Search Results (63)

Critical-sized bone defects remain a major reconstructive challenge, and the Masquelet technique has become an important option in traumatic, infectious, and post-resection settings. This review examines the role of acrylic bone cement in this technique, emphasizing its evolution from a temporary spacer to an active biomaterial that shapes the induced membrane and the local regenerative microenvironment. The article discusses the surgical and biological basis of the technique, the composition and handling characteristics of polymethyl methacrylate (PMMA) bone cement, the rationale for antibiotic-loaded spacers, and the influence of spacer-related variables such as formulation, surface properties, and geometry on membrane quality. It also addresses emerging strategies, including bioactive PMMA modifications, multifunctional cements, and degradable alternatives aimed at improving osteogenesis, angiogenesis, and infection control. Current evidence, derived mainly from in vitro studies and animal models, suggests that the spacer may play a role beyond space maintenance by participating in induced membrane formation and influencing biological signaling related to bone repair. In contrast, the clinical evidence primarily supports the reproducible use of PMMA spacers for dead-space management, infection control, and bone reconstruction. However, important gaps still remain in the translational validation of these biological properties and in the standardization of spacer formulations and antibiotic protocols. Full article

Background: Long-bone non-unions complicated by osteomyelitis remain a major reconstructive and healthcare challenge, particularly in resource-limited settings with a high prevalence of multidrug-resistant (MDR) pathogens. Conventional staged management is associated with a prolonged treatment burden, repeated procedures, and delayed functional recovery. This study evaluated the clinical, radiological, functional, and short-term safety outcomes of a single-stage approach using custom-threaded antibiotic-coated locking nails (TACLNs) in a high-resistance cohort. Methods: This prospective single-center cohort study enrolled 30 adults with osteomyelitis-associated femoral or tibial nonunion at a tertiary hospital in Peshawar, Pakistan. All patients underwent radical debridement and single-stage stabilization with a chest tube mold TACLN loaded with vancomycin and gentamicin, with culture-directed adjunctive antibiotics for resistant organisms. Outcomes were assessed at baseline, Weeks 3 and 6, and Month 6 using inflammatory markers, RUST score, VAS pain, EQ-5D-5L, ASAMI criteria, and return to work or usual activity. No formal sample size calculation was performed, and this study was exploratory in nature. Results: The cohort (mean age 44.9 ± 9.9 years) had a challenging microbiological profile, with 40.0% MDR and 13.3% extensively drug-resistant (XDR) infections. By Month 6, short-term infection control was achieved in 96.7% of patients, with significant reductions in ESR and CRP (both p < 0.001). Radiographic union was achieved in 90.0% of cases at a mean of 18.6 weeks, and the mean RUST score improved from 4.87 to 10.43 at the final follow-up. The VAS pain decreased from 5.23 at week 3 to 0.73 at month 6, EQ-5D-5L improved from 0.39 to 0.84, and 90.0% returned to work or usual activity by month 6. No cement debonding, implant failure, or nephrotoxicity was noted. Conclusions: In this single-arm exploratory cohort, TACLNs were associated with favorable short-term infection control, radiographic union, and functional recovery in osteomyelitis-associated long-bone nonunion, including in an MDR/XDR setting. The independent contribution of the threaded core design cannot be established. Larger multicenter comparative studies with longer follow-ups are needed to confirm the durability and implementation feasibility. Full article

Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty, typically managed through a two-stage revision protocol involving antibiotic-loaded spacers. This study aimed to evaluate the clinical outcomes and safety of a new multiple high-dose antibiotic-loaded cement (MHDALC) spacer against alternative classical antibiotic combinations for Gram-positive PJI. In this retrospective observational study of 102 patients (30 MHDALC vs. 72 control), the MHDALC cohort received spacers prepared with commercial cement (1 g clindamycin and 1 g gentamicin per 40 g) supplemented with manual additions of 4 g vancomycin and 2 g ceftazidime per 40 g of cement, while the control group received the same commercial cement supplemented with 4 g of vancomycin alone. Treatment failure was significantly lower in the MHDALC group (6.6%) compared to the control group (20.8%; p = 0.005). Furthermore, the time to second-stage reimplantation was drastically reduced in the MHDALC cohort (9.1 vs. 17.8 weeks; p = 0.001). Despite the substantially higher antibiotic load, no significant differences were observed regarding mechanical or surgical complications between the two groups (p = 1.00). In conclusion, the use of MHDALC spacers is an effective and safe strategy for treating Gram-positive PJI, significantly improving eradication rates and accelerating the transition to definitive reconstruction without compromising structural integrity. Full article

