Risk factors for deep infection after total knee arthroplasty: a meta-analysis

Early Versus Late Periprosthetic Joint Infection After Total Knee Arthroplasty: Do Patient Differences Exist?

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA). Little evidence exists comparing those with early versus late PJI. The purpose of the study was to determine comorbidity profile differences between patients developing early and late PJI.

METHODS

There were 72,659 patients undergoing primary TKA from 2009 to 2021, who were identified from a commercial claims and encounters database. Subjects diagnosed with PJI were categorized as either 'early' (within 90 days of index procedure) or 'late' (> 2 years after index arthroplasty). Non-infected patients within these periods served as control groups following 4:1 propensity score matching on other extraneous variables. Logistic regression analyses were performed comparing comorbidities between groups.

RESULTS

Patients were significantly younger in the late compared to the early infection group (58.1 versus 62.4 years, P < .001). When compared to those with early PJI, patients who had chronic kidney disease (13.3 versus 4.1%; OR [odds ratio] 5.17, P = .002), malignancy (20.4 versus 10.5%; OR 2.53, P = .009), uncomplicated diabetes (40.8 versus 30.6%; OR 2.00, P = .01), rheumatoid arthritis (9.2 versus 3.3%; OR 2.66, P = .046), and hypertension (88.8 versus 81.6%; OR 2.17, P = .04), were all significant predictors of developing a late PJI.

CONCLUSIONS

When compared to patients diagnosed with early PJI following primary TKA, the presence of chronic kidney disease, malignancy, uncomplicated diabetes, rheumatoid arthritis, and hypertension, were independent risk factors for the development of late PJI. Younger patients who have these comorbidities may be targets for preoperative optimization interventions that minimize the risk of PJI.

Patients Who Have Prior Solid Organ Transplants Have Increased Risk of 10-Year Periprosthetic Joint Infection Revision Following Primary Total Knee Arthroplasty: A Propensity-Matched Analysis

BACKGROUND

Total knee arthroplasty (TKA) for solid organ transplant (SOT) patients is becoming more prominent as life expectancy in this population increases. However, data on long-term (10 year) implant survivorship in this cohort are sparse. The purpose of this study was to compare 90-day, 2-year, 5-year, and 10-year implant survivability following primary TKA in patients who did and did not have prior SOT.

METHODS

The PearlDiver database was utilized to query patients who underwent unilateral elective TKA with at least 2 years of active follow-up. These patients were stratified into those who had a SOT before TKA and those who did not. The SOT cohort was propensity-matched to control patients based on age, sex, Charlson Comorbidity Index, and obesity in a 1:2 ratio. Cumulative incidence rates and hazard ratios (HRs) were compared between the SOT, matched, and unmatched cohorts.

RESULTS

No difference was observed in 10-year cumulative incidence and risk of all-cause revision surgery in TKA patients with prior SOT when compared to matched and unmatched controls. Compared to the matched control, the SOT cohort had no difference in the risk of revision when stratified by indication and timing. However, when compared to the unmatched control, patients who had prior SOT had a higher risk for revision due to periprosthetic joint infection at 10 years (HR: 1.80; 95% confidence interval: 1.17 to 2.76) as well as all-cause revision within 90 days after TKA (HR: 1.93; 95% confidence interval: 1.10 to 3.36).

CONCLUSIONS

Prior SOT patients have higher rates of all-cause revision within 90 days and periprosthetic joint infection within 10 years when compared to the general population, likely associated with the elevated number of comorbidities in SOT patients and not the transplant itself. Therefore, these patients should be monitored in the preoperative and early postoperative settings to optimize their known comorbidities.

Debridement, antibiotics, and implant retention (DAIR) for the early prosthetic joint infection of total knee and hip arthroplasties: a systematic review

PURPOSE

Early periprosthetic joint infection (PJI) represents one of the most fearsome complications of joint replacement. No international consensus has been reached regarding the best approach for early prosthetic knee and hip infections. The aim of this updated systematic review is to assess whether debridement, antibiotics, and implant retention (DAIR) is an effective choice of treatment in early postoperative and acute hematogenous PJI.

METHODS

This systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The diagnostic criteria defining a PJI, the most present pathogen, and the days between the index procedure and the onset of the PJI were extracted from the selected articles. Additionally, the mean follow-up, antibiotic regimen, and success rate of the treatment were also reported.

RESULTS

The articles included provided a cohort of 970 patients. Ten studies specified the joint of their cohort in PJIs regarding either hip prostheses or knee prostheses, resulting in 454 total knees and 460 total hips. The age of the patients ranged from 18 to 92 years old. Success rates for the DAIR treatments in the following cohort ranged from 55.5% up to a maximum of 90% (mean value of 71%).

CONCLUSION

Even though the DAIR procedure is quite limited, it is still considered an effective option for patients developing an early post-operative or acute hematogenous PJI. However, there is a lack of studies, in particular randomized control trials (RCTs), comparing DAIR with one-stage and two-stage revision protocols in the setting of early PJIs, reflecting the necessity to conduct further high-quality studies to face the burden of early PJI.

Etiology of Total Knee Arthroplasty Revisions: A Two-Decade Institutional Perspective

Total knee arthroplasty (TKA) implant survival time is determined by various patient and implant-related factors and varies significantly in recent worldwide reports. In our study, we have included 247 TKA revisions in 203 patients performed in our hospital over the last 20 years. Multiple etiologies of revisions were identified and classified into 10 categories. Time to failure was analyzed with regard to etiology, patient demographics, and other relevant data. The overall average time to revision was 44.08 months (95% confidence interval (CI) between 33.34 and 49.82 months). Age at primary implant was negatively correlated with time to revision (hazard ratio (HR) = 1.0521 and 95% CI of HR = 1.0359 to 1.0685) and female patients showed a 1.59 times higher risk of implant failure than males. Periprosthetic joint infection was the cause of 46.56% (n=115) of revisions (out of which 12.55% (n=31) were early infections, diagnosed within the first three months), while aseptic loosening was found in 31.98% (n=79) of cases. Infection correlated with a shorter time to revision compared to aseptic loosening (p<0.05). These findings emphasize the need to intensify efforts to deliver the best patient care, select the best antibiotic regimen, and improve surgical techniques to decrease the incidence of infectious complications.

Does antibiotic bone cement reduce infection rates in primary total knee arthroplasty?

INTRODUCTION

Infection after total knee arthroplasty (TKA) impacts the patient, surgeon, and healthcare system significantly. Surgeons routinely use antibiotic-loaded bone cement (ALBC) in attempts to mitigate infection; however, little evidence supports the efficacy of ALBC in reducing infection rates compared to non-antibiotic-loaded bone cement (non-ALBC) in primary TKA. Our study compares infection rates of patients undergoing TKA with ALBC to those with non-ALBC to assess its efficacy in primary TKA.

METHODS

A retrospective review of all primary, elective, cemented TKA patients over the age of 18 between 2011 and 2020 was conducted at an orthopedic specialty hospital. Patients were stratified into two cohorts based on cement type: ALBC (loaded with gentamicin or tobramycin) or non-ALBC. Baseline characteristics and infection rates determined by MSIS criteria were collected. Multilinear and multivariate logistic regressions were performed to limit significant differences in demographics. Independent samples t test and chi-squared test were used to compare means and proportions, respectively, between the two cohorts.

RESULTS

In total, 9366 patients were included in this study, 7980 (85.2%) of whom received non-ALBC and 1386 (14.8%) of whom received ALBC. There were significant differences in five of the six demographic variables analyzed; patients with higher Body Mass Index (33.40 ± 6.27 vs. 32.09 ± 6.21; kg/m2) and Charlson Comorbidity Index values (4.51 ± 2.15 vs. 4.04 ± 1.92) were more likely to receive ALBC. The infection rate in the non-ALBC was 0.8% (63/7,980), while the rate in the ALBC was 0.5% (7/1,386). After adjusting for confounders, the difference in rates was not significant between the two groups (OR [95% CI]: 1.53 [0.69-3.38], p = 0.298). Furthermore, a sub-analysis comparing the infection rates within various demographic categories also showed no significant differences between the two groups.

CONCLUSION

Compared to non-ALBC, the overall infection rate in primary TKA was slightly lower when using ALBC; however, the difference was not statistically significant. When stratifying by comorbidity, use of ALBC still showed no statistical significance in reducing the risk of periprosthetic joint infection. Therefore, the advantage of antibiotics in bone cement to prevent infection in primary TKA is not yet elucidated. Further prospective, multicenter studies regarding the clinical benefits of antibiotic use in bone cement for primary TKA are warranted.

A Systematic Review and Meta-analysis of Risk Factors for an Infection After Anterior Cruciate Ligament Reconstruction

Background

Identifying risk factors for an infection after anterior cruciate ligament reconstruction (ACLR) and following targeted preventive strategies can effectively reduce this potentially serious complication.

Purpose

To perform a systematic review and meta-analysis to identify the risk factors for an infection after ACLR.

Study Design

Systematic review; Level of evidence, 4.

