Functional and radiological outcomes of distal humerus fractures treated with pre-contoured locking compression plate

<p><strong>Background: </strong>Distal humerus intra-articular fractures are one of the complicated fractures managed by orthopaedic surgeons. We did a prospective and a retrospective study on 21 patients with these fractures treated with pre-contoured locking compression plate.</p><p><strong>Methods: </strong>The<strong> </strong>21 patients in this series were followed for a minimum of 1 year. The prospective study cases were followed at 3 months, 6 months and annually. The rating system of the Mayo elbow functional scoring system was used. The radiological evaluation was done using standard AP and lateral views.<strong></strong></p><p><strong>Results: </strong>We had 14 patients with range of motion of 50-100 degrees. There was only one patient with range of motion of &lt;50 degrees. 6 patients had the maximum range motion of &gt;100 degrees. We had 6 (23.57%) excellent, 9 (42.85%) good, 5 (23.80%) fair and 1 (4.7%) poor in the Mayo elbow scoring at the end of 1 year. We were able to compare our outcomes with a study done by Kumar et al done in 2017. They had 27 (89.66%) of excellent and good results as opposed to 27 (79.4%) in our study. Out of 21 patients in our study 17(80.95%) patients had good 11 (52.5%) / excellent 6 (28.5%) results. This was comparable with Jupiter et al. His study of 34 patients 26 (79.40/0) patients showed good 14 (41%) / excellent 13 (38.4%) result.<strong></strong></p><p><strong>Conclusions: </strong>Pre-contoured locking compression plate appears to be technically an ideal implant for comminuted osteoporotic bone providing an angle stable construct.</p>

Multi-stage controllable degradation of strontium-doped calcium sulfate hemihydrate-Tricalcium phosphate microsphere composite as a substitute for osteoporotic bone defect repairing: Degradation behavior and bone response

Various requirements for the repair of complex bone defects have motivated to development of scaffolds with adjustable degradation rates and biological functions. Tricalcium phosphate and calcium sulfate are the most commonly used bone repair materials in the clinic, how to better combine tricalcium phosphate and calcium sulfate and play their greatest advantages in the repair of osteoporotic bone defect is the focus of our research. In this study, a series of scaffolds with multistage-controlled degradation properties composed of strontium-doped calcium sulfate (SrCSH) and strontium-doped tricalcium phosphate microspheres (Sr-TCP) scaffolds were prepared, and their osteogenic activity, in vivo degradation and bone regeneration ability in tibia of osteoporotic rats were evaluated. In vitro studies revealed that different components of SrCSH/Sr-TCP scaffolds significantly promoted the proliferation and differentiation of MC3T3-E1 cells, which showed a good osteogenic induction activity. In vivo degradation results showed that the degradation time of composite scaffolds could be controlled in a large range (6-12 months) by controlling the porosity and phase composition of Sr-TCP microspheres. The results of osteoporotic femoral defect repair showed that when the degradation rate of scaffold matched with the growth rate of new bone, the parameters such as BMD, BV/TV, Tb.Th, angiogenesis marker CD31 and new bone formation marker OCN expression were higher, which promoted the rapid repair of osteoporotic bone defects. On the contrary, the slow degradation rate of scaffolds hindered the growth of new bone to a certain extent. This study elucidates the importance of the degradation rate of scaffolds for the repair of osteoporotic bone defects, and the design considerations can be extended to other bone repair materials, which is expected to provide new ideas for the development of tissue engineering materials in the future.

The miR-4739/DLX3 Axis Modulates Bone Marrow-Derived Mesenchymal Stem Cell (BMSC) Osteogenesis Affecting Osteoporosis Progression

Osteoporosis is a complex multifactorial disorder linked to various risk factors and medical conditions. Bone marrow-derived mesenchymal stem cell (BMSC) dysfunction potentially plays a critical role in osteoporosis pathogenesis. Herein, the study identified that miR-4739 was upregulated in BMSC cultures harvested from osteoporotic subjects. BMSCs were isolated from normal and osteoporotic bone marrow tissues and identified for their osteogenic differentiation potential. In osteoporotic BMSCs, miR-4739 overexpression significantly inhibited cell viability, osteoblast differentiation, mineralized nodule formation, and heterotopic bone formation, whereas miR-4739 inhibition exerted opposite effects. Through direct binding, miR-4739 inhibited distal-less homeobox 3 (DLX3) expression. In osteoporotic BMSCs, DLX3 knockdown also inhibited BMSC viability and osteogenic differentiation. Moreover, DLX3 knockdown partially attenuated the effects of miR-4739 inhibition upon BMSCs. Altogether, the miR-4739/DLX3 axis modulates the capacity of BMSCs to differentiate into osteoblasts, which potentially plays a role in osteoporosis pathogenesis. The in vivo and clinical functions of the miR-4739/DLX3 axis require further investigation.

