Does cement increase the risk of infection in primary total hip arthroplasty? Revision rates in 56,275 cemented and uncemented primary THAs followed for 0-16 years in the Norwegian Arthroplasty Register

The Epidemiology of the Revision Total Hip Arthroplasty in the United States From 2016 to 2022

Background

The number of revision total hip arthroplasties (THAs) is projected to reach 572,000 cases annually by 2030 in the United States. This may be attributed to the successes of primary THAs combined with an aging population, patients desire to remain active, and expanded indications for younger patients. Given the evolving nature of revision THAs, an epidemiological analysis of (1) etiologies; (2) demographics, including age and region; and (3) lengths of stay (LOSs) may minimize the gap between appropriate understanding and effective intervention.

Methods

From 2016 to 2022, a national, all-payer database was queried. Incidences and indications were analyzed for a total of 102,476 patients who had revision THA procedures. Patients were stratified according to etiology of failure, age, US census region, primary payor class, and mean LOS.

Results

The most common etiologies for revision THA procedures were dislocation (16.7%) and infection (12.7%), followed by periprosthetic fracture (6.9%). The largest age group was 65-74 years (30.9%), followed by >75 years (28.6%), then 55-64 (26.5%). The South had the largest total procedure cohort (36.9%), followed by the Midwest (27.5%), then the Northeast (19.7%), and the West (15.9%). The mean LOS was 4.10 days (range, 1.0-20.0).

Conclusions

Dislocation and infection remain leading indications for revision THA. These findings can properly guide surgeons toward appropriate management as well as toward active steps to minimizing these outcomes.

A Systematic Review Comparing the Outcomes of Cemented Versus Uncemented Stems in Femoral Impaction Bone Grafting for Revision Hip Arthroplasty

Femoral impaction bone grafting is a crucial technique in revision hip arthroplasty, addressing bone loss and ensuring implant stability. The choice between cemented and uncemented stems significantly influences the outcomes and long-term success of the procedure. This systematic review aims to compare the clinical outcomes of cemented versus uncemented stems in femoral impaction bone grafting. A comprehensive search of PubMed, MEDLINE Complete, and the Cochrane Library databases was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies evaluating the outcomes of femoral impaction bone grafting with cemented or uncemented stems were included. The primary outcome measured was the rate of loosening of the femoral component, while secondary outcomes included the incidence of complications such as dislocation, infection, fractures, overall patient mortality, and cardiopulmonary diseases. The literature search yielded 78 articles, with 36 meeting the inclusion criteria. These included one randomized controlled trial, 16 cohort studies (10 retrospective and six prospective), and 15 case series. Most surgeries were revision procedures, with aseptic loosening being the most common indication. For the cemented technique, 1,588 hips were analyzed, with 8.00% experiencing aseptic loosening, 3.53% dislocation, 3.87% infection, 37.33% mortality, 7.57% fractures, and 1.13% cardiopulmonary complications. For the uncemented technique, 464 hips were analyzed, with 1.72% aseptic loosening, 4.74% dislocation, 1.5% infection, 38.47% mortality, 7.76% fractures, and 0.65% cardiopulmonary complications. This systematic review highlights that both cemented and uncemented techniques for femoral impaction bone grafting offer unique benefits and challenges, with the choice depending on patient-specific factors. The uncemented technique, with a lower risk of femoral component loosening, may be better suited for younger, active patients with good bone quality, despite a slightly higher risk of fractures and dislocations. In contrast, the cemented technique, offering immediate stability, is more appropriate for elderly patients with compromised bone quality but carries a higher risk of loosening and cardiopulmonary complications. The decision should be tailored to the patient's clinical profile, including age, bone quality, comorbidities, and the surgeon's expertise.

Cement loaded with high-dose gentamicin and clindamycin does not reduce the risk of subsequent infection after aseptic total hip or knee revision arthroplasty: a preliminary study

PURPOSE

The aim of this study was to quantify the prophylactic effect of high-dose gentamicin and clindamycin antibiotic-loaded bone cement (ALBC) during revision total hip (rTHA) or knee (rTKA) arthroplasty for aseptic reasons. The hypothesis was that the raw surgical site infection (SSI) rate is lower when this particular cement is used in comparison with cement loaded with standard-dose gentamicin during rTHA or rTKA for aseptic reasons.

METHODS

This retrospective study included 290 consecutive patients undergoing aseptic rTHA or rTKA. Two consecutive cohorts were defined: the first (control group) involved 145 patients where ALBC with gentamicin only was used; the second (study group) involved 145 patients where ALBC with high-dose gentamicin and clindamycin was used. The primary endpoint was the raw SSI rate after 24 months.

RESULTS

The raw SSI rate was 8/145 (6%) in the control group and 13/145 (9%) in the study group (odds ratio 0.62, p = 0.26). There was a significant impact of the presence of any risk factor on the SSI rate (15/100 versus 6/169, odds ratio = 4.25, p = 0.002), but no significant impact of any individual risk factor. No complication or side effect related to ALBC was observed in either group.

CONCLUSION

These results do not support the routine use of gentamicin and clindamycin ALBC for fixation of revision implants after rTHA and rTKA for aseptic reasons.

Antibiotic-loaded bone cement is associated with a reduction of the risk of revision of total knee arthroplasty: Analysis of the Catalan Arthroplasty Register

PURPOSE

The purpose of this study was to analyse the impact on peri-prosthetic joint infection (PJI) rate and prosthetic survival using antibiotic-loaded bone cement (ALBC) versus plain cement during total knee arthroplasty (TKA).

METHODS

A retrospective cohort study was conducted. The main data source was the Catalan Arthroplasty Register (RACat). TKAs with surgery date between 1 January 2011 and 31 December 2020 were analysed and followed up until 31 December 2023. The main variable of interest was the type of cement (ALBC vs. plain cement), and several endpoints (septic revision, aseptic revision, and all-cause revision) were considered. The analysed outcomes were revision rates, survival rates and risk factors' hazard ratios (HR).

RESULTS

A total of 22,781 TKAs were analysed, 13,125 (57.6%) of them with plain cement and 9656 (42.4%) with ALBC. The septic revision rate was lower in the ALBC group after 3 months of follow-up (0.52% vs. 0.78%, p value = 0.04). Prosthetic survival with respect to the aseptic revision endpoint was also higher for the ALBC group during the whole follow-up period (~158 months). Regarding risk factors for infection, ALBC showed a protective effect, HR: 0.53 (0.44, 0.63), while sex (being male) and the analysed comorbidities increased the risk.

CONCLUSIONS

ALBC is associated with a reduction in both the septic revision and the aseptic revision rate after TKA, and thus with higher prosthetic survival.

LEVEL OF EVIDENCE

Level III, Therapeutic, retrospective.

Cemented Versus Cementless Femoral Fixation for Total Hip Arthroplasty Following Osteoarthritis

BACKGROUND

The mode of femoral fixation for primary total hip arthroplasty (THA) is undetermined, with reported outcomes favoring different fixation methods. This study aimed to compare postoperative complications between cemented and cementless fixation at 90 days, 1 year, and 2 years in patients aged 65 years of age and older undergoing THA for osteoarthritis.

METHODS

Using an all-payer, national database, patients 65 years and older undergoing primary THA, either with cementless (n = 56,701) or cemented (n = 6,283) femoral fixation for osteoarthritis were identified. A 1:1 propensity-matched analysis for age, sex, comorbidity index, alcohol abuse, tobacco use, obesity, and diabetes was performed, resulting in n = 6,283 patients in each cohort. Postoperative outcomes, including postoperative periprosthetic joint infection, aseptic revision, surgical site infection, pulmonary embolism, venous thromboembolism, wound complications, dislocation, periprosthetic fracture, and aseptic loosening were assessed.

RESULTS

The cemented cohort had higher rates of infection (4.5 versus 0.8%, odds ratio [OR] 5.9, 95% confidence interval [CI] 4.33 to 7.93, P < .001), aseptic revision (2.9 versus 2.0%, OR 1.47, 95% CI 1.17 to 1.85, P = .001), venous thromboembolism (1.8 versus 1.3%, OR 1.40, 95% CI 1.05 to 1.87, P < .001), and aseptic loosening (1.5 versus 0.7%, OR 2.31, 95% CI 1.60 to 3.32, P < .001) at 90-days. At 1 and 2 years, the cemented cohort had higher rates of infection, aseptic revision, and aseptic loosening (all P < .001). Rates of periprosthetic fracture were similar at all time points (all P < .001).