Methods

The PubMed, Embase, and Web of Science databases were searched from inception to September 1, 2022, for prospective and retrospective studies investigating risk factors for any type of infection after ACLR. Odds ratios (ORs) or mean differences were calculated for potential risk factors if ≥2 studies assessed the same risk factor. A qualitative analysis of variables was performed if a meta-analysis could not be conducted.

Results

A total of 17 studies with 141,991 patients were included in this review. The overall pooled infection rate was 0.86% (range, 0.24%-5.50%). There were 20 risk factors identified for analysis. Of these, 7 variables independently increased the odds of an infection after ACLR: (1) male sex (OR, 1.90 [95% CI, 1.33-2.73]), (2) diabetes (OR, 2.69 [95% CI, 1.66-4.35]), (3) hamstring tendon autograft (OR, 2.51 [95% CI, 2.03-3.10]), (4) revision ACLR (OR, 2.31 [95% CI, 1.22-4.37]), (5) professional athlete status (OR, 6.21 [95% CI, 1.03-37.38]), (6) lateral tenodesis (OR, 3.45 [95% CI, 1.63-7.28]), and (7) corticosteroid use (OR, 7.83 [95% CI, 3.68-16.63]). No significant associations were found between postoperative infections and age, body mass index, smoking, meniscal repair, or outpatient surgery.

Conclusion

This review revealed that an increased risk of infections after ACLR was associated with male sex, diabetes, hamstring tendon autograft, revision surgery, professional athlete status, lateral tenodesis, and steroid use. Knowledge of the risk factors associated with an infection after ACLR may facilitate the identification of high-risk cases and the implementation of preventive measures to mitigate the serious consequences of this complication.

Investigation of the effect of rifampicin resistance and risk factors on recovery rates after DAIR procedure in patients with prosthetic joint infection

BACKGROUND

Rifampicin plays a key role in the management of prosthetic joint infections (PJIs), however, the emergence of rifampicin resistance is associated with less favourable clinical outcomes. The purpose of this study was to investigate the impact of rifampicin resistance and other patient-related factors on recovery rates among patients with PJI undergoing debridement, antibiotics and implant retention (DAIR).

METHODS

We reviewed medical records and microbiology reports of 67 patients (37 males and 30 females) undergoing DAIR due to PJI between 2014 and 2021. Patient-related factors, co-morbidities and microbiological reports were collected and reviewed. Forty-four patients had hip, 21 had knee, 1 had shoulder and 1 had elbow joint infection. Obtained data were statistically analysed with a logistic regression model.

RESULTS

Rifampicin-sensitive organism was isolated in 47 cases. Recovery rate was 72.3% in the sensitive and 76.9% in the resistant group. We found no significant effect of rifampicin resistance on the probability of recovery. Age and diabetes mellitus showed negative clinical impact on recovery. Staphylococcus aureus and coagulase-negative Staphylococci were predominant in the rifampicin-sensitive (66.6% of the isolates) and Gram-negative rods in the resistant group (65.2%).

CONCLUSIONS

Based on our results, higher age and diabetes mellitus may have a clinically relevant negative impact on clinical outcome, however, this effect was not statistically significant. This may be due to the limited number of patients included in this study. We observed no clinically relevant effect of rifampicin-resistance, sex and body mass index (BMI) on recovery rates among patients undergoing DAIR due to PJI.

Risks of chronic steroid or immunosuppressive therapy on total shoulder arthroplasty patients

Introduction

Patients on chronic corticosteroids/immunosuppressants (SI) undergoing orthopaedic surgery are at an increased risk for surgical complications and worse outcomes. However, whether or not chronic preoperative SI use increases the risk for 30-day complications in patients undergoing primary total shoulder arthroplasty (SA) has yet to be explored.

Methods

From 2006 to 2019, the National Surgical Quality Improvement Program (NSQIP) database was used to identify all patients who underwent primary SA (anatomic TSA and reverse TSA). Patients were stratified into two cohorts: chronic preoperative SI users and those without use. Bivariate and multivariate analyses were utilized in this study.

Results

Of the 26,979 patients who underwent primary SA, 25,656 (95.1%) patients did not have SI usage whereas 1323 (4.9%) patients had chronic preoperative SI usage. Following adjustment on multivariate analyses, compared to the non-SI usage cohort, patients who used SI had an increased risk of urinary tract infections (UTIs) (OR 1.87; p = 0.009) and septic shock (OR 7.14; p = 0.002). There were no differences in mortality between the two cohorts (p = 0.058).

Discussion and Conclusion

Chronic pre-operative SI use is an independent risk factor for septic shock and UTIs following primary SA. Surgeons and patients should be aware of these risks to better inform patient counseling and surgical decision making.

Late summer is a risk factor for periprosthetic joint infection after total joint arthroplasty: A retrospective cohort study

To explore whether season is a risk factor of periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) and explain it with the theory of traditional Chinese medicine. This was a retrospective cohort study. Only patients who suffered from PJI within 1 month after TJA were included in the study. Occurrence of PJI was the outcome of this study. Chi-squared test and t test was used to assess differences for baseline characteristics. Chi-square test was used to analyze whether season was related to the occurrence of PJI. Logistic regression was used to evaluate the association between season and occurrence of PJI. The incidence of PJI in summer is significantly higher than that in winter, whether after total knee arthroplasty (Chi-square value = 6.455, P = .011) or total hip arthroplasty (Chi-square value = 6.141, P = .013). Summer was an independent risk factor for PJI (OR = 4.373, 95% confidence interval = 1.899-10.673, P = .004). To be more exact, compared to nonlate summer (19.51%), and PJI is mainly concentrated in late summer (80.49%). Late summer was an independent risk factor of PJI after TJA. The infection rate of PJI after TJA in late summer is higher than other seasons. A more thorough preoperative disinfection procedure is needed in late summer.

Is Topical Vancomycin an Option? A Randomized Controlled Trial to Determine the Safety of the Topical Use of Vancomycin Powder in Preventing Postoperative Infections in Total Knee Arthroplasty, as Compared With Standard Postoperative Antibiotics

BACKGROUND

The demand for total knee arthroplasties (TKAs) is expected to rise in the coming decades, increasing the burden of periprosthetic joint infections (PJIs). The use of intrawound vancomycin powder (VP) has proven to be effective in reducing the incidence of PJIs after spinal surgery. That said, its effectiveness in TKA remains unclear. This trial aims to examine the efficacy of intrawound vancomycin powder first versus standard postoperative antibiotics in preventing PJIs after TKA.

METHODS

This study was a double-blinded, noninferiority, randomized controlled trial. All participants received standard preoperative intravenous (IV) antibiotics (Cefazolin/Vancomycin) within 60 minutes of skin incision. Patients in the treatment group received 1 gram of VP applied intraoperatively by the orthopedic surgeon (500 mg directly on the prosthesis, 500 mg above the closed joint capsule). These patients did not receive postoperative antibiotics. Patients in the control group received standard postoperative IV antibiotics. The primary outcome was the incidence of acute surgical site infection within 42 days of procedure.

RESULTS

There were 80 patients randomized to the treatment group and 85 patients randomized to the control. Groups were matched with respect to baseline characteristics, including average age (66 versus 64), BMI (35.7 versus 33.4), and diabetics (16 versus 13). The trial was halted at 1 year as a significantly greater proportion (P = .03) of patients in the treatment group (n = 3, 3.75%) were diagnosed with PJIs compared to the control (n = 0).

CONCLUSION

Our trial demonstrated the intrawound application of VP to be inferior to standard postoperative IV antibiotics in reducing the incidence of PJIs after TKA.

Septic Olecranon Bursitis With Osteomyelitis Attributed to Cutibacterium acnes: Case Report and Literature Overview of the Dilemma of Potential Contaminants and False-Positives

We report an unusual case of acute septic olecranon bursitis, with probable olecranon osteomyelitis, where the only organism isolated in culture was initially considered a contaminant, Cutibacterium acnes. However, we ultimately considered it the likely causal organism when treatment for most of the other more likely organisms failed. This typically indolent organism is prevalent in pilosebaceous glands, which are scarce in the posterior elbow region. This case illustrates the often challenging empirical management of a musculoskeletal infection when the only organism isolated might be a contaminant, but successful eradication requires continued treatment as if it is the causal organism. The patient is a Caucasian 53-year-old male who presented to our clinic with a second episode of septic bursitis at the same location. Four years prior, he had septic olecranon bursitis from methicillin-sensitive Staphylococcus aureus that was treated uneventfully with one surgical debridement and a one-week course of antibiotics. In the current episode reported here, he sustained a minor abrasion. Cultures were obtained five separate times because of no growth and difficulty eradicating the infection. One culture grew C. acnes on day 21 of incubation; this long duration has been reported. The first several weeks of antibiotic treatment failed to eradicate the infection, which we ultimately attributed to inadequate treatment of C. acnes osteomyelitis. Although C. acnes has a well-known propensity for false-positive cultures as typically reported in post-operative shoulder infections, treatment for our patient's olecranon bursitis/osteomyelitis was successful only after several surgical debridements and a prolonged course of intravenous and oral antibiotics that targeted it as the presumptive causal organism. However, it was possible that C. acnes was a contaminant/superinfection, and another organism was the culprit, such as a Streptococcus or Mycobacterium species that was eradicated by the treatment regime targeted for C. acnes.

