[Therapeutic effect of calcaneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot].

OBJECTIVE: To explore clinical effect of vancomycin calcium sulfate combined with internal fixation on calcaneal beak-like fracture secondary to calcaneal osteomyelitis caused by diabetic foot. METHODS: From April 2018 to October 2021, a retrospective analysis was performed on 5 patients with calcaneal bone osteomyelitis secondary to diabetic foot, including 2 males and 3 females, aged from 48 to 60 years old;diabetes course ranged from 5 to 13 years;the courses of diabetic foot disease ranged from 18 to 52 days;5 patients were grade Ⅲ according to Wagner classification. All patients were treated with debridement, vancomycin bone cement implantation, negative pressure aspiration at stageⅠ, vancomycin calcium sulfate and internal fixation at stageⅡfor calcaneal beak-like fracture. Surgical incision and fracture healing time were recorded, and the recurrence of osteomyelitis was observed. American Orthopedic Foot Andankle Society (AOFAS) score and exudation at 12 months after operation were evaluated. RESULTS: Five patients were successfully completed operation without lower extremity vascular occlusion, and were followed up for 16 to 36 months. The wound healing time after internal fixation ranged from 16 to 26 days, and healing time of fractures ranged from 16 to 27 weeks. AOFAS score ranged from 65 to 91 at 12 months after operation, and 2 patients got excellent result, 2 good and 1 fair. Among them, 1 patient with skin ulcer on the back of foot caused by scalding at 5 months after operation (non-complication), was recovered after treatment;the wound leakage complication occurred in 2 patients, and were recovered after dressing change. No osteomyelitis or fracture occurred in all patients. CONCLUSION: Vancomycin calcium sulfate with internal fixation in treating calcaneal osteomyelitis secondary to calcaneal osteomyelitis caused by diabetic foot could not only control infection, but also promote fracture healing, and obtain good clinical results.

Fabrication and histological evaluation of a self-setting granular cement using calcium sulfate hemihydrate granules with different pore distribution.

Granular type of bone substitutes is currently used in the field of dentistry to restore alveolar bone defects. However, the migration of the granules from the implantation site is still an unresolved issue. In this study, the feasibility to fabricate self-setting calcium sulfate hemihydrate (CSH) granules using different ranges of loading pressure: CSH(0), CSH(50), CSH(100), and CSH(150) was investigated with the hypothesis that CSH granules with reduced microporosity can inhibit the rapid dissolution rate of the calcium sulfate dihydrate (CSD) set blocks and induce bone regeneration. After 4 weeks of implantation, the granules were mostly replaced with new bone although no significant differences were observed. Nevertheless, the granules demonstrated the ability to set within the bone defect. It is therefore concluded that the setting ability of calcium sulfate can contribute to address the issue of migration of the granules and provide a useful guide for designing setting bone substitutes.

Bio-Inspired Fluorescent Calcium Sulfate for the Conservation of Gypsum Plasterwork.

In this work, the potential of bio-inspired strategies for the synthesis of calcium sulfate (CaSO4·nH2O) materials for heritage conservation is explored. For this, a nonclassical multi-step crystallization mechanism to understand the effect of calcein- a fluorescent chelating agent with a high affinity for divalent cations- on the nucleation and growth of calcium sulfate phases is proposed. Moving from the nano- to the macro-scale, this strategy sets the basis for the design and production of fluorescent nano-bassanite (NB-C; CaSO4·0.5H2O), with application as a fully compatible consolidant for the conservation of historic plasterwork. Once applied to gypsum (CaSO4·2H2O) plaster specimens, cementation upon hydration of nano-bassanite results in a significant increase in mechanical strength, while intracrystalline occlusion of calcein in newly-formed gypsum cement improves its weathering resistance. Furthermore, under UV irradiation, the luminescence produced by calcein molecules occluded in gypsum crystals formed upon nano-bassanite hydration allows the easy identification of the newly deposited consolidant within the treated gypsum plaster without altering the substrate's appearance.

