New Insights Into Application Relevant Properties of Cu2+-Doped Brushite Cements.

Doping of brushite cements with metal ions can entail many positive effects on biological and physicochemical properties. Cu2+ ions are known to exhibit antibacterial properties and can additionally have different positive effects on cells as trace elements, whereas high Cu2+ concentrations are cytotoxic. For therapeutical applications of bone cement, a combination of good biocompatibility and sufficient mechanical properties is required. Therefore, the aim of this study was to investigate different physicochemical and biological aspects, relevant for application, of a brushite cement with Cu2+-doped ß-tricalcium phosphate, monocalcium phosphate monohydrate and phytic acid as setting retarder. Additionally, the ion release was compared with a cement with citric acid as setting retarder. The investigated cements showed good injectability coefficients, as well as compressive strength values sufficient for application. Furthermore, no antibacterial effects were detected irrespective of the Cu2+ concentration or the bacterial strain. The cell experiments with eluate samples showed that the viability of MC3T3-E1 cells tended to decrease with increasing Cu2+ concentration in the cement. It is suggested that these biological responses are caused by the difference in the Cu2+ release from the hardened cement depending on the solvent medium. Furthermore, the cements showed a steady release of Cu2+ ions to a lesser extent in comparison with a cement with citric acid as setting retarder, where a burst release of Cu2+ was observed. In conclusion, despite the anticipated antibacterial effect of Cu2+-doped cements was lacking and mammalian cell viability was slightly affected, Cu2+-concentrations maintained the physicochemical properties as well as the compressive strength of cements and the slow ion release from cements produced with phytic acid is considered advantageous compared to citric acid-based formulations.

Injectable bone cement based on magnesium potassium phosphate and cross-linked alginate hydrogel designed for minimally invasive orthopedic procedures.

Bone cement based on magnesium phosphate has extremely favorable properties for its application as a bioactive bone substitute. However, further improvement is still expected due to difficult injectability and high brittleness. This paper reported the preparation of novel biocomposite cement, classified as dual-setting, obtained through ceramic hydration reaction and polymer cross-linking. Cement was composed of magnesium potassium phosphate and sodium alginate cross-linked with calcium carbonate and gluconolactone. The properties of the obtained composite material and the influence of sodium alginate modification on cement reaction were investigated. Our results indicated that proposed cements have several advantages compared to ceramic cement, like shortened curing time, diverse microstructure, increased wettability and biodegradability and improved paste cohesion and injectability. The magnesium phosphate cement with 1.50% sodium alginate obtained using a powder-to-liquid ratio of 2.5 g/mL and cross-linking ratio 90/120 of GDL/CC showed the most favorable properties, with no adverse effect on mechanical strength and osteoblasts cytocompatibility. Overall, our research suggested that this novel cement might have promising medical application prospects, especially in minimally invasive procedures.

Growth dynamics of Escherichia coli cells on a surface having AgNbO3 antimicrobial particles.

The morphological dynamics of microbial cell proliferation on an antimicrobial surface at an early growth stage was studied with Escherichia coli on the surface of a gel supplied with AgNbO3 antimicrobial particles. We demonstrated an inhibitory surface concentration, analogous to minimum inhibitory concentration, beyond which the growth of colonies and formation of biofilm are inhibited. In contrast, at lower concentrations of particles, after a lag time the cells circumvent the antimicrobial activity of the particles and grow with a rate similar to the case in the absence of particles. The lag time depends on the surface concentration of the particles and amounts to 2 h at a concentration of ½ minimum inhibitory concentration. The applicability of these findings, in terms of estimating inhibitory surface concentration, was tested in the case of antimicrobial polymethyl methacrylate (PMMA) bone cement.

Biofilm formation of Staphylococcus aureus on various implants used for surgical treatment of destructive spondylodiscitis.