Risk Factors for Treatment Failure in Patients Who Have Knee Periprosthetic Joint Infection Treated With Two-Stage Exchange Arthroplasty as Well as Their Fate

BACKGROUND

Two-stage exchange arthroplasty is considered the gold standard treatment for chronic periprosthetic joint infection (PJI). However, there is a scarcity of research investigating the major risk factors for infection recurrence and the prognosis after infection recurrence.

METHODS

This study included 203 patients who underwent 2-stage exchange arthroplasty between June 22, 2010 and January 24, 2017. The need of reoperation for infection-related or PJI-related mortality was considered treatment failure. Participant age, gender, body mass index, comorbidities, culture results, length of hospital stay, cause of treatment failure, operative procedure, and fate were analyzed.

RESULTS

Fifty-three patients experienced treatment failure (26.1%). Mean follow-up was 63 months (range, 26-103). Based on the multivariate analyses, risk factors for treatment failure included men and positive intraoperative culture during reimplantation. Recurrent infection was most commonly caused by Staphylococcus aureus (32.1%, 17/53), and new microorganisms caused recurrent infection in 34 of 53 (64.2%) patients. In 44 patients who had treatment failure, debridement, antibiotic therapy, irrigation, and retention of prosthesis (DAIR) performed within 6 months of reimplantation and at <3 weeks from symptom onset resulted in a significantly higher success rate than the use of other DAIR protocols (P = .031).

CONCLUSION

Men and positive intraoperative culture are major risk factors for 2-stage exchange arthroplasty failure in patients who have knee PJI. Recurrent infection in these patients is usually caused by new microorganisms. DAIR within 6 months of reimplantation and at <3 weeks from symptom onset results in good outcomes in these patients.

Which Patients with Chronic Periprosthetic Joint Infection Are Less Suitable to Successful Two Stage Exchange Arthroplasty Surgery? A Retrospective Clinical Trial

BACKGROUND

Two-stage exchange (TSE) arthroplasty is currently considered the gold standard for chronic periprosthetic joint infections (PJIs), despite a failure rate reported in up to 10% of patients. Little is known about the risk factors that may compromise successful TSE arthroplasty management in such patients. The main purpose of the current study was to highlight the potential risk factors of patients with chronic PJIs after THA managed by implant removal, outlining the differences between reimplanted patients and those that were never reimplanted because of a non-eradicated infection.

METHODS

We conducted a retrospective observational study of patient candidates for TSE arthroplasty surgery, managed at the authors' institution, over a four-year timeframe. The data were retrieved from the hospital's information database. The enrolled population was divided into two Groups: A, reimplanted; B, non-reimplanted because of a non-eradicated infection within one year. For each Group, demographic information, PJI-related risk factors, type of pathogen and presence of single or polymicrobial infection, were collected and analyzed.

RESULTS

In total, 21 patients were included in the study, 14 patients in Group A and 7 in Group B. Major Depression (p = 0.049) and polymicrobial infection (p = 0.04) were more commonly observed in patients that were not reimplanted in the study period. No differences between the two groups were observed when other characteristics were compared.

CONCLUSIONS

Patients with major depression, or those hosting polymicrobial periprosthetic hip infections, are more susceptible to failure of TSE arthroplasty procedures for chronic PJIs, hampering THA reimplantation. Current findings may drive further research and contribute to the understanding of the role of these risk factors in chronic PJI patients.

Risk Factors for Periprosthetic Joint Infection after Primary Total Knee Arthroplasty

Periprosthetic joint infection (PJI) is a major adverse event of primary total knee arthroplasty (TKA) from the patient's perspective, and it is also costly for health care systems. In 2010, the reported incidence of PJI in the first 2 years after TKA was 1.55%, with an incidence of 0.46% between the second and tenth year. In 2022, it has been published that 1.41% of individuals require revision TKA for PJI. The following risk factors have been related to an increased risk of PJI: male sex, younger age, type II diabetes, obesity class II, hypertension, hypoalbuminemia, preoperative nutritional status as indicated by prognostic nutritional index (PNI) and body mass index, rheumatoid arthritis, post-traumatic osteoarthritis, intra-articular injections prior to TKA, previous multi-ligament knee surgery, previous steroid therapy, current tobacco use, procedure type (bilateral), length of stay over 35 days, patellar resurfacing, prolonged operative time, use of blood transfusions, higher glucose variability in the postoperative phase, and discharge to convalescent care. Other reported independent risk factors for PJI (in diminishing order of importance) are congestive heart failure, chronic pulmonary illness, preoperative anemia, depression, renal illness, pulmonary circulation disorders, psychoses, metastatic tumor, peripheral vascular illness, and valvular illness. Preoperative intravenous tranexamic acid has been reported to diminish the risk of delayed PJI. Knowing the risk factors for PJI after TKA, especially those that are avoidable or controllable, is critical to minimizing (ideally preventing) this complication. These risk factors are outlined in this article.

Rifampicin resistance and risk factors associated with significantly lower recovery rates after two stage revision in patients with prosthetic joint infection

PURPOSE

Rifampicin plays a key role in the management of prosthetic joint infections (PJIs), however, the emergence of rifampicin resistance is associated with less favorable clinical outcomes. The purpose of this study was to investigate the impact of rifampicin resistance and other patient-related factors on recovery rates among patients with PJI undergoing two-stage revision.

METHODS

We reviewed medical records and microbiology reports of 73 patients (41 males and 32 females) undergoing two-stage revision due to PJI between 2017 and 2019. Patient-specific data, co-morbidities and the antibiotic resistance of microbiological isolates were registered. 48 patients had hip, 22 had knee, 2 had shoulder and 1 had elbow joint infection. Obtained data were statistically analyzed with a logistic regression model.

RESULTS

Rifampicin-sensitive organism was isolated in 53 cases (72.6%). Recovery rate was 92.5% in the sensitive and 60.0% in the resistant group. We observed that rifampicin resistance significantly reduced the probability of recovery. Furthermore, in the rifampicin-sensitive group, the probability of recovery decreased with advancing age with a significant drop above the age of 60 years. The effect of age is negligible in the rifampicin-resistant group. We also found that type 2 diabetes mellitus has a negative effect on recovery. Coagulase-negative Staphylococci were predominant in the rifampicin-sensitive (50% of the isolates) and Gram-negative rods in the resistant group (40%).

CONCLUSIONS

Rifampicin resistance was associated with lower recovery rates among patients undergoing two-stage revision due to PJI. Higher age and type 2 diabetes mellitus had negative impact on clinical outcome.

The Effect of Perioperative Biologic Disease-Modifying Anti-Rheumatic Drugs on the Risk of Postoperative Complications: Surgical Site Infection, Delayed Wound Healing, and Disease Flares Following Orthopaedic Surgical Procedures

BACKGROUND

Biologic disease-modifying anti-rheumatic drugs (bDMARDs) are effective in treating inflammatory diseases and have been increasingly utilized over the past decade. Patients who receive bDMARDs have been shown to be at an increased risk for surgical site infection following surgical procedures. The severe consequences of infection following orthopaedic surgery have led to the practice of withholding bDMARDs perioperatively; however, there has been no definitive evidence showing a clear benefit of withholding the use of bDMARDs, and in doing so, patients may be at an increased risk for higher disease activity. As such, the purpose of the present study was to compare the risk of infection, delayed wound healing, and disease flares associated with the use of bDMARDs in patients undergoing orthopaedic surgical procedures.

METHODS

We performed a systematic literature search of MEDLINE, Embase, and PubMed CENTRAL databases for studies comparing continuing and withholding the use of bDMARDs in patients undergoing orthopaedic procedures. Inclusion criteria were established following the PICO (Population, Intervention, Comparison, and Outcomes) approach: Population = patients who underwent orthopaedic surgical procedures and who were taking bDMARDs. Intervention = withholding the use of bDMARDs. Comparator = continuing the use of bDMARDs. Outcomes = surgical site infection, delayed wound healing, and disease flares. Article titles and abstracts were screened prior to review of the full text. Overall odds ratios (ORs) and associated 95% confidence intervals (CIs) for pooled effects were calculated.

RESULTS

Eleven studies met the inclusion criteria, providing data for 7,344 patients, including 2,385 patients who continued and 4,959 who withheld their bDMARDs perioperatively. Continuing bDMARDs was associated with a significantly lower risk of disease flares (OR, 0.22; 95% CI, 0.05 to 0.95; p = 0.04) and nonsignificant increases in surgical site infections (OR, 1.11; 95% CI, 0.82 to 1.49; p = 0.49) and wound complications (OR, 2.16; 95% CI, 0.48 to 9.85; p = 0.32).

CONCLUSIONS

The present systematic review highlights the limited evidence supporting the current practice of stopping bDMARDs perioperatively. These findings suggest that patients may not be at an increased risk for developing infection or wound complications if bDMARDs are continued but are at an increased risk for disease flare if bDMARDs are withheld. However, our conclusions are limited by the retrospective and heterogenous nature of the data, and possibly by a lack of study power.

