Antibiotic Prophylaxis for Grade 3 Open Fractures: A Retrospective Comparison of Ceftriaxone Plus Vancomycin Versus Cefazolin Plus Gentamicin.

Background: Because of the established path of bacterial entry and contamination-associated mechanisms, grade 3 open orthopedic fractures represent a substantial infection risk. The Eastern Association for the Surgery of Trauma (EAST) guidelines recommended covering Staphylococcus aureus and adding aminoglycoside gram-negative coverage. Local institutional guidelines rely on ceftriaxone for gram negative coverage and add methicillin-resistant Staphylococcus aureus coverage with vancomycin. Patients and Methods: The electronic health records of adults admitted for a grade 3 open fracture between January 1, 2016, and October 31, 2021, were retrospectively reviewed. Patients who received cefazolin and gentamicin (CZ+GM) or ceftriaxone and vancomycin (CRO+VA) as prophylaxis were included. We recorded the rate of a composite treatment failure outcome of receipt of antibiotic agents, infection-related hospitalization, or subsequent debridement for injury-site skin and soft tissue infection or osteomyelitis. The presence of acute kidney injury (AKI) was also evaluated. Results: There were 65 patients included in the CZ+GM group and 53 patients in the CRO+VA group. Patients in the CZ+GM group were younger (mean 42.6 compared with 50.6 years; p = 0.02). Otherwise, there were no significant differences between groups' demographics, mechanism and site of injury, timeline of care, or surgical interventions. More patients in the CZ+GM arm met the composite treatment failure outcome, but it was not statistically significant (45% vs. 32%; p = 0.2). There were similar rates of treatment failure at 30 days (21% vs. 26%; p = 0.5) and for only osteomyelitis (8% vs. 9%; p = 1). Conclusions: The trend in numerically lower treatment failure rates in the CRO+VA group across outcomes provides sufficient evidence to continue the current local recommendations. Given our sample size, type 2 error may have occurred, and studies with greater power should analyze this question.

Hydroxyapatite: An antibiotic recruiting moiety for local treatment and prevention of bone infections.

Treatment of chronic osteomyelitis by radical debridement and filling of the dead space with antibiotic containing calcium sulfate/hydroxyapatite (CaS/HA) bone substitute has shown excellent long-term outcomes. However, in extensive infections, sessile bacteria may remain in bone cells or soft tissues protected by biofilm leading to recurrences. The primary aim of this study was to evaluate if systemically administrated tetracycline (TET) could bind to pre-implanted HA particles and impart an antibacterial effect locally. In vitro studies indicated that the binding of TET to nano- and micro-sized HA particles was rapid and plateaued already at 1 h. Since protein passivation of HA after in-vivo implantation could affect HA-TET interaction, we investigated the effect of serum exposure on HA-TET binding in an antibacterial assay. Although, serum exposure reduced the zone of inhibition (ZOI) of Staphylococcus aureus, a significant ZOI could still be observed after pre-incubation of HA with serum. We could in addition show that zoledronic acid (ZA) competes for the same binding sites as TET and that exposure to high doses of ZA led to reduced TET-HA binding. In an in-vivo setting, we then confirmed that systemically administered TET seeks HA particles that were pre-implanted in muscle and subcutaneous pouches in rats and mice respectively, preventing HA particles from being colonized by S. aureus. Clinical Significance: This study describes a new drug delivery method that could prevent bacterial colonization of a HA biomaterial and reduce recurrences in bone infection.

An ionic silver coating prevents implant-associated infection by anaerobic bacteria in vitro and in vivo in mice.

