A systematic review and meta-analysis of antibiotic-impregnated bone cement use in primary total hip or knee arthroplasty

In Vivo Intra-Articular Antibiotic Concentrations at 24 Hours After TKA Fall Below the Minimum Inhibitory Concentration for Most Bacteria: A Randomized Study of Commercially Available Bone Cement

BACKGROUND

The use of antibiotic-loaded bone cement (ALBC) to help reduce the risk of infection after primary total knee arthroplasty (TKA) is controversial. There is a paucity of in vivo data on the elution characteristics of ALBC. We aimed to determine whether the antibiotic concentrations of 2 commercially available ALBCs met the minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) for common infecting organisms.

METHODS

Forty-five patients undergoing TKA were randomized to receive 1 of the following: bone cement without antibiotic (the negative control; n = 5), a commercially available formulation containing 1 g of tobramycin (n = 20), or a commercially available formulation containing 0.5 g of gentamicin (n = 20). Intra-articular drains were placed, and fluid was collected at 4 and 24 hours postoperatively. An automated immunoassay measuring antibiotic concentration was performed, and the results were compared against published MIC and MBEC thresholds.

RESULTS

The ALBC treatment groups were predominantly of White (65%) or Black (32.5%) race and were 57.5% female and 42.4% male. The mean age (and standard deviation) was 72.6 ± 7.2 years in the gentamicin group and 67.6 ± 7.4 years in the tobramycin group. The mean antibiotic concentration in the tobramycin group was 55.1 ± 37.7 μg/mL at 4 hours and 19.5 ± 13.0 μg/mL at 24 hours, and the mean concentration in the gentamicin group was 38.4 ± 25.4 μg/mL at 4 hours and 17.7 ± 15.4 μg/mL at 24 hours. Time and antibiotic concentration had a negative linear correlation coefficient (r = -0.501). Most of the reference MIC levels were reached at 4 hours. However, at 24 hours, a considerable percentage of patients had concentrations below the MIC for many common pathogens, including Staphylococcus epidermidis (gentamicin: 65% to 100% of patients; tobramycin: 50% to 85%), methicillin-sensitive Staphylococcus aureus (gentamicin: 5% to 90%; tobramycin: 5% to 50%), methicillin-resistant S. aureus (gentamicin: 5% to 65%; tobramycin: 50%), Streptococcus species (gentamicin: 10% to 100%), and Cutibacterium acnes (gentamicin: 10% to 65%; tobramycin: 100%). The aforementioned ranges reflect variation in the MIC among different strains of each organism. Gentamicin concentrations reached MBEC threshold values at 4 hours only for the least virulent strains of S. aureus and Escherichia coli. Tobramycin concentrations did not reach the MBEC threshold for any of the bacteria at either time point.

CONCLUSIONS

The elution of antibiotics from commercially available ALBC decreased rapidly following TKA, and only at 4 hours postoperatively did the mean antibiotic concentrations exceed the MIC for most of the pathogens. Use of commercially available ALBC may not provide substantial antimicrobial coverage following TKA.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Periprosthetic Joint Infection After Total Knee Arthroplasty With or Without Antibiotic Bone Cement

Importance

Despite increased use of antibiotic-loaded bone cement (ALBC) in joint arthroplasty over recent decades, current evidence for prophylactic use of ALBC to reduce risk of periprosthetic joint infection (PJI) is insufficient.

Objective

To compare the rate of revision attributed to PJI following primary total knee arthroplasty (TKA) using ALBC vs plain bone cement.

Design, Setting, and Participants

This international cohort study used data from 14 national or regional joint arthroplasty registries in Australia, Denmark, Finland, Germany, Italy, New Zealand, Norway, Romania, Sweden, Switzerland, the Netherlands, the UK, and the US. The study included primary TKAs for osteoarthritis registered from January 1, 2010, to December 31, 2020, and followed-up until December 31, 2021. Data analysis was performed from April to September 2023.

Exposure

Primary TKA with ALBC vs plain bone cement.

Main Outcomes and Measures

The primary outcome was risk of 1-year revision for PJI. Using a distributed data network analysis method, data were harmonized, and a cumulative revision rate was calculated (1 - Kaplan-Meier), and Cox regression analyses were performed within the 10 registries using both cement types. A meta-analysis was then performed to combine all aggregated data and evaluate the risk of 1-year revision for PJI and all causes.

Results

Among 2 168 924 TKAs included, 93% were performed with ALBC. Most TKAs were performed in female patients (59.5%) and patients aged 65 to 74 years (39.9%), fully cemented (92.2%), and in the 2015 to 2020 period (62.5%). All participating registries reported a cumulative 1-year revision rate for PJI of less than 1% following primary TKA with ALBC (range, 0.21%-0.80%) and with plain bone cement (range, 0.23%-0.70%). The meta-analyses based on adjusted Cox regression for 1 917 190 TKAs showed no statistically significant difference at 1 year in risk of revision for PJI (hazard rate ratio, 1.16; 95% CI, 0.89-1.52) or for all causes (hazard rate ratio, 1.12; 95% CI, 0.89-1.40) among TKAs performed with ALBC vs plain bone cement.

Conclusions and Relevance

In this study, the risk of revision for PJI was similar between ALBC and plain bone cement following primary TKA. Any additional costs of ALBC and its relative value in reducing revision risk should be considered in the context of the overall health care delivery system.

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.

Utilization of Antibiotic Bone Cement in Spine Surgery: Pearls, Techniques, and Case Review

Vertebral osteomyelitis (VO) encompasses a spectrum of spinal infections ranging from isolated mild vertebral osteomyelitis to severe diffuse infection with associated epidural abscess and fracture. Although patients can often be treated with an initial course of intravenous antibiotics, surgery is sometimes required in patients with sepsis, spinal instability, neurological compromise, or failed medical treatment. Antibiotic bone cement (ABC) has been widely used in orthopedic extremity surgery for more than 150 years, both for prophylaxis and treatment of bacterial infection. However, relatively little literature exists regarding its utilization in spine surgery. This article describes ABC utilization in orthopedic surgery and explains the technique of ABC utilization in spine surgery. Surgeons can choose from multiple premixed ABCs with variable viscosities, setting times, and antibiotics or can mix in antibiotics to bone cements themselves. ABC can be used to fill large defects in the vertebral body or disc space or in some cases to coat instrumentation. Surgeons should be wary of complications such as ABC extravasation as well as an increased difficulty with revision. With a thorough understanding of the properties of the cement and the methods of delivery, ABC is a powerful adjunct in the treatment of spinal infections.

Effectiveness of antibiotic-loaded bone cement in total joint arthroplasty at a tertiary medical center: A retrospective cohort study

Background

Data regarding the effectiveness of antibiotic-loaded bone cement (ALBC) in preventing prosthetic joint infections (PJI) after total joint arthroplasty (TJA) is inconsistent. The objective of this study was to evaluate if the routine use of ALBC influenced the risk of revision surgery due to PJI.

Methods

This is a retrospective cohort study performed between January 2018 and September 2020. Adult patients aged ≥ 18 years who underwent TJA (knee or hip) and received either ALBC or plain cement (PC) were included. The outcome of this study was the rate of revision due to PJI. Multivariate analysis using logistic regression was used to identify factors that may be associated with increased risk of PJI, using STATA 15.1 (StataCorp LP, College Station, Texas, USA).

Results

A total of 844 patients were screened and 319 patients were included. There were 247 patients in ALBC group and 72 patients in the PC group. Only vancomycin powder was used in all ALBC cases, with a 2 g dose in 50% of the cases (dose ranged between 1 g and 8 g). The status of the prosthetic joint was assessed and recorded up to 2 years of the TJA. Overall, the difference in the rates of PJI between the two groups after primary arthroplasty was not statistically significant (5.6% vs 1.4%; p = 0.173; OR, 4.2; 95% CI, 0.5-33).

Conclusion

ALBC was not associated with a reduction in PJI rates after primary TJA. More research is needed to further evaluate the effectiveness of ALBC in preventing PJI.

Influence of the Type of Bone Cement Used in Two-Stage Exchange Arthroplasty for Chronic Periarticular Joint Infection on the Spacer Replacement and Reinfection Rate

BACKGROUND

Antibiotic-loaded bone cement (ALBC) spacers are used in the first stage when treating periprosthetic joint infection (PJI). This study aimed to investigate whether a spacer made from commercial ALBC or plain bone cement with additional antibiotics could affect the spacer exchange rate before reimplantation.