The incidence of spondylodiscitis has witnessed a significant increase in recent decades. Surgical intervention becomes necessary in case of bone destruction to remove infected tissue and restore spinal stability, often involving the implantation of a cage. Despite appropriate treatment, relapses occur in up to 20 percent of cases, resulting in substantial economic and social burdens. The formation of biofilm has been identified as a major contributor to relapse development. Currently, there is no consensus among German-speaking spinal surgeons or in the existing literature regarding the preferred choice of material to minimize relapse rates. Thus, the objective of this study is to investigate whether certain materials used in spinal implants exhibit varying degrees of susceptibility to bacterial attachment, thereby providing valuable insights for improving treatment outcomes.Eight cages of each PEEK, titanium-coated PEEK (Ti-PEEK), titanium (Ti), polyetherketoneketone (PEKK), tantalum (Ta) and antibiotic-loaded bone cement were incubated with 20% human plasma for 24 h. Subsequently, four implants were incubated with S. aureus for 24 h or 48 h each. The biofilm was then removed by sonication and the attained solution plated for Colony Forming Units (CFU) counting. Scanning electron microscopy was used to confirm bacterial attachment. The CFUs have been compared directly and in relation to the cages surface area. The surface area of the implants was PEEK 557 mm2, Ti-PEEK 472 mm2, Ti 985 mm2, PEKK 594 mm2, Ta 706 mm2, bone cement 123 mm2. The mean CFU count per implant and per mm2 surface area after 24 h and after 48 h was calculated. Bone cement was found to have significantly more CFUs per mm2 surface area than the other materials tested. When comparing the CFU count per implant, bone cement was statistically significantly more prone to biofilm formation than PEEK after 48 h. There was no statistical significance between the other materials when comparing both CFU count per mm2 surface area and CFU count per implant. The electron microscopic analysis showed the attachment of the bacteria, as well as production of extracellular polymeric substances (EPS) as a sign for beginning biofilm formation. Antibiotic-loaded bone cement has shown statistically significantly more bacterial attachment than the other examined materials. No difference was found between the other materials regarding bacterial attachment after 24 h and 48 h. Proposed hypotheses for further studies include testing whether differences become apparent after longer incubation or with different pathogens involved in the pathogenesis of pyogenic spondylodiscitis.

Clinical significance of modified unilateral puncture percutaneous vertebroplasty guided by 3D- printed guides in the treatment of osteoporotic vertebral compression fractures: a retrospective study.

OBJECTIVE: To investigate the clinical significance of using 3D printing guides in modified unilateral puncture percutaneous vertebroplasty (PVP) for the treatment of osteoporotic vertebral compression fractures (OVCF), and to explore a new method for preventing paravertebral vein leakage during PVP in conjunction with a previous study of the optimal puncture-side bone cement/vertebral volume ratio(PSBCV/VV%). METHODS: This retrospective study analyzed 99 patients who underwent unilateral puncture PVP between January 2023 and December 2023. Patients were divided into a guide plate group (46 patients) and a conventional group (53 patients). The guide plate group underwent modified unilateral puncture PVP with the guidance of 3D printing guides, while the conventional group underwent unilateral puncture PVP using the conventional pedicle approach. The distribution of bone cement, surgical outcomes, and the occurrence of cement leakage into paravertebral veins were observed in both groups. RESULTS: The guide plate group had significantly shorter operating time and required fewer fluoroscopies compared to the conventional group. The amount of bone cement volume (BCV) used in the guide plate group was higher, but the amount of bone cement volume on the puncture side(PSBCV), the PSBCV/VV%, and the rate of paravertebral vein leakage were lower in the guide plate group compared to the conventional group (P < 0.05). Within each group, significant improvements in anterior vertebral margin height, Cobb angle, visual analog scale (VAS) score, and Oswestry Disability Index (ODI) were observed at 1 day and 1 month postoperatively compared to preoperative values (P < 0.05). CONCLUSION: Using 3D printing guides in modified unilateral puncture PVP is a safe and effective method for treating OVCF. And it has the advantages of short operation time, less fluoroscopy, even distribution of bone cement, and a low rate of paravertebral vein leakage.