Outcomes of Antibiotic-Impregnated Calcium Sulfate, Reamer-Irrigator-Aspirator, and Locked Intramedullary Static Spacer in the Treatment of Periprosthetic Joint Infection in the Multiply Revised and Infected Knee: A Single-Center Case Series.

Background: Periprosthetic joint infection after total knee arthroplasty is commonly treated via 2-stage revision utilizing either articulating or static antibiotic cement spacers. While recent literature exhibits a slight functional advantage in favor of articulating spacers, those patients with a history of recurrent infection/multiple revision procedures are frequently excluded from these studies. The purpose of this study was to report infection eradication rates and efficacy of utilizing antibiotic-loaded locked intramedullary nail for infection for the multiply revised, infected total knee arthroplasty. Methods: A retrospective review was performed of all consecutive patients receiving static spacers between 2017 and 2020 at an academic medical center. Surgical techniques for all patients included irrigation and debridement using a reamer-irrigator-aspirator, injection of antibiotic-loaded calcium sulfate into the intramedullary canal, and nail placement. Antibiotic-loaded cement is then used to create a spacer block in the joint space. A Cox proportional hazard regression was run to identify risk factors for reinfection. Results: Forty-two knees in 39 patients were identified meeting inclusion criteria. Overall, there was an 68.8% infection eradication rate at an average of 46.9 months following spacer placement. The only risk factors identified on cox regression were increasing number of previous spacers, a surrogate for previous infections (hazards ratio = 14.818, P value = .021), and increasing operative time during spacer placement (hazards ratio = 1.014, P value = .039). Conclusions: Use of static spacers, in conjunction with reamer-irrigator-aspirator and antibiotic-loaded calcium sulfate, can be effective in treating chronic, complex periprosthetic joint infections in the setting of bone loss and or soft-tissue compromise and produced similar results to more simple infection scenarios.

Corncob-derived biodegradable packaging films: A sustainable solution for raspberry post-harvest preservation.

Plastic food packaging, with its harmful migration of microplastics and nanoplastics into food, presents significant ecological imbalance and human health risks. In this regard, using food and agricultural byproducts as packaging materials reduces environmental and economic concerns and supports their sustainable management. Herein, cellulosic residue from corncob was employed as a renewable source for developing biodegradable packaging films. It was solubilized in ZnCl2 solution, crosslinked with Ca2+ ions, and plasticized with sorbitol to form films and used to improve the shelf-life of raspberries. The optimized film possesses water vapor permeability, tensile strength, and elongation at break of 1.8(4) x10-10 g-1 s-1 Pa-1, 4.7(1) MPa, and 15.4(7)%, respectively. It displays UV-blocking and antioxidant properties and biodegrades within 29 days at 24% soil moisture. It preserves raspberries for 7 and 5 more days at room temperature and refrigeration conditions, respectively, compared to polystyrene film. Overall, more value addition could be envisioned from agricultural residues to minimize post-harvest losses and food waste through biodegradable packaging, which also aids in mitigating plastic perils.

Analysis of risk factors for the recurrence of osteomyelitis of the limb after treatment with antibiotic-loaded calcium sulfate and autologous bone graft.

