Infection following total knee arthroplasty: prevention and management

A LDH-Derived Metal Sulfide Nanosheet-Functionalized Bioactive Glass Scaffold for Vascularized Osteogenesis and Periprosthetic Infection Prevention/Treatment

Periprosthetic infection and prosthetic loosing stand out as prevalent yet formidable complications following orthopedic implant surgeries. Synchronously addressing the two complications is long-time challenging. Herein, a bioactive glass scaffold (BGS) functionalized with MgCuFe-layered double hydroxide (LDH)-derived sulfide nanosheets (BGS/MCFS) is developed for vascularized osteogenesis and periprosthetic infection prevention/treatment. Apart from the antibacterial cations inhibiting bacterial energy and material metabolism, the exceptional near-infrared-II (NIR-II) photothermal performance empowers BGS/MCFS to eliminate periprosthetic infections, outperforming previously reported functionalized BGS. The rough surface topography and the presence of multi-bioactive metal ions bestow BGS/MCFS with exceptional osteogenic and angiogenic properties, with 8.5-fold and 2.3-fold enhancement in bone mass and neovascularization compared with BGS. Transcriptome sequencing highlights the involvement of the TGF-β signaling pathway in these processes, while single-cell sequencing reveals a significant increase in osteoblasts and endothelial cells around BGS/MCFS compared to BGS.

Suction drain usage has no benefit following revision total hip and knee arthroplasty

INTRODUCTION

The use of drains after primary total joint arthroplasty (TJA) has shown little benefit. Few studies have investigated drain usage after revision TJA. The purpose of this study was to determine whether utilizing suction drains is beneficial for patients undergoing revision arthroplasty.

MATERIALS AND METHODS

We performed a comprehensive literature review utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines from the PubMed, Embase, Web of Science, and Cochrane Library. Inclusion criteria of this review were all original articles written in English investigating the efficacy and safety of closed suction drainage in revision TKA or THA, reporting at least one of the following outcome measures: (1) estimated blood loss (EBL), (2) perioperative hemoglobin change, (3) needs for transfusion, (4) postoperative infection, and (5) wound complications. Articles were excluded if they are not available in English or they included case reports, systematic reviews, comments, editorials, surveys, or animal studies prior to July 22, 2023. A total of six studies met inclusion criteria. In total, 655 patients had a drain while 1765 patients did not have a drain after revision total hip or knee arthroplasty. Primary outcomes included for meta-analysis included estimated blood loss (EBL), postoperative hemoglobin, need for transfusion. Other data extracted includes postoperative infections, and wound complications.

RESULTS

Six studies met the inclusion criteria. In total, 655 patients had drains, while 1765 patients did not after revision total hip or knee arthroplasty. The average age of the patients was 66.1+/- 3.4 years, and the average BMI was 30.3 +/-0.8. There was no difference in postoperative infections (p = 0.14), wound complications (p = 0.621) or need for transfusion (p = 0.521) between the two groups. There was also no difference in EBL (Hedges' g CI[-3.52, 2.77]) or postoperative Hb (Hedges' g CI[-1.65, 2.41]) between patients with and without drains.

CONCLUSIONS

Our results do not show any benefit from drain placement after revision total hip or knee arthroplasty. With the increased cost, time and need for drain removal, this is likely an unnecessary intervention.

LEVEL OF EVIDENCE

Level III, systematic review and meta-analysis.

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.

Presentation and management of infection in total disc replacement: A review

Background

Total disc replacement (TDR) is widely used in the treatment of cervical and lumbar spine pathologies. Although TDR infection, particularly delayed infection, is uncommon, the results can be devastating, and consensus on clinical management remains elusive. In this review of the literature, we asked: (1) What are the reported rates of TDR infection; (2) What are the clinical characteristics of TDR infection; and (3) How has infection been managed for TDR patients?

Methods

We performed a search of the literature using PubMed and Embase to identify studies that reported TDR infection rates, the identification and management of TDR infection, or TDR failures with positive cultures. Twenty database studies (17 focusing on the cervical spine and 3 on the lumbar spine) and 10 case reports representing 15 patients were reviewed along with device Summary of Safety and Effectiveness Data reports.

Results

We found a lack of clarity regarding how infection was diagnosed, indicating a variation in clinical approach and highlighting the need for a standard definition of TDR infection. Furthermore, while reported infection rates were low, the absence of a clear definition prevented robust data analysis and may contribute to underreporting in the literature. We found that treatment strategy and success rely on several factors including patient symptoms and time to onset, microorganism type, and implant positioning/stability.

Conclusions

Although treatment strategies varied throughout the extant literature, common practices in eliminating infection and reconstructing the spine emerged. The results will inform future work on the creation of a more robust definition of TDR infection and as well as recommendations for management.

Predictors of reoperation and survival experience for primary total knee arthroplasty in young patients with degenerative and inflammatory arthritis

INTRODUCTION

While total knee arthroplasty (TKA) is typically implemented in patients > 65 years old, young patients may need to undergo TKA for pain relief and functional improvement. Current data are limited by older cohorts and short-term survival rates. This study aimed to examine a large sample size of patients with degenerative and inflammatory conditions who underwent primary TKA at a young (≤ 40) age to identify predictors of reoperation, as well 15-year survivorship.

MATERIALS AND METHODS

A retrospective study was performed on 77 patients (92 surgeries) who underwent primary TKA at ≤ 40 years old, between January 1990 and January 2020. Patient charts were reviewed and a multivariable logistic regression model identified independent predictors of reoperation. Kaplan-Meier analysis was employed to build survival curves and log-rank tests analyzed survival between groups.

RESULTS

Of the 77 patients, the median age at the time of surgery was 35.7 years (IQR: 31.2-38.7) and median follow-up time was 6.88 years. Twenty-one (22.8%) primary TKAs underwent 24 reoperations, most commonly due to stiffness (n = 9, 32.1%) and infection (n = 13, 46.4%) more significantly in the OA group (p = 0.049). There were no independent predictors of reoperation in multivariable analysis, and 15-year revision-free survivorship after TKA did not differ by indication (77.3% for OA/PTOA vs. 96.7% for autoimmune, p = 0.09) or between ≤ 30 and 31-40 year age groups (94.7% vs. 83.6%, p = 0.55).

CONCLUSIONS

In this cohort of patients ≤ 40 years old, revision-free survival was comparable to that reported in the literature for older TKA patients with osteoarthritis/autoimmune conditions (81-94% at 15-years). Though nearly a quarter of TKAs required reoperation and causes of secondary surgery differed between degenerative and inflammatory arthritis patients, there were no significant predictors of increased reoperation rate. Very young patients ≤ 30 years old did not have an increased risk of revision compared to those aged 31-40 years.

When to lavage in the absence of a sonographically visible joint effusion in painful total knee arthroplasty: a retrospective longitudinal study

OBJECTIVE

To determine if knee arthroplasty without sonographically visible effusion needs to undergo lavage to rule out infection.