LEVEL OF EVIDENCE

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

Periprosthetic Knee Infection - Part 1: Risk Factors, Classification and Diagnosis

Infection is one of the most feared complications in the postoperative period of knee arthroplasties. With the progressive aging of the population and the increased incidence of degenerative joint diseases, there is an exponential increase in the number of arthroplasties performed and, consequently, in the number of postoperative infections. The diagnosis of these should follow a hierarchical protocol, with well-defined criteria, which lead to diagnostic conclusion, thus guiding the most appropriate treatment. The aim of the present update article is to present the main risk factors, classifications and, mainly, to guide diagnostic investigation in an organized manner.

Impact of antibiotic prophylaxis courses on postoperative complications following total joint arthroplasty: Finding from Chinese population

WHAT IS KNOWN AND OBJECTIVE

Prolonged antibiotic prophylaxis after total joint arthroplasty (TJA) may not assist in minimizing postoperative complications, however, data based on the Chinese population have been limited. The purpose of this study is to investigate the effect of antibiotic prophylaxis on postoperative complications after TJA in Chinese patients.

METHODS

We retrospectively reviewed 990 patients undergoing elective primary TJA surgery from January 2016 to June 2019. Patients who received a short course (≤3 days) of antibiotic prophylaxis were compared with those who received a longer course (>3 days). Logistic regression analysis and subgroup analysis were performed to control for potential confounders. Beyond that, survival analysis was used to determine the cumulative incidence of postoperative complications.

RESULTS AND DISCUSSION

Follow-up to 12 months after surgery, the prevalence of system complications in the longer course group and the short course group were 5.1% and 3.9%, respectively (p = 0.451). Similarly, no statistical differences in incisional complications (1.5% vs. 1.8%, p > 0.999) and periprosthetic joint infection (PJI) (1.0% vs. 1.0%, p > 0.999) were observed between the two groups. After performing logistic regression analysis and survival analysis, no potential association was found between the course of antibiotic prophylaxis and postoperative complications. In addition, prolonged antibiotic prophylaxis conferred no benefit for high-risk obese patients.

WHAT IS NEW AND CONCLUSION

Extended antibiotic prophylaxis did not result in a statistically significant and clinically meaningful reduction in postoperative complications. Therefore, we recommended that the duration of antibiotic prophylaxis in TJA should be shortened to 3 days or less in the Chinese population.

Ex vivo Demonstration of Functional Deficiencies in Popliteal Lymphatic Vessels From TNF-Transgenic Mice With Inflammatory Arthritis

Background: Recent studies demonstrated lymphangiogenesis and expansion of draining lymph nodes during chronic inflammatory arthritis, and lymphatic dysfunction associated with collapse of draining lymph nodes in rheumatoid arthritis (RA) patients and TNF-transgenic (TNF-Tg) mice experiencing arthritic flare. As the intrinsic differences between lymphatic vessels afferent to healthy, expanding, and collapsed draining lymph nodes are unknown, we characterized the ex vivo behavior of popliteal lymphatic vessels (PLVs) from WT and TNF-Tg mice. We also interrogated the mechanisms of lymphatic dysfunction through inhibition of nitric oxide synthase (NOS). Methods: Popliteal lymph nodes (PLNs) in TNF-Tg mice were phenotyped as Expanding or Collapsed by in vivo ultrasound and age-matched to WT littermate controls. The PLVs were harvested and cannulated for ex vivo functional analysis over a relatively wide range of hydrostatic pressures (0.5-10 cmH2O) to quantify the end diastolic diameter (EDD), tone, amplitude (AMP), ejection fraction (EF), contraction frequency (FREQ), and fractional pump flow (FPF) with or without NOS inhibitors Data were analyzed using repeated measures two-way ANOVA with Bonferroni's post hoc test. Results: Real time videos of the cannulated PLVs demonstrated the predicted phenotypes of robust vs. weak contractions of the WT vs. TNF-Tg PLV, respectively. Quantitative analyses confirmed that TNF-Tg PLVs had significantly decreased AMP, EF, and FPF vs. WT (p < 0.05). EF and FPF were recovered by NOS inhibition, while the reduction in AMP was NOS independent. No differences in EDD, tone, or FREQ were observed between WT and TNF-Tg PLVs, nor between Expanding vs. Collapsed PLVs. Conclusion: These findings support the concept that chronic inflammatory arthritis leads to NOS dependent and independent draining lymphatic vessel dysfunction that exacerbates disease, and may trigger arthritic flare due to decreased egress of inflammatory cells and soluble factors from affected joints.

Infection and periprosthetic fracture are the leading causes of failure after aseptic revision total knee arthroplasty

AIM

The purpose of this study was to clarify the medium to long term survival of aseptic revision total knee arthroplasty (RTKAs) and identify the common modes of failure following RTKAs.

MATERIALS AND METHODS

A multi-center, retrospective study included all aseptic RTKAs performed at three tertiary referral hospitals between 2003 and 2016. Patients were excluded if the revision was for prosthetic joint infection (PJI) or they had previously undergone revision surgery. Minor revisions not involving the tibial or femoral components were also excluded. Demographics, surgical data and post-operative outcomes were recorded and analyzed. Survival analysis was performed and the reasons for revision failure identified.

RESULTS

Of 235 aseptic RTKAs identified, 14.8% underwent re-revision at mean follow-up of 8.3 years. Survivorship of RTKA was 93% at 2 years and 83% at 8 years. Average age at revision was 72.9 years (range 53-91.5). The most common reasons for failure following RTKA were periprosthetic joint infection (PJI) (40%), periprosthetic fracture (25.7%) and aseptic loosening (14.3%). Of those whose RTKA failed, the average survival was 3.33 years (8 days-11.4 years). No demographic or surgical factors were found to influence RTKA survival on univariate or multivariate analysis.

CONCLUSION

PJI and periprosthetic fracture are the leading causes of re-revision surgery following aseptic revision TKA. Efforts to improve outcomes of aseptic revision TKA should focus on these areas, particularly prevention of PJI.

Do We Need to Wait 3 Months After Corticosteroid Injections to Reduce the Risk of Infection After Total Knee Arthroplasty?

BACKGROUND

Corticosteroid injections administered within 3 months before total knee arthroplasty (TKA) have been linked to increased risk of postoperative infection. However, it would be beneficial to further delineate the timing of injections to determine whether a narrower window exists for safe administration of corticosteroid injections. The purposes of our study were to (1) determine whether there were a different time frame between corticosteroid injection and primary TKA that increased infection risk and (2) determine risk factors associated with infection after TKA.

METHODS

TKA patients were identified from a national database from 2007 to 2017 and stratified based on their history of corticosteroid injections within the 6-month preoperative period. Patients who received injections were stratified into biweekly cohorts by the timing of their most recent injection. The 1-year rate of postoperative infection treated by surgical débridement was compared between injection and noninjection cohorts. Univariate logistic regressions of risk factors and a multivariate analysis for patient comorbidities and injection cohorts associated with increased infection risk were conducted.

RESULTS

In the 76,090 TKA patients identified, corticosteroid injection within 2 weeks before TKA increased the risk of postoperative infection (P = 0.02) and injections within 2 to 4 weeks trended toward increased infection in univariate regression. No significant differences were observed in any other injection time frames. In the multivariate analysis, injections within 2 weeks before TKA were identified as an independent risk factor (odds ratio: 2.89; P = 0.04) for postoperative infection. Additional risk factors included chronic obstructive pulmonary disease, coronary artery disease, diabetes, ischemic heart disease, obesity, rheumatoid arthritis, and tobacco, whereas female sex and patient aged older than 65 were protective.

DISCUSSION

Our results suggest that TKA performed within four weeks of a corticosteroid injection may be associated with a higher risk of postoperative infection; however, delaying surgery more than four weeks may not provide additional infection risk reduction. Further prospective randomized studies are needed to determine the optimal timing of TKA after corticosteroid injections.

LEVEL OF EVIDENCE

Level III.

'Should we stop or continue conventional synthetic (including glucocorticoids) and targeted DMARDs before surgery in patients with inflammatory rheumatic diseases?'

Total hip and total knee arthroplasty) remain important interventions to treat symptomatic knee and hip damage in patients with rheumatoid arthritis, with little change in utilisation rates despite the increasingly widespread use of potent conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) and targeted DMARDs including Janus kinase inhibitors and biologics. The majority of patients are receiving these immunosuppressing medications and glucocorticoids at the time they present for arthroplasty. There is minimal randomised controlled trial data addressing the use of DMARDs in the perioperative period, yet patients and their physicians face these decisions daily. This paper reviews what is known regarding perioperative management of targeted and csDMARDs and glucocorticoids.

The Value of Total Knee Replacement in Patients With Knee Osteoarthritis and a Body Mass Index of 40 kg/m2 or Greater : A Cost-Effectiveness Analysis

BACKGROUND

Total knee replacement (TKR) is an effective and cost-effective strategy for treating end-stage knee osteoarthritis. Greater risk for complications among TKR recipients with a body mass index (BMI) of 40 kg/m2 or greater has raised concerns about the value of TKR in this population.

