary bone fixation applications. Graphical abstract

Incorporating Hydrogel (with Low Polymeric Content) into 3D-Printed PLGA Scaffolds for Local and Sustained Release of BMP2 in Repairing Large Segmental Bone Defects.

Treating large bone defects remains a considerable challenge for clinicians: bone repair requires scaffolds with mechanical properties and bioactivities. Herein, based on crosslinking o-phthalaldehyde (OPA) with amine groups, 4-arm polyethylene glycol (4armPEG)-OPA/Gelatin hydrogel loaded with bone morphogenetic protein 2 (BMP2) is prepared and a three dimensional (3D)-printed poly (lactic-co-glycolic acid) (PLGA) porous scaffold is filled with the hydrogel solution. The composite scaffold, with a compression modulus of 0.68 ±0.097GPa similar to the cancellous bone, has a porosity of 56.67 ± 4.72% and a pore size of about 380µm, promoting bone growth. The hydrogel forms a porous network at low concentrations, aiding protein release and cell migration. The hydrogel degrades in approximately three weeks, and the scaffold takes five months, matching bone repair timelines. BMP2 release experiment shows a sustained BMP2 release with a 72.4 ± 0.53% release ratio. The ALP activity test and alizarin red staining shows effective osteogenic promotion, while RT-PCR confirms BMP2@Gel enhanced COL-1 and OPN expression. Animal experiments further validate the composite scaffold's bone repair efficacy. This study demonstrates the effectiveness of the hydrogel in releasing BMP2 and the mechanical support of the 3D-printed PLGA porous scaffold, providing a new treatment for bone defects.

Effect of the connection structure of zirconia dental implants on biomechanical properties

The connection structure of zirconia dental implants significantly influences their biomechanical behavior and plays a crucial role in the overall service performance of the implant system. This study aims to compare the stress distribution of zirconia implants featuring various internal connection structures under different working conditions. Four distinct types of connection structures were designed for zirconia dental implants: triangular, quadrilateral, hexagonal, and hexalobular plus connections. Additionally, the finite element method was employed to analyze these structures under three working conditions: a static load test model, a bone level model, and a torsion model. Results indicated that in the static load test model, the hexagonal structure experienced the highest stress value at 1284.9 MPa due to its thin neck wall, whereas the hexalobular plus connected implant exhibited the lowest stress value at 1252.9 MPa. In the bone level model, the triangular connection structure demonstrated poor stress distribution for cortical bone and cancellous bone at 69.606 MPa and 7.8191 MPa, respectively. Conversely, the hexalobular plus connection yielded superior stress results for cortical bone and cancellous bone, with values of 69.606 MPa and 7.8191 MPa, respectively. In the torsion model, the hexalobular plus-connected implant exhibits the highest stress value at 210.37 MPa, while maintaining the smallest force transmission angle. Therefore, given that the abutment necessitates a greater range of installation angles and improved torque transmission, the hexalobular plus connection structure may represent the optimal choice.

Assessing proximal humerus cortical bone thickness for total shoulder arthroplasty: A cadaveric study

BackgroundIn reverse total shoulder arthroplasty, a humeral osteotomy is typically performed at the anatomic neck. The quality and quantity of cancellous and cortical bone impacts sizing of implants. Little-to-no information exists characterizing the transition of this bone quality at this location. This cadaveric study focused on measuring and analyzing the transition zone of the proximal humerus bone quality to better understand the implications of utilizing different implant sizes during reverse total shoulder arthroplasty. This assessment was conducted through the usage of a newly designed indentation depth probe. MethodsAn Exactech, Inc. designed indentation depth probe was used to assess the transition from cancellous to cortical bone in 45 cadavers after a humeral osteotomy was performed. The thickness of the cortical rim was measured in regard to superior, inferior, anterior, and posterior quadrants. Linear regressions were utilized to evaluate the relationship between anatomic location in regard to cortical bone thickness. Independent sample two-tailed t-tests were also conducted to examine the relationship between spring force and bone thickness. Finally, independent sample two-tailed t-tests or Mann-Whitney U tests were utilized to examine the relationship between cortical thickness and variables including sex, age, osteoporosis, and a diagnosis of cancer. ResultsAll linear regressions were found to be insignificant excluding the relationships between inferior to anterior (p=0.003) and inferior to posterior (p=0.001). All t-tests and Mann-Whitney U tests were found to be insignificant, except for the relationship between age and the posterior aspect (p=0.04). ConclusionsIn our cohort, cortical bone thickness was not impacted by sex, diagnosis of osteoporosis, or diagnosis of cancer. Interestingly, age was found to only have an impact on the posterior aspect of the cortical bone rim. Differences in cortical bone thickness were also found in regard to both the inferior to anterior and inferior to posterior comparisons. Clinical RelevanceThis suggests that differences in cortical bone thickness can occur, and that one point of assessment might not be sufficient.