CONCLUSIONS

Cemented fixation had higher rates of infection, aseptic loosening, and aseptic revision. This finding supports the current use of cementless fixation, but the ultimate decision regarding fixation type should be based on the proper optimization of the patient's comorbidities and bone quality.

Antibiotic-loaded cement in total joint arthroplasty: a comprehensive review

This review evaluates the decision-making framework for using antibiotic-loaded cement (ALC) in the management of prosthetic joint infection (PJI). Drawing on available literature, we offer orthopaedic surgeons a guided discussion on several critical considerations. First, we explore the impact of antibiotic-loading on the mechanical properties of polymethylmethacrylate (PMMA) cement, assessing both strength and durability. We then explore the optimal antibiotic dosage to load into cement, aiming to achieve effective local concentrations for infection control without compromising mechanical stability. Furthermore, we explore how cement and antibiotic properties affect the overall antibiotic elution characteristics of ALC. Finally, we discuss risks of systemic toxicity, particularly acute kidney injury, when using ALC. The principal goal in this review is to provide a balanced approach based on best available evidence that optimises antibiotic elution from ALC whilst minimising potential harms associated with its use.

Nanocomposite orthopaedic bone cement combining long-acting dual antimicrobial drugs

Antibiotic loaded bone cements are widely used in total joint replacement (TJR); despite many limitations such as a burst release which leads to antibiotic concentration below inhibitory levels and possibly contributing to the selection of antibiotic resistant strains. In order to address such limitations and to simultaneously address antibiotic resistance and short-term antimicrobial activity, we developed a nanocomposite bone cement capable of providing a controlled release of antimicrobial agents from bone cement to act as prophylaxis or treatment against prosthetic joint infections (PJIs). Gentamicin and chlorhexidine were loaded in combination on silica nanoparticles surface using layer-by-layer coating technique (LbL) combining hydrolysable and non-hydrolysable polymers. The drug release from the nanocomposite continued for >50 days at concentrations higher than the commercial formulation containing the same amount of antimicrobial drugs, where burst release for few days were observed. Moreover, the nanocomposite bone cement showed superior antimicrobial inhibition without adversely affecting the mechanical properties or the ability of osteoblasts to grow. In vivo experiments with an infected bone lesion model along with mass-spectrometric analysis also provided further evidence of efficacy and safety of the implanted nanocomposite material as well as its prolonged drug eluting profile. The developed nanocomposite bone cement has the potential to reduce PJIs and enable treatment of resistant established infections; moreover, the newly developed LbL based nano-delivery system may also have wider applications in reducing the threat posed by antimicrobial resistance.

Incidence and risk factors for surgical site infection (SSI) after primary hip hemiarthroplasty: an analysis of the ACS-NSQIP hip fracture procedure targeted database

INTRODUCTION

Primary hip hemiarthroplasty (HHA) is frequently utilized to treat geriatric hip fractures, which are associated with significantly higher morbidity and mortality. While not particularly common, surgical site infection (SSI) is a major complication that frequently requires revision surgery in a frail population. The objective of this study was to determine the incidence of and risk factors for SSI after HHA in hip fracture patients.

MATERIALS AND METHODS

This retrospective cohort study was performed using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database. Geriatric patients (65+) who underwent HHA for non-pathologic, traumatic hip fractures between 2016-2017 were included. Demographic variables, comorbidities, operative variables, and complications were compared between "SSI" and "non-SSI" groups. Multivariate regression identified independent risk factors for postoperative SSI. Significance was set at P = 0.05.

RESULTS

A total of 6169 patients were included. The overall incidence of SSI was 1.3%. SSI was significantly associated with body mass index (BMI), preoperative functional status, congestive heart failure, chronic corticosteroid use, intraoperative time, sepsis, wound dehiscence, readmission within 30-days, and reoperation. On multivariate analysis, chronic steroid use (OR: 2.30, 95% CI: 1.13-4.70), BMI ≥ 35 kg/m² (OR: 3.59, 95% CI: 1.57-8.18), and intraoperative time ≥120 mins (OR: 2.15, 95% CI: 1.08-4.27) were found to be independent risk factors.

CONCLUSIONS

Postoperative SSI is a serious complication that is responsible for prolonged hospital stays, increased mortality, and greater healthcare costs. Here, we identified multiple risk factors for SSI after primary HHA in the US elderly population.

Influence of surface characteristics of implant materials on MRSA biofilm formation and effects of antimicrobial treatment

Introduction

One of the main causes of treatment failure in bacterial prosthetic joint infections (PJI) is biofilm formation. The topography of the biofilm may be associated with susceptibility to antimicrobial treatment. The aims of this study were to assess differences in topography of biofilms on different implant materials and the correlation thereof with susceptibility to antimicrobial treatment.

Methods

Methicillin-resistant Staphylococcus aureus (MRSA) 7-day mature biofilms were generated on disks made from titanium alloys (Ti-6Al-7Nb and Ti-6Al-4V), synthetic polymer and orthopedic bone cement, commonly used in implant surgery. The surface topography of these implant materials and the biofilms cultured on them was assessed using atomic force microscopy. This provided detailed images, as well as average roughness (Ra) and peak-to-valley roughness (Rt) values in nanometers, of the biofilm and the material surfaces. Bacterial counts within biofilms were assessed microbiologically. Antimicrobial treatment of biofilms was performed by 24-h exposure to the combination of rifampicin and ciprofloxacin in concentrations of 1-, 5- and 10-times the minimal bactericidal concentration (MBC). Finally, treatment-induced differences in bacterial loads and their correlation with biofilm surface parameters were assessed.

Results

The biofilm surfaces on titanium alloys Ti-6Al-7Nb (Ra = 186 nm) and Ti-6Al-4V (Ra = 270 nm) were less rough than those of biofilms on silicone (Ra = 636 nm). The highest roughness was observed for biofilms on orthopedic bone cement with an Ra of 1,551 nm. Interestingly, the roughness parameters of the titanium alloys themselves were lower than the value for silicone, whereas the surface of the bone cement was the roughest. Treatment with 1- and 5-times the MBC of antibiotics resulted in inter-material differences in colony forming units (CFU) counts, ultimately showing comparable reductions of 2.4-3.0 log CFU/mL at the highest tested concentration. No significant differences in bacterial loads within MRSA biofilms were observed between the various implant materials, upon exposure to increasing concentrations of antibiotics.

Discussion

The surface parameters of MRSA biofilms were determined by those of the implant materials on which they were formed. The antibiotic susceptibility of MRSA biofilms on the various tested implant materials did not differ, indicating that the efficacy of antibiotics was not affected by the roughness of the biofilm.

Patients at a high risk of PJI: Can we reduce the incidence of infection using dual antibiotic-loaded bone cement?

Prosthetic joint infection (PJI) is one of the most devastating complications of orthopedic surgery. However, not all patients are equally at the risk of severe infection. The incidences of PJI vary with the host and surgery-related risk factors. It is now generally accepted that some important medical comorbidities may predispose the patients to a high risk of PJI. Time-consuming and invasive surgical procedures, such as revision arthroplasties, are also associated with a high incidence of PJI, presumably due to the increased risk of surgical site contamination. Effective infection-preventing strategies should begin with identifying and optimizing the patients at a high risk of infection prior to surgery. Optimizing the operating room environment and antibiotic prophylaxis are also essential strategies that help minimize the overall incidence of infection in orthopedic surgery. The ideal antibiotic prophylaxis is still under debate, and discussions have emerged about whether variations or adjustments to the standard protocol are justified in patients at a high risk of infection. This also includes evaluating the possible benefits and risks of using high-dose dual antibiotic-loaded bone cement instead of low-dose single antibiotic-loaded bone cement in arthroplasty. This review summarizes the evidence showing that the combination of two local antibiotics in bone cement exerts a strong and longer-lasting antimicrobial effect against PJI-associated pathogens. This conclusion is consistent with the preliminary clinical studies showing a low incidence of PJI in high-risk patients undergoing cemented hemiarthroplasty, cemented revision, and primary arthroplasty if dual ALBC is used. These results may encourage clinicians to consolidate this hypothesis in a wider clinical range.