Mechanical characterization and cytocompatibility of linoleic acid modified bone cement for percutaneous cement discoplasty.

Minimally invasive spine treatments have been sought after for elderly patients with comorbidities suffering from advanced degenerative disc disease. Percutaneous cement discoplasty (PCD) is one such technique where cement is injected into a degenerated disc with a vacuum phenomenon to relieve patients from pain. Adjacent vertebral fractures (AVFs) are however an inherent risk, particularly for osteoporotic patients, due to the high stiffness of the used cements. While low-modulus cements have been developed for vertebroplasty through the addition of linoleic acid, there are no such variations with a high-viscosity base cement, which is likely needed for the discoplasty application. Therefore, a low-modulus polymethyl methacrylate was developed by the addition of 12%vol. linoleic acid to a high-viscosity bone cement (hv-LA-PMMA). Initial experimental validation of the cement was performed by mechanical testing under compression over a period of 24 weeks, after storage in 37 °C phosphate buffer saline (PBS) solution. Furthermore, cement extracts were used to evaluate residual monomer release and the cytotoxicity of hv-LA-PMMA using fibroblastic cells. Relative to the base commercial cement, a significant reduction of Young's modulus and compressive strength of 36% and 42% was observed, respectively. Compression-tension fatigue tests at 5 MPa gave an average fatigue limit of 31,078 cycles. This was higher than another low-modulus cement and comparable to the fatigue properties of the disc annulus tissue. Monomer release tests showed that hv-LA-PMMA had a significantly higher release between 24 h and 7 days compared to the original bone cement, similarly to other low-modulus cements. Also, the control cement showed cytocompatibility at all time points of extract collection for 20-fold dilution, while hv-LA-PMMA only showed the same for extract collections at day 7. However, the 20-fold dilution was needed for both the control and the hv-LA-PMMA extracts to demonstrate more than 70% fibroblast viability at day 7. In conclusion, the mechanical testing showed promise in the use of linoleic acid in combination with a high-viscosity PMMA cement to achieve properties adequate to the application. Further testing and in vivo studies are however required to fully evaluate the mechanical performance and biocompatibility of hv-LA-PMMA for possible future clinical application.

Percutaneous cement discoplasty for the treatment of lumbar degenerative diseases: A system review and meta-analysis.

BACKGROUND: Lumbar degenerative disease (LDD) is one of the main causes of low back pain in the elderly. Surgical treatment usually involves decompression surgery and fusion techniques; however, standard fusion surgery in elderly patients is associated with a higher rate of complications, hospital length of stay, and readmission. Although minimally invasive surgery can reduce risk and shorten hospital stays, it still cannot eliminate the inherent complications of fusion or internal fixation, especially in frail patients. Therefore, it is necessary to find a surgical technology that can not only reduce the risk of operation but also effectively reduce the inherent complications of fusion or internal fixation. The purpose of this study was to evaluate the clinical efficacy and feasibility of percutaneous cement discoplasty for the treatment of LDDs. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. The search strategy was conducted in PubMed, Web of Science, MEDLINE, Google Scholar, China National Knowledge Infrastructure, China Biology Medicine Disc, and Medical Knowledge Network Citation Database. The quality of the included study was assessed by the Methodological Index for Non-Randomized Studies (MINORS) score. The risk of bias (RoB) about the included study was assessed by the Non-Randomized Studies of Interventions (ROBINS-I) tool. The main results were summarized and analyzed in RevMan 5.4. RESULTS: Finally, we included 10 articles and collected a total of 359 patients, including 171 males (47.63%) and 180 females (52.37%), with an average age of 73.09 ±â€…2.74 years. The Methodological Index for Non-Randomized Studies (MINORS) tool was used to assess the articles included in this study, the methodological quality score of 10 retrospective studies varied from 7 to 11. The RoB was assessed using the ROBINS-I tool. Critical RoB was found in 4/10 articles, high RoB was found in 5/10 articles, and intermediate RoB was found in 1/10 articles. The study found that the Visual Analog Scale scores at 1 day (mean difference [MD]: 3.48; 95% confidence interval [CI]: 3.04, 3.93; I2 = 0%), 3 to 6 months (MD: 4.05; 95% CI: 3.53, 4.56; I2 = 65%), and 12 to 24 months (MD: 4.00; 95% CI: 3.53, 4.47; I2 = 45%) after operation were significantly different from those before operation. Meanwhile, the Oswestry Disability Index at 1 day (MD: 42.67; 95% CI: 36.78, 48.57; I2 = 76%), 3 to 6 months (MD: 42.64; 95% CI: 34.44, 50.83; I2 = 91%), and 12 to 24 months (MD: 49.22; 95% CI: 42.23, 56.22; I2 = 83 %) after operation were still significantly different from those before operation. The results with high heterogeneity (I2>50%) were analyzed by sensitivity analysis and subgroup analysis. The results still have significant statistical differences. CONCLUSION: Studies have shown that percutaneous cement discoplasty is a potential intervention for the treatment of LDDs, which can effectively relieve pain and improve dysfunction.

