Risk factors for periprosthetic joint infection following primary total hip arthroplasty: a case control study

Clostridium difficile Infection Prior to Total Hip Arthroplasty Independently Increases the Risk of Periprosthetic Joint Infection

BACKGROUND

Periprosthetic joint infection (PJI) following total hip arthroplasty (THA) is associated with major morbidity. There may be a link between the gut microbiome and an individual's overall immune system. A Clostridium difficile (C. difficile) infection portends poor gut microbiome health and has been previously associated with increased 90-day complication rates in total joint arthroplasty (TJA). The purpose of this study was to determine the effect of a previous history of C. difficile infection within 2 years of undergoing THA on PJI within 2 years postoperatively.

METHODS

Patients undergoing THA from 2010 to 2021 were identified in a patient claims database (n = 770,075). Patients who had active records 2 years before and after THA as well as a history of C. difficile infection within 2 years prior to THA (n = 1,836) were included and propensity matched to a control group using age, sex, and Elixhauser comorbidity index. The primary outcome was the 2-year incidence of postoperative PJI. The exposed C. difficile infection cohort was stratified into 4 groups based on the time proximity of the C. difficile infection. Chi-square tests and logistic regressions were used to compare the groups.

RESULTS

A C. difficile infection anytime within 2 years prior to total hip arthroplasty was independently associated with higher odds of PJI (OR [odds ratio]: 1.49 [95% CI (confidence interval) 1.09 to 2.02, P = .014]). Proximity of C. difficile infection to arthroplasty was associated with increased risk of PJI (infection 0 to 3 months before THA: OR 2.01 [95% CI 1.23 to 3.20], infection 3 to 6 months before THA: OR 1.84 [95% CI 1.06 to 3.04], infection 6 to 12 months before THA: OR 1.10 [95% CI 0.65 to 1.77], infection 1 to 2 years before THA: OR 1.40 [95% CI 0.94 to 2.06]).

CONCLUSIONS

A C. difficile infection prior to THA is an independent risk factor for PJI. Proximity of C. difficile infection is associated with increased risk of PJI. Future investigations should evaluate how to adequately optimize patients prior to THA and pursue strategies to determine appropriate timing for proceeding with THA.

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.

Longitudinal Rates, Patient Risk Factors, and Economic Impact of Superficial and Deep Incisional Surgical Site Infection After Primary and Revision Total Hip Arthroplasty: A U.S. Retrospective Commercial Claims Database Analysis

Background: Longitudinal rates, risk factors, and costs of superficial and deep incisional surgical site infection (SSI) were evaluated six months after primary total hip arthroplasty (pTHA) and revision total hip replacement (rTHA). Patients and Methods: Patients who had pTHA or rTHA between January 1, 2016 and March 31, 2018 were identified using the IBM^® MarketScan^® administrative claims databases. Kaplan-Meier survival curves evaluated time to SSI over six months. Cox proportional hazard models evaluated SSI risk factors. Generalized linear models estimated SSI costs up to 12 months. Results: The total cohort included 17,514 pTHA patients (mean [standard deviation] age 59.6 [10.1] years, 50.2% female; 66.4% commercial insurance), and 2,954 rTHA patients (61.2 [12.0] years, 52.0% female; 48.6% commercial insurance). Deep and superficial post-operative SSI at six months affected 0.30% (95% confidence interval [CI], 0.22%-0.39%) and 0.67% (95% CI, 0.55%-0.79% of patients in the pTHA, and 8.9% (95%CI: 7.8%-10.0%) and 4.8% (95% CI, 4.0%-5.6%) of patients in the rTHA cohorts. Hazards for SSI were related to patient comorbidities that included diabetes mellitus, obesity, renal failure, pulmonary or circulatory disorders, and depression. The adjusted average all-cause incremental commercial costs associated with post-operative infection ranged from $21,434 to $42,879 for superficial incisional SSI and $53,884 to $76,472 for deep incisional SSI, over a 12-month post-operative assessment period. Conclusions: The SSI rate after revision total hip arthroplasty (rTHA) was nearly 9% compared with 1.0% after pTHA. The risk of infection was influenced by several comorbid risk factors. The incremental cost associated with SSIs was substantial.

Infections of Tumor Prostheses: An Updated Review on Risk Factors, Microbiology, Diagnosis, and Treatment Strategies

Several causes contribute to the high infection rate in tumor prostheses, including extensive tissue dissection and patients' immunosuppression due to the neoplastic disease. Most of these infections develop within the first 2 years following surgery with 70% of them occurring during the first year, while they are often associated with a low pathogen burden. The pathogenesis of infections in tumor prostheses is linked to bacteria developing in biofilms. Approximately half of them are caused by Staphylococcus spp., followed by Streptococcus spp., Enterococcus spp., and Enterobacteriaceae spp., while multiple pathogens may be isolated in up to 25% of the cases, with coagulase-negative Staphylococci (CoNS) and Enterococccus spp. being the most frequent pair. Although early detection and timely management are essential for complete resolution of these challenging infections, prompt diagnosis is problematic due to the highly varying clinical symptoms and the lack of specific preoperative and intraoperative diagnostic tests. Surgical management with one- or two-stage revision surgery is the mainstay for successful eradication of these infections. The recent advances in laboratory diagnostics and the development of biofilm-resistant prostheses over the past years have been areas of great interest, as research is now focused on prevention strategies. The aim of this study is to review and consolidate the current knowledge regarding the epidemiology, risk factors, microbiology, and diagnosis of infections of tumor prostheses, and to review the current concepts for their treatment and outcomes.