Risk factors for prosthetic joint infections following total hip arthroplasty based on 33,337 hips in the Finnish Arthroplasty Register from 2014 to 2018

Background and purpose - Periprosthetic joint infection (PJI) is a devastating complication and more information on risk factors for PJI is required to find measures to prevent infections. Therefore, we assessed risk factors for PJI after primary total hip arthroplasty (THA) in a large patient cohort.Patients and methods - We analyzed 33,337 primary THAs performed between May 2014 and January 2018 based on the Finnish Arthroplasty Register (FAR). Cox proportional hazards regression was used to estimate hazard ratios with 95% confidence intervals (CI) for first PJI revision operation using 25 potential patient- and surgical-related risk factors as covariates.Results - 350 primary THAs were revised for the first time due to PJI during the study period. The hazard ratios for PJI revision in multivariable analysis were 2.0 (CI 1.3-3.2) for ASA class II and 3.2 (2.0-5.1) for ASA class III-IV compared with ASA class I, 1.4 (1.1-1.7) for bleeding > 500 mL compared with < 500 mL, 0.4 (0.2-0.7) for ceramic-on-ceramic bearing couple compared with metal-on-polyethylene and for the first 3 postoperative weeks, 3.0 (1.6-5.6) for operation time of > 120 minutes compared with 45-59 minutes, and 2.6 (1.4-4.9) for simultaneous bilateral operation. In the univariable analysis, hazard ratios for PJI revision were 2.3 (1.7-3.3) for BMI of 31-35 and 5.0 (3.5-7.1) for BMI of > 35 compared with patients with BMI of 21-25.Interpretation - We found several modifiable risk factors associated with increased PJI revision risk after THA to which special attention should be paid preoperatively. In particular, high BMI may be an even more prominent risk factor for PJI than previously assessed.

Uncemented versus cemented total hip arthroplasty for displaced femoral neck fractures in elderly patients with osteoporosis: A retrospective analysis

OBJECTIVE

This study was performed assess the clinical outcomes of elderly patients with osteoporotic femoral neck fractures (FNFs) (AO/OTA: 31B/C) treated by initial uncemented total hip arthroplasty (UTA) or cemented total hip arthroplasty (CTA).

METHODS

This study involved consecutive elderly patients with osteoporotic FNFs (AO/OTA: 31B/C) treated by initial UTA or CTA in our medical centre from 2010 to 2015. The primary outcomes were the Harris hip score (HHS) and the rates of revision, loosening, periprosthetic fracture, and dislocation.

RESULTS

In total, 224 patients were included in the final analysis (UTA, n = 114; CTA, n = 110). The mean follow-up duration was 60 months (range, 32-68 months). The mean HHS was 75.34 ± 18.82 for UTA and 80.12 ± 17.83 for CTA. Significant dissimilarities were detected in the rates of revision, loosening, and periprosthetic fracture between UTA and CTA (14.0% vs. 5.5%, 20.2% vs. 10.0%, and 12.3% vs. 4.5%, respectively). A significant difference was also detected in the probability of revision between the two groups.

CONCLUSION

Elderly patients with osteoporotic FNFs (AO/OTA: 31B/C) treated with CTA show greater improvements in functional outcomes and key orthopaedic complications than those treated with UTA.

Long-term survival after cemented versus uncemented total hip arthroplasty for treatment of acute femoral neck fracture: a retrospective study with a mean 10-year follow-up

Objective

To compare the long-term survivorship and Harris hip scores (HHSs) between cemented total hip arthroplasty (CTHA) and uncemented total hip arthroplasty (UTHA) for treatment of acute femoral neck fractures (FNFs).

Methods

Data of 224 hips (CTHA, n = 112; UTHA, n = 112) that underwent primary surgery in our medical institution from 2005 to 2017 were retrospectively analysed. The primary endpoint was the risk of all-cause revision. The difference in the risk of all-cause revision between the two groups was assessed by Kaplan–Meier survival analysis with a log-rank test and Cox regression analysis.

Results

The mean postoperative follow-up was 10 years (range, 3–13 years). The Kaplan–Meier estimated 10-year implant survival rate was significantly higher in the CTHA than UTHA group (98.1% vs. 96.2%, respectively). The adjusted Cox regression analysis demonstrated a significantly lower risk of revision in the CTHA than UTHA group. At the final follow-up, the mean HHS was significantly higher in the CTHA than UTHA group (85.10 vs. 79.11, respectively).

Conclusion

This retrospective analysis demonstrated that CTHA provided higher survival, lower revision risk, and higher functional outcome scores than UTHA. Further follow-up is necessary to verify whether these advantages of CTHA persist over time.

Is serum gentamicin concentration modified with autologous cell-saved blood transfusion after total knee arthroplasty using tranexamic acid? A randomised control trial

BACKGROUND

Self-transfusion has been proven as an effective management of blood loss after total knee arthroplasty (TKA). Considering that the high local concentration of antibiotic from bone cement is delivered intravenously through the self-transfusion process, systematic toxicity has never been evaluated. In addition, the effectiveness of self-transfusion with the routine concomitant use of other modern blood-salvage strategies, like tranexamic acid, should also be assessed. Therefore, we performed a randomised study to assess: 1) the safety of self-transfusion in TKA by comparing the gentamicin concentrations resulting from the use or not of autologous blood transfusion; 2) the efficacy of self-transfusion in TKA, with the concomitant administration of tranexamic acid.

HYPOTHESIS

Self-transfusion in TKA elevates the serum gentamicin concentration and the potential risk of nephrotoxicity.

METHODS

The serum concentration of aminoglycosides was measured in two groups of 20 patients each, after TKA, according to the use of self-transfusion. Hemoglobin, renal function and calculated blood loss were compared at several points in time between groups.

RESULTS

The only time where there was a statistically significant difference in serum gentamicin, was at 48h postoperatively between groups [0.3 ug/mL±0.21, range: 0.15 to 0.72 vs. 0.14ug/mL±0.1, range: 0 to 0.35 (p=0.02)]. There were no significant differences in total blood loss [1341mL±501, range: 830 to 2230 vs. 1263mL±459 range: 840 to 2480 (p=0.67)] and need of allogeneic blood transfusion [3 units vs. 2 units] between groups.

CONCLUSION

The use of autologous blood transfusion was found to be safe, in terms of nephrotoxicity of aminoglycosides after TKA, but it seemed to be ineffective as a blood salvage strategy, when used concomitantly with the administration of tranexamic acid.

LEVEL OF EVIDENCE

II; low-powered randomised study. CLINICALTRIALS.

GOV REGISTRATION NUMBER

NCT04505748.

Adjuvant antibiotic-loaded bone cement: Concerns with current use and research to make it work

Antibiotic-loaded bone cement (ALBC) is broadly used to treat orthopaedic infections based on the rationale that high-dose local delivery is essential to eradicate biofilm-associated bacteria. However, ALBC formulations are empirically based on drug susceptibility from routine laboratory testing, which is known to have limited clinical relevance for biofilms. There are also dosing concerns with nonstandardized, surgeon-directed, hand-mixed formulations, which have unknown release kinetics. On the basis of our knowledge of in vivo biofilms, pathogen virulence, safety issues with nonstandardized ALBC formulations, and questions about the cost-effectiveness of ALBC, there is a need to evaluate the evidence for this clinical practice. To this end, thought leaders in the field of musculoskeletal infection (MSKI) met on 1 August 2019 to review and debate published and anecdotal information, which highlighted four major concerns about current ALBC use: (a) substantial lack of level 1 evidence to demonstrate efficacy; (b) ALBC formulations become subtherapeutic following early release, which risks induction of antibiotic resistance, and exacerbated infection from microbial colonization of the carrier; (c) the absence of standardized formulation protocols, and Food and Drug Administration-approved high-dose ALBC products to use following resection in MSKI treatment; and (d) absence of a validated assay to determine the minimum biofilm eradication concentration to predict ALBC efficacy against patient specific micro-organisms. Here, we describe these concerns in detail, and propose areas in need of research.

Antibiotic-Loaded Bone Cement in Prevention of Periprosthetic Joint Infections in Primary Total Knee Arthroplasty: A Register-based Multicentre Randomised Controlled Non-inferiority Trial (ALBA trial)

INTRODUCTION

The current evidence on the efficacy of antibiotic-loaded bone cement (ALBC) in reducing the risk of periprosthetic joint infections (PJI) after primary joint reconstruction is insufficient. In several European countries, the use of ALBC is routine practice unlike in the USA where ALBC use is not approved in low-risk patients. Therefore, we designed a double-blinded pragmatic multicentre register-based randomised controlled non-inferiority trial to investigate the effects of ALBC compared with plain bone cement in primary total knee arthroplasty (TKA).