OBJECTIVE

To assess the value of TKR in recipients with a BMI of 40 kg/m2 or greater using a cost-effectiveness analysis.

DESIGN

Osteoarthritis Policy Model to assess long-term clinical benefits, costs, and cost-effectiveness of TKR in patients with a BMI of 40 kg/m2 or greater.

DATA SOURCES

Total knee replacement parameters from longitudinal studies and published literature, and costs from Medicare Physician Fee Schedules, the Healthcare Cost and Utilization Project, and published data.

TARGET POPULATION

Recipients of TKR with a BMI of 40 kg/m2 or greater in the United States.

TIME HORIZON

Lifetime.

PERSPECTIVE

Health care sector.

INTERVENTION

Total knee replacement.

OUTCOME MEASURES

Cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs), discounted at 3% annually.

RESULTS OF BASE-CASE ANALYSIS

Total knee replacement increased QALYs by 0.71 year and lifetime medical costs by $25 200 among patients aged 50 to 65 years with a BMI of 40 kg/m2 or greater, resulting in an ICER of $35 200. Total knee replacement in patients older than 65 years with a BMI of 40 kg/m2 or greater increased QALYs by 0.39 year and costs by $21 100, resulting in an ICER of $54 100.

RESULTS OF SENSITIVITY ANALYSIS

In TKR recipients with a BMI of 40 kg/m2 or greater and diabetes and cardiovascular disease, ICERs were below $75 000 per QALY. Results were most sensitive to complication rates and preoperative pain levels. In the probabilistic sensitivity analysis, at a $55 000-per-QALY willingness-to-pay threshold, TKR had a 100% and 90% likelihood of being a cost-effective strategy for patients aged 50 to 65 years and patients older than 65 years, respectively.

LIMITATION

Data are derived from several sources.

CONCLUSION

From a cost-effectiveness perspective, TKR offers good value in patients with a BMI of 40 kg/m2 or greater, including those with multiple comorbidities.

PRIMARY FUNDING SOURCE

National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health.

Type of bone graft and primary diagnosis were associated with nosocomial surgical site infection after high tibial osteotomy: analysis of a national database

PURPOSE

Although several small-scale studies have reported risk factors for surgical site infection (SSI) after high tibial osteotomy (HTO), no study has collectively analysed risk factors in a large cohort. The present study aimed to clarify the risk factors for SSI after HTO using a national database.

METHODS

Data of inpatients who underwent HTO from 2010 to 2017 were obtained from the Diagnosis Procedure Combination database in Japan. Outcome measures were the incidence of SSI and deep SSI after HTO. Associations between SSI and patient data were examined with multivariable logistic regression analysis.

RESULTS

Among 12,853 patients who underwent HTO, 195 developed SSI (1.52%) and 50 developed deep SSI (0.39%). Univariate analysis showed that male sex, smoking, and longer anaesthesia duration were associated with higher incidences of SSI, whereas a primary diagnosis of osteonecrosis and use of natural bone grafts were associated with lower incidences. In multivariable analysis, SSI was positively associated with male sex, anaesthesia duration longer than 210 min (vs. 150-210 min), and use of artificial bone graft (vs. natural bone graft). SSI was negatively associated with age ≤ 49 years (vs. 50-59 years) and a primary diagnosis of osteonecrosis (vs. osteoarthritis).

CONCLUSION

The present study revealed novel risk factors for SSI after HTO that previous studies have failed to find, including use of artificial bone graft and longer anaesthesia duration; primary diagnosis of osteonecrosis and younger age were novel protective factors. These findings will help surgeons assess risks of SSI after HTO in individual patients.

LEVEL OF EVIDENCE

III.

Higher age, female gender, osteoarthritis and blood transfusion protect against periprosthetic joint infection in total hip or knee arthroplasties: a systematic review and meta-analysis

PURPOSE

The goal of this systematic review and meta-analysis was to identify the main risk factors for periprosthetic joint infection (PJI) in patients undergoing total hip or knee arthroplasties.

METHODS

A systematic review was conducted of the potential risk factors for PJI in total hip or total knee arthroplasty. Risk factors were compared and grouped according to demographics, comorbidities, behavior, infections, native joint diseases and other patient-related and procedure-related factors. Meta-analysis (random-effects models) was conducted using odds ratio (OR) and mean difference (MD). Risk of bias (ROBBINS-I) and strength of the evidence (GRADE) were assessed.

RESULTS

The study included 37 studies (2,470,827 patients). Older age was a protective factor (MD = - 1.18). Male gender (OR 1.34), coagulopathy (3.05), congestive heart failure (2.36), diabetes mellitus (1.80), obesity (1.61), systemic neoplasia (1.57), chronic lung disease (1.52), and hypertension (1.21) increased the risk for PJI. Behavioral risk factors comprised alcohol abuse (2.95), immunosuppressive therapy (2.81), steroid therapies (1.88), and tobacco (1.82). Infectious risk factors included surgical site infections (6.14), postoperative urinary tract infections (2.85), and prior joint infections (2.15). Rheumatoid arthritis, posttraumatic native joint disease, high National Nosocomial Infections Surveillance (NNIS) system surgical patient index score, prior joint operation, American Society of Anesthesiologists score ≥ 3 and obesity were also significantly associated with higher risk of PJI. Osteoarthritis and blood transfusion were protective factors.

CONCLUSIONS

The main risk factors for PJI in each category were male gender, coagulopathy, alcohol abuse, surgical site infection (highest score) and high NNIS system surgical patient index score. Protective factors were age, female gender in TKA, osteoarthritis and blood transfusion. Optimization of modifiable risk factors for PJI should be attempted in clinical practice.

LEVEL OF EVIDENCE

II.

Unicompartmental knee arthroplasty is associated with lower proportions of surgical site infection compared with total knee arthroplasty: A retrospective nationwide database study

BACKGROUND

This study aimed to clarify the association between types of knee arthroplasty (KA) (total knee arthroplasty (TKA) or unicompatmental knee arthroplasty (UKA)) and surgical site infection (SSI) with adjustment for various factors, using a Japanese national database.

METHODS

Data on 181,608 patients who underwent unilateral primary KA for osteoarthritis from 2010 to 2017 were obtained from the Japanese Diagnosis Procedure Combination database. SSI was identified based on International Classification of Diseases 10th Revision codes. Deep SSI (i.e. periprosthetic joint infection (PJI)) was identified as SSI treated with surgical procedures. Multivariable logistic regression analyses for SSI and PJI were performed, in which dependent variables included types of KA, patient backgrounds (sex, age, body mass index (BMI), smoking status, comorbidities), and seasonality.

RESULTS

Eight percent of analyzed patients underwent UKA, while 92% underwent TKA. The proportions of SSI and PJI after UKA were 0.9% and 0.3%, respectively, both of which were lower than those after TKA (1.9% and 0.6%) (P < 0.001). Multivariable analyses showed lower proportions of SSI for UKA (adjusted odds ratio, 0.47; 95% confidence interval, 0.37-0.60; P < 0.001) and PJI (adjusted odds ratio, 0.47; 95% confidence interval, 0.34-0.65; P < 0.001) than TKA. Other factors associated with both SSI and PJI included male sex, BMI >30 kg/m², renal dysfunction and summer season.

CONCLUSION

UKA was associated with lower proportions of SSI and PJI than TKA. Surgeons should carefully consider the indication of UKA before performing TKA, especially in patients with knee unicompartmental osteoarthritis who are at a high risk for SSI or PJI.

A critical review of weight loss recommendations before total knee arthroplasty

OBJECTIVE

Increased infection risk after total knee arthroplasty (TKA) in patients with a higher body mass index (BMI), particularly a BMI ≥40kg/m², suggests that BMI reduction (through weight loss) prior to TKA may be important. However, the impact of weight loss on TKA risk reduction is unclear. Furthermore, weight loss could have detrimental consequences with respect to muscle loss and development of sarcopenic obesity, whereby a potential weight loss paradox in adults with advanced knee OA and obesity may be present. Using a critical review approach, we examined the current evidence supporting weight loss in adults with obesity and advanced knee osteoarthritis (OA). We focused on three key areas: (1) TKA complication risk with severe obesity compared to obesity (BMI ≥40kg/m² versus 30.0-39.9kg/m²); (2) weight loss recommendations for individuals with advanced knee OA; and (3) TKA outcomes after pre-surgical weight loss.

METHODS

Medline and CINAHL databases were examined from Jan 2010 to May 2020 to identify high-level and/or clinically-influential evidence (systematic reviews, meta-analyses and clinical practice guidelines).

RESULTS

The literature does not show a clear relationship between weight loss and reduction in TKA complications, and no indication that a patients' individual risk is lowered by reducing their BMI from a threshold of ≥40kg/m² to ≤39.9kg/m². Studies that have found a benefit of weight loss for knee OA have not included patients with higher BMIs (≥40kg/m²) or more advanced knee OA. Furthermore, there is unclear evidence of a benefit of pre-surgical weight loss on TKA outcomes. These are important evidence gaps, suggesting that recommendations for BMI reduction prior to TKA should be tempered by the current uncertainty in the literature.