METHODS

Patients were accrued by a retrospective search of a longitudinally maintained radiology database looking for patients referred for ultrasound guided aspiration of suspected TKA infection. Clinical presentations, laboratory tests, intraoperative findings, and follow-up were reviewed.

RESULTS

Four hundred sixty-nine patients were included (mean age of 67 years (range, 36-91)) including 251 females. Four hundred three patients had effusions, of which 57 were infected based on ultrasound-guided and surgical aspirates. Sixty-four patients lacked effusions, of which 47 underwent lavage at the clinicians' request, with 6/47 infected. Nineteen patients without effusion were not lavaged at the clinicians' request due to low suspicion, and none were infected. Patients with positive lavage cultures all had clinical risk factors. Infection rates were significantly higher in patients with joint effusion and clinical suspicion for infection compared to absent joint effusion and absent clinical suspicion. A significantly higher proportion of patients with hyperemia or moderate-severe synovial thickening on ultrasound were symptomatic and had joint effusion and positive joint cultures. Aspiration of native fluid had 85% sensitivity and 100% specificity while lavage had a sensitivity of 57% and specificity of 100%. Negative predictive value for native aspirates was 94% compared to 86% for lavage.

CONCLUSION

A TKA with low clinical suspicion of infection does not need to undergo lavage in the absence of a sonographically visible effusion.

ACR Appropriateness Criteria® Imaging After Total Knee Arthroplasty: 2023 Update

Total knee arthroplasty is the most commonly performed joint replacement procedure in the United States. This manuscript will discuss the recommended imaging modalities for six clinical variants; 1. follow-up of symptomatic or asymptomatic patients with a total knee arthroplasty. Initial imaging, 2. Suspected infection after total knee arthroplasty. Additional imaging following radiographs, 3. Pain after total knee arthroplasty. Infection excluded. Suspect aseptic loosening or osteolysis or instability. Additional imaging following radiographs, 4. Pain after total knee arthroplasty. Suspect periprosthetic or hardware fracture. Additional imaging following radiographs, 5. Pain after total knee arthroplasty. Measuring component rotation. Additional imaging following radiographs, and 6. Pain after total knee arthroplasty. Suspect periprosthetic soft-tissue abnormality unrelated to infection, including quadriceps or patellar tendinopathy. Additional imaging following radiographs. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Effects of tourniquet on surgical site wound infection and pain after total knee arthroplasty: A meta-analysis

The application of a tourniquet (TNQ) for haemostasis in total knee arthroplasty (TKA) is controversial and lacking systematic evaluation. This meta-analysis assessed relevant international data to quantitatively evaluate the implications of using TNQ in TKA, further guide clinical diagnosis and treatment, and improve postoperative outcomes. A comprehensive computerised search of PubMed, Embase, Cochrane Library, Chinese National Knowledge Infrastructure, VIP, and Wanfang databases was conducted to retrieve randomised controlled trials on the application of TNQ in TKA published from database inception to August 2023. The included data, ultimately comprising 1482 patients in 16 studies, were collated and subjected to meta-analysis using Stata 17.0 software. The results showed that the use of TNQ during TKA led to significantly higher rates of postoperative surgical site wound infection (3.96% vs. 1.79%, odds ratio: 2.15, 95% confidence intervals [CIs]: 1.11-4.16, p = 0.023) and wound pain scores on the first (standardised mean difference [SMD]: 0.65, 95% CI: 0.35-0.94, p < 0.001), second (SMD: 0.66, 95% CI: 0.01-1.31, p = 0.045), and third (SMD: 0.68, 95% CI: 0.31-1.05, pP < 0.001) day after the procedure. In conclusion, the application of TNQ in TKA increases the risk of postoperative surgical site wound infection and worsens short-term postoperative wound pain; therefore, TNQ should be used sparingly during TKA, or its use should be decided in conjunction with the relevant clinical indications and the surgeon's experience.

Low-Dose Aspirin for Venous Thromboembolism Prophylaxis is Associated With Lower Rates of Periprosthetic Joint Infection After Total Joint Arthroplasty

BACKGROUND

Aspirin as a venous thromboembolism (VTE) prophylactic agent has been shown to have antistaphylococcal and antibiofilm roles. Optimal acetylsalicylic acid (ASA) dosage would facilitate antimicrobial effects while avoiding over-aggressive inhibition of platelet antimicrobial function. Our purpose was to determine the periprosthetic joint infection (PJI) rate after total joint arthroplasty in patients receiving low-dose ASA (81 mg twice a day), in comparison to high-dose ASA (325 mg twice a day).

METHODS

We conducted a retrospective cohort study between 2008 and 2020. Eligible patients were older than 18 years, underwent primary total joint arthroplasty, both total knee arthroplasty and total hip arthroplasty, had a minimum 30-day follow-up, and received a full course ASA as VTE prophylaxis. Patients' records were reviewed for PJI, according to Musculoskeletal Infection Society criteria. Patients were excluded if they underwent revision arthroplasty, had a history of coagulopathy, or had an ASA regimen that was not completed. In total 15,825 patients were identified, 8,761 patients received low-dose ASA and 7,064 received high-dose ASA.

RESULTS

The high-dose cohort had a higher PJI rate (0.35 versus 0.10%, P = .001). This relationship was maintained when comparing subgroups comprising total knee arthroplasty (0.32 versus 0.06%, P = .019) or total hip arthroplasty (0.38 versus 0.14%, P = .035) and accounting for potentially confounding demographic and surgical variables (odds ratio = 2.59, 95% CI = 1.15-6.40, P = .028).

CONCLUSION

Comparing low-dose to high-dose ASA as a VTE prophylactic agent, low-dose ASA had a lower PJI rate. This may be attributable to a balance of anti-infective properties of ASA and antiplatelet effects.

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.

Delayed normalization of C-Reactive protein and erythrocyte sedimentation rate was not associated with inferior clinical outcomes after total knee arthroplasty

BACKGROUND

The purpose of this study aimed to identify the proportion of patients with delayed normalization of C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) after TKA, to determine postoperative thresholds predictive of prolonged elevation. Further, we aimed to determine if the clinical outcomes of patients with prolonged elevation were inferior to those without prolonged elevation.

METHODS

The records of 211 unilateral and 320 bilateral TKA were reviewed. Patients were divided into the normal and elevation group based on CRP and ESR levels at 6 weeks and 3 months. The temporal pattern of CRP and ESR change in both groups was compared, and thresholds predictive of elevation at 6 weeks and 3 months were identified. Further, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index and Tegner activity scale of both groups at 6 months, 1 year, and 2 years after TKA were compared.

RESULTS

The proportion of patients with elevated CRP and ESR at 6 weeks and 3 months was CRP: 24.2%, 10%, ESR: 51.6%, 29.9% in unilateral and CRP: 31.5%, 10.6%, ESR: 58.1%, 42.7% in bilateral TKA. The thresholds for elevation at 6 weeks and 3 months were 9.5 mg/dL, 11.4 mg/dL (CRP at 6 weeks) and 81.5 mm/h, 74.5 mm/h (ESR at 3 months). There was no difference in the WOMAC score and Tegner activity scale between both groups.