Currently, implants are utilized clinically for bone transplant procedures. However, if infectious osteomyelitis occurs at implant sites, removal of bacteria can be challenging. Moreover, altered blood flow at peri-implant infectious sites can create an anaerobic environment, making it more difficult to treat infection with antibiotics. Thus, it would be beneficial if implants could be modified to exhibit antibacterial activity, even in anaerobic conditions. Here, we show antibacterial activity of silver ions coated on titanium rods, even against the anaerobic bacteria Porphyromonas gingivalis (P. gingivalis), both in vitro and in vivo. Specifically, we implanted silver-coated or control uncoated titanium rods along with P. gingivalis in mouse femoral bone BM cavities and observed significantly inhibited P. gingivalis infection with silver-coated compared with non-coated rods, based on in vivo bio-imaging. Osteonecrosis by infectious osteomyelitis and elevation of the inflammatory factors C-reactive protein and IL-6 promoted by P. gingivalis s were also significantly reduced in the presence of silver-coated rods. Overall, our study indicates that silver ion coating of an implant represents a therapeutic option to prevent associated infection, even in anaerobic conditions or against anaerobic bacteria.

The Contemporary Epidemiology, Microbiology and Management of Chronic Osteomyelitis in US Children.

BACKGROUND: While the majority of pediatric osteomyelitis cases are acute in nature, a significant subset present with prolonged symptoms often associated with substantial morbidity. Little data exist to guide clinicians in the management of these infections. We sought to describe the epidemiology, clinical features and management of chronic osteomyelitis (CO) in children. METHODS: We reviewed hospital admissions for CO from 2011 to 2018 at Texas Children's Hospital. Cases were included if symptoms lasted ≥28 days on presentation. Cases were classified as those associated with: (1) a contiguous focus of infection; (2) penetrating trauma; (3) orthopedic hardware; (4) postacute CO (PACO, those occurring after ≥28 days of therapy for acute osteomyelitis); and (5) primary hematogenous CO. RESULTS: One hundred fourteen cases met inclusion criteria. The median patient age was 11.8 years and 35.9% had comorbidities. 70.2% of patients underwent ≥1 surgical procedure. A microbiologic etiology was identified in 72.8% of cases and Staphylococcus aureus was most common (39.4%). Contiguous focus of infection was more often associated with polymicrobial disease with or without Pseudomonas. Postacute CO was caused by S. aureus in 95%. The median duration of total therapy was 210 days. 26.3% of patients experienced treatment failure of which 46% underwent repeat hospital admission/surgery. There was no association between duration of intravenous therapy for CO and treatment failure. CONCLUSIONS: Children with CO represent a diverse group both in terms of pathogenesis and microbiology. Pathogenesis and clinical presentation can provide clues to microbiologic etiology. Prolonged intravenous therapy does not appear to improve outcomes in CO.

Osteomyocutaneous Free Fibula Flap Prevents Osteoradionecrosis and Osteomyelitis in Head and Neck Cancer Reconstruction.

BACKGROUND: Osteoradionecrosis (ORN) is one of the most severe complications of free fibula reconstruction after radiotherapy. The gold standard treatment of osteomyelitis involves extensive debridement, antibiotics, and sufficiently vascularized muscle flap coverage for better circulation. Therefore, we hypothesized that free fibula flap with muscle could decrease the risk of ORN. METHODS: This study consisted of 85 patients who underwent reconstruction with free fibula flap in head and neck cancer by a single reconstructive surgeon at Kaohsiung Veterans General Hospital over a period of 19 years (1998-2016). Patients with postoperative adjuvant radiotherapy were included in the study and were grouped by either free fibula osteocutaneous flap or free fibula osteomyocutaneous flap (with flexor hallucis longus muscle), and the incidence of ORN was compared. RESULTS: Of the 85 patients, 15 were reconstructed with osteocutaneous fibula flap and 70 were with osteomyocutaneous fibula flap. The rate of ORN or osteomyelitis was significantly lower in the muscle group (18.6%, n = 13/70 vs. 46.7%, n = 7/15, p = 0.020, Chi-square test). CONCLUSION: Vascularized muscle transfer increases perfusion of surrounding tissues and the bone flap, thereby decreasing the incidence of osteomyelitis or osteonecrosis.