Application of antibiotic bone cement combined with lobulated perforator flap based on descending branch of the lateral circumflex femoral artery in treatment of infected traumatic tissue defects of foot.

OBJECTIVE: To evaluate the clinical effectiveness of antibiotic bone cement combined with the lobulated perforator flap based on the descending branch of the lateral circumflex femoral artery (d-LCFA) in the treatment of infected traumatic tissue defects in the foot, in accordance with the Enhanced Recovery after Surgery (ERAS) concept. METHODS: From December 2019 to November 2022, 10 patients with infected traumatic tissue defects of the foot were treated with antibiotic bone cement combined with the d-LCFA lobulated perforator flap. The cohort comprised 6 males and 4 females, aged 21 to 67 years. Initial infection control was achieved through debridement and coverage with antibiotic bone cement, requiring one debridement in nine cases and two debridements in one case. Following infection control, the tissue defects were reconstructed utilizing the d-LCFA lobulated perforator flap, with the donor site closed primarily. The flap area ranged from 12 cm×6 cm to 31 cm×7 cm. Postoperative follow-up included evaluation of flap survival, donor site healing, and ambulatory function of the foot. RESULTS: The follow-up period ranged from 7 to 24 months, averaging 14 months. Infection control was achieved successfully in all cases. The flaps exhibited excellent survival rates and the donor site healed by first intention. Based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, pain and function were evaluated as excellent in 3 cases, good in 5 cases, and moderate in 2 cases. CONCLUSION: The application of antibiotic bone cement combined with the d-LCFA lobulated perforator flap is an effective treatment for infected traumatic tissue defects of the foot with the advantages of simplicity, high repeatability, and precise curative effects. The application of the d-LCFA lobulated perforator flap in wound repair causes minimal damage to the donor site, shortens hospital stays, lowers medical expenses, and accelerates patient rehabilitation, aligning with the ERAS concept. Therefore, it is a practice worth promoting in clinical use.

Comparative analysis of percutaneous vertebroplasty and kyphoplasty in the treatment of Stage III Kummell's disease without neurological symptoms: a retrospective study.