CONCLUSIONS

CRP and ESR are often elevated for a prolonged period even in the absence of infection after TKA. Such cases show distinct temporal patterns, which are predictable, and do not appear to have a significant effect on clinical outcome.

Synovial calprotectin for the diagnosis of periprosthetic joint infection: a diagnostic meta-analysis

Background

Periprosthetic joint infections (PJI) are a rare but severe complication of total joint arthroplasty (TJA). However, the diagnosis of PJI remains difficult. It is one of the research that focuses about diagnosis for PJI for majority researchers to discover a novel biomarker. This meta-analysis tried to evaluate diagnostic value of synovial calprotectin for PJI.

Methods

This meta-analysis search of the literature was conducted in PubMed, EMBASE, Web of Science, and the Cochrane Library. Literature quality was appraised using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) based on RevMan (version 5.3). The diagnostic value of calprotectin for PJI was evaluated by calculating sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), diagnostic score and area under SROC (AUC) based on the Stata version 14.0 software. We conduct subgroup analysis according to the study design, cutoff values, the country of study, and gold standard.

Results

Seven studies were included in this meta-analysis. The pooled sensitivity of synovial calprotectin for the diagnosis of PJI was 0.94 (95% CI, 0.87–0.98), and the specificity was 0.93 (95% CI, 0.87–0.96). The pooled AUC, PLR, and NLR for synovial calprotectin were 0.98 (95% CI, 0.96–0.99), 13.65 (95% CI, 6.89–27.07), and 0.06 (95% CI, 0.02–0.15), respectively. The pooled diagnostic score and DOR were 5.4 (95% CI, 3.96–6.85) and 222.32 (95% CI, 52.52–941.12), respectively.

Conclusion

In summary, this meta-analysis indicates that synovial calprotectin is a promising biomarker of assistant diagnosis for PJI, as well as recommended test for excluding diagnostic tool.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02746-2.

Interactions between the foreign body reaction and Staphylococcus aureus biomaterial-associated infection. Winning strategies in the derby on biomaterial implant surfaces

Biomaterial-associated infections (BAIs) are an increasing problem where antibiotic therapies are often ineffective. The design of novel strategies to prevent or combat infection requires a better understanding of how an implanted foreign body prevents the immune system from eradicating surface-colonizing pathogens. The objective of this review is to chart factors resulting in sub-optimal clearance of Staphylococcus aureus bacteria involved in BAIs. To this end, we first describe three categories of bacterial mechanisms to counter the host immune system around foreign bodies: direct interaction with host cells, modulation of intercellular communication, and evasion of the immune system. These mechanisms take place in a time frame that differentiates sterile foreign body reactions, BAIs, and soft tissue infections. In addition, we identify experimental interventions in S. aureus BAI that may impact infectious mechanisms. Most experimental treatments modulate the host response to infection or alter the course of BAI through implant surface modulation. In conclusion, the first week after implantation and infection is crucial for the establishment of an S. aureus biofilm that resists the local immune reaction and antibiotic treatment. Although established and chronic S. aureus BAI is still treatable and manageable, the focus of interventions should lie on this first period.

Periprosthetic Fungal Infections in Severe Endoprosthetic Infections of the Hip and Knee Joint-A Retrospective Analysis of a Certified Arthroplasty Centre of Excellence

The treatment of periprosthetic joint infections (PJI), and especially of re-infections, poses a highly complex problem in orthopaedic surgery. While fungal infections are rare, they present a special challenge. The therapy is often protracted and based on limited evidence. A total of 510 hip and knee revision surgeries were analysed for the occurrence of bacterial and fungal PJI. In patients with PJI, the duration of the hospital stay and the incidence of disarticulation of the infected joint were recorded. Out of the analysed revision arthroplasties, 43.5% were due to PJI. Monomicrobial infection occurred in 55.2%, dual microbial infection in 21.4%, and polymicrobial (≥3 different bacterial or fungal species) infection in 17.2% of the cases. Overall, Candida species were detected in 12.4% cases. Candida albicans was the main fungal pathogen. In 6.9% of cases, disarticulation of the joint was the only option to control PJI. The detection of polymicrobial infection more than doubled in follow-up revisions and there was a strong association between detection of Candida infection and disarticulation (OR 9.39). The majority of fungal infections were mixed infections of bacteria and Candida albicans. The choice of a biofilm penetrating antimycotic, e.g., caspofungin, together with a sufficient standard procedure for detection and surgical treatment can help to control the infection situation. Fungal infection often proves to be more difficult to treat than anticipated and is more frequent than expected.

Comparison of Revision Risk Based on Timing of Knee Arthroscopy Prior to Total Knee Arthroplasty

BACKGROUND

Knee arthroscopy may be performed prior to total knee arthroplasty (TKA) in patients with symptomatic degenerative knee changes that do not yet warrant TKA. The purpose of this study was to determine whether the time interval between knee arthroscopy and subsequent primary TKA is associated with increased rates of revision and certain complications following TKA.

METHODS

Data from 2006 to 2017 were collected from a national insurance database. Patients who underwent knee arthroscopy within 1 year prior to primary TKA were identified and stratified into the following cohorts based on stratum-specific likelihood ratio (SSLR) analysis: 0 to 15, 16 to 35, 36 to 43, and 44 to 52 weeks from the time of knee arthroscopy to TKA. Univariate and multivariable analyses were conducted to determine the association between these specific time intervals and rates of revision surgery, periprosthetic joint infection (PJI), aseptic loosening, and manipulation under anesthesia.

RESULTS

In total, 130,128 patients were included in this study; 6,105 (4.7%) of those patients underwent knee arthroscopy within 1 year prior to TKA and 124,023 (95.3%) underwent TKA without any prior knee surgery, including arthroscopy (the control group). Relative to the control group, the likelihood of undergoing revision surgery was significantly greater in patients who underwent knee arthroscopy ≤15 weeks (odds ratio [OR]: 1.79; 95% confidence interval [CI]: 1.43 to 2.22; p < 0.001) or 16 to 35 weeks (OR: 1.20; 95% CI: 1.01 to 1.42; p = 0.035) prior to TKA. Patients were at significantly increased risk for PJI if knee arthroscopy was done ≤35 weeks prior to TKA, and all 4 time groups that underwent knee arthroscopy within 1 year before TKA were at increased risk for manipulation under anesthesia.

CONCLUSIONS

We found a time-dependent relationship between the timing of knee arthroscopy and complications following TKA, with the prevalence of revision surgery and PJI increasing as knee arthroscopy was performed closer to the time of TKA. This study suggests that an interval of at least 36 weeks should be maintained between the 2 procedures to minimize risks of PJI and revision surgery.