Staphylococcal infection prevention using antibiotic-loaded mannitol-chitosan paste in a rabbit model of implant-associated osteomyelitis.

Antibiotic-loaded chitosan pastes have shown advantages in the treatment and coverage of complex musculoskeletal defects. We added mannitol, previously shown to increase antibiotic susceptibility of biofilm, to an injectable chitosan/polyethylene glycol paste for delivery of antibiotics. Ground sponges (0.85% acetic acid solution, 1% chitosan, 0% or 2% mannitol, 1% polyethylene glycol) were hydrated using phosphate-buffered saline with 10 mg/ml amikacin and 10 mg/ml vancomycin added to form pastes. We inoculated rabbit radial defects with 105 colony-forming units of Staphylococcus aureus (UAMS-1) and inserted titanium pins into the cortical bone. Groups compared included mannitol blend pastes, non-mannitol blends, antibiotic-loaded bone cement, vancomycin powder, and no treatment controls. We harvested tissue samples and retrieved the pins retrieved at 3 weeks. All antibiotic-loaded groups lowered bacterial growth and colony-forming unit counts in soft and bone tissue and on titanium pins in in vivo studies. The results indicate this biomaterial is capable of eluting active antibiotics at concentrations that reduce bacterial growth on biomaterials and tissue, which, in turn, may prevent biofilm formation. Blends of chitosan and mannitol may be useful in prevention and treatment of osteomyelitis and implant-associated infections.

An electroporation strategy to synthesize the membrane-coated nanoparticles for enhanced anti-inflammation therapy in bone infection.

The cell membrane-coated nanoparticles (MNPs) showed great potential in treating infectious disease due to their superior biofunctions in improving biocompatibility of nanoparticles and neutralization of pathogen or toxins. However, bone infection is accompanied with severe inflammation and bone loss, which also requires anti-inflammatory and osteoconductive treatment. The conventional membrane coating method has to undergo ultrasonication and extrusion procedures, which reduces the functionality of cell membrane and limits the choice of nanoparticles. In this study, we proposed an electroporation-based membrane coating strategy to facilitate the synthesis of MNPs to tackle those problems. Methods: Magnetic composite nanoparticles with osteoconductive Ca3(PO4)2 and bactericidal TiO2 were assembled into macrophages through phagocytosis and then collected to expose in electric field for obtaining macrophage membrane-coating nanoparticles. By using molecular dynamics simulation and materials characterizations, the cell membrane coating efficiency was confirmed. The in vitro anti-bacterial and anti-inflammatory abilities were tested by bacteria culturing and immune cells activation. Then drug-resistant bacteria induced bone infection model was established to verify its in vivo therapeutic effects. Results: The coated membrane prepared through electroporation reserved the integrality of membrane structure and right-sidedness, with more functional proteins. Those led to the superior properties of recognition and adsorption with bacteria, toxins and inflammatory cytokines. Owing to the benefits of electroporation, the MNPs exhibited significant better antibacterial and anti-inflammatory abilities for enhancing the tissue repair process. Conclusion: This study provides a novel self-assembly cell membrane coating strategy by electroporation to construct multifunctional membrane-coating nanoparticles for bone infection treatment. This strategy not only improves the functions of coated membrane, but is also proved to be universal for varies nanoparticles or cells, indicating a great potential for future applications in the bioengineering field.

Chondronecrosis with osteomyelitis in broilers: further defining a bacterial challenge model using standard litter flooring and protection with probiotics.

This report demonstrates that high levels of lameness can be induced by a limited bacterial challenge in drinking water for birds raised on litter flooring, comparable with lameness induced by the gold standard for inducing lameness, growth on suspended wire flooring. The bacterium used in the challenge was cultured from lesions in birds induced for bacterial chondronecrosis with osteomyelitis (BCO) in the wire-flooring model so the epidemiology appears similar. The litter-flooring model could better approximate broiler operations. Furthermore, the work demonstrates that 2 commercial probiotics (GalliProTect and GalliProMax) can reduce lameness in the bacterial challenge litter-flooring model. Lameness attributable to BCO is one of the most significant animal welfare issues for broiler production. The wire-flooring and litter-flooring models afford alternatives for understanding the etiology, and epidemiology of BCO, and development of management strategies to reduce lameness. Probiotics afford a promising management strategy. The results suggest that the probiotic protection may extend beyond just intestinal health and intestinal barrier function.