Is cement-augmented sacroiliac screw fixation with partially threaded screws superior to that with fully threaded screws concerning compression and pull-out force in fragility fractures of the sacrum? – a biomechanical analysis

Background Providing a stable osteosynthesis in fragility fractures of the pelvis can be challenging. Cement augmentation increases screw fixation in osteoporotic bone. Generating interfragmentary compression by using a lag screw also improves the stability. However, it is not known if interfragmentary compression can be achieved in osteoporotic sacral bone by cement augmentation of lag screws. The purpose of this study was to compare cement-augmented sacroiliac screw osteosynthesis using partially versus fully threaded screws in osteoporotic hemipelvises concerning compression of fracture gap and pull-out force. Methods Nine fresh-frozen human cadaveric pelvises with osteoporosis were used. In all specimens, one side was treated with an augmented fully threaded screw (group A), and the other side with an augmented partially threaded screw (group B) after generating a vertical osteotomy on both sides of each sacrum. Afterwards, first a compression test with fracture gap measurement after tightening of the screws was performed, followed by an axial pull-out test measuring the maximum pull-out force of the screws. Results The fracture gap was significantly wider in group A (mean: 1.90 mm; SD: 1.64) than in group B (mean: 0.91 mm; SD: 1.03; p = 0.028). Pull-out force was higher in group A (mean: 1696 N; SD: 1452) than in group B (mean: 1616 N; SD: 824), but this difference was not statistically significant (p = 0.767). Conclusions Cement augmentation of partially threaded screws in sacroiliac screw fixation allows narrowing of the fracture gap even in osteoporotic bone, while resistance against pull-out force is not significantly lower in partially threaded screws compared to fully threaded screws.

Heterogeneous Tissue Modulus Improved Prediction of Mechanical Behavior in Osteoporotic Vertebral Cancellous Bone

The structural integrity of cancellous bone, which is essential to skeletal load-bearing capacity, is governed chiefly by apparent density, trabecular architecture, and tissue material properties. Metabolic bone disorders such as osteoporosis can affect each of these factors separately, resulting in compromised load-bearing function. While the impact of apparent density and architecture on bone mechanical behavior has been well-documented, much less is known about the influence of tissue material properties, particularly in osteoporotic bone. The goal of the present study is to isolate the influence of tissue material properties on the pre-yield mechanical response of normal and osteoporotic cancellous bone to uniaxial compression using finite element (FE) models derived from 3D micro-computed tomography images. Both average tissue material properties and the degree of tissue material heterogeneity vary between individuals. Therefore, three sets of FE models were created to study the relative importance of these two factors: 1) models with material homogeneity within and between subjects, 2) models with material homogeneity within subjects only, and 3) models with material heterogeneity within and between subjects. The results of finite element analyses were compared to data gathered from physical testing with matched conditions. For normal bone, incorporating material heterogeneity within and between subjects had no significant effect on model performance. For osteoporotic bone, incorporating material heterogeneity within subjects did not affect model performance, but models that incorporated subject-specific average material properties were significantly more accurate in replicating the results of physical testing. We conclude that, while the influence of bone apparent density and trabecular architecture on apparent stiffness are dominant in healthy bone, average material properties also play a role in osteoporotic bone. Osteoporosis is diagnosed based on apparent density alone, so our findings suggest a need to consider other patient-specific differences that may affect average tissue material properties, such a bone remodeling rate, in clinical assessments of osteoporotic bone structural integrity.

Cellulose Acetate Nanofibers: Incorporating Hydroxyapatite (HA), HA/Berberine or HA/Moghat Composites, as Scaffolds to Enhance In Vitro Osteoporotic Bone Regeneration