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.

Higher 2-Year Cumulative Incidence of Mental Health Disorders Following Antibiotic Spacer Placement for Chronic Periprosthetic Joint Infection following Total Joint Arthroplasty

BACKGROUND

The relationship of chronic periprosthetic joint infection (PJI) treatment on the development and relapse of mood disorders remains largely unreported. This study aims to compare the incidence of different mental health disorders following antibiotic spacer placement for chronic PJI when compared to aseptic revisions and primary procedures.

METHODS

Patients who underwent antibiotic spacer for septic total hip and knee arthroplasty (PJI THA/TKA) were identified in the PearlDiver Database using Current Procedure Terminology (CPT) codes for hip and knee antibiotic spacers. Patients who underwent aseptic revision and primary-THA/TKA were also identified using CPT codes. The incidences of depressive, anxiety, bipolar, psychotic, and stress disorders were identified within 2 years following the index procedures via Kaplan-Meier Analysis.

RESULTS

The risk of depressive (hazard ratio (HR): 1.5; P < .001) and stress (HR: 1.5; P < .001) disorders were significantly higher in those who underwent PJI-THA when compared to aseptic revision, with the added risk of bipolar when compared to primary THA. The risk of depressive (HR: 1.6; P < .001), stress (HR: 1.4; P < .001), bipolar (HR: 1.3; P < .001), and psychotic disorders (HR: 1.5; P = .003) were significantly higher in those who underwent PJI-TKA when compared to aseptic revision, with the added risk of anxiety when compared to primary TKA.

CONCLUSION

Patients who undergo spacer placement for septic-THA/TKA have a disproportionately higher incidence of mental health disorders within 2 years following surgery when compared those undergoing aseptic revisions and primary procedures. Due to this higher risk, physicians should strongly consider collaborative care with psychiatrists or mental health professionals.

LEVEL OF EVIDENCE

III.

Prevention of Orthopedic Prosthetic Infections Using Evidence-Based Surgical Site Infection Care Bundles: A Narrative Review

Background: The number of primary/revision total joint replacements (TJR) are expected to increase substantially with an aging population and increasing prevalence of comorbid conditions. The 30-day re-admission rate, in all orthopedic specialties, is 5.4% (range, 4.8%-6.0%). A recent publication has documented that the surgical site infection (SSI) infection rate associated with revision total knee (rTKR, 15.6%) and revision total hip (rTHR, 8.6%) arthroplasties are four to seven times the rate of the primary procedures (2.1%-2.2%). These orthopedic infections prolong hospital stays, double re-admissions, and increase healthcare costs by a factor of 300%. Methods: A search of PubMed/MEDLINE, EMBASE and the Cochrane Library publications, which reported the infection risk after TKR and THR, was undertaken (January 1, 1995 to December 31, 2021). The search also included documentation of evidence-based practices that lead to improved post-operative outcomes. Results: The evidence-based approach to reducing the risk of SSI was grouped into pre-operative, peri-operative, and post-operative periods. Surgical care bundles have existed within other surgical disciplines for more than 20 years, although their use is relatively new in peri-operative orthopedic surgical care. Pre-admission chlorhexidine gluconate (CHG) showers/cleansing, staphylococcal decolonization, maintenance of normothermia, wound irrigation, antimicrobial suture wound closure, and post-operative wound care has been shown to improve clinical outcome in randomized controlled studies and meta-analyses. Conclusions: Evidence-based infection prevention care bundles have improved clinical outcomes in all surgical disciplines. The significant post-operative morbidity, mortality, and healthcare cost, associated with SSIs after TJR can be reduced by introduction of evidence-based pre-operative, intra-operative, and post-operative interventions.

Incision site fat thickness and 90-day complications for direct anterior and posterior approach total hip arthroplasty

BACKGROUND

Defining the distribution of subcutaneous fat around the hip in relation to different approaches for total hip arthroplasty (THA) may lead to a better understanding of the relationship between obesity and complications. The purpose of this study was to: (1) describe the intraoperative thickness of subcutaneous fat at the incision site for direct anterior (DAA) and posterior approaches (PA) for THA; and (2) examine the relationship between fat thickness and 90-day postoperative complications.

METHODS

Intraoperative fat measurements were obtained at the anterior incision site (AT-IS) of the DAA (n = 60) and the lateral incision site (LT-IS) of the PA (n = 64). Lateral hip fat thickness was measured from preoperative anteroposterior pelvis radiographs (LT-XR). Body mass index (BMI), sex, age, and 90-day complications were collected retrospectively.

RESULTS

Patients within the same demographic groupings had significantly more fat laterally than anteriorly, between 9.6 mm and 17.96 mm. Return to the OR was significantly associated with BMI, AT-IS, and LT-IS. Wound complications were significantly associated with AT-IS. Periprosthetic joint infection (PJI) was significantly associated with BMI and LT-IS. No outcome variables were associated with LT-XR, approach, sex, or age. LT-XR was strongly correlated with AT-IS and LT-IS.