CONCLUSION

Evidence to support a benefit of weight loss prior to TKA is lacking. Until knowledge gaps are clarified, it is recommended that practitioners consider individual patient needs and risk before recommending weight loss (and therefore BMI reduction).

Cost-effectiveness of dental antibiotic prophylaxis in total knee arthroplasty recipients with type II diabetes mellitus

Objective

Type II diabetes mellitus (T2DM) is prevalent in knee osteoarthritis (OA) patients undergoing total knee arthroplasty (TKA) and increases risk for prosthetic joint infection (PJI). We examined the cost-effectiveness of antibiotic prophylaxis (AP) before dental procedures to reduce PJI in TKA recipients with T2DM.

Design

We used the Osteoarthritis Policy Model, a validated computer simulation of knee OA, to compare two strategies among TKA recipients with T2DM (mean age 68 years, mean BMI 35.4 kg/m2): 1) AP before dental procedures and 2) no AP. Outcomes included quality-adjusted life expectancy (QALE) and lifetime medical costs. We used published efficacy of AP. We report incremental cost-effectiveness ratios (ICERs) and considered strategies with ICERs below well-accepted willingness-to-pay (WTP) thresholds cost-effective. We conducted sensitivity analyses to examine the robustness of findings to uncertainty in model input parameters. We used a lifetime horizon and healthcare sector perspective.

Results

We found that AP added 1.0 quality-adjusted life-year (QALY) and $66,000 for every 1000 TKA recipients with T2DM, resulting in an ICER of $66,000/QALY. In sensitivity analyses, reduction of the probability of PJI, T2DM-associated risk of infection, or attribution of infections to dental procedures by 50% resulted in ICERs exceeding $100,000/QALY. Probabilistic sensitivity analyses showed that AP was cost-effective in 32% and 58% of scenarios at WTP of $50,000/QALY and $100,000/QALY, respectively.

Conclusions

AP prior to dental procedures is cost-effective for TKA recipients with T2DM. However, the cost-effectiveness of AP depends on the risk of PJI and efficacy of AP in this population.

Risk Factors of Periprosthetic Infection in Patients with Tumor Prostheses Following Resection for Musculoskeletal Tumor of the Lower Limb

Tumor prostheses for the lower limb following resection of musculoskeletal tumors is useful limb salvage management; however, as compared with routine total joint replacement, an increased incidence of deep periprosthetic infection of tumor prosthesis has been observed. The risk factors for periprosthetic infection of tumor prosthesis remain unclear. This study examines the risk factors and outcomes of periprosthetic infection. This was a retrospective observational study including 121 patients (67 males and 54 females) who underwent tumor prosthesis of the lower limb after resection of musculoskeletal tumors between 1 January 2000 and 30 November 2018. Among a total of 121 tumor prostheses, 7 were total femurs, 47 were proximal femurs, 47 were distal femurs, and 20 were proximal tibias. The incidence of postoperative infection and its risk factors were analyzed. Forty-five patients (37%) had osteosarcoma, 36 patients (30%) had bone metastasis, and 10 patients (8%) had soft-tissue tumors invading the bone. The mean operating time was 229 min, and the mean follow-up duration was 5.9 years. Deep periprosthetic infection was noted in 14 patients (12%). In the multivariate analysis, the risk factors for postoperative infection were identified as being male (hazard ratio [HR], 11.2316; p = 0.0100), soft-tissue tumor (HR, 52.2443; p = 0.0003), long operation (HR, 1.0056; p = 0.0184), and radiotherapy (HR, 6.5683; p = 0.0476). The incidence of periprosthetic infection in our institution was similar to that of previous reports. Patients undergoing tumor prosthesis of the lower limb who were male, had a soft-tissue tumor, were predicted to have a long operation, and who underwent radiation, had an increased possibility of postoperative infection.

Sex-based differences in the outcomes of total hip and knee arthroplasty: a narrative review

Total joint arthroplasty (TJA) is an effective treatment for end-stage osteoarthritis, which aims to alleviate pain and improve function and mobility. Despite the remarkable success of TJA, complications can arise, leading to unplanned hospital readmission, implant failure, morbidity and mortality. Recently, there has been a growing interest in analysing sex-based differences in diseases and response to medical interventions. This review summaries evidence pertaining to the widening gap between men and women regarding the utilization and outcome of TJA surgery. Interactions between sex and patient-reported outcome, implant failure and medical complication are complex and often demonstrate conflicting results. Significantly, there is a global consensus that men are at a higher risk of developing prosthetic joint infection following joint arthroplasty. Guided by the literature, there is a clear need for standardized methods of collecting, analysing and reporting sex-specific data to improve outcomes for both men and women who undergo TJA.

Does well-controlled overt hypothyroidism increase the risk of total knee arthroplasty?

BACKGROUND

Overt hypothyroidism is widely accepted as a risk factor for adverse events following total knee arthroplasty (TKA). However, no prior study has preoperatively reversed hypothyroidism and reevaluated its risk. This retrospective study aimed at investigating whether well-controlled overt hypothyroidism would still increase the risk of TKA.

METHODS

Between November 2009 and November 2016, patients diagnosed with overt hypothyroidism but well controlled and underwent TKA were compared with euthyroid TKA patients. Data were extracted from our departmental database. Chi-squared test and t-tests were used for comparisons.

RESULTS

Hypothyroid patients had more blood loss and lower postoperative haemoglobin (Hb) and haematocrit level than the control group (all P < 0.05). Although the postoperative anaemia rate was lower in the control group (P = 0.01), there was no significant difference in the transfusion rate between the two groups (2.99% versus 7.46%, P = 0.10) or in the rates of other complications (P > 0.05). Interestingly, intramuscular venous thrombosis rate in hypothyroid patients was significantly lower than that in the control group (1.49% versus 9.70%, P = 0.00). Clinical outcome scores were comparable between the two groups throughout the course. And only one case of infection occurred in the hypothyroid patients.

CONCLUSION

Well-controlled overt hypothyroidism did not increase the risk of TKA, except for perioperative blood loss. Surgeons should be aware that even if hypothyroidism is reversed, the risk of more perioperative blood loss still exists and that, consequently, perioperative blood management is still essential in this population.

Chronic Corticosteroid Use as a Risk Factor for Perioperative Complications in Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Osteoarthritis may be caused by or concurrent with diseases such as rheumatoid arthritis or systemic lupus erythematosus, which rely on chronic corticosteroids regimens for treatment. If a total knee or hip arthroplasty is needed, this chronic treatment method has been associated with poorer surgical outcomes.

METHODS

A retrospective analysis of data collected by the American College of Surgeons National Surgical Quality Improvement Program was conducted. The Current Procedural Terminology codes were used to identify 403,566 total knee arthroplasty and total hip arthroplasty patients who were then stratified by the use of chronic corticosteroids for univariate analysis.

RESULTS

Forteen thousand seven hundred seventy-four of the patients identified were prescribed chronic corticosteroid regimens. A statistically significant difference was observed in perioperative complications for patients prescribed with corticosteroids, including higher rates of surgical site infection (P = 0.0001), occurrence of deep incisional surgical site infection (P < 0.0001), occurrences of organ space surgical site infection (P < 0.0001), wound dehiscence (P < 0.0001), general would infection (P < 0.0001), pneumonia (P < 0.0001), occurrences of unplanned intubation (P = 0.0002), urinary tract infection (P < 0.0001), and readmission (P < 0.0001). No statistically significant difference was observed in the 30-day mortality between the 2 groups (0.63), venous thromboembolic event (0.42), cerebrovascular accident (0.12), myocardial infarction (0.49), cardiac arrest (0.098), deep vein thrombosis (0.17), or sepsis (0.52).

CONCLUSION

Many of the notable differences in complications may be directly attributed to the immunosuppressive nature of corticosteroids. With increased knowledge of which perioperative complications to monitor, surgeons can tailor treatment strategies to this population that reduce morbidity and improve outcomes.

Possible risk factors for acute and chronic deep periprosthetic joint infections in primary total knee arthroplasty. Do BMI, smoking, urinary tract infections, gender, and ASA classification have an impact?

Purpose

Aim of this retrospective study was to evaluate the impact of the patient related factors body mass index (BMI), urinary tract infection, current smoking, gender, and American Society of Anesthesiologists (ASA) classification on the incidence of acute and chronic deep periprosthetic joint infections (PJI) in total knee arthroplasty (TKA).

Methods

All patients undergoing revision surgery for a deep PJI of primary TKA between July 2012 and December 2016 were included in this study. All relevant data was collected from the medical records. Acute deep PJI was defined when PJI was diagnosed within the first 6 weeks after primary TKA, chronic PJI was defined when patients demonstrated PJI later than 6 weeks after primary TKA.

Results

A total of 57 patients was included in this study with 13 cases of acute PJI and 44 of chronic PJI. Overweight patients (BMI > 25 kg/m²) represent a significantly larger proportion in both PJI groups (p < 0.05). Current smokers had an significantly increased risk for acute and chronic PJI (p < 0.05). In the acute PJI group 46.2% patients had an postoperative urinary tract infection.

Conclusion

An elevated BMI (>25 kg/m²), current smoking and urinary tract infection are possible risk factors for acute and chronic deep PJI. After primary TKA screening for urinary tract infection is recommendable to prevent predominantly acute deep PJI.