Background: Antibiotic-loaded bone cement (ALBC) is widely used for local antibiotic delivery in joint arthroplasty to prevent and treat prosthetic joint infections (PJIs). In this study, we evaluated the efficacy of cemented Kirschner (K)-wires coated with various ALBC formulations using a Galleria mellonella infection model against multidrug-resistant (MDR) Staphylococcus aureus and Enterococcus faecalis. Methods: We tested commercially available bone cements, including gentamicin-only formulations (PALACOS R+G) and dual-antibiotic formulations, combining gentamicin with either clindamycin (COPAL G+C) or vancomycin (COPAL G+V), alongside an antibiotic-free control (PALACOS R). In vitro assays—including minimum inhibitory/bactericidal concentration (MIC/MBC) determination, antibiotic release kinetics, agar diffusion, and antibiofilm evaluations—demonstrated effective antibiotic release and significant antimicrobial activity against both planktonic and biofilm-associated bacteria. Results: In vivo, ALBC-coated K-wires were well tolerated in G. mellonella and significantly protected the larvae from S. aureus infection compared to controls. Notably, dual-antibiotic formulations provided superior protection, correlating with substantial reductions in bacterial colonisation on implant surfaces and in surrounding tissues. Conclusions: These findings support the utility of the G. mellonella model as a high-throughput, cost-effective platform for the preclinical evaluation of antimicrobial strategies to prevent and treat PJIs and further demonstrate the effectiveness of dual-loaded ALBC against multidrug-resistant bacteria. Full article

Objectives: Polymethyl methacrylate (PMMA) bone cement is vital for prosthetic fixation in orthopedic surgery, yet its exothermic polymerization can exceed 80 °C, surpassing the 50 °C threshold for thermal osteonecrosis, risking implant failure. This pilot study assesses two cooling strategies—precooling cement components and saline irrigation on the polymerization temperature and compressive strength of antibiotic-loaded PMMA, comparing hand mixing (HM) and vacuum mixing (VM) to optimize thermal management while preserving mechanical integrity in controlled settings relevant to orthopedic applications. Methods: Antibiotic-loaded Simplex bone cement (Stryker, Kalamazoo, MI, USA) was prepared using HM and VM, per ISO 5833. Each batch was divided into three groups: control, precooled (components at 6 °C overnight), and saline irrigation (8 °C saline during setting). Each group included 20 cylindrical samples (1.5 cm × 3 cm), cured for 24 h. Core temperatures were monitored with embedded thermometers, and compressive strength was measured in megapascals (MPa) using a hydraulic press (C092-06, MATEST). Welch’s t-test was used for statistical analysis. Results: HM controls reached 76.2 °C, precooled 63.6 °C, and saline 66 °C; VM controls hit 71.8 °C, precooled 58.8 °C, and saline 63.6 °C. HM strengths were 16–17 MPa, with precooling reducing to 16.49 MPa (p = 0.051) and saline maintaining 17.07 MPa (p = 0.820). VM strengths were 76–80 MPa, with precooling at 78.45 MPa (p < 0.001) and saline at 76.77 MPa (p = 0.010). Failure modes varied: controls (uniform cracking), precooled (shear failure), and saline (mixed cracking/crumbling). Conclusions: Precooling significantly lowers temperatures but compromises strength in HM samples, limiting its use in load-bearing applications. Saline irrigation offers moderate thermal control while preserving mechanics, particularly in HM, suggesting a viable strategy for reducing thermal necrosis risk. VM ensures superior strength, supporting safe cooling application. Full article