Gentamicin-Coated Tibia Nail in Fractures and Nonunion to Reduce Fracture-Related Infections: A Systematic Review.

The incidence of a fracture-related infection (FRI) can reach 30% of open tibia fractures (OTF). The use of antibiotic-coated implants is one of the newest strategies to reduce the risk of infection in orthopedic surgery. The aim of this study was to investigate the efficacy and safety of a gentamicin-coated tibia nail in primary fracture fixation (FF) and revision surgery (RS) of nonunion cases in terms of FRI incidence. We conducted a systematic review according to the PRISMA checklist on Pub-Med, Cochrane, and EMBASE. Of the 32 studies, 8 were included, for a total of 203 patients treated: 114 were FF cases (63% open fractures) and 89 were RS cases, of which 43% were infected nonunion. In the FF group, four FRI were found (3.8%): three OTF (Gustilo-Anderson III) and one closed fracture; bone healing was achieved in 94% of these cases. There were four relapses of infection and one new onset in the RS group; bone healing occurred in 88% of these cases. No side effects were found. There were no significant differences in terms of FRI, nonunion, and healing between the two groups. Gentamicin-coated tibia nail is an effective therapeutic option in the prophylaxis of high-risk fracture infections and in complex nonunion cases.

Chondronecrosis with osteomyelitis in broilers: further defining lameness-inducing models with wire or litter flooring to evaluate protection with organic trace minerals.

The feed additive Availa-ZMC was investigated for the ability to reduce lameness in broilers using 2 alternative models for inducing lameness. The mixture of organic trace minerals was effective in reducing lameness by 20% in the wire flooring model and 25% in the litter flooring model with the bacterial challenge. Lameness in both models is overwhelmingly attributable to bacterial chondronecrosis with osteomyelitis. The reduction in lameness was associated, at least in part, with enhanced intestinal barrier integrity mediated by elevated expression of tight junction proteins and stimulation of bactericidal killing of adherent peripheral blood monocytes obtained from the birds treated with Availa-ZMC. Lameness is a major animal welfare concern in broiler production. The wire flooring model and litter flooring model with the bacterial challenge are effective models for evaluation of management strategies for mitigating infectious causes of lameness.

Beneficial Effect of TaON-Ag Nanocomposite Titanium on Antibacterial Capacity in Orthopedic Application.

PURPOSE: In this study, a novel oxygenated nanocomposite thin film, TaON-Ag, was investigated in vitro and in vivo to evaluate its biocompatibility and antibacterial ability. MATERIAL AND METHODS: The antibacterial ability of TaON-Ag nanocomposite-coated titanium (Ti) was evaluated using the Kirby-Bauer disk diffusion susceptibility test. The effects of TaON-Ag nanocomposite-coated metal on osteogenesis were further evaluated in an in vitro osteogenic culture model with rat marrow-derived mesenchymal stem cells (rMSCs). Furthermore, titanium rods coated with TaON-Ag were implanted into a rat femur fracture model either with or without osteomyelitis to investigate the effects of TaON-Ag in osteogenesis. RESULTS: The TaON-Ag-coated Ti exhibited an effective antibacterial effect against Staphylococcus aureus, coagulase-negative Staphylococcus, and the Gram-negative strains Escherichia coli and Pseudomonas aeruginosa. Using an osteogenic culture with rMSCs and a rat femoral fracture model, the TaON-Ag-coated Ti did not interfere with the ossification of rMSCs in vitro or during fracture healing in vivo. Field-emission scanning electron microscopy (FE-SEM) revealed that coating with TaON-Ag could inhibit pathogen adhesion and biofilm formation in both Staphylococcus aureus and Escherichia coli. CONCLUSION: Using the proposed novel oxygenation process, TaON-Ag nanocomposite-coated Ti yielded robust biocompatibility and antibacterial ability against common microorganisms in orthopedic infections, thereby demonstrating potential for use in clinical applications.