METHODS

Patients undergoing two-stage exchange arthroplasty due to chronic PJI from January 2014 to August 2021 were retrospectively reviewed. The exclusion criteria included arthroplasty in the setting of septic arthritis, megaprosthesis, atypical pathogen infection, spacer placement unrelated to PJI, and spacer exchange due to mechanical complications. The patient demographics, brand of cement, and microbiology were recorded manually. The primary outcome was the incidence of spacer exchange due to persistent infection and the secondary outcome was the incidence of reinfection after reimplantation. A multivariate logistic regression analysis and Chi-square test were conducted to identify the effect of cement type on the spacer exchange.

RESULTS

A total of 334 patients underwent two-stage exchange arthroplasty for PJI. The spacer exchange rates in the commercial and non-commercial ALBC groups were 6.4% and 25.1%, respectively (p = 0.004). After controlling for confounding factors, there were significant differences between the commercial group and non-commercial groups in the spacer exchange rate (adjusted OR = 0.25; 95% CI = 0.72-0.87, p = 0.029). The use of commercial ALBC was not associated with a lower reinfection rate after reimplantation (p = 0.160).

CONCLUSIONS

In a two-stage exchange arthroplasty scenario, the spacer comprised of commercial ALBC resulted in a lower spacer exchange rate than the plain bone cement, both of which had additional antibiotics. However, the use of commercial ALBC was not associated with a lower incidence of reinfection following reimplantation.

Novel Tuning of PMMA Orthopedic Bone Cement Using TBB Initiator: Effect of Bone Cement Extracts on Bioactivity of Osteoblasts and Osteoclasts

Bone cement containing benzoyl peroxide (BPO) as a polymerization initiator are commonly used to fix orthopedic metal implants. However, toxic complications caused by bone cement are a clinically significant problem. Poly (methyl methacrylate) tri-n-butylborane (PMMA-TBB), a newly developed material containing TBB as a polymerization initiator, was found to be more biocompatible than conventional PMMA-BPO bone cements due to reduced free radical generation during polymerization. However, free radicals might not be the only determinant of cytotoxicity. Here, we evaluated the response and functional phenotypes of cells exposed to extracts derived from different bone cements. Bone cement extracts were prepared from two commercial PMMA-BPO cements and an experimental PMMA-TBB. Rat bone marrow-derived osteoblasts and osteoclasts were cultured in a medium supplemented with bone cement extracts. More osteoblasts survived and attached to the culture dish with PMMA-TBB extract than in the culture with PMMA-BPO extracts. Osteoblast proliferation and differentiation were higher in the culture with PMMA-TBB extract. The number of TRAP-positive multinucleated cells was significantly lower in the culture with PMMA-TBB extract. There was no difference in osteoclast-related gene expression in response to different bone cement extracts. In conclusion, PMMA-TBB extract was less toxic to osteoblasts than PMMA-BPO extracts. Although extracts from the different cement types did not affect osteoclast function, PMMA-TBB extract seemed to reduce osteoclastogenesis, a possible further advantage of PMMA-TBB cement. These implied that the reduced radical generation during polymerization is not the only determinant for the improved biocompatibility of PMMA-TBB and that the post-polymerization chemical elution may also be important.

Effectiveness of antibiotics loaded bone cement in primary total knee arthroplasty: A systematic review and meta-analysis

INTRODUCTION

The application of antibiotics loaded bone cement (ALBC) in the revision of failed total knee arthroplasty (TKA) has been widely accepted to reduce risk of peri-prosthetic infection. However, the prophylactic use of ALBC in primary TKA remains controversial. This study was aimed to identify the prophylactic effect on peri-prosthetic infection and safety of ALBC in primary TKA.

HYPOTHESIS

The application of ALBC could reduce the risk of peri-prosthetic infection in primary TKA.

MATERIALS AND METHODS

Electronic platforms including PubMed, EMBASE, and CENTRAL were retrieved to identify studies comparing outcomes of prophylactic ALBC and plain cement in primary TKA. For outcomes reported as dichotomous variable and continuous variable, risk ratio (RR) and weighted mean difference (WMD) as well as their 95% confidence intervals (95% CI) were selected as the effect sizes for pooling. While for those outcomes reported the adjusted effect sizes such as odds ratio (OR, derived from multivariate logistic regression), and hazard ratio (HR, derived from multivariate COX proportional hazard model), the reported effect sizes were selected for pooling.

RESULTS

A total of 17 studies with 2,074,844 patients (1,093,920 in ALBC group and 980,924 in plain cement group) were eligible for final inclusion. No significant difference was found between ALBC and plain cement groups both for the unadjusted (RR=1.02, 95% CI: 0.86∼1.21, p=0.832) and adjusted (OR=0.94, 95% CI: 0.76∼1.17, p=0.596) peri-prosthetic infection rate. ALBC application was related to significantly increased length of hospital stay (WMD=0.13, 95% CI: 0.10∼0.17, p<0.001). There was no significance on the difference of operation related adverse events between two groups (RR=1.31, 95% CI: 0.68∼2.52, p=0.420). Significantly increased risks of acute renal failure and readmission, and temporarily increased ototoxicity in ALBC group were reported in one of the primary study.

DISCUSSION

There is no sufficient evidence supporting decreased peri-prosthetic infection rate with ALBC application in primary TKA. What's more, it must be taken into consideration about the safety and added cost of additional impregnated antibiotics.

LEVEL OF EVIDENCE

III; meta-analysis.

When and How Should I Use Antibiotic Cement in Primary and Revision Joint Arthroplasty?

Periprosthetic joint infections (PJIs) remain one of the most challenging and devastating complications associated with total joint arthroplasty. Therefore, prevention and the ability to effectively treat PJIs are critical. One such tool for both the prevention and treatment of PJIs is the use of antibiotic-loaded bone cement (ALBC). ALBC provides an effective local delivery method of antibiotics. Low dose (<2 g per 40-g batch) is commonly used for prophylaxis, while high dose (>3.6 g per 40-g batch) is used for the treatment of PJIs. This review focuses on the efficacy, safety, and cost-effectiveness of ALBC for both the prevention as well as the treatment of PJIs.

Antibiotic Cement Utilization for the Prophylaxis and Treatment of Infections in Spine Surgery: Basic Science Principles and Rationale for Clinical Use

Antibiotic bone cement (ABC) is an effective tool for the prophylaxis and treatment of osteomyelitis due to the controlled, sustained release of local antibiotics. ABC has been proven to be effective in the orthopedic fields of arthroplasty and extremity trauma, but the adoption of ABC in spine surgery is limited. The characteristics of ABC make it an optimal solution for treating vertebral osteomyelitis (VO), a serious complication following spine surgery, typically caused by bacterial and sometimes fungal and parasitic pathogens. VO can be devastating, as infection can result in pathogenic biofilms on instrumentation that is dangerous to remove. New techniques, such as kyphoplasty and novel vertebroplasty methods, could amplify the potential of ABC in spine surgery. However, caution should be exercised when using ABC as there is some evidence of toxicity to patients and surgeons, antibiotic allergies, bone cement structural impairment, and possible development of antibiotic resistance. The purpose of this article is to describe the basic science of antibiotic cement utilization and review its usage in spine surgery.

Timely explantation of tobramycin-impregnated beads and bone cement to avoid haemodialysis in a patient with worsening renal failure

A male patient with right total knee arthroplasty complicated by prosthetic joint infection on intravenous antimicrobials developed an acute kidney injury (AKI) with creatinine up to 7.3 mg/dL ('normal' range (0.5-1.2 mg/dL)) after hardware removal and tobramycin loaded polymethylmethacrylate beads and spacer placement. The AKI was initially attributed to intravenous vancomycin. Despite discontinuing vancomycin, the AKI worsened. A tobramycin level was collected and resulted at 5.5 µg/mL. Due to high suspicion for aminoglycoside-induced renal toxicity and to prevent haemodialysis, the antibiotic cement spacer with tobramycin-impregnated beads was removed. After the removal, tobramycin level rapidly decreased and renal functions improved. AKI is an increasingly recognised complication related to antibiotic-loaded bone cement (ALBC) due to the systemic absorption of antibiotics. With this case we highlight the early recognition of ALBC-induced renal toxicity necessitating explantation of ALBC and beads in order to prevent haemodialysis and emphasise monitoring aminoglycoside levels in the early postoperative period.

Infection after primary total knee arthroplasty: a randomized controlled prospective study of the addition of antibiotics to bone cement

Objective  The present prospective, randomized and controlled study was conducted with 286 patients submitted to primary total knee arthroplasty (TKA) with the objective of evaluating the efficacy of the addition of antibiotics to bone cement as a way to prevent post arthroplasty infection (PAI).

Methods  The patients were randomized into two groups: bone cement without antibiotic (No ATB, n  = 158) or cement with antibiotic (ATB, n  = 128), in which 2 g of vancomycin was added to 40 g of cement. The patients were followed up for 24 months after surgery.