Objective: We aimed to evaluate the efficacy of antibiotic-loaded calcium sulfate combined with autologous iliac bone transplantation in the treatment of limb-localized osteomyelitis (Cierny-Mader type III) and analyze the causes and risk factors associated with infection recurrence. Methods: Clinical data of 163 patients with localized osteomyelitis of the extremities treated with antibiotic-loaded calcium sulfate combined with autologous iliac bone transplantation in Xi'an Honghui Hospital from January 2017 to December 2022 were retrospectively analyzed. All patients were diagnosed with localized osteomyelitis through clinical examination and treated with antibiotic-loaded calcium sulfate combined with autologous iliac bone. Based on the infection recurrence status, the patients were divided into the recurrence group and the non-recurrence group. The clinical data of the two groups were compared using univariate analysis. Subsequently, the distinct datasets were included in the binary logistic regression analysis to determine the risk and protective factors. Results: This study included 163 eligible patients, with an average age of 51.0 years (standard deviation: 14.9). After 12 months of follow-up, 25 patients (15.3%) experienced infection recurrence and were included in the recurrence group; the remaining 138 patients were included in the non-recurrence group. Among the 25 patients with recurrent infection, 20 required reoperation, four received antibiotic treatment alone, and one refused further treatment. Univariate analysis showed that education level, smoking, hypoproteinemia, open injury-related infection, and combined flap surgery were associated with infection recurrence (p < 0.05). Logistic regression analysis showed that open injury-related infection (odds ratio [OR] = 35.698; 95% confidence interval [CI]: 5.997-212.495; p < 0.001) and combined flap surgery (OR = 41.408; 95% CI: 5.806-295.343; p < 0.001) were independent risk factors for infection recurrence. Meanwhile, high education level (OR = 0.009; 95% CI: 0.001-0.061; p < 0.001) was a protective factor for infection recurrence. Conclusion: Antibiotic-loaded calcium sulfate combined with autologous iliac bone transplantation is an effective method for treating limb-localized osteomyelitis. Patients without previous combined flap surgery and non-open injury-related infections have a relatively low probability of recurrence of infection after treatment with this surgical method. Additionally, patients with a history of smoking and hypoproteinemia should pay attention to preventing the recurrence of infection after operation. Providing additional guidance and support, particularly in patients with lower education levels and compliance, could contribute to the reduction of infection recurrence.

The Roles of Oil-Water Interfaces in Forming Ultrasmall CaSO4 Nanoparticles.

In natural and engineered environmental systems, calcium sulfate (CaSO4) nucleation commonly occurs at dynamic liquid-liquid interfaces. Although CaSO4 is one of the most common minerals in oil spills and oil-water separation, the mechanisms driving its nucleation at these liquid-liquid interfaces remain poorly understood. In this study, using in situ small-angle X-ray scattering (SAXS), we examined CaSO4 nucleation at oil-water interfaces and found that within 60 minutes of reaction, short rod-shaped nanoparticles (with a radius of gyration (Rg) of 17.2 ± 2.7 nm and a length of 38.2 ± 5.8 nm) had formed preferentially at the interfaces. Wide-angle X-ray scattering (WAXS) analysis identified these nanoparticles as gypsum (CaSO4·2H2O). In addition, spherial nanoparticles measuring 4.1 nm in diameter were observed at oil-water interfaces, where surface-enhanced Raman spectroscopy (SERS) revealed an elevated pH compared to the bulk solution. The negatively charged oil-water interfaces preferentially adsorb calcium ions, collectively promoting CaSO4 formation there. CaSO4 particle formation at the oil-water interface follows a nonclassical nucleation (N-CNT) pathway by forming ultrasmall amorphous spherical particles which then aggregate to form intermediate nanoparticles, subsequently growing into nanorod-shaped gypsum. These findings of this study provide insights into mineral scaling during membrane separation and can inform more efficient oil transport in energy recovery systems.

Enhancing Concrete Mechanical Properties through Basalt Fibers and Calcium Sulfate Whiskers: Optimizing Compressive Strength, Elasticity, and Pore Structure.