Not Just Endocarditis: Hospitalizations for Selected Invasive Infections Among Persons With Opioid and Stimulant Use Diagnoses-North Carolina, 2010-2018.

BACKGROUND: While increases in overdoses, viral hepatitis, and endocarditis associated with drug use have been well-documented in North Carolina, the full scope of invasive drug-related infections (IDRIs) has not. We characterized trends in IDRIs among hospitalized patients in North Carolina. METHODS: We compared invasive infections that were related or not related to drug use among hospitalized patients aged 18-55 years based on retrospective review of administrative records from 2010-2018. Hospitalizations for endocarditis, central nervous system/spine infections, osteomyelitis, and septic arthritis were labeled as IDRIs if discharge codes included opioid and/or amphetamine misuse. Trends, rates, and distributions were calculated. RESULTS: Among 44 851 hospitalizations for the specified infections, 2830 (6.3%) were IDRIs. The proportion of infections attributable to drug use increased from 1.5% (2010) to 13.1% (2018), and the rate grew from 1.2 to 15.1 per 100 000. Compared with those who had non-drug-related infections, patients with IDRIs were younger (median age, 35 vs 46 years), more likely to be non-Hispanic white (81% vs 56%), and had longer hospitalizations (median, 8 vs 6 days). 43% of hospitalizations for IDRIs involved infective endocarditis. CONCLUSIONS: The rate of IDRIs in North Carolina increased substantially during 2010-2018, indicating an urgent need for enhanced infection prevention, harm reduction, and addiction services aimed at community and inpatient settings.

Liposomes for Intra-Articular Analgesic Drug Delivery in Orthopedics: State-of-Art and Future Perspectives. Insights from a Systematic Mini-Review of the Literature.

Background and objectives: Liposomal structures are artificial vesicles composed of one or several lamellae of phospholipids which surround an inner aqueous core. Given the amphoteric nature of phospholipids, liposomes are promising systems for drug delivery. The present review provides an updated synthesis of the main techniques for the production of liposomes for orthopedic applications, focusing on the drawbacks of the conventional methods and on the advantages of high pressure techniques. Materials and Methods: Articles published in any language were systematically retrieved from two major electronic scholarly databases (PubMed/MEDLINE and Scopus) up to March 2020. Nine articles were retained based on the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) guidelines. Results: Liposome vesicles decrease the rate of inflammatory reactions after local injections, and significantly enhance the clinical effectiveness of anti-inflammatory agents providing controlled drug release, reducing toxic side effects. Conclusions: This review presents an update on the improvement in musculoskeletal ailments using liposome treatment.

Retrospective analysis of risk factors for deep infection in lower limb Gustilo-Anderson type III fractures.