Results  Regarding preoperative demographic data, the distribution of patients between groups was homogeneous ( p  < 0.05). In the 24-month period, the overall infection rate was of 2.09% (6/286), with no difference (odds ratio [OR] = 1.636; 95% confidence interval [CI]: 0.294–9.080; p  = 0.694) between the ATB group (1.56%; 2/128) and the No ATB group (2.53%; 4/158). In the No ATB group, the infection was caused by methicillin-resistant Staphylococcus aureus (MRSA) ( n  = 2), methicillin-sensitive S. aureus (MSSA) ( n  = 1) and Eschirichia coli ( n  = 1). Proteus mirabilis and MSSA were isolated from patients in the ATB group. Among the comorbidities, all patients with PAI were hypertensive and nondiabetic. Two rheumatoid arthritis patients who developed PAI were from the ATB group.

Conclusion  The use of cement with ATB reduced the absolute number of infections, but without statistical difference between the groups; thus, routine use should not be encouraged.

Ceramic Bearings Are Associated With a Significantly Reduced Revision Rate in Primary Hip Arthroplasty: An Analysis From the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man

BACKGROUND

Prosthetic joint infection (PJI) is a devastating complication. Studies have suggested reduction in PJI with the use of ceramic bearings.

METHODS

Adult patients who underwent total hip arthroplasty (THA) using an uncemented acetabular component with ceramic-on-ceramic (CoC), ceramic-on-polyethylene (CoP), or metal-on-polyethylene (MoP) bearing surfaces between 2002 and 2016 were extracted from the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man. A competing risk regression model to investigate predictors of each revision outcome was used. Time-to-event was determined by duration of implantation since primary surgery with competing risks being death or revision. The results were adjusted for age, gender, American Association of Anaesthesiologists grade, body mass index, surgical indication, intraoperative complications, and implant data.

RESULTS

In total, 456,457 THAs (228,786 MoP, 128,403 CoC, and 99,268 CoP) were identified. Multivariable modeling showed that the risk of revision for PJI was significantly lower with CoC (risk ratio 0.748, P < .001) and CoP (risk ratio 0.775, P < .001) compared to MoP. Significant reduction in risk of aseptic and all-cause revision was also seen. The significant protective effect of ceramic bearing was predominantly seen 2 years after implantation. Aseptic revision beyond 2 years reduced by 18.1% and 24.8% for CoC and CoP (P < .001), respectively. All-cause revision rate beyond 2 years reduced by 21.6% for CoC and 27.1% for CoP (P < .001) CONCLUSION: This study demonstrates an association between the use of ceramic as part of the bearing, with lower rates of revision for all causes, revision for infection, and revision for aseptic causes, supporting ceramic bearings in THA.

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.

Increasing but levelling out risk of revision due to infection after total hip arthroplasty: a study on 108,854 primary THAs in the Norwegian Arthroplasty Register from 2005 to 2019

Background and purpose - Focus on prevention, surveillance, and treatment of infection after total hip arthroplasty (THA) in the last decade has resulted in new knowledge and guidelines. Previous publications have suggested an increased incidence of surgical revisions due to infection after THA. We assessed whether there have been changes in the risk of revision due to deep infection after primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 2005-2019.Patients and methods - Primary THAs reported to the NAR from January 1, 2005 to December 31, 2019 were included. Adjusted Cox regression analyses with the first revision due to deep infection after primary THA were performed. We investigated changes in the risk of revision as a function of time of primary THA. Time was stratified into 5-year periods. We studied the whole population of THAs, and the subgroups: all-cemented, all-uncemented, reverse hybrid (cemented cup), and hybrid THAs (cemented stem). In addition, we investigated factors that were associated with the risk of revision, and changes in the time span from primary THA to revision.Results - Of the 108,854 primary THAs that met the inclusion criteria, 1,365 (1.3%) were revised due to deep infection. The risk of revision due to infection, at any time after primary surgery, increased through the period studied. Compared with THAs implanted in 2005-2009, the relative risk of revision due to infection was 1.4 (95% CI 1.2-1.7) for 2010-2014, and 1.6 (1.1-1.9) for 2015-2019. We found an increased risk for all types of implant fixation. Compared to 2005-2009, for all THAs, the risk of revision due to infection 0-30 days postoperatively was 2.2 (1.8-2.8) for 2010-2014 and 2.3 (1.8-2.9) for 2015-2019, 31-90 days postoperatively 1.0 (0.7-1.6) for 2010-2014 and 1.6 (1.0-2.5) for 2015-2019, and finally 91 days-1 year postoperatively 1.1 (0.7-1.8) for 2010-2014 and 1.6 (1.0-2.6) for 2015-2019. From 1 to 5 years postoperatively, the risk of revision due to infection was similar to 2005-2009 for both the subsequent time periodsInterpretation - The risk of revision due to deep infection after THA increased throughout the period 2005-2019, but appears to have levelled out after 2010. The increase was mainly due to an increased risk of early revisions, and may partly have been caused by a change of practice rather than a change in the incidence of infection.

Release characteristics of enoxaparin sodium-loaded polymethylmethacrylate bone cement

BACKGROUND

This study aimed to prepare the polymethylmethacrylate (PMMA) bone cement release system with different concentrations of enoxaparin sodium (ES) and to investigate the release characteristics of ES after loading into the PMMA bone cement.

METHODS

In the experimental group, 40 g Palacos®R PMMA bone cement was loaded with various amount of ES 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, respectively. The control group was not loaded with ES. Scanning electron microscopy (SEM) was used to observe the surface microstructure of the bone cement in the two groups. In the experiment group, the mold was extracted continuously with pH7.4 Tris-HCL buffer for 10 days. The extract solution was collected every day and the anti-FXa potency was measured. The experiment design and statistical analysis were conducted using a quantitative response parallel line method.

RESULTS

Under the SEM, it was observed that ES was filled in the pores of PMMA bone cement polymer structure and released from the pores after extraction. There was a burst effect of the release. The release amount of ES on the first day was 0.415, 0.858, 1.110, 1.564, 1.952, and 2.513, respectively, from the six groups with various ES loading amount of 4000, 8000, 12,000, 16,000, 20,000, and 24,000 AXaIU, all reaching the peak of release on the first day. The release decreased rapidly on the next day and entered the plateau phase on the fourth day.

CONCLUSION

The prepared ES-PMMA bone cement has high application potential in orthopedic surgery. ES-PMMA bone cement shows good drug release characteristics. The released enoxaparin sodium has a local anti-coagulant effect within 24 h after application, but it will not be released for a long time, which is complementary to postoperative anti-coagulation therapy.

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.

Antibiotic-Laden Bone Cement Use and Revision Risk After Primary Total Knee Arthroplasty in U.S. Veterans

BACKGROUND

It is controversial whether the use of antibiotic-laden bone cement (ALBC) in primary total knee arthroplasty (TKA) affects periprosthetic joint infection (PJI) or revision rates. The impact of ALBC on outcomes of primary TKA have not been previously investigated in U.S. veterans, to our knowledge. The purposes of this study were to quantify utilization of ALBC among U.S. veterans undergoing primary TKA and to determine if ALBC usage is associated with differences in revision TKA rates.

METHODS

Patients who had TKA with cement from 2007 to 2015 at U.S. Veterans Health Administration (VHA) hospitals with at least 2 years of follow-up were retrospectively identified. Patients who received high-viscosity Palacos bone cement with or without gentamicin were selected as the final study cohort. Patient demographic and comorbidity data were collected. Revision TKA was the primary outcome. All-cause revisions and revisions for PJI were identified from both VHA and non-VHA hospitals. Unadjusted and adjusted regression analyses were performed to identify variables that were associated with increased revision rates.

RESULTS

The study included 15,972 patients who had primary TKA with Palacos bone cement at VHA hospitals from 2007 to 2015. Plain bone cement was used for 4,741 patients and ALBC was used for 11,231 patients. Utilization of ALBC increased from 50.6% in 2007 to 69.4% in 2015. At a mean follow-up of 5 years, TKAs with ALBC had a lower all-cause revision rate than those with plain bone cement (5.3% versus 6.7%; p = 0.0009) and a lower rate of revision for PJI (1.9% versus 2.6%; p = 0.005). On multivariable regression, ALBC use was associated with a lower risk of all-cause revision compared with plain bone cement (hazard ratio [HR]: 0.79, 95% confidence interval [CI]: 0.68 to 0.92; p = 0.0019). Seventy-one primary TKAs needed to be implanted with ALBC to avoid 1 revision TKA.

CONCLUSIONS

The utilization of ALBC for primary TKAs performed at VHA hospitals has increased over time and was associated with a lower all-cause revision rate and a lower rate of revision for PJI.

LEVEL OF EVIDENCE

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

Is the use of antibiotic-loaded bone cement associated with a lower risk of revision after primary total hip arthroplasty?