Background: There is no consensus on the optimal type of antibiotic-loaded bone cement (ALBC) spacer for ue in the first stage of revision total hip arthroplasty (THA) as a method for treating/managing periprosthetic joint infection (PJI) following THA. The purpose of this study was to determine the influence of ALBC spacer type on a collection of outcome metrics for revision THA (rHA). We hypothesized that infectious complications would be comparable across spacer types, while mechanical complications would be more common with the use of hemiarthroplasty ALBC spacer designs in rHA. Methods: This was a multicenter retrospective review of 144 patients who underwent a planned two-stage revision for THA for PJI between 2011 and 2022. Patients were stratified into three groups: pre-molded articulating hemiarthroplasty ALBC (PHA) spacers, custom articulating hemiarthroplasty ALBC (CHA) spacers, and custom ALBC THA (CTHA) spacers. The types and incidence of complications that arose during the time that the spacer was in situ were obtained. In total, 29 (20.1%) PHA, 11 (7.6%) CHA, and 104 (72.2%) CTHA patients were included. Results: CHA patients were significantly younger (mean age: 54.1 years) than PHA (mean age: 63.9) and CTHA (mean age: 63.9) patients (p = 0.011). The proportion of patients discharged home was significantly higher in the CHA group (81.8%) compared to that in both the CTHA group (64.4%) and the PHA group (34.5%) (p = 0.02). The re-revision rate for hip PJI was higher for CHA (18.2%), followed by PHA (13.8%) and CTHA (5.8%), while hemiarthroplasty spacers had the highest dislocation rate (13.8% in PHA and 18.2% in CHA vs. 3.8% in CTHA, p = 0.055). The vast majority of the outcome metrics did not differ among the three spacer groups, with examples being the incidence of dislocations, the incidence of all types of unplanned procedures for treating/managing re-infection, the time to the second stage in the rHA, and the proportion of spacers that were not removed until the second stage in the rHA. Conclusions: For the vast majority of the outcome metrics determined, the difference among the three study groups was not significant. Thus, the present results suggest that antibiotic-loaded cement spacer type does not influence outcomes when a spacer is used in the first stage of a two-stage protocol for the revision of a THA. Full article

Prophylactic measures and treatment strategies of implant-related bone and joint infections frequently involve the local delivery of high doses of antimicrobial drugs into the affected bone tissue or articular space in addition to the use of systemic antibiotics. Antibiotic-loaded biomaterials, such as Polymethyl Methacrylate (PMMA) cement, calcium sulfate, calcium phosphate, bioglass, and others, have proven to be clinically effective. However, they suffer from important limitations regarding elution and freedom of choice of admixable antimicrobial drugs. In order to overcome these shortcomings, the techniques of direct intraosseous or intra-articular injection/infusion of antibiotics via needles/cannulas or catheters are gaining popularity. Their attractiveness is based on the potential to achieve extremely high drug concentrations in situ, which can be maintained for as long as the catheters are left in place without increased risks of systemic toxicity. Although these methods are still in an experimental stage, reports on their clinical outcomes look promising. This articles summarizes the knowledge of when, how, and in which clinical settings the different modes and philosophies of local antibiotic delivery work best, with the aim to provide surgeons and infectious disease physicians guidance in clinical practice. This will help to optimize the use for the sake of the patients. Full article

Antibiotic-loaded bone cements (ALBCs) are used to prevent and treat periprosthetic joint infections (PJI). This study compares the in vitro release and antibacterial effectiveness of gentamicin from Palacos^® R+G and tobramycin from Simplex^® T. Standardized cylindrical specimens of Palacos^® R+G and Simplex^® T were incubated in phosphate-buffered saline. Antibiotic release was quantified using high-performance liquid chromatography (HPLC) over 14 and 42 days. Antibacterial efficacy was assessed using inhibition zone tests (IZT) against Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli over 42 days. Palacos^® R+G exhibited a significantly higher and more sustained antibiotic release of gentamicin compared to tobramycin from Simplex^® T. The cumulative release of gentamicin from Palacos^® R+G was 1.148 µg/cm², while Simplex^® T released 198.87 µg/cm² tobramycin over 14 days. Inhibition zone tests showed that Palacos^® R+G maintained antibacterial activity for 42 days, while Simplex^® T’s activity diminished after 14 days. Statistical analysis confirmed significant differences in antibacterial efficacy between the two cements. Palacos^® R+G demonstrated superior gentamicin release and sustained antibacterial activity compared to tobramycin from Simplex^® T. These findings suggest that Palacos^® R+G may offer better clinical outcomes in preventing and treating PJIs. Full article