OBJECTIVE: This study analyzes the safety and efficacy of percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP) treatments for Stage III Kummell's disease without neurological symptoms, comparing the advantages and disadvantages of these two minimally invasive surgical methods. METHODS: A retrospective analysis was conducted on 53 patients with non-neurological Stage III Kummell's disease treated with PVP and PKP at our hospital from December 2018 to January 2023. Patients were divided into PVP (25 cases) and PKP (28 cases) groups based on the surgical method. There were no significant differences in general preoperative data between the two groups (all p > 0.05), ensuring comparability. The study compared surgical duration, volume of bone cement injected, distribution pattern of bone cement, rate of bone cement leakage, and preoperative, postoperative, and final follow-up scores of Visual analogue scale(VAS) and Oswestry disability index(ODI). Additionally, relative anterior height of the injured vertebrae, and Cobb angle of deformity, along with their changes at preoperative, postoperative, and final follow-up stages were calculated and analyzed. RESULTS: No significant preoperative differences were observed between the groups (p > 0.05). The PKP group had longer surgeries, higher cement volumes (p < 0.001), and lower leakage rates (p < 0.05), with primarily chunky cement distributions versus mixed distributions in the PVP group. No complications other than cement leakage occurred. VAS and ODI scores showed no significant changes at various time points (p > 0.05) but improved significantly from preoperative (p < 0.001). Both groups saw improved vertebral heights and Cobb angles post-surgery (p < 0.05), with more significant improvements in the PKP group (p < 0.05). Over time, both groups experienced gradual vertebral height loss and increased Cobb angles, more pronounced in the PKP group (p < 0.05). At the final follow-up, there were no statistical differences in vertebral height and Cobb angle between the two groups (p > 0.05). CONCLUSION: The study evaluates the safety and efficacy of PVP and PKP for Stage III Kummell's disease without neurological symptoms, comparing the merits of both minimally invasive techniques.

Cemented in place: kyphoplasty-associated pulmonary cement embolism: a case report.

BACKGROUND: Kyphoplasty-associated cement extravasation into surrounding tissue and vasculature can lead to life-threatening complications. We present a rare case of significant inferior vena cava cement burden that resulted in pulmonary embolism. CASE PRESENTATION: A 74-year-old Caucasian woman with a history of severe osteoporosis, recurrent falls, and spinal compression fracture status post-kyphoplasty of the L4-L5 vertebrae, presents to the emergency department 2 days post-vertebral kyphoplasty due to chest pain, back pain, and dyspnea. Computed tomography of the chest and abdomen showed a metallic density within the inferior vena cava extending superiorly approximately 10 cm from the vertebral L5 level. She was also found to have right lower lobe pneumonia. The patient finished a 10-day course of antibiotics and was discharged home with a 1-month long course of anticoagulation with apixaban per recommendations of a multidisciplinary team consisting of Hematology/Oncology, Interventional Radiology, Vascular Surgery, and Orthopedic Surgery. Unfortunately, the patient was readmitted a month later with shortness of breath. Work up was notable for an influenza type A infection and computed tomography findings of pulmonary cement embolism. The respiratory distress was resolved with supportive care. Despite pulmonary cement burden, the multidisciplinary care team recommended no further anticoagulation. Patient was discharged home with close clinical follow-up and 6 months has since passed at the time of this report without reported complications. CONCLUSIONS: A large cement burden in the inferior vena cava leading to pulmonary cement embolism is a rare event. A high burden of cement predisposes development of pulmonary embolism. A short course of anticoagulation may only be needed for asymptomatic patients.

Polyacrylic acid-reinforced organic-inorganic composite bone adhesives with enhanced mechanical properties and controlled degradability.

Bone adhesives, as alternatives to traditional bone fracture treatment methods, have great benefits in achieving effective fixation and healing of fractured bones. However, current available bone adhesives have limitations in terms of weak mechanical properties, low adhesion strength, and inappropriate degradability, hindering their clinical applications. The development of bone adhesives with strong mechanical properties, adhesion strength, and appropriate degradability remains a great challenge. In this study, polyacrylic acid was incorporated with tetracalcium phosphate and O-phospho-L-serine to form a new bone adhesive via coordination and ionic interactions to achieve exceptional mechanical properties, adhesion strength, and degradability. The bone adhesive could achieve an initial adhesion strength of approximately 3.26 MPa and 0.86 MPa on titanium alloys and bones after 15 min of curing, respectively, and it increased to 5.59 MPa and 2.73 MPa, after 24 h of incubation in water or simulated body fluid (SBF). The compressive strength of the adhesive increased from 10.06 MPa to 72.64 MPa over two weeks, which provided sufficient support for the fractured bone. Importantly, the adhesive started to degrade after 6 to 8 weeks of incubation in SBF, which is beneficial to cell ingrowth and the bone healing process. In addition, the bone adhesives exhibited favorable mineralization capability, biocompatibility, and osteogenic activity. In vivo experiments showed that it has a better bone-healing effect compared with the traditional polymethyl methacrylate bone cement. These results demonstrate that the bone adhesive has great potential in the treatment of bone fractures.