AIMS

The aim of this study was to investigate whether the use of antibiotic-loaded bone cement influenced the risk of revision surgery after primary total hip arthroplasty (THA) for osteoarthritis.

METHODS

The study involved data collected by the National Joint Registry (NJR) for England and Wales, Northern Ireland and the Isle of Man between 1 September 2005 and 31 August 2017. Cox proportional hazards were used to investigate the association between use of antibiotic-loaded bone cement and the risk of revision due to prosthetic joint infection (PJI), with adjustments made for the year of the initial procedure, age at the time of surgery, sex, American Society of Anesthesiologists (ASA) grade, head size, and body mass index (BMI). We looked also at the association between use of antibiotic-loaded bone cement and the risk of revision due to aseptic loosening or osteolysis.

RESULTS

The cohort included 418,857 THAs of whom 397,896 had received antibiotic-loaded bone cement and 20,961 plain cement. After adjusting for putative confounding factors, the risk of revision for PJI was lower in those in whom antibiotic-loaded bone cement was used (hazard ration (HR) 0.79; 95% confidence interval (CI) 0.64 to 0.98). There was also a protective effect on the risk of revision due to aseptic loosening or osteolysis, in the period of > 4.1 years after primary THA, HR 0.57, 95% CI 0.45, 0.72.

CONCLUSION

Within the limits of registry analysis, this study showed an association between the use of antibiotic-loaded bone cement and lower rates of revision due to PJI. The findings support the continued use of antibiotic-loaded bone cement in cemented THA. Cite this article: Bone Joint J 2020;102-B(8):997-1002.

Antibiotics and cement: what I need to know?

We conducted a systematic review about antibiotic-loaded bone cement (ALBC) with a focus on clinical evidence about ALBC in general, concerns about ALBC and ALBC cost.

The role of antibiotic-loaded bone cement in complicated knee arthroplasty: relevance of gentamicin allergy and benefit from revision surgery - a case control follow-up study and algorithmic approach

BACKGROUND

Antibiotic-loaded (particularly gentamicin) bone cement (BC) is widely used in total joint arthroplasty (TJA) to prevent periprosthetic infections (PPIs), but may itself cause implant failure. In light of a complete lack in literature, the objective was to assess the clinical relevance of gentamicin allergy for failure of cemented total knee arthroplasties in 25 out of 250 patients with positive patch test reactions to gentamicin and otherwise unexplained symptoms by evaluating benefits from revision with change to gentamicin-free cement.

METHODS

Fifteen of these 25 patients and their treating orthopaedic surgeons agreed to a re-assessment. They were surveyed regarding interim course of therapy and symptoms, including re-assessment of the Knee Injury and Osteoarthritis Outcome Score (KOOS), and underwent follow-up clinical and radiographic investigations. The initial use of gentamicin-loaded BC was reaffirmed by review of the primary implantation operative reports and respective implant passports. Primary and follow-up KOOS scores were analyzed regarding benefits from revision surgery by comparing nine patients with revision to six without revision.

RESULTS

Mean follow-up time was 38 months. The entirety of patients experienced an improvement of self-reported symptoms, with revision surgery (i.e., switching to gentamicin-free BC or uncemented total knee arthroplasty) yielding significantly greater improvement (p = 0.031): the nine revised patients reported a significant symptom relief (p = 0.028), contrary to the six unrevised patients (p = 0.14). Interestingly, the decision to proceed with revision surgery was significantly correlated with higher symptom severity (p = 0.05).

CONCLUSION

In symptomatic total knee arthroplasty with gentamicin allergy, uncemented revision arthroplasty or change to gentamicin-free BC provides significant symptom relief.

Comparison of infection in cemented, cementless and hybrid primary total knee arthroplasty: a network meta-analysis and systematic review of randomized clinical trials

BACKGROUND

Prosthetic joint infection (PJI) is a serious complication of joint replacement surgeries. Surgeons often take extra measures to reduce the risk of PJI. Whilst many studies have compared between cemented, cementless and hybrid fixation (femoral cementless, tibial cemented), most focus on survivorship, clinical and function outcome scores as primary endpoints. This meta-analysis aims to study the association between fixation methods and risk of PJI in primary total knee arthroplasty (TKA).

METHODS

A systematic review and network meta-analysis of randomized controlled trials (RCT) were performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Data from studies assessing prevalence of PJI in each fixation type were extracted and analysed.

RESULTS

Twelve RCT comprising a total of 1573 knees were included. Six RCT compared between cemented (n = 486 knees) and cementless (n = 440 knees) fixation, while six RCT compared between hybrid (n = 324 knees) and cementless (n = 323 knees) fixation. Network meta-analysis did not reveal any fixation type that significantly increased the infection rate in TKA. Rate of all infection was lowest in cemented TKA as compared to cementless (odds ratio (OR) 0.90, 95% confidence interval (CI) 0.35-2.28) and hybrid (OR 0.63, 95%CI 0.13-2.99) TKA. Rate of PJI requiring revision surgery was lowest in cementless TKA as compared to cemented (OR 0.89, 95%CI 0.30-2.41) and hybrid (OR 0.57, 95%CI 0.09-2.71) TKA. Rate of PJI not requiring revision surgery was lowest in cemented TKA as compared to hybrid (OR 0.56, 95%CI 0.06-6.10) and cementless (OR 0.55, 95% 0.14-5.63).

CONCLUSION

Unlike total hip arthroplasties, fixation method is not a predisposing risk factor for infections in TKA. However, this meta-analysis may not have sufficient statistical power to show a significant difference between fixation types. It is recommended that prophylactic precautions against other known risk factors for infection should still be clinically practiced.

LEVEL OF EVIDENCE

Level I, meta-analysis of randomized controlled trials.

Antibiotic containing bone cement in prevention of hip and knee prosthetic joint infections: A systematic review and meta-analysis

BACKGROUND

Prosthetic joint infection (PJI) is the most serious total joint arthroplasty (TJA) complication despite several aseptic and antiseptic preventive measures. There is no clear evidence or even consensus, whether antibiotic-loaded bone cement (ALBC) should be used, in addition to systemic short-term routine antibiotic prophylaxis, to reduce the risk of PJI in primary TJA. We aimed to analyze the efficacy of ALBC for prevention of PJI in patients undergoing primary TJA.

METHODS

We searched systematically for randomized controlled trials (RCTs) in PubMed, Scopus, Embase, Web of Science and Cochrane library. Two reviewers independently screened potentially eligible studies according to predefined selection criteria and assessed the risk of bias using a modified version of the Cochrane risk of bias tool. PJI was prespecified as the primary outcome of interest. The meta-analyses were based on risk ratios using random-effects model per default. For the purpose of sensitivity, the corresponding fixed effects model odds ratios were calculated with the use of the Peto method as well. To evaluate a potential difference in effect sizes using different types (subgroups) of antibiotics used in bone cement, and at different follow-up periods, we performed stratified meta-analyses.

RESULTS

Thirty-seven studies were eligible for the systematic review and qualitative synthesis, and 9 trials (6507 total joint arthroplasties) were included in this meta-analysis. Overall ALBC significantly reduced the risk of PJI following primary TJAs (RRs, 0.36; 95% CIs, 0.16 to 0.80; P = 0.01) with a moderate degree of inconsistency (I2 = 47%). Based on stratified meta-analyses the use of gentamicin appeared to have a better effect (P = 0.0005) in the total hip arthroplasty. Pooled data of different antibiotics used in knee arthroplasties showed a significant association of cefuroxime (RRs, 0.08; 95% CIs, 0.01 to 0.63; P = 0.02). Further, ALBCs significantly reduced the PJI at one and two years of follow-up (P = 0.03 and P = 0.005 respectively).

CONCLUSIONS

The evidence suggests that ALBCs are effective in reducing the PJI following primary TJA; i.e. between 20 and 84% reduced risk. However, the clear limitations of the available trial evidence highlight the need for joint-specific confirmatory trials, that will need to be designed as cluster-randomized trials of clinics in countries with well-functioning arthroplasty registries.The translational potential of this article: This meta-analysis highlights the prophylactic potential of ALBCs in lowering the risk of infection following primary hip or knee arthroplasties but emphasizes the need for more recent confirmatory trials.

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.