This study presents the development of a degradable and biocompatible calcium phosphate cement (CPC) co-loaded with gentamicin (1.25 wt%) and vancomycin (4.25 wt%) for the local treatment of polymicrobial bone infections. The antibiotics were incorporated—individually or in combination—into the solid phase of Graftys^® Quickset (GQS), an injectable CPC. Antibiotic loading modifies some of the intrinsic properties of the GQS cement. Porosity exceeded 53%, compressive strength reduced around 5 MPa, which is comparable to calcium sulphates cements, and the setting time, although extended, remained within the clinically acceptable threshold (<20 min), ensuring suitable handling. A burst release of both antibiotics was observed within the first 24 h, with sustained release over time and no cytotoxic effects on human osteoblasts. The dual-loaded cement exhibited broad-spectrum antibacterial activity against both Gram-positive and Gram-negative strains, including methicillin-resistant isolates, in both planktonic and biofilm forms. Notably, the combination of both antibiotics demonstrated superior efficacy compared to either antibiotic alone. These findings suggest that this dual-antibiotic-loaded CPC offers a promising strategy for localised treatment of complex bone infections such as osteomyelitis, where polymicrobial involvement and antibiotic resistance pose significant therapeutic challenges. Full article

Antibiotic-loaded cement spacers play a crucial role in two-stage revision arthroplasty of infected total hip and knee prostheses. There is still controversy regarding whether the elution from antibiotic-loaded cement spacers is greater than the MIC for a prolonged time between stages. Therefore, the aim of the current review was to determine how long spacers elute antibiotics above the MIC for most causative microorganisms, as well as to evaluate what factors influence that elution. Independent of methodological differences and weaknesses of the studies themselves, several study results indicate that after an early peak of antibiotic release from the spacer in the first 1 to 2 days (followed by a gradual decline), a sufficient release above the MIC for most causative bacteria continues for 6 to 12 weeks. Full article

Poly(methyl methacrylate) (PMMA)-based bone cements are widely used in orthopaedic surgery, yet their inherent brittleness, lack of bioactivity, and exothermic polymerization remain critical limitations. Recent strategies have focused on modifying PMMA with functional additives to improve not only mechanical performance but also thermal behaviour and biological interactions. This study investigates the mechanical properties of two commercial PMMA cements—Palamed^® (antibiotic-free) and Refobacin Plus G (gentamicin-loaded)—reinforced with glassy carbon (GC) particles of two different grain sizes (0.4–1.2 µm and 20–50 µm) and various concentrations. The results demonstrate that coarse GC particles (20–50 µm) significantly reduced compressive strength, particularly in the antibiotic-loaded cement. In contrast, the incorporation of fine GC particles (0.4–1.2 µm) did not markedly impair mechanical performance in Palamed^®, suggesting better compatibility with the PMMA matrix. In addition to mechanical enhancement, the structural and chemical stability of glassy carbon may contribute to improved biological response and reduced polymerization heat. These findings highlight the potential of glassy carbon as a functional additive for designing PMMA-based biomaterials that combine improved mechanical properties with favourable characteristics for long-term implant integration. Full article

Background/objectives: Vancomycin is commonly used in the treatment of periprosthetic joint infection (PJI), and trough concentrations are measured to ascertain that they are within the therapeutic range. It has not been investigated what proportion of vancomycin concentrations during treatment of PJI patients is accurately within this range, how many dose adjustments are commonly needed, and which patient factors predispose towards aberrations from the desired range. Method: In this single-center cohort study, we investigated vancomycin trough concentrations in 108 patients with surgically treated PJI who received IV administered vancomycin treatment post-operatively. Patients were identified in our local arthroplasty register, and data beyond what was available in the register were collected from electronic medical charts. Results: Of the final study cohort, 41% were women, and the median age was 71 (IQR 63–79) years. Most patients had PJI of the hip (73%), the majority (54%) underwent a debridement, antibiotics and implant retention (DAIR) procedure prior to vancomycin treatment, and 39% received vancomycin-loaded bone cement during the preceding revision procedure. Of 791 vancomycin trough measurements, only 58.2% were within the target range of 15–20 mg/L, 18.5% were below, and 23.4% were above. A total of 71% of all patients required at least one dose adjustment, and the median length of vancomycin treatment was 8 days. We observed positive correlations of vancomycin trough concentrations with both age (Spearman’s rho = 0.35, p < 0.001) and pre-treatment creatinine concentrations (Spearman’s rho = 0.34, p < 0.001), but no statistically significant difference between patients who had received vancomycin-loaded bone cement and those who had not. Conclusions: In our PJI patients, a high proportion of vancomycin trough concentrations were outside the therapeutic range, despite adherence to local and national guidelines. We can also confirm that caution needs to be exerted in patients of advanced age and those with compromised kidney function. Alternative broad-spectrum antibiotics that do not require as extensive therapeutic drug monitoring should be further explored. Full article