LEVEL OF EVIDENCE

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

Revision for periprosthetic joint infection rate stratified by seasonality of operation in a national population of total and unicompartmental knee arthroplasty patients: a register-based analysis

Aim: The aim of this study was to investigate whether the revision rate for periprosthetic joint infection (PJI) depends on the season of the primary procedure using a national population of knee arthroplasty (KA) patients. Seasonal variation of some surgical procedures has been observed to impact subsequent infection risks, with a higher risk of revision for surgeries performed during summer, but an analysis of PJI rates based on a national arthroplasty register has yet to be completed. We hypothesized that an increased risk of revision due to PJI could be demonstrated in a national population when primary surgery was performed during the summer. Methods: The Danish Knee Arthroplasty Registry (DKR) was used to determine the risk of revision due to PJI within 2 years after primary surgery. All primary KA procedures between 1 January 1997 and 31 December 2014 and revisions until 31 December 2016 were identified. Smoothing spline regression was used to identify possible seasonal pattern effects of the primary procedure on revision risk, and logistic regression was used to calculate risk of infection differences between seasons. Results: A total number of 124 809 primary procedures was registered in the study period. After excluding duplicates and matching primary procedures with the first revisions within 2 years after the primary procedure, 3391 were identified. Of these, 348 cases were recorded with an indication of deep infection requiring revision. Spline regression analyses did not demonstrate any clear seasonal pattern of the primary procedure regarding the risk of revision for infection or any other cause. Logistic regression found a decreased risk of revision for infection when the primary procedure was performed during the summer in the years 1997 to 2005, no influence on the risk of revision for infection in 2005 to 2012, and an increased risk of revision for infection following summer procedures during the years 2013 to 2014. Conclusion: It was not possible to demonstrate a consistent seasonal variation of the risk of revision for PJI following primary KA. This is most likely because the underlying etiologies for PJI are not subject to seasonal variation.

Increased Diagnostic Certainty of Periprosthetic Joint Infections by Combining Microbiological Results with Histopathological Samples Gained via a Minimally Invasive Punching Technique

Background: The diagnosis of low-grade infections of endoprostheses is challenging. There are still no unified guidelines for standardised diagnostic approaches, recommendations are categorised into major and minor criteria. Additional histopathological samples might sustain the diagnosis. However, ambulatory preoperative biopsy collection is not widespread. Method: 102 patients with hip or knee endoprosthesis and suspected periprosthetic joint infection (PJI) were examined by arthrocentesis with microbiological sample and histopathological punch biopsy. The data were retrospectively analysed for diagnosis concordance. Results: Preoperative microbiology compared to intraoperative results was positive in 51.9% (sensitivity 51.9%, specificity 97.3%). In comparison of preoperative biopsy to intraoperative diagnostic results 51.9% cases were positive (sensitivity 51.9%, specificity 100.0%). The combination of preoperative biopsy and microbiology in comparison to intraoperative results was positive in 70.4% of the cases (sensitivity 70.4%, specificity 97.3%). Conclusion: The diagnosis of PJI is complex. One single method to reliably detect an infection is currently not available. With the present method histopathological samples might be obtained quickly, easily and safely for the preoperative detection of PJI. A combination of microbiological and histopathological sampling increases the sensitivity up to 18.5% to detect periprosthetic infection.

Minimizing Penile Prosthesis Implant Infection: What Can We Learn From Orthopedic Surgery?

The implantation of penile protheses for the surgical treatment of erectile dysfunction has risen in popularity over the past several decades. Considerable advances have been made in surgical protocol and device design, specifically targeting infection prevention. Despite these efforts, device infection remains a critical problem, which causes significant physical and emotional burden to the patient. The aim of this review is to broaden the discussion of best practices by not only examining practices in urology, but additionally delving into the field of orthopedic surgery to identify techniques and approaches that may be applied to penile prothesis surgery.

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.

Unusual Listeria monocytogenes hematogenous infection in total knee replacement treated with one-stage revision surgery

Septic arthritis due to Listeria monocytogenes (LM) is extremely rare and most infections due to this organism are seen in immunocompromised patients. We describe a patient without immunological compromise, with a late total knee arthroplasty infection caused by LM treated with one-stage revision surgery. She had an elevated erythrocyte sedimentation rate (79 mm/h) and C-reactive protein (13 mg/dL). Aspiration of the knee joint yielded purulent fluid; cultures showed LM. The patient was given 6 weeks of intravenous ampicillin, followed by trimethoprim/sulfamethoxazole, and finally amoxicillin orally for 7 months. Two years after revision surgery, radiographs showed no evidence of implant loosening. This is a single case and although one-stage approach seemed to have worked, it should not be recommended on the basis of a single report.

An evidence-based review of enhanced recovery after surgery in total knee replacement surgery

Rationale: Enhanced recovery after surgery is gaining popularity among orthopaedic surgeons across the globe and hence a strong evidence base had to be reviewed to make an evidence-based sustainable protocol.

Methods

The following databases, PubMed, OVID, Cochrane database and EMBASE were searched. The search was limited to 15 components of enhanced recovery after surgery programme which is divided into preoperative, intraoperative and postoperative phases. Inclusion criteria were restricted to articles published in English within the last 15 years and articles comprising of unicompartmental arthroplasty, revision knee arthroplasty, bilateral simultaneous knee arthroplasty and only hip arthroplasty excluded. The full texts were analysed and controversies and limitations of various studies were summarised.

Discussion

Each component of the programme was thoroughly reviewed and strength and weaknesses of the evidence base summarised. The strength of the evidence was assessed by critically appraising the study methodology and justifying the appropriateness of the inclusion in enhanced recovery after surgery protocol.

Conclusion

Enhanced recovery after surgery has already been used successfully in various surgical specialities. Enhanced recovery after surgery programmes in knee arthroplasty are yet to be established as a universal practice to be adopted globally. This evidence-based review provides an insight into the best evidence linked to each component and their rationale for inclusion in the proposed enhanced recovery after surgery protocol.

Prosthetic Joint Infection Trends at a Dedicated Orthopaedics Specialty Hospital

Introduction

Historically, a majority of prosthetic joint infections (PJIs) grew Gram-positive bacteria. While previous studies stratified PJI risk with specific organisms by patient comorbidities, we compared infection rates and microbiologic characteristics of PJIs by hospital setting: a dedicated orthopaedic hospital versus a general hospital serving multiple surgical specialties.

Methods

A retrospective review of prospectively collected data on 11,842 consecutive primary hip and knee arthroplasty patients was performed. Arthroplasty cases performed between April 2006 and August 2008 at the general university hospital serving multiple surgical specialties were compared to cases at a single orthopaedic specialty hospital from September 2008 to August 2016.

Results

The general university hospital PJI incidence rate was 1.43%, with 5.3% of infections from Gram-negative species. In comparison, at the dedicated orthopaedic hospital, the overall PJI incidence rate was substantially reduced to 0.75% over the 8-year timeframe. Comparing the final two years of practice at the general university facility to the most recent two years at the dedicated orthopaedics hospital, the PJI incidence was significantly reduced (1.43% vs 0.61%). Though the overall number of infections was reduced, there was a significantly higher proportion of Gram-negative infections over the 8-year timeframe at 25.3%.