The Effect of TBB, as an Initiator, on the Biological Compatibility of PMMA/MMA Bone Cement

Acrylic bone cement is widely used in orthopedic surgery for treating various conditions of the bone and joints. Bone cement consists of methyl methacrylate (MMA), polymethyl methacrylate (PMMA), and benzoyl peroxide (BPO), functioning as a liquid monomer, solid phase, and polymerization initiator, respectively. However, cell and tissue toxicity caused by bone cement has been a concern. This study aimed to determine the effect of tri-n-butyl borane (TBB) as an initiator on the biocompatibility of bone cement. Rat spine bone marrow-derived osteoblasts were cultured on two commercially available PMMA-BPO bone cements and a PMMA-TBB experimental material. After a 24-h incubation, more cells survived on PMMA-TBB than on PMMA-BPO. Cytomorphometry showed that the area of cell spread was greater on PMMA-TBB than on PMMA-BPO. Analysis of alkaline phosphatase activity, gene expression, and matrix mineralization showed that the osteoblastic differentiation was substantially advanced on the PMMA-TBB. Electron spin resonance (ESR) spectroscopy revealed that polymerization radical production within the PMMA-TBB was 1/15–1/20 of that within the PMMA-BPO. Thus, the use of TBB as an initiator, improved the biocompatibility and physicochemical properties of the PMMA-based material.

A review of calcium phosphate cements and acrylic bone cements as injectable materials for bone repair and implant fixation

Treatment of bone defects caused by trauma or disease is a major burden on human healthcare systems. Although autologous bone grafts are considered as the gold standard, they are limited in availability and are associated with post-operative complications. Minimally invasive alternatives using injectable bone cements are currently used in certain clinical procedures, such as vertebroplasty and balloon kyphoplasty. Nevertheless, given the high incidence of fractures and pathologies that result in bone voids, there is an unmet need for injectable materials with desired properties for minimally invasive procedures. This paper provides an overview of the most common injectable bone cement materials for clinical use. The emphasis has been placed on calcium phosphate cements and acrylic bone cements, while enabling the readers to compare the opportunities and challenges for these two classes of bone cements. This paper also briefly reviews antibiotic-loaded bone cements used in bone repair and implant fixation, including their efficacy and cost for healthcare systems. A summary of the current challenges and recommendations for future directions has been brought in the concluding section of this paper.

Staphylococcus aureus Prosthetic Joint Infection Is Prevented by a Fluorine- and Phosphorus-Doped Nanostructured Ti-6Al-4V Alloy Loaded With Gentamicin and Vancomycin

Prosthetic joint infection (PJI) is one of the most devastating complications in orthopedic surgery. One approach used to prevent PJI is local antibiotic therapy. This study evaluates the antibiotic release, in vitro cytocompatibility and in vivo effectiveness in preventing PJI caused by Staphylococcus aureus (S. aureus) of the fluorine- and phosphorus-doped, bottle-shaped, nanostructured (bNT) Ti-6Al-4V alloy loaded with a mixture of gentamicin and vancomycin (GV). We evaluated bNT Ti-6Al-4V loading with a mixture of GV, measuring the release of these antibiotics using high-performance liquid chromatography. Further, we describe bNT Ti-6Al-4V GV cytocompatibility and its efficacy against S. aureus using an in vivo rabbit model. GV was released from bNT Ti-6Al-4V following a Boltzmann non-linear model and maximum release values were obtained at 240 min for both antibiotics. The cell proliferation of MCT3T3-E1 osteoblastic cells significantly increased at 48 (28%) and 168 h (68%), as did the matrix mineralization (52%) of these cells and the gene expression of three of the most important markers related to bone differentiation (more than threefold for VEGF and BGLAP, and 65% for RunX) on bNT Ti-6Al-4V GV compared with control. In vivo study results show that bNT Ti-6Al-4V GV can prevent S. aureus PJI according to histopathological and microbiological results. According to our results, bNT Ti-6Al-4V loaded with a mixture of GV using the soaking method is a promising biomaterial with favorable cytocompatibility and osteointegration, demonstrating local bactericidal properties against S. aureus. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:588-597, 2020.

Does the Effectiveness and Mechanical Strength of Kanamycin-Loaded Bone Cement in Musculoskeletal Tuberculosis Compare to Vancomycin-Loaded Bone Cement

BACKGROUND

Antibiotic-loaded bone cement (ALBC) is used to deliver antimycobacterial agents into the focal lesion of musculoskeletal tuberculosis. Although kanamycin is currently used as an antimycobacterial agent for the treatment of multidrug-resistant tuberculosis, there is no information about its suitability in ALBC.

METHODS

An in vitro experiment was conducted with cylindrical shape of 40 g of bone cement with 1, 2, and 3 g of kanamycin. Eluate (1 mL) was extracted from each specimen to measure the level of elution and antimycobacterial activity on days 1, 4, 7, 14, and 30. The quantity of kanamycin in eluates was evaluated by a liquid chromatography-mass spectrometry system, and the antimycobacterial activity of eluates against Mycobacterium tuberculosis H37Rv was calculated by comparing the minimal inhibitory concentration. The ultimate compression strength was conducted using a material testing system machine (Instron 3366; Instron, Norwood, MA) before and after elution.

RESULTS

Eluates from ALBC containing 2 and 3 g of kanamycin had effective antimycobacterial activity for 30 days, whereas eluates from ALBC containing 1 g of kanamycin were partially active until day 30. The pre-eluted compression strength of kanamycin-loaded cement and vancomycin-loaded cement was weaker as they contained a larger amount of antibiotics. There was no statistical difference between the strength of all kanamycin regimens and 1 g of vancomycin in the ultimate compression test. After 30 days of elution, the strength of all kanamycin-loaded cement and vancomycin-loaded cement cylinders was significantly lower than that of initial specimens (P < .05).

CONCLUSION

The antimycobacterial activity of ALBC containing more than 2 g of kanamycin was effective during a 30-day period. The ultimate compression strength of bone cement loaded with 1-3 g of kanamycin was comparable with 1 g of vancomycin while maintaining effective elution until day 30.

Can nasal Staphylococcus aureus screening and decolonization prior to elective total joint arthroplasty reduce surgical site and prosthesis-related infections? A systematic review and meta-analysis

Background

Nasal Staphylococcus aureus (S. aureus) screening and decolonization has been widely used to reduce surgical site infections (SSIs) prior to total knee and hip arthroplasty (TKA and THA). However, it remains considerably controversial. The aim of this study was to ascertain whether this scheme could reduce SSIs and periprosthetic joint infections (PJIs) following elective primary total joint arthroplasty (TJA).

Methods

A systematic search was performed in MEDLINE, Embase, and the Cochrane Library until October, 2019. Outcomes of interest included SSI, PJI, superficial infection, and different bacterial species that caused infections. Data from eligible studies were then extracted and synthesized. Pooled odds ratios (OR) and 95% confidence intervals (CIs) were calculated. We also performed additional analyses to evaluate whether there were differences in postoperative SSIs caused by S. aureus or other bacteria.

Results

Nine studies were included in our meta-analysis. The pooled data elucidated that nasal S. aureus screening and decolonization dramatically mitigated the risk of SSI, PJI, and superficial infection compared to nondecolonization group. The analysis of bacterial species causing infection also showed that the S. aureus infections postoperative were significantly decreased in the decolonization group. However, there was no statistical difference in the SSI caused by other bacteria between the two groups.

Conclusion

S. aureus screening and decolonization prior to elective primary THA and TKA could significantly decrease the risk of SSI and PJI. However, more robust studies are needed to further evaluate the impact of S. aureus screening and decolonization on infection risk after TJA.

Cutibacterium acnes Infection in Orthopedics: Microbiology, Clinical Findings, Diagnostic Strategies, and Management

Cutibacterium (formerly called Propionibacterium) acnes is a human skin flora often implicated in orthopedic infections. The unique characteristics of this microorganism make the diagnosis of infection difficult. The diagnosis often is made based on clinical evidence, radiographic signs, and laboratory and/or surgical findings combined. Treatment often involves both pharmacologic and surgical methods. In addition, formation of biofilms and increased resistance to drugs exhibited by the microorganism can require combined antimicrobial therapy. Prophylactic measures are particularly important, but no single method has been shown to fully eliminate the risk of C acnes infections. Previous reports have focused on C acnes infections involving surgical implants or after certain orthopedic procedures, particularly in the shoulder and spine. This article reviews current clinical, diagnostic, and treatment principles for C acnes in orthopedics in general. [Orthopedics. 2020; 43(1):52-61.].

Antibiotic-impregnated bone cement for preventing infection in patients receiving primary total hip and knee arthroplasty: A meta-analysis

BACKGROUND

Surgical-site infections after primary total joint arthroplasty (TJA) are a significant issue. Antibiotic-impregnated bone cement (AIBC) has been widely used for the treatment of infected joints, but routine use of AIBC in primary TJA remains controversial. In this systematic review, we evaluated the efficacy of AIBC in reducing surgical-site infections after primary TJA.

METHODS

We systematically searched Pubmed, EMbase, Cochrane Library, CMB, CNKI, and WanFang Data for studies (published until June 1, 2019) evaluating AIBC use in reducing infection rates. Two reviewers independently screened the literature according to inclusion and exclusion criteria, extracted data, and assessed the methodological quality of included studies. Meta-analysis was performed using Review Manager 5.3 software. The registration number is CRD42017078341 in PROSPERO.