Factors associated with infection of primary total knee prosthesis in older adults in a referral hospital in Peru. 2012-2015

OBJECTIVE

To determine the risk factors associated with prosthetic knee infection in elderly patients in a referral hospital in Peru.

PATIENTS AND METHODS

A case and control study was performed. The calculated sample was 44 cases and 132 controls. The data were collected retrospectively from clinical records. U-Mann Whitney and Chi-square tests were performed in the comparison of cases and controls. Odds ratios (OR) were calculated in a binary logistic regression analysis to identify the risk factors, a P<.05 and a 95% confidence interval (CI) were considered significant.

RESULTS

Significant (P<.05) risk factors evidenced in the bivariate analysis were obesity (OR=9.72; 95%CI: 4.47-21.14), smoking (OR=4.06; 95%CI: 1.59-10.39), rheumatoid arthritis (OR=4.66; 95%CI: 1.52-14.32), diabetes mellitus type2 (OR=5.63; 95%CI: 2.69-11.78), persistent drainage (OR=9.27; 95%CI: 3.85-22.31), superficial infection (OR=6.87; 95%CI: 3.25-14.49) and prolonged hospital stay (OR=4.67; 95%CI: 2.26-9.64). In the multivariate analysis where it was adjusted for confounding variables, it was determined that risk factors were obesity (ORa=9.14; 95%CI: 3.28-25.48), diabetes mellitus (ORa=3.77; 95%CI: 1.38-10.32), persistent drainage (ORa=4.64; 95%CI: 1.03-20.80) and superficial wound infection (ORa=27.35; 95%CI: 2.57-290.64).

CONCLUSIONS

Risk factors for prosthetic knee infection identified in this study are preventable. The main risk factors were obesity, diabetes mellitus type2, superficial wound infection and persistent drainage, which were considered together or separately to be risk factors in the population studied.

Surgical site infection after primary total knee arthroplasty is associated with a longer duration of surgery

PURPOSE

Surgical site infection (SSI) is a serious complication following total knee arthroplasty (TKA) leading to considerable morbidity. The incidence is reported to be up to 2%. Risk factors continue to be an area of intense debate. Our study aims to report the incidence of SSI and identify possible risk factors in our patients undergoing TKA.

METHODS

Prospectively collected data for 905 patients who underwent elective unilateral TKA by a single surgeon from February 2004 to July 2014 were reviewed. Patient demographics and relevant co-morbidities such as diabetes and heart disease were analysed. The presence of superficial wound infections and/or prosthetic joint infections was included.

RESULTS

The overall infection rate was 1.10% (10 of 905 patients). Six patients (0.66%) were diagnosed with superficial infections and four with PJI (0.44%). The mean operative duration for TKA with SSI was significantly longer at 90.5 ± 28.2 min, compared to 72.2 ± 20.3 min in TKA without SSI ( p = 0.03). All superficial infections occurred within the first month post-surgery and were self-limiting with oral antibiotics. The four patients with PJI required repeated procedures following TKA, including debridement, implant removal and/or revision arthroplasty. None of the 10 patients had a history of diabetes. There were no significant differences in demographics and co-morbidities between those who developed infection after TKA and those who did not.

CONCLUSION

An overwhelming majority had good outcomes with only four deep infections resulting in revision surgery. We report that the risk of infection in TKA was significantly associated with a longer operative duration.

Low Body Mass Index and Low Intelligence Quotient Are Infection Risk Factors in Vagus Nerve Stimulation

BACKGROUND

Risk factors for infection after vagus nerve stimulation (VNS) device implantation represent an important issue but remain unclear. We hypothesized that specific risk factors for infection would be associated with VNS device implantation. This study reviewed patients with epilepsy who underwent VNS device implantation and undertook a statistical analysis of risk factors for surgical site infection (SSI).

METHODS

We reviewed all medical records for patients who underwent VNS therapy in our facility between August 2011 and May 2018. Age, sex, height, body weight, body mass index (BMI), intelligence quotient (IQ), surgical incision opening time, blood loss, epilepsy classification, activities of daily living, and generator replacement were statistically compared between cases with and without SSI.

RESULTS

We performed 208 VNS device implantation surgeries at our facility during the study period. Among these, 150 patients underwent initial implantation, 56 patients underwent first generator replacement, and 2 patients underwent second replacement. Six patients (2.7%) with initial implantation and 3 patients (5.4%) with first replacement showed SSI. Low BMI was a risk factor for infection at initial implantation (P < 0.0012) using a BMI within 1.78 kg/m² of the cutoff for being underweight (100% sensitivity, 25% specificity). Low IQ (P = 0.0015) was also a risk factor for SSI.

CONCLUSIONS

This study identified low BMI and low IQ at initial implantation as risk factors for infection.

Is Routine Urinary Screening Indicated Prior To Elective Total Joint Arthroplasty? A Systematic Review and Meta-Analysis

BACKGROUND

Prosthetic joint infection (PJI) is a serious complication after total joint arthroplasty, and prevention is of great importance. The genitourinary tract is a potential source of bacterial seeding and one that can be easily managed. Despite little supportive evidence, routine urine screening and subsequent treatment before elective surgery in patients without symptoms has found its way into clinical practice in many countries. This systematic review and meta-analysis aims to ascertain whether asymptomatic bacteriuria (ASB) is a risk factor for PJI and if so, whether preoperative antibiotic treatment is effective in reducing its risk.

METHODS

PubMed, Ovid Medline, and Cochrane databases were searched using a systematic strategy. Selection of papers was exclusive to include only those which offered information about PJI rate specifically in patients with or without asymptomatic abnormal urinalysis or bacteriuria and/or information on whether ASB patients were preoperatively treated with antibiotics or not to be included in the analysis.

RESULTS

Six-hundred sixty-three papers were screened, and 10 papers were ultimately included (28,588 patients). Results show an increased risk of developing PJI among ASB patients (odds ratio = 3.64, 95% confidence interval = 1.40-9.42). However, most PJI microorganisms are unrelated to those previously found in the urine and preoperative antibiotic therapy does not influence PJI risk (odds ratio = 0.98, 95% confidence interval = 0.39-2.44).

CONCLUSION

Routine urinary screening prior to elective total joint arthroplasty and treatment of asymptomatic patients is not recommended.

Wound closure and follow-up after total knee arthroplasty - Do they affect the rate of antibiotic prescription?

BACKGROUND

This study aimed to evaluate risk factors for oral antibiotic prescription in the first six weeks after primary TKA, particularly whether the wound closure method (staples or sutures) and two-week follow-up clinician (surgeon or general practitioner (GP)) altered antibiotic use.

METHODS

Four thousand eight hundred forty-six TKAs from January 2013 to December 2016 at three tertiary hospitals in Auckland, New Zealand were analysed by manual review of patient electronic records and a national prescription database. Surgeon preference dictates the method of wound closure and whether wound review is followed up by the operating surgeon or by the patient's GP. Univariate and multivariate analysis was carried out to identify significant patient and surgical risk factors for oral antibiotic prescribing.

RESULTS

Oral antibiotics were prescribed in 24% of patients following primary TKA. Twenty-six percent of patients closed with staples were prescribed oral antibiotics versus 19% with sutures (adjusted OR = 1.4, p < 0.004). Excluding re-presentations and readmissions, GPs prescribed oral antibiotics in 22% of patients compared to seven percent of patients seen by surgeons (adjusted OR = 2.8, p < 0.001). Other risk factors for antibiotic prescription included increasing age, BMI and ASA score.

CONCLUSION

Oral antibiotic prescribing rates are higher if the wound was closed with staples and if a GP performed the two-week follow-up. Improved communication between surgeons and GPs are required to ensure adequate follow-up following TKA and appropriate oral antibiotic use.

Obese patients have higher rates of polymicrobial and Gram-negative early periprosthetic joint infections of the hip than non-obese patients

Background

Obese patients are more likely to develop periprosthetic joint infection (PJI) after primary total joint arthroplasty. This study compared the clinical and microbiological characteristics of non-obese, obese and severely obese patients with early PJI, in order to ultimately optimize antibiotic prophylaxis and other prevention measures for this specific patient category.

Methods

We retrospectively evaluated patients with early PJI of the hip and knee treated with debridement, antibiotics and implant retention (DAIR) between 2006 and 2016 in three Dutch hospitals. Only patients with primary arthroplasties indicated for osteoarthritis were included. Early PJI was defined as an infection that developed within 90 days after index surgery. Obesity was defined as a BMI ≥30kg/m² and severe obesity as a BMI ≥35kg/m².

Results

A total of 237 patients were analyzed, including 64 obese patients (27.0%) and 62 severely obese patients (26.2%). Compared with non-obese patients, obese patients had higher rates of polymicrobial infections (60.3% vs 33.3%, p<0.001) with more often involvement of Enterococcus species (27.0% vs 11.7%, p = 0.003). Moreover, severely obese patients had more Gram-negative infections, especially with Proteus species (12.9% vs 2.3%, p = 0.001). These results were only found in periprosthetic hip infections, comprising Gram-negative PJIs in 34.2% of severely obese patients compared with 24.7% in obese patients and 12.7% in non-obese patients (p = 0.018).