To study the effects of basalt fibers (BFs), calcium sulfate whiskers (CSWs), and modified calcium sulfate whiskers (MCSWs) on the compressive strength and dynamic modulus of elasticity of concrete, this paper utilizes Mercury Intrusion Porosimetry (MIP) to measure the microstructure of concrete and calculate the fractal dimension of pore surface area. The results indicate that both CSWs and BFs can increase the compressive strength of concrete. CSWs can enhance the dynamic modulus of elasticity of concrete, while the effect of BFs on the dynamic modulus of elasticity is not significant. The improvement in compressive strength and dynamic modulus of elasticity provided by MCSWs is significantly greater than that provided by CSWs. Both CSWs and BFs can effectively improve the pore structure of concrete and have a significant impact on the surface fractal dimension. CSWs inhibit the formation of ink-bottle pores, while BFs increase the number of ink-bottle pores. Due to the ink-bottle pore effect, the fractal dimension of the capillary pore surface is generally greater than three, lacking fractal characteristics. The compressive strength and dynamic modulus of elasticity of concrete have a good correlation with the fractal dimensions of large pores and transition pores.

A Bioactive Degradable Composite Bone Cement Based on Calcium Sulfate and Magnesium Polyphosphate.

Calcium sulfate bone cement (CSC) is extensively used as a bone repair material due to its ability to self-solidify, degradability, and osteogenic ability. However, the fast degradation, low mechanical strength, and insufficient biological activity limit its application. This study used magnesium polyphosphate (MPP) and constructed a composite bone cement composed of calcium sulfate (CS), MPP, tricalcium silicate (C3S), and plasticizer hydroxypropyl methylcellulose (HPMC). The optimized CS/MPP/C3S composite bone cement has a suitable setting time of approximately 15.0 min, a compressive strength of 26.6 MPa, and an injectability of about 93%. The CS/MPP/C3S composite bone cement has excellent biocompatibility and osteogenic capabilities; our results showed that cell proliferation is up to 114% compared with the control after 5 days. After 14 days, the expression levels of osteogenic-related genes, including Runx2, BMP2, OCN, OPN, and COL-1, are about 1.8, 2.8, 2.5, 2.2, and 2.2 times higher than those of the control, respectively, while the alkaline phosphatase activity is about 1.7 times higher. Therefore, the CS/MPP/C3S composite bone cement overcomes the limitations of CSC and has more effective potential in bone repair.

Semi-focal bone transport versus traditional bone transport technique for the management of large tibial bone defects after trauma.

How to deal with large tibial bone defects is still controversial. The purpose of this research was to compare the semi-focal bone transport (SFBT) technique with traditional bone transport (TBT) technique for treating such patients. Sixty-two patients were included and retrospectively analyzed. In all cases, after radical debridement large tibial bone defects remained. Patients were treated by the SFBT or TBT technique. The distraction, consolidation duration and complications were recorded by the patients' medical files. Based on the Association for the Study and Application of Methods of Ilizarov (ASAMI) standard, the bone and functional results were evaluated. The mean bone defect size was 7.7 ± 1.6 cm and 7.5 ± 2.1 cm for SFBT and TBT patients. The mean external fixation index (EFI) was 1.51 ± 0.14 months/cm and 1.89 ± 0.25 months/cm for SFBT and TBT patients (p < 0.05), respectively. With respect to bone and function results, there was no significant differences between the two groups (p > 0.05). The mean number of complications per patient was 1.1 ± 0.6 and 1.6 ± 0.7 for SFBT and TBT patients (p < 0.05). Compared to the traditional bone transport technique, patients using the semi-focal bone transport technique achieved better clinical effects, including shorter EFI and less complications. Therefore, the SFBT technique could be a new option for patients with large tibial bone defects.

Application of Calcium Sulfate Whiskers to Cement-Based Materials: A Review.

In recent years, significant attention has been paid to the use of calcium sulfate whiskers (CSWs) to enhance the performance of cement-based materials (CBM). This technology has attracted widespread interest from researchers because it enhances the performance and sustainability of CBM by modifying the crystal structure of calcium sulfate. This article summarizes the fundamental properties and preparation methods of calcium sulfate whisker materials as well as their applications in cement, potential advantages and disadvantages, and practical applications and prospects. The introduction of CSWs has been demonstrated to enhance the strength, durability, and crack resistance of CBM while also addressing concerns related to permeability and shrinkage. The application of this technology is expected to improve the quality and lifespan of buildings, reduce maintenance costs, and positively impact the environment. The use of CSWs in CBM represents a promising material innovation that offers lasting and sustainable advancement in the construction industry.