RESULTS

In total, 10 studies were included, resulting in a sample size of 13,909 arthroplasty cases. The overall pooled data demonstrated that, compared with systemic antibiotics, AIBC was more effective in decreasing deep infection rates (odds ratio [OR] = 0.35, 95% confidence interval [CI] = 0.14-0.89, P = .030), although there were higher superficial infection rates with AIBC (OR = 1.53, 95% CI = 1.11-2.11, P = .010). Compared to systemic antibiotics alone, AIBC with systemic antibiotics significantly decreased deep infection rates (OR = 0.55, 95% CI = 0.41-0.75, P = .0001) but there was no difference in superficial infection rates (OR = 1.43, 95% CI = 0.81-2.54, P = .220). In the subgroup analysis, both randomized controlled trials and cohort studies had reduced deep infection rates after primary TJA (OR = 0.61, 95% CI = 0.37-0.99, P = .050 and OR = 0.49, 95% CI = 0.34-0.70, P = .0001, respectively). AIBC decreased deep infection rates in both total hip and knee arthroplasty (OR = 0.25, 95% CI = 0.12-0.52, P = .0002 and OR = 0.62, 95% CI = 0.45-0.87, P = .005, respectively). Deep infection rates were significantly decreased by AIBC with gentamicin (OR = 0.31, 95% CI = 0.20-0.49, P < .00001) but unaffected by AIBC with cefuroxime (OR = 0.35, 95% CI = 0.10-1.20, P = .100). Deep infection rates in the AIBC and control groups were similar when laminar airflow was applied to the operating room (OR = 0.90, 95% CI = 0.60-1.35, P = .620); however, without laminar airflow, the efficacy of AIBC in decreasing deep infection rates was significantly higher than that of control group (OR = 0.21, 95% CI = 0.08-0.59, P = .003).

CONCLUSIONS

AIBC may significantly decrease deep infection rates after primary total hip and knee arthroplasty, with or without systemic antibiotics.

Antibiotic-loaded bone cement is associated with a lower risk of revision following primary cemented total knee arthroplasty: an analysis of 731,214 cases using National Joint Registry data

AIMS

Antibiotic-loaded bone cements (ALBCs) may offer early protection against the formation of bacterial biofilm after joint arthroplasty. Use in hip arthroplasty is widely accepted, but there is a lack of evidence in total knee arthroplasty (TKA). The objective of this study was to evaluate the use of ALBC in a large population of TKA patients.

MATERIALS AND METHODS

Data from the National Joint Registry (NJR) of England and Wales were obtained for all primary cemented TKAs between March 2003 and July 2016. Patient, implant, and surgical variables were analyzed. Cox proportional hazards models were used to assess the influence of ALBC on risk of revision. Body mass index (BMI) data were available in a subset of patients.

RESULTS

Of 731 214 TKAs, 15 295 (2.1%) were implanted with plain cement and 715 919 (97.9%) with ALBC. There were 13 391 revisions; 2391 were performed for infection. After adjusting for other variables, ALBC had a significantly lower risk of revision for any cause (hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77 to 0.93; p < 0.001). ALBC was associated with a lower risk of revision for all aseptic causes (HR 0.85, 95% CI 0.77 to 0.95; p < 0.001) and revisions for infection (HR 0.84, 95% CI 0.67 to 1.01; p = 0.06). The results were similar when BMI was added into the model, and in a subanalysis where surgeons using only ALBC over the entire study period were excluded. Prosthesis survival at ten years for TKAs implanted with ALBC was 96.3% (95% CI 96.3 to 96.4) compared with 95.5% (95% CI 95.0 to 95.9) in those implanted with plain cement. On a population level, where 100 000 TKAs are performed annually, this difference represents 870 fewer revisions at ten years in the ALBC group.

CONCLUSION

After adjusting for a range of variables, ALBC was associated with a significantly lower risk of revision in this registry-based study of an entire nation of primary cemented knee arthroplasties. Using ALBC does not appear to increase midterm implant failure rates. Cite this article: Bone Joint J 2019;101-B:1331-1347.

Effect of Antibiotic-Impregnated Bone Cement in Primary Total Knee Arthroplasty

BACKGROUND

The purpose of this study is to evaluate the effect of commercially available antibiotic-impregnated bone cement (AIBC) on (1) prosthetic joint infections (PJIs) and (2) surgical site infections (SSIs) after primary total knee arthroplasty (TKA).

METHODS

A review of primary TKAs between 2014 and 2017 from an institutional database was conducted. This identified 12,541 cases which were separated into AIBC (n = 4337) and non-AIBC (8,164) cohorts. Medical records were reviewed for PJIs and SSIs (mean 2-year postoperative period). Infection rates between the cohorts were compared with univariate analyses followed by subanalysis of high risk patients (defined as having 2 or more of the following characteristics: >65 years, body mass index >40, or Charlson Comorbidity Index score >3). To control for confounders, multivariate analyses were performed with regression models adjusted for age, gender, body mass index, comorbidities, year, operative times, and lengths of stay.

RESULTS

On univariate analysis, PJI rates were higher in the AIBC cohort (1.0%) compared to the non-AIBC cohort (0.5%, P < .001). Subanalysis of the high risk patients also showed that PJI rates were higher in the AIBC cohort (1.9% vs 0.6%, P < .01). After adjusting for potential confounders, no significant associations between PJIs and AIBC use were found (odds ratio 1.4, 95% confidence interval 0.9-2.3, P = .133). Similarly, no significant differences in SSI rates were observed between the AIBC (2.9%) and non-AIBC cohorts (2.4%, P = .060) and no significant associations between SSIs and AIBC were found with multivariate analysis (odds ratio 1.0, 95% confidence interval CI 0.8-1.3, P = .948).

CONCLUSION

This study found that there was no clinically or statistically significant decrease in infection rates with AIBC in primary TKAs.

Antibiotic-Loaded Bone Cement in Primary Total Knee Arthroplasty: Utilization Patterns and Impact on Complications Using a National Database

BACKGROUND

The routine usage of antibiotic-loaded bone cement (ALBC) in primary total knee arthroplasty (TKA) is controversial. Its effectiveness in reducing infection risk remains unclear while high-dose antibiotics can lead to multiple adverse effects. The purpose of this population-based study is to evaluate utilization patterns of ALBC in primary TKA and its impact on clinical outcomes.

METHODS

This retrospective cohort study used data from the nationwide Premier Healthcare claims database (2006-2016). Multivariable models estimated associations between ALBC use and early postoperative infection, kidney injury, allergic reaction, hospital readmission, cost, and length of stay.

RESULTS

ALBC was used in 27.2% of all primary TKAs (N = 1,184,270). Usage increased from 17.3% to 30.2% in 2006-2010, then plateaued. Study covariates differed minimally between groups, suggesting nonselective ALBC use. Utilization was lower in rural (21.4%) and higher in large (>500 beds; 29.4%) hospitals. After adjusting for relevant covariates, ALBC use was associated with significantly decreased odds for early postoperative infection (odds ratio, 0.89; confidence interval, 0.83-0.96) and increased odds for acute kidney injury (odds ratio, 1.06; confidence interval, 1.02-1.11).

CONCLUSION

With utilization rates of around 30%, we found that ALBC reduced odds for early postoperative infection and increased odds for kidney injury. Strong consideration should be given for selective use of ALBC in primary TKA.

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.

Bacterial biofilm formation is variably inhibited by different formulations of antibiotic-loaded bone cement in vitro

PURPOSE

The aim of the present study was to quantitatively assess biofilm growth on the surface of bone cements discs containing different antibiotics, including colistin and linezolid. Biofilms of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Staphylococcus epidermidis were grown on bone cement discs for 96 h.

METHODS

Biofilm amounts were measured by confocal laser microscopy using live/dead staining and dedicated software at different time intervals (48, 72, and 96 h).

RESULTS

Bone cement containing vancomycin was not effective at reducing MRSA biofilm formation 96 h following bacterial inoculation. At a comparable time interval, linezolid-, clindamycin-, and aminoglycoside-loaded cement was still active against this biofilm. At the 72- and 96-h observations, S. epidermidis biofilm was present only on tobramycin and gentamicin discs. P. aeruginosa biofilms were present on cement discs loaded with colistin at all time intervals starting from the 48-h observation, whereas no biofilms were detected on tobramycin or gentamicin discs.

CONCLUSION

Bone cements containing different antibiotics have variable and time-dependent windows of activity in inhibiting or reducing surface biofilm formation. The effectiveness of bone cement containing vancomycin against MRSA biofilm is questionable. The present study is clinically relevant, because it suggests that adding the right antibiotic to bone cement could be a promising approach to treat periprosthetic infections. Indeed, the antibiofilm activity of different antibiotic-loaded bone cements could be preoperatively assessed using the current methodology in two-stage exchange procedures.