Background: The use of antibiotic-loaded bone cements (ALBCs) in arthroplasty has been well established for the prevention and treatment of infections. Tigecycline (Tig), a broad-spectrum antibiotic, has shown efficacy against various pathogens, including vancomycin-resistant strains. Method: ISO and DIN mechanical and microbiological inhibition zone tests were performed on PMMA cement with manually added Tigecycline. Results: Manually adding 0.5 and 1.0 g Tigecycline to PMMA always meets the mechanical requirements of ISO and DIN standards. Mixtures containing 0.5 g were microbiologically effective for up to 7 days and those containing 1.0 g were effective for 28–42 days. Conclusion: In revision surgery, manually adding Tigecycline in doses of 0.5–1 g to 40 g of PMMA is effective against MRSA, VRE, and ESBL without negatively affecting the cement’s properties. Full article

The aim of this review is to investigate the effective role of local antimicrobial protection for one-stage cemented and cementless hip revision surgery. Twelve studies reporting the results of cemented single-stage procedures with a minimum two-year follow-up were reviewed. When pooling together the data, no infection recurrence was observed on average in 83.3% of the patients (a range of 75.0% to 100%). Only two papers included patients treated without the use of antibiotic-loaded bone cement, with an average infection control of 95.9% in a total of 195 patients. This figure appears to be better than the 80.7% infection control obtained by pooling together all the remaining studies. Concerning cementless one-stage revision, a total of 17 studies, reporting on 521 patients, showed an average of 90.0% (range 56.8% to 100%) no infection recurrence at a minimum two-year follow-up. No comparative study investigated cementless revision with or without local antibacterial protection. The pooled data showed an average infection control of 86.7%, without the application of local antibacterials, compared to 90.1% to 100% with local antimicrobial protection, depending on the technology used. No statistical difference could be found, either considering local antibacterial strategies alone or pooled together. No side effects had been reported by any local antibacterial technique. Local antibacterial protection for one-stage hip revision surgery, although safe and largely performed in the clinical setting, appears to still rely mainly on experts’ opinions with no prospective or comparative trial, hence no definitive conclusion can be drawn concerning its effective role in one-stage hip revision surgery. Full article

The increasing numbers of total joint replacements and related implant-associated infections demand solutions, which can provide a high-dose local delivery of antibiotics. Antibiotic-loaded bone cement (ALBC) is an accepted treatment method for infected joint arthroplasties. The mechanical properties of low-dose gentamicin-loaded bone cement (BC) in medium- and high-viscosity versions were compared to unloaded BC using a vacuum mixing system. As an additional control group, manual mixed unloaded BC was used. In a uniaxial compression test, ultimate compressive strength, compressive yield strength, and compression modulus of elasticity, as well as ultimate and yield strain, were determined according to ISO 5833-2022 guidelines. All groups exceeded the minimum compressive strength (70 MPa) specified in the ISO 5833 guidelines. Both ALBC groups showed a similar ultimate compressive and yield strength to the unloaded BC. The results showed that vacuum mixing increased the compression strength of BC. ALBC showed similar compressive strength to their non-antibiotic counterparts when vacuum mixing was performed. Added low-dose gentamicin acted as a plasticizer on bone cement. From a biomechanical point of view, the usage of gentamicin-based ALBC formulations is viable. Full article