Defining the shelf-life of calcium sulfate beads embedded with tobramycin and vancomycin.

Background: Antibiotic-laden calcium sulfate beads are gaining popularity in the treatment of orthopaedic infections such as fracture-related infection and osteomyelitis. Calcium sulfate beads have several advantages over polymethylmethacrylate (PMMA) beads as they are bioabsorbable, have demonstrated improved elution characteristics, and have lower peak polymerization temperatures than seen in PMMA. The ability to make and store antibiotic beads for later use has the potential to standardize dosing and decrease operating room times and healthcare costs. This study aims to determine the antibiotic efficacy of premade, antibiotic-laden calcium sulfate beads. Methods: Calcium sulfate beads containing vancomycin or tobramycin were molded to 4.8 mm in diameter and stored for shelf-life durations of three and six months at 20 °C. A subset of beads was tested immediately after creation. At the designated time points, beads were placed into a buffer solution and incubated at 37 °C with agitation. Antibiotic eluent was collected at 1-hour, 4-hour, 24-hour, and 48-hour timepoints. Eluent concentrations were inferred from a prior study implementing the same calcium sulfate bead model. Eluent was used in microbroth dilution assays to determine its minimum inhibitory concentration (MIC) against methicillin-sensitive Staphylococcus aureus. Results: MIC assays for tobramycin and vancomycin against S. aureus yielded concentrations consistent with previously reported ranges. MIC results across different bead shelf lives also remained consistent without an increase in MIC with increasing shelf life for either antibiotic. Conclusions: Shelf life up to six months does not impact the efficacy of tobramycin or vancomycin eluent from calcium sulfate beads in vitro compared to beads made and tested immediately. These results provide preliminary evidence that tobramycin and vancomycin retain their antimicrobial activity in calcium sulfate beads for at least six months stored at room temperature. Additional studies on sterilization techniques are necessary prior to considering use of prefabricated antibiotic-loaded calcium sulfate beads in clinical practice.

Limitations and modifications in the clinical application of calcium sulfate.

Calcium sulfate and calcium sulfate-based biomaterials have been widely used in non-load-bearing bone defects for hundreds of years due to their superior biocompatibility, biodegradability, and non-toxicity. However, lower compressive strength and rapid degradation rate are the main limitations in clinical applications. Excessive absorption causes a sharp increase in sulfate ion and calcium ion concentrations around the bone defect site, resulting in delayed wound healing and hypercalcemia. In addition, the space between calcium sulfate and the host bone, resulting from excessively rapid absorption, has adverse effects on bone healing or fusion techniques. This issue has been recognized and addressed. The lack of sufficient mechanical strength makes it challenging to use calcium sulfate and calcium sulfate-based biomaterials in load-bearing areas. To overcome these defects, the introduction of various inorganic additives, such as calcium carbonate, calcium phosphate, and calcium silicate, into calcium sulfate is an effective measure. Inorganic materials with different physical and chemical properties can greatly improve the properties of calcium sulfate composites. For example, the hydrolysis products of calcium carbonate are alkaline substances that can buffer the acidic environment caused by the degradation of calcium sulfate; calcium phosphate has poor degradation, which can effectively avoid the excessive absorption of calcium sulfate; and calcium silicate can promote the compressive strength and stimulate new bone formation. The purpose of this review is to review the poor properties of calcium sulfate and its complications in clinical application and to explore the effect of various inorganic additives on the physicochemical properties and biological properties of calcium sulfate.

Co-delivery of rhBMP-2 and zoledronic acid using calcium sulfate/hydroxyapatite carrier as a bioactive bone substitute to enhance and accelerate spinal fusion.

Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been FDA-approved for lumbar fusion, but supraphysiologic initial burst release due to suboptimal carrier and late excess bone resorption caused by osteoclast activation have limited its clinical usage. One strategy to mitigate the pro-osteoclast side effect of rhBMP-2 is to give systemic bisphosphonates, but it presents challenges with systemic side effects and low local bioavailability. The aim of this in vivo study was to analyze if posterolateral spinal fusion (PLF) could be improved by utilizing a calcium sulfate/hydroxyapatite (CaS/HA) carrier co-delivering rhBMP-2 and zoledronic acid (ZA). Six groups were allocated (CaS/HA, CaS/HA + BMP-2, CaS/HA + systemic ZA, CaS/HA + local ZA, CaS/HA + BMP-2 + systemic ZA, and CaS/HA + BMP-2 + local ZA). 10-week-old male Wistar rats, were randomly assigned to undergo L4-L5 PLF with implantation of group-dependent scaffolds. At 3 and 6 weeks, the animals were euthanized for radiography, µCT, histological staining, or biomechanical testing to evaluate spinal fusion. The results demonstrated that the CaS/HA biomaterial alone or in combination with local or systemic ZA didn't support PLF. However, the delivery of rhBMP-2 significantly promoted PLF. Combining systemic ZA with BMP-2 didn't enhance spinal fusion. Notably, the co-delivery of rhBMP-2 and ZA using the CaS/HA carrier significantly enhanced and accelerated PLF, without inhibiting systemic bone turnover, and potentially reduced the dose of rhBMP-2. Together, the treatment regimen of CaS/HA biomaterial co-delivering rhBMP-2 and ZA could potentially be a safe and cost-effective off-the-shelf bioactive bone substitute to enhance spinal fusion.

Enhancing cartilage regeneration and repair through bioactive and biomechanical modification of 3D acellular dermal matrix.

Acellular dermal matrix (ADM) shows promise for cartilage regeneration and repair. However, an effective decellularization technique that removes cellular components while preserving the extracellular matrix, the transformation of 2D-ADM into a suitable 3D scaffold with porosity and the enhancement of bioactive and biomechanical properties in the 3D-ADM scaffold are yet to be fully addressed. In this study, we present an innovative decellularization method involving 0.125% trypsin and 0.5% SDS and a 1% Triton X-100 solution for preparing ADM and converting 2D-ADM into 3D-ADM scaffolds. These scaffolds exhibit favorable physicochemical properties, exceptional biocompatibility and significant potential for driving cartilage regeneration in vitro and in vivo. To further enhance the cartilage regeneration potential of 3D-ADM scaffolds, we incorporated porcine-derived small intestinal submucosa (SIS) for bioactivity and calcium sulfate hemihydrate (CSH) for biomechanical reinforcement. The resulting 3D-ADM+SIS scaffolds displayed heightened biological activity, while the 3D-ADM+CSH scaffolds notably bolstered biomechanical strength. Both scaffold types showed promise for cartilage regeneration and repair in vitro and in vivo, with considerable improvements observed in repairing cartilage defects within a rabbit articular cartilage model. In summary, this research introduces a versatile 3D-ADM scaffold with customizable bioactive and biomechanical properties, poised to revolutionize the field of cartilage regeneration.

Point-of-Care Coating of Revision Femoral Stems With Antibiotic-Loaded Calcium Sulfate: Reduction in Infection After 2nd Stage Reimplantation but Not With Aseptic Revisions.