METHODS AND ANALYSIS

A minimum of 9,172 patients undergoing full-cemented primary TKA will be recruited and equally randomised into the ALBC group and the plain bone cement group. This trial will be conducted in Norwegian hospitals that routinely perform cemented primary TKA. The primary outcome will be risk of revision surgery due to PJI at 1-year of follow-up. Secondary outcomes will be: risk of revision due to any reason including aseptic loosening at 1, 6, 10 and 20 years of follow-up; patient-related outcome measures like function, pain, satisfaction and health-related quality of life at 1, 6 and 10 years of follow-up; risk of changes in the microbial pattern and resistance profiles of organisms cultured in subsequent revisions at 1, 6, 10 and 20 years of follow-up; cost-effectiveness of routine ALBC versus plain bone cement use in primary TKA. We will use 1:1 randomisation with random permuted blocks and stratify by participating hospitals to randomise patients to receive ALBC or plain bone cement. Inclusion, randomisation and follow-up will be through the Norwegian Arthroplasty Register.

ETHICS AND DISSEMINATION

The trial was approved by the Western Norway Regional Committees on Medical and Health Research Ethics (reference number: 2019/751/REK vest) on 21 June 2019. The findings of this trial will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04135170.

Methicillin-Resistant Staphylococcus epidermidis Lineages in the Nasal and Skin Microbiota of Patients Planned for Arthroplasty Surgery

Staphylococcus epidermidis, ubiquitous in the human nasal and skin microbiota, is a common causative microorganism in prosthetic joint infections (PJIs). A high proportion of PJI isolates have been shown to harbor genetic traits associated with resistance to/tolerance of agents used for antimicrobial prophylaxis in joint arthroplasties. These traits were found within multidrug-resistant S. epidermidis (MDRSE) lineages of multiple genetic backgrounds. In this study, the aim was to study whether MDRSE lineages previously associated with PJIs are present in the nasal and skin microbiota of patients planned for arthroplasty surgery but before hospitalization. We cultured samples from nares, inguinal creases, and skin over the hip or knee (dependent on the planned procedure) taken two weeks (median) prior to admittance to the hospital for total joint arthroplasty from 66 patients on agar plates selecting for methicillin resistance. S. epidermidis colonies were identified and tested for the presence of mecA. Methicillin-resistant S. epidermidis (MRSE) were characterized by Illumina-based whole-genome sequencing. Using this method, we found that 30/66 (45%) of patients were colonized with MRSE at 1–3 body sites. A subset of patients, 10/66 (15%), were colonized with MDRSE lineages associated with PJIs. The qacA gene was identified in MRSE isolates from 19/30 (63%) of MRSE colonized patients, whereas genes associated with aminoglycoside resistance were less common, found in 11/30 (37%). We found that MDRSE lineages previously associated with PJIs were present in a subset of patients’ pre-admission microbiota, plausibly in low relative abundance, and may be selected for by the current prophylaxis regimen comprising whole-body cleansing with chlorhexidine-gluconate containing soap. To further lower the rate of S. epidermidis PJIs, the current prophylaxis may need to be modified, but it is important for possible perioperative MDRSE transmission events and specific risk factors for MDRSE PJIs to be investigated before reevaluating antimicrobial prophylaxis.

The effect of antibiotic-loaded bone cement on risk of revision following hip and knee arthroplasty

AIMS

This study aimed to compare the effect of antibiotic-loaded bone cement (ALBC) versus plain bone cement (PBC) on revision rates for periprosthetic joint infection (PJI) and all-cause revisions following primary elective total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

MEDLINE, Embase, Web of Science, and Cochrane databases were systematically searched for studies comparing ALBC versus PBC, reporting on revision rates for PJI or all-cause revision following primary elective THA or TKA. A random-effects meta-analysis was performed. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID CRD42018107691).

RESULTS

Nine studies and one registry report were identified, enabling the inclusion of 371,977 THA and 671,246 TKA. Pooled analysis for THA demonstrated ALBC was protective against revision for PJI compared with PBC (relative risk (RR) 0.66, 95% confidence interval (CI) 0.56 to 0.77; p < 0.001), however, no differences were seen for all-cause revision rate (RR 0.62, 95% CI 0.35 to 1.09; p = 0.100). For TKA, there were no significant differences in revision rates for PJI or all causes between ALBC and PBC (RR 0.92, 95% CI 0.59 to 1.45; p = 0.730, and RR 0.73, 95% CI 0.53 to 1.02; p = 0.060, respectively).

CONCLUSION

ALBC demonstrated a protective effect against revision for PJI compared with PBC in THA with no difference in all-cause revisions. No differences in revision rates for PJI and all-cause revision between ALBC and PBC for TKA were observed. Cite this article: Bone Joint J 2021;103-B(1):7-15.

Antibiotics in Bone Cements Used for Prosthesis Fixation: An Efficient Way to Prevent Staphylococcus aureus and Staphylococcus epidermidis Prosthetic Joint Infection

Prosthetic joint infections (PJIs) are one of the most frequent reasons for arthroplasty revision. These infections are mostly associated with the formation of biofilm, notably by staphylococci, such as Staphylococcus aureus and Staphylococcus epidermidis. To minimize the rates of PJIs following primary or revision total joint arthroplasty, antibiotic-loaded bone cements (ALBCs) can be used for prosthesis fixation. However, its use is still debated. Indeed, various studies reported opposite results. In this context, we aimed to compare the prophylactic anti-biofilm activity of ALBCs loaded with two antibiotics with ALBC loaded with only one antibiotic. We compared commercial ready-to-use cements containing gentamicin alone, gentamicin plus vancomycin, and gentamicin plus clindamycin to plain cement (no antibiotic), investigating staphylococcal biofilm formation for 10 strains of S. aureus and S. epidermidis with specific resistance to gentamicin, vancomycin, or clindamycin. Firstly, we performed disk diffusion assays with the elution solutions. We reported that only the cement containing gentamicin and clindamycin was able to inhibit bacterial growth at Day 9, whereas cements with gentamicin only or gentamicin and vancomycin lost their antibacterial activity at Day 3. Then, we observed that all the tested ALBCs can inhibit biofilm formation by methicillin-susceptible staphylococci without other antibiotic resistance ability. Similar results were observed when we tested vancomycin-resistant or clindamycin-resistant staphylococci, with some strain-dependent significant increase of efficacy for the two antibiotic ALBCs when compared with gentamicin-loaded cement. However, adding vancomycin or clindamycin to gentamicin allows a better inhibition of biofilm formation when gentamicin-resistant strains were used. Our in vitro results suggest that using commercially available bone cements loaded with gentamicin plus vancomycin or clindamycin for prosthesis fixation can help in preventing staphylococcal PJIs following primary arthroplasties, non-septic revisions or septic revisions, especially to prevent PJIs caused by gentamicin-resistant staphylococci.

The Impact of Antibiotic-Loaded Bone Cement on Antibiotic Resistance in Periprosthetic Knee Infections

Backgroud

Antibiotic-loaded bone cement (ALBC) is commonly used in total knee arthroplasty (TKA), especially among high-risk patients. While previous studies have reported on the efficacy of ALBC in reducing the rate of periprosthetic joint infection (PJI), its impact on antibiotic resistance has not been determined. The purpose of this study was to investigate antibiotic resistance among organisms causing PJIs after TKA in which ALBC was utilized.

Methods

A retrospective review from December 1998 through December 2017 identified 36 PJIs that met inclusion criteria. Patients with culture-negative infection and unknown cement type were excluded. Patient characteristics, infecting organism, and antibiotic susceptibilities were recorded. ABLC included an aminoglycoside in all cases.

Results

There was no difference in the type of PJI between the 2 groups. Staphylococcus species was the most commonly isolated, with 9 of 16 cases (56.3%) using non-ALBC and 14 of 20 (65.0%) cases using ALBC. Of those infected with Staphylococcus, there was no significant difference in antibiotic susceptibilities between groups. Overall, there were only 3 cases where the infecting organism was aminoglycoside resistant (standard cement, 1; ALBC, 2).

Conclusions

These results suggest that the use of ALBC does not increase the risk of antibiotic resistance or affect the pattern of infection, even as the use of ALBC continues to increase, particularly among high-risk patients.