CONCLUSIONS

Regardless of BMI, sex, or age more soft tissue was encountered with a PA compared to a DAA. General adiposity was associated with return to the OR. Excess incisional fat was associated with wound complications following a DAA and PJI after a PA. LT-XR and clinical examination near the proposed incision, may provide helpful data in making preoperative risk assessments.

Does Surgical Approach for Total Hip Arthroplasty Impact Infection Risk in the Obese Patient? A Systematic Review

This systematic review evaluated the combined effects of obesity and surgical approach on periprosthetic joint infection (PJI) rates after total hip arthroplasty (THA). Wound complication and PJI rates were elevated among patients with body mass index (BMI) of 30 kg/m2 or greater and 35 kg/m2 or greater, respectively, with the direct anterior approach (DAA). A BMI of 30 kg/m2 or greater also increased the risk of PJI with the posterior approach. Patients with BMI of 30 kg/m2 or greater undergoing anterolateral approach THA did not have increased risk of PJI. Patients with elevated BMI (≥30 kg/m2) are at risk for PJI, regardless of approach. Patients undergoing DAA THA who have BMI of 35 kg/m2 or greater may have an increased risk of PJI compared with those undergoing THA with other approaches. [Orthopedics. 2022;45(2):e67-e72.].

Patients' risk factors for periprosthetic joint infection in primary total hip arthroplasty: a meta-analysis of 40 studies

BACKGROUND

Periprosthetic joint infection (PJI) is a catastrophic complication after total hip arthroplasty (THA). Our meta-analysis aimed to identify the individual-related risk factors that predispose patients to PJI following primary THA.

METHODS

Comprehensive literature retrieval from Pubmed, Web of Science, and the Cochrane Library was performed from inception to Feb 20th, 2021. Patient-related risk factors were compared as per the modifiable factors (BMI, smoke and alcohol abuse), non-modifiable factors (gender, age), and medical history characteristics, such as diabetes mellitus (DM), avascular necrosis (AVN) of femoral head, femoral neck fracture, rheumatoid arthritis (RA), cardiovascular disease (CVD), and osteoarthritis (OA) etc. The meta-analysis was applied by using risk ratios with 95% corresponding intervals. Sensitivity analysis and publication bias were performed to further assess the credibility of the results.

RESULTS

Overall, 40 studies with 3,561,446 hips were enrolled in our study. By implementing cumulative meta-analysis, higher BMI was found associated with markedly increased PJI risk after primary THA [2.40 (2.01-2.85)]. Meanwhile, medical characteristics including DM [1.64 (1.25-2.21)], AVN [1.65 (1.07-2.56)], femoral neck fracture [1.75 (1.39-2.20)], RA [1.37 (1.23-1.54)], CVD [1.34 (1.03-1.74)], chronic pulmonary disease (CPD) [1.22 (1.08-1.37)], neurological disease [1.19 (1.05-1.35)], opioid use [1.53 (1.35-1.73)] and iron-deficiency anemia (IDA) [1.15 (1.13-1.17)] were also significantly correlated with higher rate of PJI. Conversely, dysplasia or dislocation [0.65 (0.45-0.93)], and OA [0.70 (0.62-0.79)] were protective factors. Of Note, female gender was protective for PJI only after longer follow-up. Besides, age, smoking, alcohol abuse, previous joint surgery, renal disease, hypertension, cancer, steroid use and liver disease were not closely related with PJI risk.

CONCLUSION

Our finding suggested that the individual-related risk factors for PJI after primary THA included high BMI, DM, AVN, femoral neck fracture, RA, CVD, CPD, neurological disease, opioid use and IDA, while protective factors were female gender, dysplasia/ dislocation and OA.

Infection and Mechanical Complications Are Risk Factors for New Diagnosis of a Mental Health Disorder After Total Joint Arthroplasty

Background

Prior studies have demonstrated that depression is an independent risk factor for developing a prosthetic joint infection (PJI) after total joint arthroplasty (TJA). To our knowledge, there is no literature examining whether PJI or aseptic failure increases the risk of developing a new mental health diagnosis.

Methods

PearlDiver Patient Database (Colorado Springs, CO) was used to identify 80,826 patients who underwent TJA without a pre-existing diagnosis of depression, anxiety, a stress and/or adjustment disorder, and/or current use of a selective serotonin reuptake inhibitor within the year prior to surgery. The odds of developing a new mental health issue or being prescribed a selective serotonin reuptake inhibitor within 1 year of an uncomplicated TJA was compared to those who developed PJI or mechanical failure within 90 days after TJA as well as to those who subsequently underwent revision surgery within 30 days of either complication using Fisher’s exact test and Baptista-Pike.

Results

A total of 6474 (8%) patients were diagnosed with a new mental health issue after TJA. PJI or mechanical failure led to significantly higher odds of new diagnoses with an odds ratio of 1.67 (95% confidence interval = 1.26, 2.22) and 1.57 (1.24, 2.00), respectively. Undergoing revision surgery for PJI or mechanical failure increased the odds of developing a new mental health diagnosis to 2.10 (1.29, 3.42) and 2.24 (1.36, 3.72), respectively. There was no significant difference comparing those who developed PJI vs those who sustained mechanical complications.

Conclusion

Patients who sustain complications after TJA are at increased odds of receiving a new mental health diagnosis, an effect further amplified if revision surgery is required.