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.

Duration of antibiotic treatment and risk of recurrence after surgical management of orthopaedic device infections: a multicenter case-control study

Background

Device-related infections in orthopaedic and trauma surgery are a devastating complication with substantial impact on morbidity and mortality. Systemic suppressive antibiotic treatment is regarded an integral part of any surgical protocol intended to eradicate the infection. The optimal duration of antimicrobial treatment, however, remains unclear. In a multicenter case-control study, we aimed at analyzing the influence of the duration of antibiotic exposure on reinfection rates 1 year after curative surgery.

Methods

This investigation was part of a federally funded multidisciplinary network project aiming at reducing the spread of multi-resistant bacteria in the German Baltic region of Pomerania. We herein used hospital chart data from patients treated for infections of total joint arthroplasties or internal fracture fixation devices at three academic referral institutions. Subjects with recurrence of an implant-related infection within 1 year after the last surgical procedure were defined as case group, and patients without recurrence of an implant-related infection as control group. We placed a distinct focus on infection of open reduction and internal fixation (ORIF) constructs. Uni- and multivariate logistic regression analyses were employed for data modelling.

Results

Of 1279 potentially eligible patients, 269 were included in the overall analysis group, and 84 contributed to an extramedullary fracture-fixation-device sample. By multivariate analysis, male sex (odds ratio [OR] 2.06, 95% confidence interval [CI] 1.08 to 3.94, p = 0.029) and facture fixation device infections (OR 2.05, 95% CI 1.05 to 4.02, p = 0.036) remained independent predictors of reinfection. In the subgroup of infected ORIF constructs, univariate point estimates suggested a nearly 60% reduced odds of reinfection with systemic fluoroquinolones (OR 0.42, 95% CI 0.04 to 2.46) or rifampicin treatment (OR 0.41, 95% CI 0.08 to 2.12) for up to 31 days, although the width of confidence intervals prohibited robust statistical and clinical inferences.

Conclusion

The optimal duration of systemic antibiotic treatment with surgical concepts of curing wound and device-related orthopaedic infections is still unclear. The risk of reinfection in case of infected extramedullary fracture-fxation devices may be reduced with up to 31 days of systemic fluoroquinolones and rifampicin, although scientific proof needs a randomized trial with about 1400 subjects per group. Concerted efforts are needed to determine which antibiotics must be applied for how long after radical surgical sanitation to guarantee sustainable treatment success.

Audiometric threshold shifts after total knee arthroplasty by using gentamicin-loaded bone cement

Background/aim

The aim of this study was to investigate postoperative audiometric threshold shifts in patients who underwent primary total knee arthroplasty (TKA) using gentamicin-loaded bone cement (GLBC) in comparison with the ones who underwent TKA without GLBC.

Materials and methods

Forty patients (gentamicin group) who underwent primary TKA using GLBC and 29 patients (control group) who underwent primary TKA using standard bone cement were included in this prospective case-control study. Baseline pure-tone audiometric evaluation was performed preoperatively and repeated at the postoperative third day for all patients. Control audiometric evaluation was performed weekly for patients who were diagnosed with ototoxicity according to audiometric threshold shifts.

Results

Ototoxicity was diagnosed in 8 of 40 patients (20%) in the gentamicin group according to postoperative audiometric threshold shifts, whereas no ototoxicity was observed in the control group. Patients who were diagnosed with ototoxicity had no permanent audiometric threshold shifts in follow-up audiometric evaluation and these patients had no clinical complaints of difference in hearing.

Conclusion

According to our results, audiometric threshold shifts can be detected in patients who undergo primary TKA using gentamicin loaded bone cement. However, no permanent shifts were observed during close follow-up.

Cemented versus uncemented femoral component total hip arthroplasty in elderly patients with primary osteoporosis: retrospective analysis with 5-year follow-up

Objective

To compare medium-term clinical and radiological outcomes of primary unilateral uncemented (UN) or cemented (CE) femoral component total hip arthroplasty (THA) in elderly patients with osteoporosis.

Methods

Consecutive patients with osteoporosis who underwent primary unilateral UN or CE THAs at our institution from 2006 to 2013 were retrospectively reviewed. All consecutive procedures were managed by high-volume surgeons, using UN or CE THA approaches. Follow-up assessments occurred at 1, 3, 6, 9, and 12 months postoperatively, and yearly thereafter. Patient-related functional outcomes were assessed using the Harris Hip Score (HHS). Primary and secondary endpoints were early revision (<5 years) and functional outcome.

Results

In total, 496 primary unilateral THAs (CE, n = 184; UN, n = 182) were assessed with a median follow-up period of 75 months (range, 65–86 months). From 3 months after surgery to the final follow-up, HHS was consistently superior in the CE group. Respective prosthetic loosening rates in the UN and CE groups were 26.4% and 16.8% at a minimum of 5 years. There was a significant difference in rate of early revision (7.6% CE vs. 14.8% UN).

Conclusion

Compared with UN THA, CE THA exhibits a superior outcome in elderly patients with primary osteoporosis.

The mid-term outcome of dialysis-dependent patients undergoing primary total knee arthroplasty and total hip arthroplasty: A retrospective study

BACKGROUND

Dialysis-dependent patients undergoing primary total knee and total hip arthroplasty have been associated with higher in-hospital mortality and complication rates. We investigated the mid-term implant survival, patient survival, and functional outcomes in these patients and reviewed our complications.

METHODS

We retrospectively reviewed dialysis-dependent patients undergoing primary total knee or total hip arthroplasty in our hospital between November 2004 and January 2015, with a minimum follow-up of 24 months. Thirty-four patients with 39 total knee arthroplasties were included (M:F, 33.3%:66.7%, mean age: 68.8 years, mean follow-up: 55.9 ± 28.3 months). Twenty-seven patients with 31 total hip arthroplasties were included (M:F, 22.6%:77.4%, mean age: 62.3 years, mean follow-up: 55.8 ± 23.4 months).

RESULTS

In the total knee arthroplasty group, there were two in-hospital mortality cases (3.5%) and two cases of implant failure (5.1%). The mean Knee Society Score was 84.0 ± 20.7. In the total hip arthroplasty group, there were three cases of implant failure (9.7%). The mean Harris Hip Score was 81.1 ± 23.9. The complications we encountered for both groups were instability and infection.

CONCLUSION

Dialysis-dependent patients who had undergone total joint arthroplasty are associated with high mortality rate. In our experience, satisfactory mid-term results can be achieved in these patients with manageable complications and low-implant failure rates.

Antibiotic-loaded Bone Cement as Prophylaxis in Total Joint Replacement

One of its most serious complications associated with arthroplasty is the development of infections. Although its prevalence is only between 0.5% and 3%, in some cases it can lead to death. Therefore, an important challenge in joint surgery is the prevention of infections when an arthroplasty is performed. The use of antibiotic-loaded cements could be a suitable tool due to numerous advantages. The main advantage of the use of antibiotic loading into bone cement derives directly from antibiotic release in the effect site, allowing achievement of high concentrations at the site of action, and minimal or no systemic toxicity. This route of administration was first described by Buchholz and Engelbrecht. In the case of infection treatment, this is an established method and its good results have been confirmed. However, its role in infection prevention, and, therefore, the use of these systems in clinical practice, has proved controversial because of the uncertainty about the development of possible antibiotic resistance after prolonged exposure time, their effectiveness, the cost of the systems, toxicity and loosening of mechanical properties. This review discusses all these topics, focusing on effectiveness and safety, antibiotic decisions, cement type, mixing method, release kinetics and future perspectives. The final objective is to provide the orthopaedic surgeons the right information in their clinical practice based on current evidence.

Cement mantle thickness does not influence serum or local gentamicin concentrations in hybrid total hip arthroplasty: a randomised controlled trial

INTRODUCTION

We investigated the in vivo gentamicin elution kinetics of Hi-Fatigue Gentamicin Bone Cement (AAP Biomaterials GmbH) in serum and drain fluid after hybrid hip arthroplasty and the relationship with cement mantle thickness.

METHODS

We compared in a randomised, non-blinded prospective study, the local and systemic gentamicin concentrations in 2 groups. The thin cement mantle group ( n = 16) received a stem implanted line-to-line with the broach, whereas the thick group ( n = 14) had an undersized stem. Gentamicin concentrations were measured in drain fluid and serum at set intervals for 3 days postoperatively.

RESULTS

In both groups, local gentamicin concentrations were similar. After a high initial burst above the minimal inhibitory concentration (thin: 57.2 mg/L (SD 34.4), thick: 54.9 mg/L (SD 19.9), p = 0.823) local gentamicin concentrations declined rapidly. In both groups, serum concentrations never exceeded toxic levels (maximum 1.08 mg/L).