Risk Factors for Periprosthetic Joint Infection Following Primary Total Hip Arthroplasty: A 15-Year, Population-Based Cohort Study

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most devastating complications following total hip arthroplasty. The purposes of this study were to determine risk factors for PJI after primary total hip arthroplasty for osteoarthritis using a Canadian population-based database collected over 15 years and to determine the incidence of PJI, the time to PJI following primary total hip arthroplasty, and whether the PJI rate had changed over 15 years.

METHODS

We performed a population-based cohort study using linked administrative databases in Ontario. We included all primary total hip arthroplasties performed for osteoarthritis in patients who were ≥55 years of age. We used a Cox proportional hazards model to analyze the effect of surgical and patient factors on the risk of developing PJI. We calculated 1, 2, 5, and 10-year PJI rates. We used the Cochran-Armitage test to assess the evidence of trends in PJI rates over time.

RESULTS

A total of 100,674 patients who were ≥55 years of age underwent a primary total hip arthroplasty for osteoarthritis. The cumulative incidence for PJI at 15 years was 1.44% (95% confidence interval [CI], 1.38% to 1.50%). Risk factors associated with the development of PJI include male sex (hazard ratio [HR], 1.43 [95% CI, 1.30 to 1.51]), type-2 diabetes mellitus (HR, 1.51 [95% CI, 1.31 to 1.70]), and being discharged to convalescent care (HR, 1.36 [95% CI, 1.05 to 1.77]). Sixty-two percent of PJI cases occurred within 2 years after the surgical procedure and 98% occurred within 10 years. The rate of PJI following primary total hip arthroplasty did not change over the 15 years of our study period.

CONCLUSIONS

The risk of developing PJI following primary total hip arthroplasty did not change in 15 years, despite improvements in other arthroplasty outcomes. Male sex, type-2 diabetes mellitus, and discharge to convalescent care were associated with an increased risk of PJI. The surgical approach, income quintile, and use of bone-grafting or cement were not significantly associated with increased risk of infection in our cohort.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Consensus statement for perioperative care in total hip replacement and total knee replacement surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations

Background and purpose - There is a large volume of heterogeneous studies across all Enhanced Recovery After Surgery (ERAS®) components within total hip and total knee replacement surgery. This multidisciplinary consensus review summarizes the literature, and proposes recommendations for the perioperative care of patients undergoing total hip replacement and total knee replacement with an ERAS program.Methods - Studies were selected with particular attention being paid to meta-analyses, randomized controlled trials, and large prospective cohort studies that evaluated the efficacy of individual items of the perioperative treatment pathway to expedite the achievement of discharge criteria. A consensus recommendation was reached by the group after critical appraisal of the literature.Results - This consensus statement includes 17 topic areas. Best practice includes optimizing preoperative patient education, anesthetic technique, and transfusion strategy, in combination with an opioid-sparing multimodal analgesic approach and early mobilization. There is insufficient evidence to recommend that one surgical technique (type of approach, use of a minimally invasive technique, prosthesis choice, or use of computer-assisted surgery) over another will independently effect achievement of discharge criteria.Interpretation - Based on the evidence available for each element of perioperative care pathways, the ERAS® Society presents a comprehensive consensus review, for the perioperative care of patients undergoing total hip replacement and total knee replacement surgery within an ERAS® program. This unified protocol should now be further evaluated in order to refine the protocol and verify the strength of these recommendations.

3D-additive deposition of an antibacterial and osteogenic silicon nitride coating on orthopaedic titanium substrate

A 3D-additive manufacturing approach produced a dense Si₃N₄ ceramic coating on a biomedical grade commercially pure titanium (cp-Ti) substrate by an automatic laser-sintering procedure. Si₃N₄ coatings could be prepared with thicknesses from the single to the tens of microns. A coating thickness, t = 15 ± 5 μm, was selected for this study, based on projections of homogeneity and scratching resistance. The Si₃N₄ coating met the 20 N threshold required for biomaterial applications, according to the standard scratch testing (ASTM C1624-05). The Si₃N₄ coating imparted both the antibacterial and osteogenic properties of bulk Si₃N₄ to the cp-Ti substrate. Both properties were comparable to those previously described for bulk Si₃N₄ biomedical implants. The newly developed Si₃N₄-coating was applied to commercially available Ti-alloy acetabular shells for total hip arthroplasty. A "glowing" test based on luciferase gene transformation was applied to visualize the colonization of gram-negative Escherichia coli on Si₃N₄-coated and uncoated Ti-alloy acetabular shells. The results showed that the coating technology conferred resistance to Staphylococcus epidermidis and Escherichia coli adhesion onto the bulk acetabular sockets.

The Economics of Antibiotic Cement in Total Knee Arthroplasty: Added Cost with No Reduction in Infection Rates

BACKGROUND

To reduce the substantial clinical and financial burden of periprosthetic joint infection (PJI), some surgeons advocate for the use of antibiotic-loaded bone cement (ALBC) in primary total knee arthroplasty (TKA), although its effectiveness continues to be debated in the literature. The purpose of this study was to determine whether the routine use of ALBC is cost-effective in reducing PJI after primary TKA.

METHODS

We retrospectively reviewed a consecutive series of patients undergoing cemented primary TKA at two hospitals within our institution from 2015 to 2017. We compared demographics, comorbidities, costs, and PJI rates between patients receiving ALBC and plain cement. We performed a multivariate regression analysis to determine the independent effect of ALBC on PJI rate. We calculated readmission costs for PJI and reduction in PJI needed to justify the added cost of ALBC.

RESULTS

Of 2511 patients, 1077 underwent TKA with ALBC (43%), with no difference in PJI rates (0.56% vs 0.14%, P = .0662) or complications (1.2% vs 1.6%, P = .3968) but higher cement costs ($416 vs $117, P < .0001) and overall procedure costs ($6445 vs $5.968, P < .0001). ALBC had no effect on infection rate (P = .0894). Patients readmitted with PJI had higher overall 90-day episode-of-care claims costs ($49,341 vs $19,032, P < .001). To justify additional costs, ALBC would need to prevent infection in one of every 101 patients.

CONCLUSION

Routine use of ALBC in primary TKA is not cost-effective, adding $299 to the cost of episode of care without a reduction in PJI rate. Further study is needed to determine whether select use of ALBC would be justified in high-risk patients.

Influence of Fixation Methods on Prosthetic Joint Infection Following Primary Total Knee Replacement: Meta-Analysis of Observational Cohort and Randomised Intervention Studies

The type of fixation used in primary total knee replacement (TKR) may influence the risk of prosthetic joint infection (PJI). We conducted a systematic review and meta-analysis to assess published evidence linking type of fixation (cemented, uncemented, or hybrid) with the risk of PJI following primary TKR. Randomised controlled trials (RCTs) and observational cohort studies comparing fixation methods and reporting PJI incidence following primary TKR were identified in MEDLINE, Embase, Web of Science, and Cochrane Library up until November 2018. Summary measures were relative risks (RR) with 95% confidence intervals (CIs). We identified 32 eligible articles (24 observational studies and 8 RCTs) involving 1,161,292 TKRs. In pooled analysis of observational studies, uncemented fixation was associated with a decreased overall PJI risk when compared with cemented fixation at 0.76 (0.64–0.89). Comparing antibiotic-loaded cemented fixation with plain cement, there was no significant difference in overall PJI risk at 0.95 (0.69–1.31), but PJI risk was increased in the first 6-month postoperative period to 1.65 (1.12–2.43). Limited data from RCTs showed no differences in PJI risk among the fixation types. Observational evidence suggests uncemented fixation may be associated with lower PJI risk in primary TKR when compared with cemented fixation. In the early postoperative period, antibiotic-loaded cemented fixation may be associated with increased PJI risk when compared with plain cement. This may either reflect appropriate selection of higher risk patients for the development of PJI to cemented and antibiotic-loaded cement or may reflect a lower PJI risk in uncemented TKR due to factors such as shorter operative time.