Modification of polymethylmethacrylate bone cement with halloysite clay nanotubes.

BACKGROUND: Polymethylmethacrylate (PMMA) bone cement is used in orthopedics and dentistry to get primary fixation to bone but doesn't provide a mechanically and biologically stable bone interface. Therefore, there was a great demand to improve the properties of the PMMA bone cement to reduce its clinical usage limitations and enhance its success rate. Recent studies demonstrated that the addition of halloysite nanotubes (HNTs) to a polymeric-based material can improve its mechanical and thermal characteristics. OBJECTIVES: The purpose of the study is to assess the compressive strength, flexural strength, maximum temperature, and setting time of traditional PMMA bone cements that have been manually blended with 7 wt% HNT fillers. METHODS: PMMA powder and monomer liquid were combined to create the control group, the reinforced group was made by mixing the PMMA powder with 7 wt% HNT fillers before liquid mixing. Chemical characterization of the HNT fillers was employed by X-ray fluorescence (XRF). The morphological examination of the cements was done using a scanning electron microscope (SEM). Analytical measurements were made for the compressive strength, flexural strength, maximum temperature, and setting time. Utilizing independent sample t-tests, the data was statistically assessed to compare mean values (p < 0.05). RESULTS: The findings demonstrated that the novel reinforced PMMA-based bone cement with 7 wt% HNT fillers showed higher mean compressive strength values (93 MPa) and higher flexural strength (72 MPa). and lower maximum temperature values (34.8 °C) than the conventional PMMA bone cement control group, which was (76 MPa), (51 MPa), and (40 °C), respectively (P < 0.05). While there was no significant difference in the setting time between the control and the modified groups. CONCLUSION: The novel PMMA-based bone cement with the addition of 7 wt% HNTs can effectively be used in orthopedic and dental applications, as they have the potential to enhance the compressive and flexural strength and reduce the maximum temperatures.

Cemented Versus Uncemented Reverse Shoulder Arthroplasty Treatment of Proximal Humerus Fractures: National Shoulder Arthroplasty Data from Türkiye.

Background: This study evaluated national trends in cemented and uncemented reverse shoulder arthroplasty (RSA) for proximal humerus fractures using a comprehensive national surgical database. This study aimed to compare RSA used in the treatment of proximal humerus fractures with the literature and to determine the country's trend. Methods: A cross-sectional study was conducted using the health records of individuals aged ≥ 18 years who underwent RSA for proximal humerus fractures between 2016 and 2022. Patients were divided into cemented and uncemented groups, and demographic data (age, sex), duration of hospital stay, transfusions, revisions, mortality, and Charlson Comorbidity Index (CCI) scores were analyzed. Results: A total of 618 cemented RSA and 1,364 uncemented RSA procedures were reviewed. Patients who underwent cemented RSA were significantly older than those who had uncemented RSA (p = 0.002). Transfusion rates were higher in the cemented RSA group (p = 0.006). The frequency of revision surgery was 6.1%. Younger age and male sex were associated with revision (p < 0.001). CCI scores were higher among transfused patients than non-transfused patients (p < 0.001). The incidence of cemented RSA was 11.7% and 49% in 2016 and 2022, respectively. Differences were found among hospital types and geographical regions. Conclusions: While cemented RSA has been gaining attention and increased application in recent years for proximal humerus fractures, uncemented RSA still predominates. The choice between these 2 methods is largely influenced by regional and hospital-level factors. The type of RSA and high CCI scores were found to have no significant impact on the risk of surgical revision.

Periprosthetic Femoral Fractures-Beyond B2.