Background: Infection rates in revision total hip arthroplasty are lower when antibiotic loaded cemented stems are utilized. Inspired by this technique, a point-of-care coating of antibiotic-loaded calcium sulfate (CaSO4) was applied to cementless revision stems in aseptic revision and 2nd stage reimplantation total hip arthroplasty. Methods: One hundred eleven consecutive femoral stems were coated. Just prior to insertion, 10 cc of CaSO4 was mixed with 1 g vancomycin and 240 mg tobramycin with the paste applied to the stem. The results were compared to a matched cohort (N = 104) performed across the previous 5 years. The surgical methods were comparable, but for the stem coating. The study group was followed for a minimum of 3 years. Results: In the study cohort of 111 patients, there were 69 aseptic revisions with one periprosthetic joint infection (PJI) (1.4%) and 42 second-stage reimplantations with 2 PJIs (4.8%). In the control cohort of 104 patients, there were 74 aseptic revisions with one PJI (1.4%) and 30 second-stage reimplantations with 7 PJIs (23.3%). There was no significant reduction in PJI rate in the aseptic revision subgroup (1.4% study vs 1.4% control group), P = 1.000. Antibiotic stem coating reduced PJI rate in the 2nd stage reimplantation subgroup (23.3% control vs 4.8% study group), P = .028. In both groups, there were no cases of aseptic stem loosening. Conclusions: Point-of-care antibiotic coating of cementless revision femoral stems reduces PJI infection rate in 2nd stage reimplantations only. We theorize that microbes persist in the endosteal cortices after resection and may contribute to infection recurrence.

Are Biodegradable Calcium Sulfate Antibiotic Beads Effective and Safe Adjuvants for Diabetic Foot Osteomyelitis?

INTRODUCTION:  Diabetic foot osteomyelitis (DFO) is a highly morbid condition that commonly affects diabetic patients. Biodegradable calcium-sulfate antibiotic beads (CaSO4) are theoretical adjuvant agents to reduce morbidity in DFO. However, there is a paucity of research on the safety and effectiveness of CaSO4 beads in DFO. Therefore, the purpose of this study was to assess the safety and effectiveness of CaSO4 beads in different DFO locations. METHODS: We conducted a retrospective cohort study between January 1, 2015 and January 1, 2022 of patients with DFO who underwent surgical intervention and adjuvant CaSO4 beads placement. The location of DFO was determined based on the forefoot, midfoot, or hindfoot locations. Outcomes measured were ulcer-free time points of three and six months as well as recurrence of DFO at 12 months. Safety was also evaluated with incidences of acute kidney injury, wound drainage, and hypercalcemia. RESULTS: Forty-five cases were included. Of these, only 9/45 (20%) and 13/45 (29%) were ulcer-free at three months and six months, respectively. DFO recurred in 19/45 (42%) patients. Safety outcomes were significant for wound drainage (62%) and acute kidney injury (9%). Stratifying according to the location of DFO showed no statistically significant difference in outcomes. CONCLUSION: In this cohort study, adjuvant CaSO4 beads showed high rates of ulcer persistence and DFO recurrence. Given the limited benefits seen here and the potential for high rates of wound drainage, the use of adjuvant CaSO4 beads should be used cautiously until a multicenter randomized clinical trial is conducted to definitely evaluate the safety and effectiveness of CaSO4 beads in DFO.

The effect of different antibiotic combinations in calcium sulfate cement on the growth of Cutibacterium acnes and Staphylococcus periprosthetic shoulder infection isolates.