Implant Fixation and Risk of Prosthetic Joint Infection Following Primary Total Hip Replacement: Meta-Analysis of Observational Cohort and Randomised Intervention Studies

Prosthetic joint infection (PJI), although uncommon, is a dreaded and devastating complication of total hip replacement (THR). Whether implant-related factors, such as the fixation method, influences the risk of PJI following THR is contentious. We conducted a systematic review and meta-analysis to evaluate the body of evidence linking fixation methods (cemented, uncemented, hybrid, or reverse hybrid) with the risk of PJI following primary THR. Observational studies and randomised controlled trials (RCTs) comparing fixation methods, and reporting PJI incidence following THR, were identified through MEDLINE, Embase, Web of Science, Cochrane Library, and reference lists of relevant studies up to 24 April 2019. Summary measures were relative risks (RRs) (95% confidence intervals, CIs). We identified 22 eligible articles (based on 11 distinct observational cohort studies comprising 2,260,428 THRs and 4 RCTs comprising 945 THRs). In pooled analyses of observational studies, all cemented fixations (plain and antibiotic combined), plain cemented fixations, hybrid fixations, and reverse hybrid fixations were each associated with an increased overall PJI risk when compared with uncemented fixations: 1.10 (95% CI: 1.04–1.17), 1.50 (95% CI: 1.27–1.77), 1.49 (95% CI: 1.36–1.64), and 1.49 (95% CI: 1.14–1.95), respectively. However, in the first six months, uncemented fixations were associated with increased PJI risk when compared to all cemented fixations. Compared to antibiotic-loaded cemented fixations, plain cemented fixations were associated with an increased PJI risk (1.52; 95% CI: 1.36–1.70). One RCT showed an increased PJI risk comparing plain cemented fixations with antibiotic-loaded cemented fixations. Uncemented and antibiotic-loaded cemented fixations remain options for the prevention of PJI in primary THR.

Studying Biofilm and Clinical Issues in Orthopedics

The association between biofilm-forming microorganisms and prosthetic joint infection influences all aspect of management including approaches to diagnosis, management and prevention. This article will provide an overview of new anti-biofilm strategies for management of prosthetic joint infection.

Staphylococcal resistance profiles in deep infection following primary hip and knee arthroplasty: a study using the NJR dataset

INTRODUCTION

This study aimed to (1) report the rates of resistance against a variety of antibiotics for pure Staphylococcal infections, and (2) examine the impact of ALBC use at primary surgery has on resistance patterns for patients undergoing first-time revision of primary hip and knee arthroplasty for indication of infection.

MATERIALS AND METHODS

Data from the National Joint Registry database for England and Wales were linked to microbiology data held by Public Health England to identify a consecutive series of 258 primary hip and knee arthroplasties performed between April 2003 and January 2014 that went on to have a revision for Staphylococcal deep periprosthetic infection. Multivariate binary logistic regression was used to study predictors of microorganism resistance to a range of antimicrobials.

RESULTS

After adjusting for patient and surgical factors, multivariate analysis showed the use of gentamicin-loaded bone cement at the primary surgery was associated with a significant increase in the risk of Staphylococcal gentamicin resistance (odds ratio 8.341, 95% CI 2.297-30.292, p = 0.001) and methicillin resistance (odds ratio 3.870, 95% CI 1.319-11.359, p = 0.014) at revision for infection.

CONCLUSIONS

Clinicians must anticipate the possibility of antibiotic resistance to ALBC utilised at primary surgery.

Antibiotic-laden Bone Cement in Primary and Revision Hip and Knee Arthroplasty

Antibiotic-laden bone cement (ALBC) has a number of different uses in primary and revision total joint arthroplasty. However, considerable controversy remains regarding how and when it is best used. The prophylactic use of low-dose ALBC in primary cemented total hip arthroplasty is well supported by the literature, conferring both clinical and economic benefits. In contrast, conclusive evidence on the clinical efficacy or economic benefit of the routine use of ALBC in primary total knee arthroplasty remains elusive. Given the currently available evidence, we cannot determine definitively whether the routine use of ALBC in primary total knee arthroplasty is justified, although selective use in patients with a high risk of infection seems warranted. The routine use of ALBC in revision total joint arthroplasty is well accepted, with good supporting evidence in studies of both aseptic and first-stage revision procedures. Although limited clinical evidence exists on the use of ALBC at the time of definitive component reimplantation after septic revision, the rationale for its use is strong.

Enhanced recovery after surgery for primary hip and knee arthroplasty: a review of the evidence

Enhanced recovery after surgery (ERAS) protocols produce significant clinical and economic benefits in a range of surgical subspecialties. There is a long tradition of applying clinical pathways to the perioperative care of joint arthroplasty patients. Enhanced recovery after surgery represents the next step in the evolution of standardized care. To date, reports of full ERAS pathways for hip or knee arthroplasty are lacking. In this narrative review, we present the evidence base that can be usefully applied to constructing ERAS pathways for hip or knee arthroplasty. The history and rationale for applying ERAS to joint arthroplasty are explained. Evidence demonstrates improved outcomes after joint arthroplasty when a standardized approach to care is implemented. The efficacy of individual ERAS components in hip or knee replacement is considered, including preoperative education, intraoperative anaesthetic techniques, postoperative analgesia, and early mobilization after joint arthroplasty. Interventions lacking high-quality evidence are identified, together with recommendations for future research. Based on currently available evidence, we present a model ERAS pathway that can be applied to perioperative care of patients undergoing hip or knee arthroplasty.

Cementless Stem for Femoral Neck Fractures in a Patient’s 10th Decade of Life: High Rate of Periprosthetic Fractures

Background:

Subsidence of cementless femoral stems in hemiarthroplasty (HA) and increased fracture rates are ongoing concerns of orthopedic surgeons when treating fractures in very old patients. Additionally, bone cement implantation syndrome may result in perioperative cardiac or pulmonary complications, especially in older patients, leading to morbidity and mortality. This study was performed to analyze possible subsidence and intraoperative fractures in a cohort of very old patients treated with cementless stems.

Methods:

We retrospectively analyzed a consecutive cohort of patients aged ≥90 years with femoral neck fractures treated by uncemented HA and an anterior minimally invasive approach. Immediate full-weight bearing was allowed postoperatively. Pelvic radiographs were examined for subsidence immediately postoperatively and 6 weeks later.

Results:

We treated 109 patients (74% women; mean age, 93 years; range, 90-102 years) by HA from January 2010 to March 2016. The 30-day mortality rate was 16%, and the morbidity rate was 47%. There were 11 (12%) intraoperative fractures: 8 (Vancouver B₂) had to be addressed immediately during the primary operation, while 3 (1 Vancouver B₁ and 2 Vancouver A_G) were treated conservatively. One periprosthetic femoral fracture (Vancouver B₁) was documented during follow-up. In 17 patients, subsidence of >2.0 mm (median, 3.9 mm; range, 2.5-9.0 mm) was documented.

Conclusion:

Early subsidence was low in this very old cohort treated with an uncemented stem and not showing a periprosthetic fracture. The risk of intraoperative periprosthetic fractures was high. The use of uncemented implants in osteoporotic bone continues to be an intervention with high risk and should only be performed by experienced surgeons.

Level of Evidence:

Level III, Therapeutic study.

Nano-carrier based drug delivery systems for sustained antimicrobial agent release from orthopaedic cementous material

Total joint replacement (TJR), such as hip and knee replacement, is a popular procedure worldwide. Prosthetic joint infections (PJI) after this procedure have been widely reported, where treatment of such infections is complex with high cost and prolonged hospital stay. In cemented arthroplasties, the use of antibiotic loaded bone cement (ALBC) is a standard practice for the prophylaxis and treatment of PJI. Recently, the development of bacterial resistance by pathogenic microorganisms against most commonly used antibiotics increased the interest in alternative approaches for antimicrobial delivery systems such as nanotechnology. This review summarizes the efforts made to improve the antimicrobial properties of PMMA bone cements using nanotechnology based antibiotic and non-antibiotic delivery systems to overcome drawbacks of ALBC in the prophylaxis and treatment of PJIs after hip and knee replacement.

In vivo serum concentration of vancomycin in antibiotic-loaded acrylic cement for the treatment and prevention of periprosthetic hip infection

BACKGROUND

Although antibiotic-loaded acrylic cement (ALAC) is used to prevent and treat periprosthetic hip infection, it is unknown how much antibiotic is deposited in the body in vivo, how high the serum concentration rises, or how long its effects last. The aim of this study was firstly to determine the amount of vancomycin (VCM) deposited as ALAC in the body, and secondly to assess the safety and drug elution profile of VCM in ALAC.