The proliferation of hip arthroplasty has seen concomitant increases in periprosthetic femoral fractures (PFFs). The most common pattern involves fracture at the level of a loose prosthesis (B2). B2 PFFs have a unique mechanopathogenesis linked to the tendency of polished taper-slip cemented stems to subside in the cement. Such stems carry a much higher PFF risk than other cemented designs. Mega-data, consistent across national registries, suggest that increasing application of the taper-slip principle has resulted in the emergence of highly polished, very low friction cemented prostheses. These have the propensity to migrate within the cement, increasing B2 PFF risk. This would explain the strong association between cobalt-chromium stems and PFF. Is PFF the mode of failure of polished taper-slip stems rather than aseptic loosening? Established wisdom teaches that B2 PFFs should be managed with revision surgery. There is a large body of new evidence that, in certain instances, fixation results in outcomes at least equivalent to revision arthroplasty, with shorter surgical time, decreased transfusion requirements, and lower dislocation risk. This is so in B2 PFFs around cemented polished taper-slip stems with an intact bone-cement interface. We outline advances in understanding of B2 PFF with special reference to mechanopathogenesis and indications for fixation.

Preparation of composite calcium phosphate cement scaffold loaded with Hedysarum polysaccharides and its efficacy in repairing bone defects.

It's imperative to create a more ideal biological scaffold for bone defect repair. Calcium phosphate bone cements (CPC) could be used as a scaffold. Some ingredients and osteogenic factors could be added to improve its poor mechanical properties and biological activity. As a macromolecule extracted from traditional Chinese medicine, Hedysarum polysaccharides (HPS) would significantly promote the osteogenic activity of bone biomaterials. Zirconium oxide and starch were added to the solid phase and citric acid was added to the liquid phase to optimize CPC. HPS was loaded onto the scaffold as an osteogenic factor, and the prepared CPS + HPS was characterized. Further, the cytocompatibility of CPS + HPS was assessed according to activity, differentiation, and calcification in neonatal rat calvarial osteoblasts, and the biosafety of CPS + HPS was evaluated according to acute toxicity, pyrogen, sensitization, and hemolysis. The success of CPS + HPS in repairing bone defects was evaluated by using a rabbit femur implantation experiment. After optimization, CPS-20-CA-5 containing 10% starch and 5% citric acid displayed the highest mechanical strength of 28.96 ± 0.03 MPa. HPS-50 was demonstrated to exert the best osteogenic effect. The combination of CPS + HPS achieved HPS-loaded CPC. Material characterization, cytocompatibility, biosafety, and femoral implantation experiments indicated that CPS + HPS possessed better pressure resistance and improved osteogenic ability in bone defect repair.CPS + HPS demonstrated effective pressure resistance and superior osteogenic ability, which may be of great significance for bone defects and bone tissue engineering to promote bone regeneration and repair.

Cementless Total Knee Arthroplasty: A State-of-the-Art Review.

¼ The demographic profile of candidates for total knee arthroplasty (TKA) is shifting toward younger and more active individuals.¼ While cemented fixation remains the gold standard in TKA, the interest is growing in exploring cementless fixation as a potentially more durable alternative.¼ Advances in manufacturing technologies are enhancing the prospects for superior long-term biological fixation.¼ Current research indicates that intermediate to long-term outcomes of modern cementless TKA designs are comparable with traditional cemented designs.¼ The selection of appropriate patients is critical to the success of cementless fixation techniques in TKA.¼ There is a need for high-quality research to better understand the potential differences and relative benefits of cemented vs. cementless TKA systems.

Effects of implant precoating and fat contamination on the stability of the tibial baseplate.