Conclusion

In transitioning from a multispecialty university hospital to a dedicated orthopaedic hospital, the PJI incidence has been significantly reduced despite a greater Gram-negative proportion (25.3% versus 5.3%). These results suggest a change in the microbiologic profile of PJI when transitioning to a dedicated orthopaedic facility and that greater Gram-negative antibiotic coverage could be considered.

Knee replacement surgery significantly elevates the urinary inflammatory biomarkers neopterin and 7,8-dihydroneopterin

CONTEXT

Knee arthroplasty surgery is significant trauma, leading to an activated immune system causing inflammation and oxidative stress. Many current biomarkers are invasive, costly, and often slow to analyse, limiting their use for rapid inflammatory measurements.

OBJECTIVES

We have examined the use of urinary neopterin and total neopterin in knee arthroplasty patients to non-invasively measure oxidative stress and inflammation from immune system activation. We aim to validate the use of these biomarkers for quick, cost effective and predictive measurements of post-surgical inflammation assessment.

METHODOLOGY

19 Knee arthroplasty patients were analysed pre-operatively and for a defined post-operative period to determine the urinary levels of neopterin and total neopterin (neopterin +7,8-dihydroneopterin) using high performance liquid chromatography with fluorescence detection. These results were then compared to a control group of 20 participants with normal knee function.

RESULTS

7,8-Dihydroneopterin was stable in urine over 12 h when refrigerated. Knee arthritis was associated with an increase in pre-operative neopterin (oxidative stress) and total neopterin (inflammation). The subsequent arthroplasty surgery generated a significant increase neopterin and total neopterin. Both biomarkers were reduced immediately post-operatively, before becoming elevated on the following days. There was no clear evidence of an association between initial neopterin and total neopterin levels and a patient's level of inflammation during in-hospital recovery.

CONCLUSIONS

The stability of 7,8-dihydroneopterin in urine allows for its use as an inflammatory marker. Urinary neopterin and total neopterin provided a fast, non-invasive, and simple measure of oxidative stress and inflammation after knee arthroplasty.

Preoperatively elevated serum inflammatory markers increase the risk of periprosthetic joint infection following total knee arthroplasty in patients with osteoarthritis

Background

The purpose of this study was to evaluate the prevalence of preoperatively elevated serum inflammatory markers and to determine its association with periprosthetic joint infection (PJI) in patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA).

Methods

From January 2010 to May 2014, we retrospectively reviewed 3,376 consecutive patients who were scheduled for unilateral TKA due to OA. Patients with inflammatory arthritis, posttraumatic arthritis, previous knee surgery, simultaneous surgery or arthroplasty, and comorbidity with autoimmune disease, hepatitis, renal disease, respiratory tract infections, urinary tract infection, and malignancy were excluded. One hundred and forty patients with preoperatively elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) were enrolled. The control group was matched by age, sex, body mass index, and year of index surgery in 1:1 ratio. All patients were followed for a minimum of 1 year or until the occurrence of PJI. PJI was defined based on the criteria in the International Consensus Meeting. A multivariate Cox proportional hazards model was utilized to calculate the HR and 95% CI.

Results

The prevalence of preoperatively elevated inflammatory markers was 4.1%. The rate of PJI was significantly higher in the both elevated ESR and CRP groups (12.5%, 4/32) compared with both normal group (1.4%, 2/140) and either high group (0.9%, 1/108) (P<0.001). Patients with preoperative elevated ESR and CRP had a significant risk of PJI compared to those with normal serum inflammatory markers (HR: 15.8, 95% CI: 2.57–96.7, P=0.003) after adjusting confounding factors. The cumulative rate for PJI was 6.3% (95% CI: 0%–14.27%) at 1 year and 16.5% (95% CI: 0%–30.66%) at 5 years for both high ESR and CRP groups, which was significantly higher than other 2 groups (P=0.0002).

Conclusion

Although the prevalence of preoperatively elevated ESR and CRP is low, routine examination of ESR and CRP preoperatively might be necessary to prevent subsequent PJI in patients with OA following TKA.

Does Prior Failed Debridement Compromise the Outcome of Subsequent Two-Stage Revision Done for Periprosthetic Joint Infection Following Total Knee Arthroplasty?

BACKGROUND

There has been a debate regarding the outcomes of 2-stage revision total knee arthroplasty (TKA) when debridement, antibiotics, irrigation, and implant retention (DAIR) had been carried out previously. The purpose of this study is to evaluate the influence of prior failed DAIR (F-DAIR) on the outcomes of 2-stage revision TKA done for periprosthetic joint infection (PJI).

METHODS

This is a retrospective study of a consecutive series of 184 knees that completed 2-stage revision TKA for PJI, operated by a single surgeon between January 2000 and July 2011. The cohort was divided into 2 groups: (1) with previous F-DAIR (88 knees) and (2) direct 2-stage revision (96 knees).

RESULTS

At an average follow-up of 5.3 years, the failure rate was 23.86% (21/88 knees) in the F-DAIR group and 15.62% (15/96) in the direct 2-stage revision group. Prior F-DAIR procedure was associated with approximately twice the risk of failure compared to direct 2-stage surgery (hazards ratio 1.94, 95% confidence interval 1.01-3.714, P = .047). Excluding PJIs caused by methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, and Pseudomonas from analysis revealed similar failure rates between the 2 groups. The Knee Society Clinical Score, Knee Society Functional Score, and final range of motion at final follow-up were lower in the F-DAIR group. Incidence of culture negativity and infection with resistant organisms was higher in the F-DAIR group. The rates of eradication of methicillin-resistant Staphylococcus aureus and Pseudomonas infection were much lower in the F-DAIR group.

CONCLUSION

A failed prior DAIR results in higher failure rates, lower functional outcome, and increased risk of wound-related complications.

ACR Appropriateness Criteria® Imaging After Total Knee Arthroplasty

Total knee arthroplasty (TKA) is the most commonly performed joint replacement procedure in the United States and annual demand for primary TKA is expected to grow by 673% by 2030. The first part provides an overview of imaging modalities (radiographs, CT, MRI, ultrasound, and various nuclear medicine studies) and discusses their usefulness in the imaging evaluation of TKA. The second part focuses on evidence-based imaging and imaging-guided intervention algorithms for the workup of TKA and its complications, including routine follow-up, component wear, periprosthetic infection, aseptic loosening, granulomas/osteolysis, conventional and rotational instability, periprosthetic fracture, patellar complications, and a variety of periprosthetic soft tissue abnormalities. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Does Use of Lidocaine Affect Culture of Synovial Fluid Obtained to Diagnose Periprosthetic Joint Infection (PJI)? An In Vitro Study

Background

Synovial fluid culture (SFC) is recommended as one of the major diagnostic criteria by the Musculoskeletal Infection Society (MSIS) for diagnosing periprosthetic joint infection (PJI). Local anesthetic agents are used for anesthesia and analgesia in some clinical settings to relieve pain. As a local anesthetic, lidocaine is safely used in arthrocentesis to obtain synovial fluid. The goal of this study was to determine if infiltration anesthesia with additive-free lidocaine 2% has antibacterial effects that might interfere with subsequent SFC.