Preoperative Allergy Testing for Patients Reporting Penicillin and Cephalosporin Allergies is Cost-Effective in Preventing Infection after Total Knee and Hip Arthroplasty

BACKGROUND

Routine preoperative allergy testing in patients reporting penicillin and cephalosporin allergies increases the number able to receive cefazolin, which should reduce the risk of infection after total knee and hip arthroplasty (TKA/THA), but it remains unclear whether this practice is cost-effective. Using a break-even analysis, we calculated the cost-effectiveness of routine preoperative allergy testing for infection prevention in total joint arthroplasty patients reporting penicillin and cephalosporin allergies.

METHODS

The cost of a penicillin allergy evaluation, the cost of revision arthroplasty for prosthetic joint infection (PJI), and baseline rates of PJI in patients receiving a noncefazolin antibiotic in the perioperative period were derived from existing literature. A break-even economic model using these variables was constructed to calculate the absolute risk reduction (ARR) in infection rate needed for preoperative allergy testing to be cost-effective. The number needed to treat (NNT) was calculated from the ARR.

RESULTS

Preoperative allergy testing before TKA and THA in patients reporting penicillin and cephalosporin allergies was cost-effective if the initial infection rate decreased by an ARR of 0.810% (NNT = 123) and 0.655% (NNT = 153) for TKA and THA, respectively. Cost-effectiveness was maintained with varying allergy consultation costs, infection rates, and costs associated with PJI treatment.

CONCLUSION

Routine preoperative allergy testing and clearance are cost-effective infection prevention strategies among patients reporting penicillin and cephalosporin allergies in the setting of elective joint arthroplasty. Widespread adoption of this practice may considerably reduce the economic and societal burden associated with prosthetic infections.

Correlation between Body Mass Index and Periprosthetic Joint Infection following Total Joint Arthroplasty: A protocol for systematic review and meta analysis

BACKGROUND

Despite rapid reports on the correlation between body mass index (BMI) and periprosthetic joint infection (PJI) after total joint arthroplasty, some have conducted regression tests or meta-analyses with controversial results. In this study, we systematically meta-analyzed relevant trials and carefully evaluated the correlation for verification.

METHODS

Literature on the correlation between BMI and PJI following total joint arthroplasty was retrieved in PubMed, Embase and Cochrane Library due September 2019. Stata 13.0 software was adopted for data synthesis and analyses of publication bias and sensitivity. Random-effect models were used to summary the overall estimate of the multivariate adjusted odds ratio (OR)/hazard ratio/rate ratio with 95% confidence intervals (CIs).

RESULTS

A total of 29 observational studies representing 3,204,887 patients were included. The meta-analysis revealed that the risk of postoperative PJI significantly increased by 1.51 times in the obese group (OR = 1.51; 95% CI = 1.30-1.74 for the obese group vs. the non-obese group), and by 3.27 times in the morbid obese group (OR = 3.27; 95% CI = 2.46-4.34 for the morbid obese group vs the non-morbid obese group). A significant association remained consistent, as indicated by subgroup analyses and sensitivity analyses.

CONCLUSION

Our findings demonstrate that postoperative PJI is positively correlated with BMI, with obese patients showing a greater risk of developing PJI than non-obese patients. Similarly, morbid obese patients present a higher risk of PJI than non-morbid obese patients. However, this conclusion needs to be corroborated by more prospective studies.

Intraoperative and Postoperative Infection Prevention

Implementation of strategies for prevention of surgical site infection and periprosthetic joint infection is gaining further attention. We provide an overview of the pertinent evidence-based guidelines for infection prevention from the World Health Organization, the Centers for Disease Control and Prevention, and the second International Consensus Meeting on Musculoskeletal Infection. Future work is needed to ascertain clinical efficacy, optimal combinations, and the cost-effectiveness of certain measures.

Comparison of Functional Outcomes and Associated Complications in Patients Who Underwent Total Hip Arthroplasty for Femoral Neck Fracture in Relation to Their Underlying Medical Comorbidities

Purpose

In patients with independent mobility, full hip range of motion and sufficient muscle strength for daily life without cognitive impairment, treatment of a femoral neck fracture with total hip arthroplasty (THA) may be a better option compared to bipolar hip hemiarthroplasty. Here, functional outcomes and complications in patients who underwent THA for femoral neck fracture based on their comorbidity status were analyzed.

Materials and Methods

Between January 2013 and December 2018, 110 patients were treated with THA for femoral neck fractures at our institution. These patients were retrospectively analyzed for clinical outcomes at final follow-up (mean=24.4 months, range: 6-81 months) using the Harris hip score (HHS) and the presence or absence of two potential comorbidities: i) diabetes mellitus (DM; 35 with and 75 without) and ii) hypertension (HTN; 50 with and 60 without).

Results

The incidence of superficial infections at the surgical site in patients with DM was significantly higher compared with patients without DM (P=0.024). There were no significant differences in other potential complications based on DM status. HHS at final follow-up between patients with and without DM and with and without HTN were not significantly different (83.3 vs. 81.0, P=0.39 and 81.6 vs. 82.4, P=0.75, respectively).

Conclusion

Superficial infections occurred more frequently in patients with DM compared with patients without DM. DM and HTN status are not correlated with HHS.