BACKGROUND: Open fractures are among the most severe injuries observed in orthopedic patients. Treating open fractures is difficult because such patients with infections may require multiple operations and amputations. Furthermore, only a few studies have focused on antibiotic prophylaxis in open fractures and evaluated how to cover lost soft tissue to increase the success rate of reconstruction. We evaluated the risk factors for deep infection in lower limb Gustilo-Anderson (G-A) type III fractures. MATERIALS AND METHODS: This retrospective study investigated patients who underwent surgical procedures for lower limb G-A type III fractures between January 2007 and January 2017 at our institution. We enrolled 110 patients with 114 lower limb G-A type III fractures (77 G-A type IIIA fractures and 37 G-A type IIIB fractures) who were followed up for at least 2 years. We compared patients presenting infections with those without infections by assessing the following factors: severe contamination, diabetes, smoking, Injury Severity Scale, segmental fracture, location of fracture, G-A classification, damage control surgery, methods of surgery, timing of fixation, combination of antibiotics used, duration of antibiotic prophylaxis, timing of wound closure, and soft-tissue reconstruction failure. RESULTS: Eighteen fractures presented deep infections. Compared with patients without infections, patients developing infections differed significantly in terms of severe contamination (P < 0.01), G-A classification (P < 0.01), duration of antibiotic prophylaxis (P < 0.01), timing of wound closure (P < 0.01), and incidence of soft-tissue reconstruction failure (P < 0.01). Skin grafting was associated with significantly higher failure rates than muscle and free flap reconstructions (P = 0.04). Treatment with antibiotics was significantly longer in patients with drug-resistant bacterial infections than in those without infections (P < 0.01). CONCLUSION: Early flaps rather than skin grafting should be used to cover G-A type IIIB fractures, because skin grafting resulted in the highest failure rate among soft-tissue reconstructions in open fractures. Longer duration of antibiotic use had a significant impact not only on deep infection rates but also on the presence of drug-resistant bacteria. These findings suggest that prolonged use of antibiotics should be avoided in cases of open fractures. LEVEL OF EVIDENCE: Level IV retrospective observational study.

Therapeutic potential of dalbavancin in a rat model of methicillin-resistant Staphylococcus aureus (MRSA)-osteomyelitis.

Bacterial osteomyelitis is a major clinical challenge in human and veterinary patients. This infection is an infrequent but feared complication of orthopedic surgery and is mainly caused by methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study was to evaluate the efficacy of dalbavancin (dosed for either 7 or 14 days) in an MRSA-osteomyelitis tibial bone model. A total of 39 rats were included in the study. All animals received an inoculum of a clinical strain of MRSA (106 colony-forming units [CFU]) injected into the proximal tibia under general anesthesia. Dalbavancin was injected intraperitoneally for 7 or 14 days in 13 animals each; the remaining 13 animals received saline solution. After treatment, the animals were sacrificed. Infected tibiae were recovered for histological evaluation and microbiological analysis (MRSA count per gram of bone). Rats that received dalbavancin showed a statistically significant reduction of MRSA counts compared with the control group: median 0 CFU/g bone (14 days of dalbavancin) vs. 70 CFU/g bone (7 days of dalbavancin) and 1600 CFU/g bone (control). Histological evaluation showed typical signs of osteomyelitis in the control group, whereas there were no signs of bone infection in 92% of the rats that received 14 days of dalbavancin. According to this model, dalbavancin seems to have good efficacy for treating serious Gram-positive bone infections, including those caused by MRSA.

Incidence, types and outcomes of sternal wound infections after cardiac surgery in Saudi Arabia. A retrospective medical chart review.

OBJECTIVES: To determine the incidence, types, risk factors, identify organisms, and assess outcomes of surgical wound infections (SWIs) after cardiac surgery at a tertiary hospital in Riyadh, Saudi Arabia. Methods: This historical cohort study reviewed the chart of  patients who underwent cardiac surgery at King Khalid University Hospital, Riyadh, Saudi Arabia between January 2009 and December 2014. The proforma contained personal data, comorbidities, type of surgery, microbiological analysis, and management outcomes. Results: A total of 1241 patients were enrolled in the study comprising 1,032 (83.2%) men and 209 (16.8%) women. Forty (3.2%) patients developed SWI, of which 32 (2.5%) were superficial and 8 (0.7%) were deep. Gender, obesity, diabetes mellitus, non-use of statins, and coronary artery bypass graft (CABG) surgery were not significant predictors of infection in the study. Methicillin-susceptible Staphylococcus aureus was isolated predominantly in 45%, followed by Klebsiella and Pseudomonas species. Methicillin-resistant Staphylococcus aureus, Enterococcus faecium, and extended ß-lactamase-producing gram-negative organisms were pathogens isolated in last 3 years of the review.  Simple and vacuum assisted closure therapies led to complete resolution in 32 (80%) patients, while 8 (20%) developed sternal osteomyelitis. All patients survived except one with a deep SWI who died of uncontrolled sepsis.  Conclusion: Despite the low incidence of postoperative SWIs, the risk of sternal osteomyelitis development persists. Meticulous choice of CABG components and appropriate postoperative management, especially detecting early signs of SWI could contribute to lower its incidence and complications.