Material/Methods

Eight isolates of reference strains of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Streptococcus pyogenes, and Candida albicans were incubated on the plates. Each bacterial suspension was formed by 50-fold dilution before the test lidocaine 2% was added. For each strain, bacterial suspension was divided into 2 groups (5 samples each) exposed either lidocaine 2% or sterile non-bacteriostatic 0.45% saline. The antimicrobial property of lidocaine 2% was determined by measuring the bacterial density on agar plates incubated for 24 h and comparing it with controls unexposed to lidocaine 2%.

Results

Exposure to lidocaine 2% negatively affected microbial viability in vitro. Of the lidocaine 2% exposure, reference strains but no Streptococcus pyogenes strain resulted in fewer colony-forming units compared with the sterile saline control. The antibacterial property of lidocaine 2% appears to affect the ability to culture the organism in synovial fluid.

Conclusions

Lidocaine 2% has strong antimicrobial activities against some commonly encountered bacterial strains in PJI. As a result, infiltration anesthesia with additive-free lidocaine 2% before the arthrocentesis procedure may affect the results of SFC. To further evaluate its potential antibacterial usefulness in clinical applications, studies are needed to assess the ability of lidocaine to reduce the risk of iatrogenic infections.

Synovial Fluid Leukocyte Esterase in the Diagnosis of Peri-Prosthetic Joint Infection: A Systematic Review and Meta-Analysis

BACKGROUND

Peri-prosthetic joint infection (PJI) is a serious and frequent complication of total joint arthroplasty (TJA). Recently, synovial fluid leukocyte esterase (LE), measurement of which is convenient and fast, has been examined as a marker of PJI. We summarized the articles describing synovial fluid LE as a biomarker for the diagnosis of PJI and assessed its diagnostic value in patients suspected of having PJI.

METHODS

We searched with appropriate key words in PubMed, Embase, Web of Science, the Cochrane database, and Science Direct. Eligible studies providing sufficient data to construct 2 × 2 contingency tables were chosen on the basis of several criteria, and the quality of the chosen studies was assessed. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated for those studies. The summary receiver operating characteristic (SROC) curve and the area under the SROC (AUSROC) were used to evaluate the overall diagnostic performance of LE.

RESULTS

Eleven studies were found suitable for this systematic review. Among them, eight articles with a total of 1,011 participants qualified for meta-analysis. The pooled sensitivity, specificity, and DOR were 0.90 (95% confidence interval [CI] 0.76-0.96), 0.97 (95% CI 0.95-0.98), and 310.76 (95% CI 103.86-929.88), respectively. The SROC was 0.98 (95% CI 0.96-0.99). Sub-group analysis indicated that the sample inclusion criteria might be the main source of heterogeneity. Publication bias was suggested by an asymmetrical funnel plot (p = 0.144).

CONCLUSION

Although the result of synovial fluid LE assay can be influenced by sample-related factors, it is more specific as a means to exclude PJI.

Synovial Fluid C-reactive Protein as a Diagnostic Marker for Periprosthetic Joint Infection: A Systematic Review and Meta-analysis

Background:

Periprosthetic joint infection (PJI) is the main cause of failure following total joint arthroplasty. Until now, the diagnosis of PJI is still confronted with technical limitations, and the question of whether synovial fluid biomarker, C-reactive protein (CRP), can provide high value in the diagnosis of PJI remains unanswered and, therefore, was the aim of the study.

Methods:

First, we conducted a systematic review on CRP in the diagnosis of PJI by searching online databases using keywords such as “periprosthetic joint infection”, “synovial fluid”, and “C-reactive protein”. Eligible studies providing sufficient data to construct 2 × 2 contingency tables were then selected based on the list of criteria and the quality of included studies was assessed subsequently. Finally, the reported sensitivity, specificity, diagnostic odds ratio (DOR), summary receiver operating characteristic (SROC) curve, and the area under the SROC (AUSROC) were pooled together and used to evaluate overall diagnostic performance.

Results:

Seven studies were included in our review, six of which comprising a total of 456 participants were further investigated in our meta-analysis. The pooled sensitivity, specificity, and DOR were 0.92 (95% confidence interval [CI]: 0.86–0.96), 0.90 (95% CI: 0.87–0.93), and 101.40 (95% CI: 48.07–213.93), respectively. The AUSROC was 0.9663 (standard error, 0.0113).

Conclusions:

Synovial fluid CRP is a good biomarker for the diagnosis of PJI with high sensitivity and specificity.

Elevated Body Mass Index Is Associated With Early Total Knee Revision for Infection

BACKGROUND

Obesity affects over half a billion people worldwide, including one-third of men and women in the United States. Obesity is associated with higher postoperative complication rates after total knee arthroplasty (TKA). It remains unknown whether obese patients progress to revision TKA faster than nonobese patients.

METHODS

A total of 666 consecutive primary TKAs referred to an academic tertiary care center for revision TKA were retrospectively stratified according to body mass index (BMI), reason for revision TKA, and time from primary to revision TKA.

RESULTS

When examining primary TKAs referred for revision TKA, increasing BMI adversely affected the mean time to revision TKA. The percent of referred TKAs revised by 5 years was 54% for a normal BMI, 64% for an overweight patient, 71% for an obese class I patient, 68% for an obese class II patient, and 73% for a morbidly obese patient. There was a significant difference in time to revision TKA between patients with normal BMI and elevated BMI (P = .005). There was a significant increase in early revision TKA for infection in patients with an elevated BMI (54%, 74/138) when compared with the normal BMI patients (24%, 8/33, P < .003, relative risk ratio = 2.3, absolute risk = 30%, number needed to treat = 3.3). There was no significant increase in acute, early, midterm, or late revision TKA for aseptic loosening and/or osteolysis, instability, stiffness, or other causes between patients with normal BMI and elevated BMI.

CONCLUSION

An elevated BMI is a risk factor for early referral to a tertiary care center for revision TKA. Specifically, orthopedic surgeons should convey to overweight and obese patients that they have at least a 130% increased relative risk and a 30% absolute risk of revision TKA for an early infection if referred for revision TKA. Patient expectations and counseling as well as reimbursement should account for the greater risks when performing a TKA on patients with an elevated BMI.

Approach to Decrease Infection Following Total Joint Arthroplasty

Surgical site infection in total joint arthroplasty is a challenging complication that warrants discussion with regard to prevention and management. Limiting postoperative infection rate is a paramount quest in the orthopedic community. Several preoperative risk factors have been identified in orthopedic literature with regards to likelihood of developing postoperative infection. This article evaluates several factors that predispose total joint arthroplasty patients to infection. Methods of patient surgical preparation designed to decrease postoperative infection, decreasing intraoperative traffic during procedural settings, and elaborate intraoperative prophylactic advancements are assessed. Approaches to decrease postoperative infection by discussing means of lowering rates of postoperative transfusion, wound drainage, and hematoma formation are analyzed.