Impact of patient comorbidities on surgical site infection within 90 days of primary and revision joint (hip and knee) replacement

BACKGROUND

The frequency of primary and revision total knee and hip replacements (pTKRs, rTKRs, pTHRs, and rTHRs, respectively) is increasing in the United States due to demographic changes. This study evaluated the impact of preoperative patient and clinical factors on the risk of surgical site infection (SSI) within the 90-day period after primary and revision total joint replacements (TJR).

METHODS

A retrospective observational cohort study was designed using the IBM MarketScan and Medicare databases, 2009-2015. Thirty-four comorbidities were assessed for all patients, and multivariable logistic regression models were used to evaluate factors associated with higher odds of SSI after adjusting for other patient and clinical preoperative conditions.

RESULTS

The study included a total of 335,134 TKRs and 163,547 THRs. SSI rates were 15.6% and 8.6% after rTKR and rTHR, respectively, compared with 2.1% and 2.1% for pTKR and pTHR, respectively. Comorbidities with the greatest adjusted effect on SSI across all TJRs were acquired immunodeficiency syndrome (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.06-2.34; P = .0232), paralysis (OR, 1.56; 95% CI, 1.26-1.94; P < .0001), coagulopathy (OR, 1.48; 95% CI, 1.36-1.62; P < .0001), metastatic cancer (1.48; 95% CI, 1.24-1.76; P < .0001), and congestive heart failure (OR, 1.39; 95% CI, 1.30-1.49; P < .0001).

CONCLUSIONS

SSI occurred most commonly among patients after revision TJR and were related to many patient comorbidities, including diabetes, congestive heart failure, and coagulopathy, which were significantly associated with a higher risk of SSI after TJR.

Is Elective Soft Tissue Hand Surgery Associated with Periprosthetic Joint Infection after Total Joint Arthroplasty?

BACKGROUND

Although current guidelines do not recommend the routine use of surgical antibiotic prophylaxis to reduce the risk of surgical site infection following clean, soft tissue hand surgery, antibiotics are nevertheless often used in patients with an existing joint prosthesis to prevent periprosthetic joint infection (PJI), despite little data to support this practice.

QUESTIONS/PURPOSES

(1) Is clean, soft tissue hand surgery after THA or TKA associated with PJI risk? (2) Does surgical antibiotic prophylaxis before hand surgery decrease PJI risk in patients with recent THA or TKA?

METHODS

We assessed all patients who underwent THA or TKA between January 2007 and December 2015 by retrospective analysis of the IBM® MarketScan® Databases, which provide a longitudinal view of all healthcare services used by a nationwide sample of millions of patients under commercial and supplemental Medicare insurance coverage-particularly advantageous given the relatively low frequency of hand surgery after THA/TKA and of subsequent PJI. The initial search yielded 940,861 patients, from which 509,896 were excluded for not meeting continuous enrollment criteria, having a diagnosis of PJI before the observation period, or having another arthroplasty procedure before or during the observation period; the final study cohort consisted of 430,965 patients of which 147,398 underwent THA and 283,567 underwent TKA. In the treated cohort, 8489 patients underwent carpal tunnel release, trigger finger release, ganglion or retinacular cyst excision, de Quervain's release, or soft-tissue mass excision within 2 years of THA or TKA. The control cohort was comprised of 422,476 patients who underwent THA or TKA but did not have subsequent hand surgery. The primary outcome was diagnosis or surgical management of a PJI within 90 days of the index hand surgery for the treated cohort, or within a randomly assigned 90-day observation period for each patient in the control group. Propensity score matching was used to match treated and control cohorts by patient and treatment characteristics and previously-reported risk factors for PJI. Logistic regression before and after propensity score matching was used to assess the association of hand surgery with PJI risk and the association of surgical antibiotic prophylaxis before hand surgery with PJI risk in the treated cohort. Other possible PJI risk factors were also explored in multivariable logistic regression. Statistical significance was assessed at α = 0.01.

RESULTS

Hand surgery was not associated with PJI risk after propensity score matching of treated and control cohorts (OR, 1.39; 99% CI, 0.60-3.22; p = 0.310). Among patients who underwent hand surgery after arthroplasty, surgical antibiotic prophylaxis before hand surgery was not associated with decreased PJI risk (OR 0.42; 99% CI, 0.03-6.08; p = 0.400).

CONCLUSIONS

Clean, soft-tissue hand surgery was not found to be associated with PJI risk in patients who had undergone primary THA or TKA within 2 years before their hand procedure. While the effect of PJIs can be devastating, we do not find increased risk of infection with hand surgery nor data supporting routine use of surgical antibiotic prophylaxis in this setting.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Impact of preoperative mental health status on functional outcome 1 year after total hip arthroplasty

Background

The aim of this prospective cohort study was to determine the effect of preoperative mental health status on functional outcome 1 year after total hip arthroplasty (THA).

Methods

Data were collected for 677 patients from a randomized controlled trial in Alberta who received primary THA between April 2005 and June 2006 (sex, age, body mass index [BMI], comorbidities, back pain and need for another lower limb arthroplasty procedure within 1 yr after surgery). The Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and 36-Item Short Form Health Survey (SF-36) mental health component were administered before surgery and 1 year after. We conducted multiple linear regression to determine the effect of mental health on the WOMAC score at 1 year.