CONCLUSION

In hybrid total hip arthroplasty, Hi-Fatigue Gentamicin Bone Cement resulted in effective and safe gentamicin concentrations. Clinical trial protocol number: PMCI 12/02.

Current Options and Emerging Biomaterials for Periprosthetic Joint Infection

PURPOSE OF REVIEW

Infection in the setting of total joint arthroplasty, referred to as periprosthetic joint infection (PJI), is a devastating complication requiring prolonged and costly treatment. The unique environment around an artificial joint and ability of surrounding tissues to sequester bacteria collectively make prevention, diagnosis, and treatment of this condition challenging. In light of the unique pathogenesis of PJI, this review explores the limitations of contemporary treatments and discusses novel treatment options.

RECENT FINDINGS

Recent advancements in local antibiotic delivery platforms for preventing and treating PJI include titanium nanotube arrays, synthetic polymers, resorbable hydrogels, and cyclodextrin-based drug delivery options. In particular, cyclodextrins have facilitated great advancements in other clinical disorders and have demonstrated early promise as a future option in the arena of PJI. Novel treatment modalities for PJI optimize the implant surfaces to prevent bacterial biofilm formation or provide prolonged intra-articular antibiotic dosing to eradicate bacteria.

Do local antibiotics reduce periprosthetic joint infections? A retrospective review of 744 cases

Periprosthetic joint infections (PJI) are uncommon but not rare and have significant morbidity and financial implications. Local antibiotics have been used successfully in other areas of orthopedics to reduce postoperative infections, but this method has not been proven in total joint arthroplasty (TJA). Beginning January 1, 2014, our primary investigators began using surgical site lavage with providone-iodine solution and administering 2 g of vancomcyin powder in the surgical wound prior to capsule closure for all primary and revision total hip and knee arthroplasties. We performed a retrospective chart review of patients two years prior to this date and two years after to compare occurrence of PJI. The groups were broken down into patients who received local antibiotics versus those who did not. The groups were further broken down by type of surgery performed; primary or revision total hip or knee arthroplasty. Administration of local antibiotics was preventative for PJI only in the primary total knee arthroplasty group (aOR = 0.28, 0.09-0.89). Administration of local antibiotics trended towards a preventative effect for PJI in the other groups but was not statistically significant. Patients receiving local antibiotics had similar blood urea nitrogen and creatinine levels postoperatively compared to the no antibiotics group indicating minimal systemic effects of local vancomycin powder. While the use of local antibiotics may prevent PJI, more data is required especially in the revision arthroplasty groups.

Local Antibiotic Delivery Systems: Current and Future Applications for Diabetic Foot Infections

Foot infections are common among diabetic patients with peripheral neuropathy and/or peripheral arterial disease, and it can be the pivotal event leading to a minor or major amputation of the lower extremity. Treatment of diabetic foot infections, especially deep-seated ones, remains challenging, in part because impaired blood perfusion and the presence of biofilms can impair the effectiveness of systemic antibiotics. The local application of antibiotics is an emerging field in the treatment of diabetic foot infections, with demonstrable advantages. These include delivery of high concentrations of antibiotics in the affected area, limited systemic absorption, and thus negligible side effects. Biodegradable vehicles, such as calcium sulfate beads, are the prototypical system, providing a good elution profile and the ability to be impregnated with a variety of antibiotics. These have largely superseded the nonbiodegradable vehicles, but the strongest evidence available is for calcium bead implantation for osteomyelitis management. Natural polymers, such as collagen sponge, are an emerging class of delivery systems, although thus far, data on diabetic foot infections are limited. There is recent interest in the novel antimicrobial peptide pexiganan in the form of cream, which is active against most of the microorganisms isolated in diabetic foot infections. These are promising developments, but randomized trials are required to ascertain the efficacy of these systems and to define the indications for their use. Currently, the role of topical antibiotic agents in treating diabetic foot infections is limited and outside of routine practice.

A cost-effectiveness modelling study of strategies to reduce risk of infection following primary hip replacement based on a systematic review

BACKGROUND

A deep infection of the surgical site is reported in 0.7% of all cases of total hip arthroplasty (THA). This often leads to revision surgery that is invasive, painful and costly. A range of strategies is employed in NHS hospitals to reduce risk, yet no economic analysis has been undertaken to compare the value for money of competing prevention strategies.

OBJECTIVES

To compare the costs and health benefits of strategies that reduce the risk of deep infection following THA in NHS hospitals. To make recommendations to decision-makers about the cost-effectiveness of the alternatives.

DESIGN

The study comprised a systematic review and cost-effectiveness decision analysis.

SETTING

77,321 patients who had a primary hip arthroplasty in NHS hospitals in 2012.

INTERVENTIONS

Nine different treatment strategies including antibiotic prophylaxis, antibiotic-impregnated cement and ventilation systems used in the operating theatre.

MAIN OUTCOME MEASURES

Change in the number of deep infections, change in the total costs and change in the total health benefits in quality-adjusted life-years (QALYs).

DATA SOURCES

Literature searches using MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature and the Cochrane Central Register of Controlled Trials were undertaken to cover the period 1966-2012 to identify infection prevention strategies. Relevant journals, conference proceedings and bibliographies of retrieved papers were hand-searched. Orthopaedic surgeons and infection prevention experts were also consulted.

REVIEW METHODS

English-language papers only. The selection of evidence was by two independent reviewers. Studies were included if they were interventions that reported THA-related deep surgical site infection (SSI) as an outcome. Mixed-treatment comparisons were made to produce estimates of the relative effects of competing infection control strategies.

RESULTS

Twelve studies, six randomised controlled trials and six observational studies, involving 123,788 total hip replacements (THRs) and nine infection control strategies, were identified. The quality of the evidence was judged against four categories developed by the National Institute for Health and Care Excellence Methods for Development of NICE Public Health Guidance ( http://publications.nice.org.uk/methods-for-the-development-of-nice-public-health-guidance-third-edition-pmg4 ), accessed March 2012. All evidence was found to fit the two highest categories of 1 and 2. Nine competing infection control interventions [treatments (Ts) 1-9] were used in a cohort simulation model of 77,321 patients who had a primary THR in 2012. Predictions were made for cases of deep infection and total costs, and QALY outcomes. Compared with a baseline of T1 (no systemic antibiotics, plain cement and conventional ventilation) all other treatment strategies reduced risk. T6 was the most effective (systemic antibiotics, antibiotic-impregnated cement and conventional ventilation) and prevented a further 1481 cases of deep infection, and led to the largest annual cost savings and the greatest gains to QALYs. The additional uses of laminar airflow and body exhaust suits indicate higher costs and worse health outcomes.

CONCLUSIONS

T6 is an optimal strategy for reducing the risk of SSI following THA. The other strategies that are commonly used among NHS hospitals lead to higher cost and worse QALY outcomes. Policy-makers, therefore, have an opportunity to save resources and improve health outcomes. The effects of laminar air flow and body exhaust suits might be further studied if policy-makers are to consider disinvesting in these technologies.

LIMITATIONS

A wide range of evidence sources was synthesised and there is large uncertainty in the conclusions.

FUNDING

The National Institute for Health Research Health Technology Assessment programme and the Queensland Health Quality Improvement and Enhancement Programme (grant number 2008001769).

The association between cement type and the subsequent risk of revision surgery in primary total hip replacement

Background and purpose - To further improve the success of joint replacement surgery, attention needs to be paid to variations associated with improved or worsened outcomes. We investigated the association between the type of bone cement used and the risk of revision surgery after primary total hip replacement. Methods - We conducted a prospective study of data from the National Joint Registry for England and Wales between April 1, 2003 and December 31, 2013. 199,205 primary total hip replacements performed for osteoarthritis where bone cement was used were included. A multilevel over-dispersed piecewise Poisson model was used to estimate differences in the rate of revision by bone cement type adjusted for implant type, head size, age, sex, ASA grade, and surgical approach. Results - The rate of revision was higher in DePuy CMW3 medium viscosity with gentamicin (IRR 2.0, 95% CI 1.5-2.7) and DePuy SmartSet high viscosity plain (IRR 2.7, 95% CI 1.1-5.5), and lower in DePuy CMW1 high viscosity plain (IRR 0.44, 95% CI 0.19-0.89) bone cements compared with Heraeus Palacos high viscosity with gentamicin. Revision rates were similar between plain and antibiotic-loaded bone cement. Interpretation - The majority of bone cements performed similarly well, excluding DePuy SmartSet high viscosity and CMW3 high viscosity with gentamicin, which both had higher revision rates. We found no clear differences by viscosity or antibiotic content.