Mimicking the Architecture and Dissolution Chemistry of Cancellous Bone Tissue to Optimize the Biocompatibility of Bioactive Scaffolds.

Synthesis of mechanically stable porous scaffolds with an architecture analogous to cancellous bone tissue poses significant challenges to bioactive glass (BG) based scaffolds. This is primarily due to densification and crystallization of the BG's during heat treatment. This study presents a modified BG series (42SiO2-xTiO2-24Na2O-21CaO-13P2O5, where x = 8 and 16 TiO2). TiO2 replaced the SiO2 concentration in the glass and was incorporated due to its biocompatibility and influence on glass structure. Material characterization determined that TiO2 did not induce crystallization within the glass but did increase the glass transition temperature (Tg) from 520°C to 600°C thereby indicating a more stable network connectivity. Scaffolds were synthesized using the foam replication method, resulting in scaffolds with a pore size of approximately 500 μm with the BG-4 composition (30SiO2-12TiO2-24Na2O-21CaO-13P2O5) retaining its amorphous character post-heat treatment. Scaffold ion release was monitored over 5-60 days in simulated body fluid (SBF). Si4+ release was found to decrease, while Ca2+ levels increased in SBF as TiO2 replaced SiO2 within the glass series. Cytocompatibility studies revealed that MC3T3 Osteoblast cells proliferated on the BG-4 scaffold surface and at its interface within culture media, and cell numbers were not significantly reduced.

Biomechanical Analysis of Diffuse Idiopathic Skeletal Hyperostosis and Osteoporosis: Vertebral Fracture Risk Evaluation Using Finite Element Modeling with Clinical and Micro-CT Data in an Elderly Donor

Introduction: Biomechanical analysis of spinal structures is crucial in the evaluation of injuries, the risk of fracture, and age-related changes. Osteoporotic vertebrae are very fragile and therefore constitute a serious risk, especially in the elderly. Methods: At present, clinically relevant decision making in fracture risk assessment is predicated upon finite element analysis (FEA), which utilizes high-resolution computed tomography (CT) scans from clinical practice alongside micro-CT scans from laboratory settings. Of particular interest is the utilization of cortical vertebral body thicknesses, as meticulously measured via micro-CT. The data from a body donation over 80 years old with diffuse idiopathic skeletal hyperostosis (DISH) and osteoporosis (OP) were utilized through FEA to evaluate stresses in cortical and trabecular bone and to predict the stiffness and deformability of the examined vertebral bodies. Results: The investigation revealed a higher density of cortical and cancellous bone in vertebrae affected by DISH. Cortical density was highest in the thoracic section (median 188 µm), while cancellous bone density was 222 HU in the cervical vertebrae. The load on cortical bone increased as we progressed towards the lumbar spine; however, it remained quite constant in cancellous bone. Despite a low bone density, we registered no fractures in vertebrae. Conclusions: The data showed that DISH increased the thickness of the cortical bone and the density of the cancellous bone. The combination of increased cortical and cancellous bone density might reduce the risk of fracture in patients with low bone density. These conclusions emphasize the significance of biomechanical properties in the assessment of fracture risk and have important implications for clinical practice, particularly in relation to the prevention of vertebral fractures in osteoporotic patients with DISH.

023. Isolated Calvarial Tuberculosis in An Immunocompromised Patient: A Case Report

Background: Isolated Calvarial tuberculosis is a rare occurrence, first reported by Reid in 1842, with majority of cases (75-90%) appearing under the age group of 20-30 years and involving frontal and parietal bones because of the greater amount of cancellous bone with diploic channels. The Human Immunodeficiency Virus (HIV) Infection is currently a huge threat to Indonesia, with Tuberculosis (TB) infection is one example of opportunistic infection that can lead to death in People living with HIV. The objective of this article is to report a rare case of Isolated Calvarial Tuberculosis in an Immunocompromised Patient Case: A 26-year-old male, known to be immunocompromised with HIV infection, presented to hospital with chief complaint of a painless lump on the left temple since 1 month prior. Head CT-Scan examination revealed osteolytic appearance in the left frontal area and swelling of the surrounding soft tissue. The patient then underwent surgery with intraoperative findings of a cystic mass filled with yellowish fluid. A craniotomy of the surrounding healthy bone including the dura mater and excision of the overlying soft tissue were performed, and histopathological result revealed a chronic tuberculosis inflammation. Conclusion: Calvarial Tuberculosis is a rare form of skeletal tuberculosis occurring in younger population, but can also present in older patient with immunocompromised state, that present with main complaint of painless swelling or lump in the frontal or parietal area because of its favourable bone structure. Diagnostic including X-ray and CT-Scan with microbiologic findings of multiple epithelioid granulomas with Langerhans type giant cells. Preferred treatment including both surgical and antituberculosis therapy to achieve favourable outcome.