Association of Cigarette Use and Complication Rates and Outcomes Following Total Ankle Arthroplasty

BACKGROUND

Tobacco use is a known risk factor for increased perioperative complications and having worse functional outcomes in many orthopedic procedures. To date, no study has elucidated the effect of cigarette smoking on complications or functional outcome scores after total ankle replacement (TAR).

METHODS

We retrospectively reviewed the records of 642 patients who had TAR between June 2007 and February 2014 with a known smoking status. These patients were separated into 3 groups based on their smoking status: 34 current smokers, 249 former smokers, and 359 nonsmokers. Outcome scores and perioperative complications, which included infection, wound complications, revision surgeries, and nonrevision surgeries were compared between the groups.

RESULTS

When comparing perioperative complications in the active smokers to the nonsmokers, we found a statistically significant increased risk of wound breakdown (hazard ratio [HR] 3.08, P = .047). Although the active smokers had an increased rate of infection (HR 2.61, P = .392), revision surgery (HR 1.75, P = .470), and nonrevision surgery (HR 1.69, P = .172), these findings were not statistically significant. With regard to outcome scores, all groups demonstrated improvement at 1- and 2-year follow-up compared with their preoperative outcome scores. However, the active smokers had less improvement in their outcome scores than the nonsmokers at 1- and 2-year follow-up. Furthermore, there was no significant difference in the outcome scores when comparing the nonsmokers to the former smokers.

CONCLUSION

Active cigarette smokers undergoing TAR had a significantly higher risk of wound complications and worse outcome scores compared with nonsmokers and former smokers. Furthermore, tobacco cessation appeared to reverse the effects of smoking, which allowed TAR to be an effective and safe procedure for providing pain relief and improving function in former smokers as they had perioperative complication rates and outcomes similar to nonsmokers.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

The Use of a Closed-Suction Drain in Revision Knee Arthroplasty May Not Be Necessary: A Prospective Randomized Study

BACKGROUND

The benefit of suction drains (SD) for the first 24-48 hours following joint replacement surgery is controversial. We aimed to determine if there is any difference in the early outcome of revision TKA when performed with, or without SD.

METHODS

83 cases indicated for revision knee arthroplasty were randomized to receive (42) or not receive (41) a deep intra-articlular drain. First-stage revisions for treating periprosthetic infection were excluded. Patients were statistically compared for demographic parameters, early complications and early knee functional outcome. The assessed outcomes included total blood loss, number of transfusions, fever and wound complication rate at 24 months follow-up. In addition, the change in knee society score at 12 weeks postoperatively was compared between the groups.

RESULTS

There were no significant difference in demographic factors, wound complications, knee scores at 12 weeks and infection rate 24 months after surgery in either group. Average blood loss was 1856ml and 1533ml for the drain and no drain groups, respectively (P value=0.0470). The need for transfusion was significantly less in the no-drain group with an average of 0.15 unit/patient as compared to an average 0.37 unit/patient for the drain group (P value=0.0432).

CONCLUSION

We were unable to find a point of superiority for using a drain for revision knee arthroplasty. Future studies with longer follow-up and larger population of patients are needed to make a valid conclusion.

A resorbable antibiotic eluting bone void filler for periprosthetic joint infection prevention

Periprosthetic joint infection (PJI) following total knee arthroplasty is a globally increasing procedural complication. These infections are difficult to treat and typically require revision surgery. Antibiotic-loaded bone cement is frequently utilized to deliver antibiotics to the site of infection; however, bone cement is a nondegrading foreign body and known to leach its antibiotic load, after an initial burst release, at subtherapeutic concentrations for months. This work characterized a resorbable, antibiotic-eluting bone void filler designed to restore bone volume and prevent PJI. Three device formulations were fabricated, consisting of different combinations of synthetic inorganic bone graft material, degradable polymer matrices, salt porogens, and antibiotic tobramycin. These formulations were examined to determine the antibiotic's elution kinetics and bactericidal potential, the device's degradation in vitro, as well as osteoconductivity and device resorption in vivo using a pilot rabbit bone implant model. Kirby-Bauer antibiotic susceptibility tests assessed bactericidal activity. Liquid chromatography with tandem mass spectrometry measured antibiotic elution kinetics, and scanning electron microscopy was used to qualitatively assess degradation. Results indicated sustained antibiotic release from all three formulations above the Staphylococcus aureus minimum inhibitory concentration for a period of 5 to 8 weeks. Extensive degradation was observed with the Group 3 formulation after 90 days in phosphate-buffered saline, with a lesser degree of degradation observed in the other two formulations. Results from the pilot rabbit study showed the Group 3 device to be biocompatible, with minimal inflammatory response and no fibrous encapsulation in bone. The device was also highly osteoconductive-exhibiting an accelerated mineral apposition rate. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1632-1642, 2016.

Total Knee Arthroplasty Within Six Months After Knee Arthroscopy Is Associated With Increased Postoperative Complications

A national database was queried for patients who underwent TKA following ipsilateral knee arthroscopy. Three cohorts were created: TKA within 6 months of knee arthroscopy (n=681), TKA between 6 months and 1 year after knee arthroscopy (n=1301) and TKA between 1 and 2 years after knee arthroscopy (n=1069). An age-matched control group of TKA without prior knee arthroscopy was also created (n=37,235). The incidences of infection (OR 2.0, P=0.004), stiffness (OR 2.0, P=0.001) and VTE (OR 1.6, P=0.047) were higher in patients who underwent TKA within 6 months after knee arthroscopy compared to controls. There was no increase in complications when TKA was performed more than six months after knee arthroscopy.

Impact of obesity on the risk of wound infection following surgery: results from a nationwide prospective multicentre cohort study in England

We sought to assess the impact of body mass index on the risk of surgical site infection in a prospective cohort study of 206 National Health Service (NHS) hospitals in England between 2007 and 2011. Body mass index was available for 159,720 of 350,089 operations among patients undergoing abdominal hysterectomy, coronary artery bypass graft, hip replacement, knee replacement, or large-bowel surgery. Among these patients, the risk of surgical site infection ranged from 0.65% for knee replacement to 11.04% for large-bowel surgery. Overall, 127,512 (79.8%) patients were overweight or obese (body mass index of ≥25 kg/m(2)). Obesity was associated with a 1.1-fold to 4.4-fold increase in the adjusted odds of developing surgical site infection as compared with normal weight, depending on the type of surgery. The population-attributable fraction (PAF) for body mass index was greatest in overweight (body mass index of 25.0-29.9 kg/m(2)) patients undergoing coronary artery bypass graft, accounting for 15% of their overall risk of surgical site infection (PAF 0.15; 95% CI 0.09-0.22). Being overweight or obese substantially increased the likelihood of patients developing surgical site infection. Given the increasingly high proportion of the surgical population who are overweight, this is likely to place a considerable additional burden on the NHS. Strategies for mitigating this excess risk need to be found.

Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model

Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n = 12). Rabbits in the control group were injected with sterile saline (n = 12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4 hours after injection of technetium-99m-labeled annexin V (150 MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ± 0.29 in the early phase and 2.19 ± 0.34 in the delay phase, both of which were significantly higher than those of the control group (P = 0.03 and P = 0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model.

Recognizing and managing infections in total joint arthroplasty

Periprosthetic joint infections are a devastating complication of joint arthroplasty procedures, affecting 1% to 4% of patients. With the increasing demand for joint replacement, the clinical and financial burden of periprosthetic joint infections is challenging. This article reviews the diagnosis and treatment of periprosthetic joint infections.

Primary Total Knee Arthroplasty in Super-obese Patients: Dramatically Higher Postoperative Complication Rates Even Compared to Revision Surgery

This study utilized a national database to evaluate 90 day postoperative complication rates after total knee arthroplasty (TKA) in super obese (BMI > 50 kg/m(2)) patients (n = 7666) compared to non-obese patients (n = 1,212,793), obese patients (n = 291,914), morbidly obese patients (n = 169,308) and revision TKA patients (n = 28,812). Super obese patients had significantly higher rates of local and systemic complications compared to all other BMI groups as well as those undergoing revision TKA with higher rates of venous thromboembolism (VTE), infection, and medical complications. Super obesity is associated with dramatically increased rates of postoperative complications after TKA compared to non-obese, obese, and morbidly obese patients as well as those undergoing revision TKA.

Unsatisfactory outcome of arthrodesis performed after septic failure of revision total knee arthroplasty

BACKGROUND

Periprosthetic infection is one of the most dreaded orthopaedic complications. Current treatment procedures include one-stage or two-stage revision total knee arthroplasty. If the periprosthetic infection is no longer controllable after several revision total knee arthroplasties, many surgeons regard knee arthrodesis as a promising option. The aim of our study was to ascertain whether intramedullary nailing results in the suppression or eradication of an infection and to identify risk factors for persistent infection.

METHODS

All patients who had undergone intramedullary nailing following septic failure of revision total knee arthroplasty between 1997 and 2013 were included in the study. Pathogens, risk factors predisposing to persistent infection, and the rate of persistent infections were recorded. In addition, a visual analog scale (VAS) and Knee injury Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS), Lysholm, Short Form-36 (SF-36), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaires were completed to assess clinical outcomes and quality of life.

RESULTS

Twenty-six patients were included in the study. Thirteen (50%) had a persistent infection requiring additional revision surgery. Nineteen patients (73%) reported persistent pain (VAS score of >3). All scores showed marked impairment of quality of life.

CONCLUSIONS

Intramedullary nailing following septic failure of revision total knee arthroplasty must be regarded with skepticism, and we cannot recommend it. Repeat revision total knee arthroplasty or amputation should be considered as an alternative in such difficult cases.

Long term follow-up of successfully treated superficial wound infections following TKA

The relevance of wound complications in association with acute prosthetic joint infection (PJI) is well known. However, whether a successfully treated superficial infection can result in a chronic deep infection remains unclear. The aim of this study was to determine the prevalence, treatment and late complications of superficial wound infections following TKA. In a 3000 TKA prospective cohort, 45 superficial infections were diagnosed and treated successfully with antibiotic therapy along with or without surgical debridement. None of the cases developed deep chronic PJI at 70 months of follow-up. Three cases were in need of a TKA exchange due to aseptic loosening. A successfully treated superficial wound infection does not result in a chronic deep TKA infection.

Optimizing perioperative management of total joint arthroplasty

Clinical pathways for total joint arthroplasty have been shown to reduce costs and significantly impact perioperative outcomes mainly through reducing provider variability. Effective clinical pathways link evidence to individual practice and balance costs with local experience, outcomes, and access to resources for responsible perioperative management. Common components of clinical pathways with major impact on perioperative outcomes are: 1) implementing pathways designed to include multimodal analgesia with regional anesthesia, 2) use of tranexamic acid to reduce blood loss, and 3) preconditioning followed by participation in early, accelerated rehabilitation programs to prevent postoperative complications related to immobility.

Tranexamic Acid Reduces Blood Loss and Transfusion in Patients Undergoing Total Knee Arthroplasty without Tourniquet: A Prospective Randomized Controlled Trial

Introduction :

Blood loss during and after total knee arthroplasty (TKA) can lead to substantial morbidity and the need for blood transfusions. There are several methods to minimize blood loss and to decrease transfusion rates in patients undergoing TKA. Tranexamic acid is an antifibrinolytic agent with known efficacy for achieving these goals. Currently, many surgeons are performing TKA without the use of tourniquet. Consequently, the aim of the study is to evaluate whether tranexamic acid reduces blood loss during and after TKA without the adjunctive use of above-the-knee tourniquet.

Methods :

We performed a prospective randomized controlled trial (1:1 fashion) on the use of tranexamic acid versus placebo in 50 patients undergoing TKA (without tourniquet). The treatment group received two (preoperative and postoperative) 15 mg/kg doses. The primary endpoint was blood transfusion rate. We collected data about demographic and procedural characteristics, hemoglobin and hematocrit values, drain blood loss at 24 hours as well as adverse events.

Results :

There were no transfusions in the treatment group, whereas 32% of the control group required transfusion (p<0.01). The treatment group had higher hematocrit and hemoglobin levels at 24, 48 and 72 hours after surgery (all p<0.01) and lower drain loss at 24hours (363.4±141 vs 626±260ml, p=<0,001). There were no in-hospital or six-month thromboembolic complications.

Discussion :

A double-dose of tranexamic acid was safe and effective, reducing blood loss and preventing the need of blood transfusion in patients undergoing TKA without above-the-need tourniquet.

Flaps for closure of soft tissue defects in infected revision knee arthroplasty

PURPOSE

Total knee arthroplasty revision has wound healing deficits of up to 20 %. Defects in the knee region of multimorbid patients are hard to treat as complete explantation and revision arthroplasty is often too burdensome for them. In this study, we present our results with flaps for the treatment of defects after knee replacement, arthrodesis or osteosynthesis.

METHODS

Twenty-five patients (26 knees) with defects in the knee region were treated with flaps. Mean follow-up was 37 months (13-61) and the patients had a mean age of 72 years (49-85). A total of 39 flaps were performed (27 muscle flaps, seven fascio-cutaneous flaps and five free flaps).

RESULTS

Patients with more than three comorbidities showed higher risk of complications after surgery. Fifteen patients showed no infection at last follow up. Five patients received an arthrodesis of the knee, two showed persistent infection of the implant with fistula, and three were amputated above the knee.

CONCLUSIONS

Amputation could be avoided in 22 cases (85 %). The gastrocnemius muscle flap showed good results in the treatment of defects after arthroplasty or arthrodesis of the knee in multimorbid patients. This procedure can be used if further revision surgery is not indicated.