Results

The mean WOMAC and SF-36 mental health scores were significantly increased at 1 year (p < 0.001 and p = 0.01, respectively). There was a strong correlation between improvement in WOMAC score at 1 year and presurgery SF-36 mental health score (0.13, 95% confidence interval [CI] 0.06 to 0.2). Age (–0.34, 95% CI –0.45 to –0.24), obesity (–2.9, 95% CI –5.32 to –0.4), back pain (–5.75, 95% CI –8.04 to –3.46) and awaiting another joint arthroplasty operation (–6.18, 95% CI –8.9 to –3.47) had a negative impact on the WOMAC score.

Conclusion

There was a strong correlation between presurgery mental health and the resolution of pain and improved functioning 1 year after THA. We recommend that patients receive appropriate counselling and, where appropriate, medical therapy before THA.

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.

Primary Total Hip Arthroplasty in Patients Less Than 50 Years of Age at a Mean of 16 Years: Highly Crosslinked Polyethylene Significantly Reduces the Risk of Revision

BACKGROUND

The purpose of this study is to evaluate clinical and radiographic outcomes of patients less than 50 years of age undergoing primary total hip arthroplasty (THA) at a minimum of 10 years.

METHODS

Three hundred nine consecutive THAs performed on 273 patients were reviewed. At a minimum of 10 years, 13 were deceased and 23 were lost to follow-up leaving 273 THAs in 237 patients who were followed for a mean of 16 years (range 10-19.9). The cohort consisted of 116 females (49%) and 121 males (51%), with a mean age of 42.3 years at the time of surgery (range 19-49). The majority of preoperative diagnoses included osteoarthritis in 149 (63%) and avascular necrosis in 55 (23%). Two hundred sixteen had highly crosslinked polyethylene (HXLPE) and 57 had non-HXLPE acetabular liners. The femoral stems were cementless in 98% (266/273) and the acetabular components were cementless in all cases. Femoral head composition was cobalt-chromium in all cases and the majority of sizes in the non-HXLPE cohort were 28 mm (52/57; 91%), while the HXLPE group primarily consisted of 28 mm (141/216; 65%) and 32 mm (74/216; 34%) heads. Analysis involved Kaplan-Meier survivorship with a log-rank test for equivalence, Fisher's exact test for pairwise comparisons, and a paired t-test for Harris Hip Score, with alpha = 0.05 being statistically significant.

RESULTS

There were 6 revisions for wear in the non-HXLPE group (10.5%) compared to none in the HXLPE group (P < .001). Similarly, survivorship with revision for any reason as the endpoint at 16 years was significantly higher at 93.0% in the XLPE group (95% confidence interval 88.7-95.7) compared to 85.7% (95% confidence interval 73.5-92.6) in the non-HXLPE group (P = .023). Additional revisions in the HXLPE group included 6 for instability (2.8%), 5 secondary to infection (2.4%), and 3 stem failures (1.4%). Non-wear-related revisions in the non-HXLPE group included 5 due to instability (8.8%) and 3 due to stem failures (5.3%). The mean Harris Hip Scores for the entire cohort improved from a mean of 46.2 points preoperatively to 89.8 points at most recent follow-up (P < .001).

CONCLUSION

The use of HXLPE has led to a significant reduction in the risk of failure in patients <50 years old, with over 93% survivorship at 16 years. Instability and infection, however, remain substantial causes of failure.

LEVEL OF EVIDENCE

Therapeutic Level III.

Longer Operative Time Results in a Higher Rate of Subsequent Periprosthetic Joint Infection in Patients Undergoing Primary Joint Arthroplasty

BACKGROUND

Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA.

METHODS

We retrospectively reviewed 17,342 primary unilateral total knee arthroplasty and total hip arthroplasty performed at a single institution between 2005 and 2016, with a minimum follow-up of 1 year. A multivariate logistic regression model was conducted to identify the association between operative time and the development of SSI within 90 days and PJI within 1 year.

RESULTS

Overall, the incidence of 90-day SSI and 1-year PJI was 1.2% and 0.8%, respectively. Patients with an operative time of >90 minutes had a significantly higher incidence of SSI and PJI (2.1% and 1.4%, respectively) compared to cases lasting between 60 and 90 minutes (1.1% and 0.7%), and those lasting ≤60 minutes (0.9% and 0.7%, P < .01). In the multivariate model, the risk for infection increased by an odds ratio of 1.346 (95% confidential interval 1.114-1.627) for 90-day SSI and 1.253 (95% confidential interval 1.060-1.481) for 1-year PJI for each 20-minute increase in operative time.

CONCLUSION

In patients undergoing primary TJA, each 20-minute increase in operative time was associated with nearly a 25% increased risk of subsequent PJI. We advocate that surgeons pay close attention to this underappreciated risk factor while maintaining safe operative practices, which minimize unnecessary steps and wasted time in the operating room.

Age alone is not a risk factor for periprosthetic joint infection

BACKGROUND

It is not known whether age alone or the increased comorbidities in older patients are responsible for the higher rate of periprosthetic joint infection (PJI) in older patients.

AIM

To test the hypothesis that age alone is not a risk factor for PJI after total joint arthroplasty.

METHODS

This retrospective study included the review of 23,966 patients undergoing primary total hip and knee arthroplasty between January 1^st, 2010 and December 31^st, 2016 at a single institution. Patients who developed PJI, as defined by International Consensus Meeting criteria, were identified. All enrolled patients were divided into three groups that included patients aged <65 years (N = 12,761), 65-74 years (N = 6850) and ≥75 years (N = 4355). Using multivariate analysis and propensity score matching analysis, the possible association between age and PJI was examined.