The specific objective of this study was to stabilize a simple valid method to prepare pure nanorod hydroxyapatite (HA) mixed with berberine chloride (BER) and Moghat water extract (ME) as composites for incorporation into cellulose acetate (CA) nanofibers to be used as novel bone scaffolds and to determine their efficacy in bone regeneration process In Vitro. Preparation of HA/BER and HA/ME composites were performed by mixing powders using the ball-milling machine. The HA, HA/BER, and HA/ME composites at a concentration of 6.25, 12.5, 25, 50, 100, and 200 mg were mixed with CA solution (13%), then the fiber was formed using electrospinning technique. The properties of the obtained CA fibers were investigated (SEM, TEM, EDX, FTIR, TGA, water uptake, porosity, and mechanical tests). The efficacy of HA and HA composites loaded into CA nanofiber on osteoblast and osteoclast differentiation were measured by tacking ALP, osteocalcin, TRAcP, calcium, and total protein concentration. Moreover, their effects on cell differentiation (CD90 and PARP- ɣ) and death markers (GSK3b, MAPK, Wnt-5 and β-catenin) were evaluated by using ELISA and qPCR. The obtained TEM results indicated that the continuous CA and CA/HA composites electrospun fibers have ultrafine fiber diameters of about 200 nm and uniform distribution of discrete n-HA clusters throughout. In addition, hydrocortisone (HCT) was found to increase the formation of adipocytes and osteoclastic markers CD90 and p38-MAPK which indicated the bone lose process take placed. Treatment with CA loaded with HA, HA/BER or HA/ME decreased CD90, Wnt-5, PARP- ɣ, GSK3b and p38-MAPK associated elevation of osteogenic markers: ALP and osteocalcin. Moreover, HCT overexpressed RANKL and down expressed Osterix gene. Treatment with CA/HA/BER or CA/HA/ME downregulated RANKL and upregulated Osterix associated with a reduction in RANKL/OPG ratio, at p < 0.05. In conclusion, novel CA composite nanofibers (CA/HA/BER and CA/HA/ME) reversed the HCT adverse effect on osteoblast cell death through canonical and non-canonical pathways regulated by Wnt/β-catenin and Wnt/Ca(2+) pathways. Furthermore, our data confirmed that the novel scaffolds create a crosstalk between RUNX-2, RANKL, p38-MAPK, and Wnt signals which positively impact bone regeneration process. Treatment with CA/HA/BER is better compared to the treatment with CA/HA/ME. Nevertheless, both are considered as alternative biomaterial scaffolds with a potential for biomedical applications in the field of bone tissue engineering.

Conjunction of gallium doping and calcium silicate mediates osteoblastic and osteoclastic performances of tricalcium phosphate bioceramics

Gallium-containing biomaterials are considered promising for reconstructing osteoporotic bone defects, owing to the potent effect of gallium on restraining osteoclast activities. Nevertheless, the gallium-containing biomaterials were demonstrated to disturb the osteoblast activities. In this study, tricalcium phosphate (TCP) bioceramics were modified by gallium doping in conjunction with incorporation of calcium silicate (CS). The results indicated that the incorporation of CS promoted transition of β-TCP to α-TCP, and accelerated densification process, but did not improve the mechanical strength of bioceramics. The silicon released from the composite bioceramics diminished the inhibition effect of released gallium on osteoblast activities, and maintained its effect on restraining osteoclast activities. The TCP-based bioceramics doped with 2.5 mol% gallium and incorporated with 10 mol% CS are considered suitable for treating the bone defects in the osteoporotic environment.

Cultivation of hierarchical 3D scaffolds inside a perfusion bioreactor: scaffold design and finite-element analysis of fluid flow

The use of porous 3D scaffolds for the repair of bone nonunion and osteoporotic bone is currently an area of great interest. Using a combination of thermally-induced phase separation (TIPS) and 3D-plotting (3DP), we have generated hierarchical 3DP/TIPS scaffolds made of poly(lactic-co-glycolic acid) (PLGA) and nanohydroxyapatite (nHA). A full factorial design of experiments was conducted, in which the PLGA and nHA compositions were varied between 6‒12% w/v and 10‒40% w/w, respectively, totaling 16 scaffold formulations with an overall porosity ranging between 87%‒93%. These formulations included an optimal scaffold design identified in our previous study. The internal structures of the scaffolds were examined using scanning electron microscopy and microcomputed tomography. Our optimal scaffold was seeded with MC3T3-E1 murine preosteoblastic cells and subjected to cell culture inside a tissue culture dish and a perfusion bioreactor. The results were compared to those of a commercial CellCeram™ scaffold with a composition of 40% β-tricalcium phosphate and 60% hydroxyapatite (β-TCP/HA). Media flow within the macrochannels of 3DP/TIPS scaffolds was modeled in COMSOL software in order to fine tune the wall shear stress. CyQUANT DNA assay was performed to assess cell proliferation. The normalized number of cells for the optimal scaffold was more than twofold that of CellCeram™ scaffold after two weeks of culture inside the bioreactor. Despite the substantial variability in the results, the observed improvement in cell proliferation upon culture inside the perfusion bioreactor (vs. static culture) demonstrated the role of macrochannels in making the 3DP/TIPS scaffolds a promising candidate for scaffold-based tissue engineering.