New Alternative Therapeutic Strategy for Gustilo Type IIIB Open Fractures, Using an Intra-Wound Continuous Negative Pressure Irrigation Treatment System.

The treatment of Gustilo type IIIB and IIIC open fractures remains a challenging problem, because the infection rate is 15-45%. Infection can lead to serious complications such as osteomyelitis or amputation. The intra-wound continuous negative pressure and irrigation treatment (IW-CONPIT) was developed for infected wounds and intractable ulcers, and is very effective in suppressing infection and accelerating wound healing. Here the IW-CONPIT was applied to severe open fractures for the purpose of preventing infection. After thorough debridement and lavage of the wound, bony stabilization is performed by external fixation. Dermal matrix is grafted onto any areas where the bone or tendon is exposed. A sponge containing two tubes is placed over the entire surface of the wound including the dermal matrix. Then it is covered with a film dressing to make the wound completely airtight. A bottle of physiologic saline solution is attached to one tube, and a continuous aspirator is attached to the other. This system maintains negative pressure on the wound surface, which is continuously irrigated. Thirty-five patients were treated with this method. A superficial infection developed in two cases but was resolved by additional debridement and continued application of IW-CONPIT. Complete wound healing was obtained with split thickness skin graft in all cases. There were no complications such as osteomyelitis, delayed bone union or amputation. IW-CONPIT was able to definitively prevent wound infection in Gustilo type ⅢB open fractures. We believe this method will become a standard treatment option for this condition.

Two-staged time-dependent materials for the prevention of implant-related infections.

Infection is a main cause of implant failure. Early implant-related infections often occur in the first 4 weeks post-operation. Inhibiting bacterial adhesion and biofilm formation at the early stage and promoting subsequent implant osseointegration are important for implant success. Our previous studies demonstrated that dimethylaminododecyl methacrylate (DMADDM) provided dental materials with antibacterial effects. In the present study, DMADDM and hydroxyapatite (HA) are loaded on to the titanium (Ti) surface via poly dopamine (PDA) self-polymerization. This local DMADDM-delivery Ti is referred as Ti-PHD. Here we report the two-staged capability of Ti-PHD: (1) in the first stage, releasing DMADDM during the high-infection-risk initial period post-implantation for 4 weeks; (2) then in the second stage, enhancing osteogenesis and promoting osseointegration. Ti-PHD has a porous surface with higher average roughness and greater hydrophilicity than pure Ti. Its biocompatibility is verified in vitro and in vivo. During the first 4 weeks of release, both DMADDM remaining on Ti surface and DMADDM released into the soaking medium greatly reduced the adherence and growth of pathogens. This is further confirmed by the prevention of bone destruction in a rat osteomyelitis model. After releasing DMADDM for 4 weeks, Ti-PHD promotes osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) and new bone formation around the implants in vivo. This article represents the first report on the two-staged, time-dependent antibacterial and osteogenesis effects of Ti-PHD, demonstrating its potential for clinical applications to inhibit implant-associated infections. STATEMENT OF SIGNIFICANCE: The present study develops a two-staged time-dependent system for local dimethylaminododecyl methacrylate (DMADDM) delivery via Ti implant (referred to as Ti-PHD). DMADDM and hydroxyapatite (HA) are loaded on to the Ti surface with poly dopamine (PDA). Ti-PHD can release DMADDM during the high-risk period of infection in the first stage, and then promote osseointegration and new bone formation in the second stage. This bioactive and therapeutic Ti is promising to inhibit infections and enhance implant success.