FINDINGS

The incidence of PJI in the entire cohort was 0.72% (171 out of 23,966). Multivariate analysis adjusting for all variables, except age, demonstrated that, compared to the patients aged <65 years, there was no statistically significant difference in the rate of PJI for patients aged 65-74 years (odds ratio: 0.89; 95% confidence interval: 0.55-1.42; P = 0.62) or for patients aged ≥75 years (0.69; 0.36-1.32; P = 0.26).

CONCLUSION

When adjusting for confounding variables, age alone is not a risk factor for PJI. Studies evaluating the influence of age on the incidence of PJI should take into account the other confounding variables that contribute to PJI.

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.

Incidence of surgical-site infection following open reduction and internal fixation of a distal femur fracture: An observational case-control study

Surgical-site infection (SSI) is a common complication in orthopedic surgery; however, SSI after surgically managed distal femur fractures was not well studied. The aim of this study was to investigate the incidence of SSI and identify some modifiable and nonmodifiable risk factors.The patients' electronic medical records (EMRs) were reviewed to identify those who sustained a distal femur fracture and treated by open reduction and internal fixation (ORIF) between March 2014 and February 2018. SSI was defined based on the Centers for Disease Control criteria and confirmed according to the descriptions in EMR. Univariate and multivariate logistic regression models were used to determine the independent risk factors associated with SSI.Totally, EMRs of 665 patients who underwent ORIF of distal femur fractures were reviewed and 24 SSIs were found, indicating the overall incidence of SSI was 3.6%. The rate of deep SSI was 1.2% and superficial SSI was 2.4%. Staphylococcus aureus was the most common causative pathogen, either alone (7/15, 46.7%) or as a mixed infection (3/15, 20%), followed by mixed bacterial (4/15, 26.7%) and S epidermidis (2/15, 13.3%) and others. Patients with SSI had approximately twice the length of hospital stay as those without SSIs (29.0 vs 16.0 days, P < .001). Open fracture, temporary use of external fixation, obesity, smoking, diabetes mellitus, and preoperative reduced albumin level were identified as independent risk factors associated with SSI, and current smoking and preoperative reduced albumin level were the true modifiable factors.Patients should be encouraged to cease smoking as early as possible and increase the good-quality protein intake to reduce or prevent the occurrence of SSI. An explanation of the nonmodifiable risk factors should be included when patients are counseled about their increased risk of SSI.

The influence of bearing surfaces on periprosthetic hip infections: analysis of thirty nine thousand, two hundred and six cementless total hip arthroplasties

PURPOSE

Periprosthetic hip infection (PHI) is a devastating complication. The association between PHI and bearing surfaces as well as patient-related factors has been recently investigated, with contradictive outcomes. The dataset of Emilia-Romagna region Registry for Orthopaedic Prosthetic Implants (RIPO) has been assessed to investigate, if the bearing choice influenced the risk of septic loosening occurrence.

METHODS

RIPO data about 39,206 cementless total hip arthroplasties (THA), collected since 2003, were analysed. Age, gender, BMI, diabetes and bearing surfaces were evaluated. The end point of the study was the revision of at least a single component due to sepsis.

RESULTS

Adjusted and unadjusted survival rates showed that ceramic-on-ceramic (COC) implants had the lower incidence of PHIs, whereas metal-on-metal (MOM) THAs were significantly more prone to infection. In MOM cohort, stemmed implants were involved in 28 out of 30 cases. Among the demographical features and comorbid conditions, only diabetes statistically influenced the rate of sepsis.

CONCLUSIONS

Bearing surfaces influenced the rate of PHI; in particular, stemmed MOM implants were at higher risk, probably due to metal debris consequent to taperosis. Despite the preliminary results, stemmed MOM THAs should be used with care, and diabetic patients should be warned about increased septic risks.

Extended Oral Antibiotic Prophylaxis in High-Risk Patients Substantially Reduces Primary Total Hip and Knee Arthroplasty 90-Day Infection Rate

BACKGROUND

Total joint arthroplasty (TJA) episodic payment models shift risk and cost of periprosthetic joint infection (PJI) to surgeons and hospitals, causing some to avoid treating high-risk patients. Furthermore, there are little data to support optimization of host factors preoperatively to decrease PJI, and recent literature supports using extended antibiotic prophylaxis following reimplantation TJA. The purpose of this study was to evaluate whether extended oral antibiotic prophylaxis minimized PJI after primary TJA in high-risk patients.

METHODS

A retrospective cohort study was performed of 2,181 primary total knee arthroplasties (TKAs) and primary total hip arthroplasties (THAs) carried out from 2011 through 2016 at a suburban academic hospital with modern perioperative and infection-prevention protocols. Beginning in January 2015, extended oral antibiotic prophylaxis for 7 days after discharge was implemented for patients at high risk for PJI. The percentages of patients diagnosed with PJI within 90 days were identified and compared between groups that did and did not receive extended oral antibiotic prophylaxis, with p ≤ 0.05 indicating significance.

RESULTS

The 90-day infection rates were 1.0% and 2.2% after the TKAs and THAs, respectively. High-risk patients without extended antibiotic prophylaxis were 4.9 (p = 0.009) and 4.0 (p = 0.037) times more likely to develop PJI after TKA and THA, respectively, than high-risk patients with extended antibiotic prophylaxis.