Conclusions

Our results demonstrate that obese patients with early periprosthetic hip infections have higher rates of polymicrobial infections with enterococci and Gram-negative rods, which stresses the importance of improving preventive strategies in this specific patient category, by adjusting antibiotic prophylaxis regimens, improving disinfection strategies and optimizing postoperative wound care.

Shoulder Joint Infections with Negative Culture Results: Clinical Characteristics and Treatment Outcomes

Background

The incidence of septic arthritis of the shoulder joint is increasing as the population ages. The prevalence of shoulder infection is also increasing because of the growing use of arthroscopy and expansion of procedures in the shoulder. However, cultures do not always identify all microorganisms, even in symptomatic patients. The incidence of negative cultures ranges from 0% to 25%. Few studies have reported clinical features and treatment outcomes of culture-negative shoulder infections. This cohort study addresses culture-negative shoulder joint infections in nonarthroplasty patients. This study aimed to compare clinical characteristics and treatment outcomes of patients with culture-negative results to those with culture-positive results. Our hypothesis was that culture-negative infections would have more favorable outcomes than culture-positive infections.

Methods

We retrospectively reviewed data of 36 patients (17 culture-negative and 19 culture-positive) with shoulder infections between June 2004 and March 2015. The minimum follow-up duration was 1.2 years (mean, 5 ± 3.8 years; range, 1.2-11 years). We assessed preoperative demographic data and characteristics, laboratory markers, imaging and functional scores, intraoperative findings, and postoperative findings of both groups.

Results

Culture-negative patients (17/36, 47.2%) had a significantly lower occurrence of repeated surgical debridement (culture-negative vs. culture-positive: 1.2 ± 0.4 vs. 2.4 ± 1.7, p = 0.002) without osteomyelitis. In the multiple logistic regression analysis, the presence of osteomyelitis [odds ratio (OR) = 9.7, 95% confidence interval (CI): 1.0-91.8, p=0.04)] and the number of surgical debridements (OR = 5.3, 95% CI: 1.3-21.6, p=0.02) were significantly associated with culture-positive infections.

Conclusions

Culture-negative infections without osteomyelitis are less severe than culture-positive infections. Culture-negative infections can be controlled more easily and are not necessarily a negative prognostic factor for shoulder joint infections.

Atopic dermatitis is a novel demographic risk factor for surgical site infection after anterior cruciate ligament reconstruction

PURPOSE

Although various risk factors for surgical site infection after anterior cruciate ligament reconstruction (ACLR) have been reported, the number of studies with large sample sizes on this topic is limited. The aim of the present study was to clarify the risk factors for early surgical site infection after ACLR in a large cohort using a national database in Japan.

METHODS

The data of patients who underwent ACLR from 2010 to 2015 were obtained from the Diagnosis Procedure Combination database, which covers approximately half of all hospital admissions in Japan. The outcome measures were the prevalences of surgical site infection and deep surgical site infection after ACLR during hospitalization. The association between the occurrence of surgical site infection and patients' demographic data, including sex, age, body mass index (BMI), smoking status, preoperative steroid use, and comorbidities such as diabetes, hepatic dysfunction, renal dysfunction, and atopic dermatitis, were examined using a multivariable logistic regression model.

RESULTS

Among 30,536 patients who underwent ACLR, 288 patients with surgical site infection (0.94%) and 86 with deep surgical site infection (0.28%) were identified. The univariate analysis showed that higher prevalences of surgical site infection and deep surgical site infection were associated with male sex, a higher BMI, atopic dermatitis, and preoperative steroid use. Patients with diabetes or hepatic dysfunction had a significantly higher prevalence of surgical site infection. The multivariable analysis showed that surgical site infection was significantly associated with male sex vs. female sex; odds ratio (OR), 2.90; 95% confidence interval (CI), 2.17-3.89, age of ≤ 19 vs. 20-29 years; OR, 1.56; 95% CI 1.13-2.15, BMI of ≥ 30.0 vs. 18.5-22.9 kg/m²; OR, 1.72; 95% CI 1.16-2.54, diabetes (OR, 2.70; 95% CI 1.28-5.71), atopic dermatitis (OR, 7.19; 95% CI 2.94-17.57), and preoperative steroid use (OR, 6.18; 95% CI 2.32-16.52).

CONCLUSION

Atopic dermatitis, preoperative steroid use, young age (≤ 19 years), obesity (BMI of ≥ 30.0 kg/m²), male sex, and diabetes were independent demographic risk factors for surgical site infection after ACLR. The present study will be useful when surgeons evaluate the risk of SSI after ACLR in terms of demographic aspects.

LEVEL OF EVIDENCE

III.

The Impact of Diabetes on Patient Outcomes After Total Knee Arthroplasty in an Asian Population

BACKGROUND

Diabetes is implicated with poorer outcomes and more complications after total knee arthroplasty (TKA). We aim to determine whether diabetes affects infection risk, functional outcomes, patient-reported outcome measures, and patient satisfaction in Asian patients after TKA.

METHODS

Prospectively collected data for 905 patients who underwent unilateral TKA by a single surgeon from February 2004 to July 2014 were reviewed, of which 123 (13.6%) patients suffered from diabetes. At 2-year follow-up, the change in range of motion of the operated knee, body mass index, Knee Society Score, Oxford Knee Score (OKS), and Short Form-36 from baseline was compared between diabetic and nondiabetic patients. We also analyzed the length of hospitalization stay, infection risk, and patient satisfaction between the 2 groups.

RESULTS

Compared with nondiabetic patients, diabetic patients had significantly poorer preoperative OKS (37.6 on 8.3 to 35.8 .38.0, P = .02) and Short Form-36 Mental Component Score (48.3 Me11.2 to 51.7 1.10.7, P = .01). At 2-year follow-up, diabetes continued to be associated with poorer OKS of 21.2 018.4 and Knee Society Score Function score of 64.7 Fu20.9 compared to 19.1 0.6.2 (P = .02) and 71.8 0220.1 (P = .01) respectively in nondiabetic patients. Interestingly, the difference in mental well-being was no longer significant after TKA. A significantly larger proportion of diabetic patients (50%) had a reduction in body mass index after TKA compared to 36% in nondiabetic patients (P < .01). There was no difference in range of motion, length of hospitalization stay, infection risk, and patient satisfaction.

CONCLUSION

Despite poorer physical scores throughout, diabetic patients are no less satisfied and had significantly greater improvement in mental well-being and weight reduction after surgery.

Indications and Guidelines for Debridement and Implant Retention for Periprosthetic Hip and Knee Infection

PURPOSE OF REVIEW

Prosthetic joint infection is one the most common causes of revision surgery after hip or knee replacement. Debridement and implant retention (DAIR) is one method of treating these infections; however, significant controversy exists. The purpose of our review was to describe current knowledge about indications, intraoperative/postoperative patient management, and outcomes of DAIR.

RECENT FINDINGS

Patient selection affects the success of DAIR. Medical comorbidities, duration of symptoms, and nature of infectious organism all influence outcomes. Intraoperative techniques such as open arthrotomy, extensive debridement, copious irrigation, and exchange of modular parts remain current standards for DAIR. Postoperative administration of antibiotics tailored to operative cultures remains critical. Antibiotic suppression may increase the success of DAIR. DAIR provides reasonable infection eradication between 50 and 80% with improved outcomes in appropriately selected patients. More research is needed on the use of adjuvant therapies intraoperatively and the role of postoperative antibiotic suppression.

Periarticular Soft Tissue Envelope Size and Postoperative Wound Complications Following Total Knee Arthroplasty

BACKGROUND

Periprosthetic joint infection following total knee arthroplasty (TKA) is a serious complication often related to obesity which leads to poor patient outcomes and increased resource utilization. A periarticular soft tissue index (PASTI) may help predict postoperative wound complications than BMI alone.

METHODS

Three hundred seventy-six TKA patients with a preoperative, lateral knee X-ray radiograph and 1 year of follow up were analyzed. We used 2 pairs of soft tissue and bony measurements, one referencing the femur and the other the tibia. A high PASTI was defined as a ratio >3.0. Minor complications involved clinical interventions related to the surgical wound. Major complications involved return to the operating room.

RESULTS

More minor complications occurred in high PASTI for both tibial (20.9% vs 6.4%; odds ratio 3.89, 95% confidence interval 1.94-7.79, P < .001) and femoral measurements (15.3% vs 7.2%; odds ratio 2.09, 95% confidence interval 1.06-4.15, P = .013). Major complications were also more frequent in high PASTI, though not statistically significant. The proportion of obesity (BMI > 30) in both minor (12.4% vs 7.7%, P = .140) and major complications (2.8% vs 3.3%, P = .788) was not statistically different.

CONCLUSION

More wound complications occurred in patients with high PASTI, while no difference was seen using BMI. BMI has traditionally approximated patient size, but does not describe variations in body habitus. PASTI is a more reliable and direct way to assess the periarticular soft tissue envelope size, which is associated with postoperative wound complications in the knee.