METHODS

We administered VCM to prevent infection after total hip arthroplasty (THA) or to treat patients with methicillin-resistant Staphylococcus aureus. Patients were classified into two groups: a low-dose group (21 hips) that received primary THA for high-risk cases, revision THA without infection, or one-staged revision THA for infection; and a high-dose group (6 hips) that received cement beads during a two-staged revision THA. The amount of VCM placed as ALAC into the hip was calculated using the remaining ALAC. The serum concentrations of VCM and creatinine were evaluated at postoperative days 1, 4, 7, 14, and 28, and at 3 and 6 months.

RESULTS

The mean amount of VCM placed as ALAC into the hip was 0.9 g and 3.4 g for cemented THA and cement beads, respectively (P < 0.0001). The mean serum concentration of VCM from ALAC in the high-dose group was significantly increased compared with that in the low-dose group on postoperative days 1, 4, 7, 14, and 28 (P < 0.0001), but it remained within a clinically safe range. No significant differences were observed between the preoperative and postoperative serum creatinine levels of either group.

CONCLUSION

The average serum concentrations of VCM from ALAC were always less than the effective blood concentration, and were detectable until 6 months after surgery.

Is the Commercial Antibiotic-Loaded Bone Cement Useful in Prophylaxis and Cost Saving After Knee and Hip Joint Arthroplasty? The Transatlantic Paradox

BACKGROUND

The use of antibiotic-loaded bone cement (ALBC) has proven to be effective in preventing periprosthetic infection (PPI) after total hip (THA) and knee arthroplasty (TKA). However, the economic benefit of using ALBC routinely remains controversial.

METHODS

A total of 2518 patients subjected to THA, partial hip arthroplasty, and TKA between 2009 and 2012 were identified in our prospectively collected registry. Two groups were defined: before (2009-2010) and after the introduction of ALBC (2011-2012). The risks of PPI associated with each type of surgery in each group were determined and compared. Patients subjected to THA without cemented implants were used as controls, and possible bias associated with changes in infection rate during the study period and other variables were controlled. The costs of the use of ALBC were calculated, along with the savings per case of PPI avoided. The minimum follow-up for discarding PPI was 2 years.

RESULTS

Following the introduction of ALBC, a global decrease of 57% was observed in the risk of PPI (P = .001). By type of surgery, the decrease was 60.6% in the case of TKA (P = .019) and 72.6% in the case of cemented hip arthroplasty (partial and total; P = .009). No decrease in infection rate was noted in uncemented hip arthroplasty (P = .42). The total saving associated with the use of ALBC was €1,123,846 (€992 per patient): €440,412 after TKA (€801 per patient) and €686,644 after cemented hip arthroplasty (€2672 per patient).

CONCLUSION

The use of ALBC has been found to be effective in preventing PPI after TKA and hip arthroplasty, with a favorable cost-efficiency profile using standardized cost and infection rates in our setting.

Total hip replacement: A meta-analysis to evaluate survival of cemented, cementless and hybrid implants

AIM

To determine whether cemented, cementless, or hybrid implant was superior to the other in terms of survival rate.

METHODS

Systematic searches across MEDLINE, CINAHL, and Cochrane that compared cemented, cementless and hybrid total hip replacement (THR) were performed. Two independent reviewers evaluated the risk ratios of revision due to any cause, aseptic loosening, infection, and dislocation rate of each implants with a pre-determined form. The risk ratios were pooled separately for clinical trials, cohorts and registers before pooled altogether using fixed-effect model. Meta-regressions were performed to identify the source of heterogeneity. Funnel plots were analyzed.

RESULTS

Twenty-seven studies comprising 5 clinical trials, 9 cohorts, and 13 registers fulfilled the research criteria and analyzed. Compared to cementless THR, cemented THR have pooled RR of 0.47 (95%CI: 0.45-0.48), 0.9 (0.84-0.95), 1.29 (1.06-1.57) and 0.69 (0.6-0.79) for revision due to any reason, revision due to aseptic loosening, revision due to infection, and dislocation respectively. Compared to hybrid THR, the pooled RRs of cemented THR were 0.82 (0.76-0.89), 2.65 (1.14-6.17), 0.98 (0.7-1.38), and 0.67 (0.57-0.79) respectively. Compared to hybrid THR, cementless THR had RRs of 0.7 (0.65-0.75), 0.85 (0.49-1.5), 1.47 (0.93-2.34) and 1.13 (0.98-1.3).

CONCLUSION

Despite the limitations in this study, there was some tendency that cemented fixation was still superior than other types of fixation in terms of implant survival.

Still no single gold standard for using cementless femoral stems routinely in total hip arthroplasty

Background

There is now a clear trend with increased usage of cementless femoral stems for all ages and most patients. As the number of total hip arthroplasties (THAs) performed annually continues to increase with expanding indications for THA and demands for improved quality of life, so will the prevalence of THA in the elderly and aging populations. This is worrisome as the risk of complications with cementless femoral stems increases in elderly patients and those with poor bone quality. The purpose of this study is to analyze the available data from comparative studies to determine whether cementless femoral stems are overused and whether cemented stems warrant increased consideration.

Methods

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, searches were performed to find original studies comparing cementless and cemented femoral stems; large population registry studies and reports were also included.

Results

This systematic review documents that older patients with cementless fixation increase the risk of revision, there is no clear fixation advantage in midaged patients, and younger patients fare better with cementless fixation. Complications after THA create burdens on the health care system and on patients.

Conclusions

Using evidence-based data should be better guidance in selecting the most reliable implants for THA. Although cementless femoral fixation for THA has evolved to the “new standard,” it has not been proven to be the “gold standard” for all patients.

The impact of patient and surgical factors on the rate of infection after primary total knee arthroplasty: an analysis of 64,566 joints from the New Zealand Joint Registry

AIMS

The aim of this study was to identify risk factors for prosthetic joint infection (PJI) following total knee arthroplasty (TKA).

PATIENTS AND METHODS

The New Zealand Joint Registry database was analysed, using revision surgery for PJI at six and 12 months after surgery as primary outcome measures. Statistical associations between revision for infection, with common and definable surgical and patient factors were tested.

RESULTS

A total of 64 566 primary TKAs have been recorded on the registry between 1999 and 2012 with minimum follow-up of 12 months. Multivariate analysis showed statistically significant associations with revision for PJI between male gender (odds ratio (OR) 1.85, 95% confidence interval (CI) 1.24 to 2.74), previous surgery (osteotomy (OR 2.45 95% CI 1.2 to 5.03), ligament reconstruction (OR 1.85, 95% CI 0.68 to 5.00)), the use of laminar flow (OR 1.6, 95% CI 1.04 to 2.47) and the use of antibiotic-laden cement (OR 1.93, 95% CI 1.19 to 3.13). There was a trend towards significance (p = 0.052) with the use of surgical helmet systems at six months (OR 1.53, 95% CI 1.00 to 2.34).

CONCLUSION

These findings show that patient factors remain the most important in terms of predicting early PJI following TKA. Furthermore, we found no evidence that modern surgical helmet systems reduce the risk of PJI and laminar flow systems may actually increase risk in TKA. The use of this registry data assists the estimation of the risk of PJI for individual patients, which is important for both informed consent and the interpretation of infection rates at different institutions.

TAKE HOME MESSAGE

Infection rates in TKA are related to both individual patient and surgical factors, and some modern methods of reducing infection may actually increase infection risk.

Surgical Site Infection After Total Knee Arthroplasty: Risk Factors in Patients With Timely Administration of Systemic Prophylactic Antibiotics

BACKGROUND

Surgical site infection (SSI) after total knee arthroplasty (TKA) is a catastrophic complication. Administration of prophylactic antibiotics within 60 minutes before surgery is a well-established strategy to prevent SSI. The study is aimed to identify the risk factors for SSI regarding primary TKA in patients with timely administration of systemic prophylactic antibiotics.

METHODS

A retrospective review of patients with primary TKA between 2009 and 2013 was conducted. Patients who had prophylactic antibiotics administered after skin incision or >60 minutes before skin incision were excluded.

RESULTS

Of the 3152 patients enrolled, the incidence of SSI and deep-implant SSI was 1.52% and 0.79%, respectively. Charlson Comorbidity Index ≥3 was an independent risk factor for both SSI (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.24-4.44, P = .01) and deep-implant SSI (OR, 3.46; 95% CI, 1.52-7.91, P < .01). Optimal dose of systemic antibiotics adjusted by patients' body weight for prophylaxis (OR, 0.29; 95% CI, 0.17-0.62, P < .01) and using antibiotic-laden bone cement (OR, 0.33; 95% CI, 0.17-0.64, P < .01) were significant protective factors for SSI. Meanwhile, using antibiotic-laden bone cement (OR, 0.31; 95% CI, 0.13-0.76, P = .01) also significantly decreased the risk of deep-implant SSI.