BACKGROUND: Periprosthetic joint infections (PJI) of the shoulder are a devastating complication of shoulder arthroplasty and are commonly caused by Staphylococcus and Cutibacterium acnes. Absorbable calcium sulfate (CS) beads are sometimes used for delivering antibiotics in PJI. This study evaluates the in vitro effect of different combinations of gentamicin, vancomycin, and ertapenem in beads made from CS cement on the growth of C acnes and coagulase-negative Staphylococcus (CNS) strains. METHODS: Three strains of C acnes and 5 strains of CNS from clinically proven shoulder PJI were cultured and plated with CS beads containing combinations of vancomycin, gentamicin, and ertapenem. Plates with C acnes were incubated anaerobically while plates with Staphylococcus were incubated aerobically at 37 °C. Zones of inhibition were measured at intervals of 3 and 7 days using a modified Kirby Bauer technique, and beads were moved to plates containing freshly streaked bacteria every seventh day. This process was run in triplicate over the course of 56 days. Statistical analysis was conducted using SPSS v. 28 with repeated measures analysis of variance (ANOVA) and pairwise comparisons with Tukey correction. RESULTS: In experiments with C acnes, beads containing ertapenem + vancomycin and vancomycin alone formed the largest zones of inhibition over time (P < .001). In experiments with Staphylococcus, beads containing vancomycin alone formed the largest zones of inhibition over time for all 5 strains (P < .001). Zones of inhibition were 1.4x larger for C acnes than for Staphylococcus with beads containing vancomycin alone. For both C acnes and Staphylococcus, beads containing ertapenem had the strongest initial effect, preventing all bacterial growth in C acnes and almost all growth for Staphylococcus during the first week but dropping substantially by the second week. Beads containing gentamicin alone consistently created smaller zones of inhibition than beads containing vancomycin alone, with vancomycin producing zones 5.3x larger than gentamicin in C acnes and 1.3x larger in Staphylococcus (P < .001). DISCUSSION: These data suggest that for both C acnes and Staphylococcal species, CS beads impregnated with vancomycin were most effective at producing a robust antibiotic effect. Additionally, ertapenem may be a viable supplement in order to create a more potent initial antibiotic effect but is not as effective as vancomycin when used alone. Gentamicin alone was not effective in maintaining consistent and long-term antibiotic effects. These results indicate that amongst the antibiotics currently commercially available to be used with CS, vancomycin is consistently superior to gentamicin in the setting of C. acnes and CNS.

Effects of aligned PLGA/SrCSH composite scaffolds on in vitro growth and osteogenic differentiation of human mesenchymal stem cells.

Strontium (Sr) has important functions in bone remodeling. Incorporating strontium-doped α-calcium sulfate hemihydrate (SrCSH) into poly(lactic-co-glycolic acid) (PLGA) fibrous scaffolds were expected to increase its bio-activity and provide a potential material for bone tissue engineering. In the present study, Sr-containing aligned PLGA/SrCSH fibrous scaffolds similar to the architecture of natural bone were prepared via wet spinning. CCK-8 assay revealed that Sr-containing scaffolds possessed better bioactivity and supported favorable cell growth effectively. The aligned PLGA/SrCSH fibers exerted a contact effect on cell attachment, inducing regular cell alignment and influencing a series of cell behaviors. Releasing of high concentration Sr from a-PLGA/SrCSH scaffolds could induce high expression levels of BMP-2, increase ALP activity and upregulate RUNX-2 expression, and further promote the expressions of COL-I and OCN and the maximum mineralization. This study demonstrated that Sr and ordered structure in a-PLGA/SrCSH fibrous scaffolds could synergistically enhance the osteogenic differentiation of umbilical cord mesenchymal stem cells (UCMSCs) by regulating cell arrangement and expressions of osteogenic genes.

A novel method to fabricate monetite granules for bone graft applications.

Monetite granules were reported to be able to balance osteoclastic resorption and new bone formation. However, to date, the dehydration of preset brushite has been the well-known method for preparing monetite granules. In the present study, for the first time, monetite granules could be prepared from the phase transformation of calcium sulfate dihydrate (CSD) granules through immersion in NaH2PO4 solution under hydrothermal conditions. CSD granules could be fully transformed into monetite granules at a reaction temperature of 125°C for 24 h. The obtained monetite granules were eight times more soluble in acetate buffer than in Tris-HCl buffer. Furthermore, monetite granules were two times more soluble in acetate buffer but comparable in Tris-HCl buffer compared to xenograft HA. The initial cytotoxicity test indicated that the novel monetite granules were nontoxic. In short, novel monetite granules were successfully prepared, exhibited better solubility in osteoclastic simulation than xenograft HA and were nontoxic.