BACKGROUND: Approximately 5% of primary total knee arthroplasty patients require revision within 10 years, often due to distal component loosening. Application of a thin layer of PMMA cement as precoating on the tibial component aims to prevent aseptic loosening. This study investigates the impact of precoating and fat contamination on tibial baseplate stability. METHODS: Two groups of NexGen® stemmed tibial implants (size 4) were studied: Option implants (N = 12) and PMMA Precoat implants (N = 12). Each implant design was divided into two subgroups, (N = 6), with one subgroup featuring bone marrow fat at the implant-cement interface and the other without contamination. In a mechanical testing machine, the implants underwent uniaxial loading for 20,000 cycles, while recording vertical micromotion and migration of the tibial baseplates. Subsequently, a push-out test assessed fixation strength at the cement interfaces. Results were compared using non-parametric statistics and presented as median and min-to-max ranges. RESULTS: Option implants exhibited higher micromotion in dry conditions compared to precoated implants (p = 0.03). Under contamination, both designs demonstrated similar micromotion values. Fixation strength did not significantly differ between designs under dry, uncontaminated conditions (p > 0.99). However, under contaminated conditions, the failure load for the non-coated Option implant was nearly half that of the uncontaminated counterparts (3517 N, 2603-4367 N vs 7531 N, 5163-9000 N; p = 0.002). Precoat implants displayed less susceptibility to fat contamination (p = 0.30). CONCLUSION: NexGen® implant PMMA precoating might reduce the risk of aseptic loosening and revision surgery in case of eventual bone-marrow fat contamination.

Management of infected bone defects of the femoral shaft by Masquelet technique: sequential internal fixation and nail with plate augmentation.

BACKGROUND: To evaluate the effectiveness of a sequential internal fixation strategy and intramedullary nailing with plate augmentation (IMN/PA) for bone reconstruction in the management of infected femoral shaft defects using the Masquelet technique. METHODS: We performed a retrospective descriptive cohort study of 21 patients (mean age, 36.4 years) with infected bone defects of the femoral shaft treated by the Masquelet technique with a minimum follow-up of 18 months after second stage. After aggressive debridement, temporary stabilisation (T1) was achieved by an antibiotic-loaded bone cement spacer and internal fixation with a bone cement-coated locking plate. At second stage (T2), the spacer and the locking plate were removed following re-debridement, and IMN/PA was used as definitive fixation together with bone grafting. We evaluated the following clinical outcomes: infection recurrence, bone union time, complications, and the affected limb's knee joint function. RESULTS: The median and quartiles of bone defect length was 7 (4.75-9.5) cm. Four patients required iterative debridement for infection recurrence after T1. The median of interval between T1 and T2 was 10 (9-19) weeks. At a median follow-up of 22 (20-27.5) months, none of the patients experienced recurrence of infection. Bone union was achieved at 7 (6-8.5) months in all patients, with one patient experiencing delayed union at the distal end of bone defect due to screws loosening. At the last follow-up, the median of flexion ROM of the knee joint was 120 (105-120.0)°. CONCLUSIONS: For infected femoral shaft bone defects treated by the Masquelet technique, sequential internal fixation and IMN/PA for the reconstruction can provide excellent mechanical stability, which is beneficial for early functional exercise and bone union, and does not increase the rate of infection recurrence.

A novel strategy for calcium magnesium phosphate/carboxymethyl chitosan composite bone cements with enhanced physicochemical properties, excellent cytocompatibility and osteogenic differentiation.

Artificial bone substitutes for bone repair and reconstruction still face enormous challenges. Previous studies have shown that calcium magnesium phosphate cements (CMPCs) possess an excellent bioactive surface, but its clinical application is restricted due to short setting time. This study aimed to develop new CMPC/carboxymethyl chitosan (CMCS) comg of mixed powders of active MgO, calcined MgO and calcium dihydrogen phosphate monohydrate. With this novel strategy, it can adjust the setting time and improve the compressive strength. The results confirmed that CMPC/CMCS composite bone cements were successfully developed with a controllable setting time (18-70 min) and high compressive strength (87 MPa). In addition, the composite bone cements could gradually degrade in PBS with weight loss up to 32% at 28 d. They also promoted the proliferation of pre-osteoblasts, and induced osteogenic differentiation. The findings indicate that CMPC/CMCS composite bone cements hold great promise as a new type of bone repair material in further and in-depth studies.