CONCLUSION

Our findings highlight the importance of appropriate dosage of prophylactic antibiotics and use of antibiotic-laden cement in preventing SSI after primary TKA. For prevention of deep-implant SSI, using antibiotic-laden bone cement seems to be an advisable strategy.

Formulation and characterization of antimicrobial quaternary ammonium dendrimer in poly(methyl methcarylate) bone cement

The use of novel antimicrobial molecules in bone cement can improve efficiency of recuperation after arthroplasty or joint replacement surgeries, avoiding the risks associated with antibiotic resistant antimicrobial agents. Nanomaterials particularly dendrimers are particularly useful for making broad spectrum killing agents owing to their large surface areas and functionalities. Therefore, we have synthesized generation 1 quaternary ammonium dendrimer of tripropylene glycol diacrylate (TPGDA) using octyl iodide (OI) [TPGDA G1.0 (=) quaternary octyl iodide (QOI)] and capitalized on their capabilities of contact killing based mechanism. We formulated different TPGDA G1.0 (=) QOI antimicrobial agent loaded liquid component composed of methyl methacrylate monomer and N,N-dimethyl-p-toluidine coinitiator. Different polymethyl methacrylate (PMMA) based experimental bone cement formulations were made and dendrimer concentration was optimized. Mechanical strength and compressive modulus of modified bone cement decreased on increasing concentrations and 10% was optimized for further analysis. The mechanical strength of bone cement yield the similar trend in wet conditions bone cement immersed in artificially created stimulated body fluids. Ten percent TPGDA G1.0 (=) QOI in bone cement was sufficient to kill gram positive and negative bacteria and its property is retained even after a period of 30 days. Thus novel dendritic structures show promise for clinical antimicrobial activity while retaining mechanical properties of bone cements. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 521-530, 2017.

Postoperative Deep Infection After Cemented Versus Cementless Total Hip Arthroplasty: A Meta-Analysis

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty (THA). The objective of this meta-analysis was to compare the PJI rate between cemented and cementless THAs. Eight clinical studies (2 randomized controlled trials and 6 observational studies) were available for the analysis. Meta-analysis (with a fixed-effects model) and subgroup analysis were performed by research design and meta-regression was performed by continuous moderator. The overall incidence of PJI was 0.4% (357/84,200). The incidence was 0.5% (310/67,531) in cemented group, and 0.3% (47/16,669) in cementless group (P=0.008). The meta-analysis revealed that the use of cement in THA was associated with an increased risk of PJI (odds ratio 1.53; 95% confidence interval 1.120 to 2.100; P=0.008).

Local antibiotic therapy strategies in orthopaedic trauma: Practical tips and tricks and review of the literature

The use of local antibiotics for the prevention of infection in the setting of open fractures and as part of the treatment of osteomyelitis is well established. Antibiotics are most commonly incorporated into polymethylmethacrylate (PMMA) cement, which can then be formed into beads, moulded to fit a bone defect or used to coat a guide wire or IM nail. Newer delivery vehicles and techniques are being evaluated to improve upon these methods. Many factors influence how local antibiotics are applied. Treatment strategies are challenging to standardise due to the variability of clinical presentations. The presence of hardware, upper versus lower extremity, healed versus non-healed fracture and quality of soft tissues overlying the affected bone, as well as patients' comorbidities all need to be considered. Despite the accepted use of local antibiotic therapy in orthopaedic trauma, high-quality evidence regarding the use of local antibiotics is lacking. Indications, techniques, dosages, types of antibiotics, elution properties and pharmacokinetics are poorly defined in the clinical setting. The purpose of our manuscript is to review current strategies and provide practical tips for local application of antibiotics in orthopaedic trauma. We focus on delivery vehicles, types of antibiotics, dosage recommendations when mixed with PMMA and indications.

Lack of efficacy of prophylactic application of antibiotic-loaded bone cement for prevention of infection in primary total knee arthroplasty: results of a meta-analysis

BACKGROUND

Deep incisional surgical site infection (SSI) is a devastating and costly complication of primary total knee arthroplasty (TKA). The effectiveness of antibiotic-loaded bone cement (ALBC) in preventing these infections remains controversial.

METHODS

A meta-analysis was conducted to assess the efficacy of ALBC in preventing deep infection in primary TKA after a detailed and systematic search of the PubMed, Embase, CNKI, and Cochrane databases had been performed to identify appropriate comparative trials on the prophylactic use of ALBC in primary TKA.

RESULTS

Five comparative trials were included. In total, 3,461 patients (ALBC group) received ALBC, whereas 3,176 patients (non-antibiotic-loaded cement; NALBC group) did not. The incidence of deep incisional SSI in the ALBC group was 1.32% (n=46) whereas the incidence in the NALBC group was 1.89% (n=60), figures which are not significantly different. No adverse events associated with ALBC were reported in any studies.

CONCLUSION

Statistical analysis did not reveal a significantly different incidence of deep or superficial SSI in patients receiving and not receiving antibiotic-loaded cement. The prophylactic application of ALBC thus did not show efficacy in primary TKA. More large-sample studies are required to confirm this finding.

No decreased infection rate when using antibiotic-impregnated cement in primary total joint arthroplasty

There has been much debate and controversy about the routine use of antibiotic-impregnated bone cement in primary total joint arthroplasty. The purpose of this study was to undertake a meta-analysis to determine whether the use of antibiotic-impregnated bone cement would reduce the incidence of infection after primary total joint arthroplasty. Of 313 citations identified for screening, 6 trials reporting 26,791 patients were eligible for data extraction and meta-analysis. The authors found no statistically significant difference between antibiotic-impregnated bone cement and plain bone cement in terms of the incidence of infection. The results indicated that the use of antibiotic-impregnated bone cement in primary total joint arthroplasty did not lead to a decrease in the rate of infection.

Increasing Resistance of Coagulase-Negative Staphylococci in Total Hip Arthroplasty Infections: 278 THA-Revisions due to Infection Reported to the Norwegian Arthroplasty Register from 1993 to 2007

We investigated bacterial findings from intraoperative tissue samples taken during revision due to infection after total hip arthroplasty (THA). The aim was to investigate whether the susceptibility patterns changed during the period from 1993 through 2007. Reported revisions due to infection in the Norwegian Arthroplasty Register (NAR) were identified, and 10 representative hospitals in Norway were visited. All relevant information on patients reported to the NAR for a revision due to infection, including bacteriological findings, was collected from the medical records. A total of 278 revision surgeries with bacterial growth in more than 2 samples were identified and included. Differences between three 5-year time periods were tested by the chi-square test for linear trend. The most frequent isolates were coagulase-negative staphylococci (CoNS) (41%, 113/278) and Staphylococcus aureus (19%, 53/278). The proportion of CoNS resistant to the methicillin-group increased from 57% (16/28) in the first period, 1993-1997, to 84% (52/62) in the last period, 2003-2007 (P = 0.003). There was also significant increase in resistance for CoNS to cotrimoxazole, quinolones, clindamycin, and macrolides. All S. aureus isolates were sensitive to both the methicillin-group and the aminoglycosides. For the other bacteria identified no changes in susceptibility patterns were found.

Antibacterial surface treatment for orthopaedic implants

It is expected that the projected increased usage of implantable devices in medicine will result in a natural rise in the number of infections related to these cases. Some patients are unable to autonomously prevent formation of biofilm on implant surfaces. Suppression of the local peri-implant immune response is an important contributory factor. Substantial avascular scar tissue encountered during revision joint replacement surgery places these cases at an especially high risk of periprosthetic joint infection. A critical pathogenic event in the process of biofilm formation is bacterial adhesion. Prevention of biomaterial-associated infections should be concurrently focused on at least two targets: inhibition of biofilm formation and minimizing local immune response suppression. Current knowledge of antimicrobial surface treatments suitable for prevention of prosthetic joint infection is reviewed. Several surface treatment modalities have been proposed. Minimizing bacterial adhesion, biofilm formation inhibition, and bactericidal approaches are discussed. The ultimate anti-infective surface should be “smart” and responsive to even the lowest bacterial load. While research in this field is promising, there appears to be a great discrepancy between proposed and clinically implemented strategies, and there is urgent need for translational science focusing on this topic.