CONCLUSIONS

Extended postoperative antibiotic prophylaxis led to a statistically significant and clinically meaningful reduction in the 90-day infection rate of selected patients at high risk for infection. We encourage further study and deliberation prior to adoption of a protocol involving extended oral antibiotic prophylaxis after high-risk TJA, with the benefits weighed appropriately against potential adverse consequences such as increasing the development of antimicrobial resistance.

LEVEL OF EVIDENCE

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

The projected burden of complex surgical site infections following hip and knee arthroplasties in adults in the United States, 2020 through 2030

BACKGROUND

As the US population ages, the number of hip and knee arthroplasties is expected to increase. Because surgical site infections (SSIs) following these procedures contribute substantial morbidity, mortality, and costs, we projected SSIs expected to occur from 2020 through 2030.

METHODS

We used a stochastic Poisson process to project the number of primary and revision arthroplasties and SSIs. Primary arthroplasty rates were calculated using annual estimates of hip and knee arthroplasty stratified by age and gender from the 2012-2014 Nationwide Inpatient Sample and standardized by census population data. Revision rates, dependent on time from primary procedure, were obtained from published literature and were uniformly applied for all ages and genders. Stratified complex SSI rates for arthroplasties were obtained from 2012-2015 National Healthcare Safety Network data. To evaluate the possible impact of prevention measures, we recalculated the projections with an SSI rate reduced by 30%, the national target established by the US Department of Health and Human Services (HHS).

RESULTS

Without a reduction in SSI rates, we projected an increase in complex SSIs following hip and knee arthroplasty of 14% between 2020 and 2030. We projected a total burden of 77,653 SSIs; however, meeting the 30% rate reduction could prevent 23,297 of these SSIs.

CONCLUSIONS

Given current SSI rates, we project that complex SSI burden for primary and revision arthroplasty may increase due to an aging population. Reducing the SSI rate to the national HHS target could prevent 23,000 SSIs and reduce subsequent morbidity, mortality, and Medicare costs.

Postoperative Blood Glucose Levels Predict Infection After Total Joint Arthroplasty

BACKGROUND

Perioperative hyperglycemia has many etiologies, including medication, impaired glucose tolerance, uncontrolled diabetes mellitus, or stress, the latter of which is common in patients postoperatively. Our study investigated the influence of postoperative blood glucose levels on periprosthetic joint infection after elective total joint arthroplasty to determine a threshold for glycemic control for which surgeons should strive during a patient's hospital stay.

METHODS

A single-institution retrospective review was conducted on 24,857 primary total joint arthroplasties performed from 2001 to 2015. Of these, 13,196 had a minimum follow-up of 1 year (mean, 5.9 years). Postoperative day 1 morning blood glucose levels were utilized and were correlated with periprosthetic joint infection, as defined by the International Consensus Group on Periprosthetic Joint Infection. Multivariable analysis was used to determine the influence of several important covariates on infection. An alpha level of 0.05 was used to determine significance.

RESULTS

The rate of periprosthetic joint infection increased linearly from blood glucose levels of ≥115 mg/dL. Multivariable analysis revealed that blood glucose levels were significantly associated with periprosthetic joint infection (p = 0.028). The optimal blood glucose threshold to reduce the likelihood of periprosthetic joint infection was 137 mg/dL. The periprosthetic joint infection rate in the entire cohort was 1.59% (1.46% in patients without diabetes compared with 2.39% in patients with diabetes; p = 0.001). There was no significant association between blood glucose level and periprosthetic joint infection in patients with diabetes (p = 0.276), although there was a linear trend.

CONCLUSIONS

The relationship between postoperative blood glucose levels and periprosthetic joint infection increased linearly, with an optimal cutoff of 137 mg/dL. Immediate and strict postoperative glycemic control may be critical in reducing postoperative complications, as even mild hyperglycemia was significantly associated with periprosthetic joint infection.

LEVEL OF EVIDENCE

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

Risk Factors for Surgical Site Infection Following Lower Limb Arthroplasty: A Retrospective Cohort Analysis of 3932 Lower Limb Arthroplasty Procedures in a High Volume Arthroplasty Unit

BACKGROUND

Surgical site infection (SSI) is a debilitating complication of lower limb arthroplasty with significant morbidity and increased costs. Numerous risk factors are associated with SSI.

METHODS

In an effort to identify novel risk factors for SSI, we undertook a retrospective cohort study of 1832 primary total hip arthroplasties and 2100 primary total knee arthroplasties performed in our high volume arthroplasty unit over a 2-year period.

RESULTS

Two risk factors were identified for SSI following total hip arthroplasty: body mass index ≥30 and peri-operative blood transfusion. Eight risk factors were identified for SSI following total knee arthroplasty: hypertension, peri-operative blood transfusion, skin closure using 2-octyl cyanoacrylate, use of oral steroids, reduced serum mean cell volume, reduced mean cell hemoglobin, elevated serum neutrophil count, and use of warfarin or rivaroxaban for venous thromboembolism prophylaxis.

CONCLUSIONS

Our work proposes a number of previously undocumented risk factors in relation to SSI. Further investigation is required to ascertain the magnitude of their effect.

Obesity Is Independently Associated With Early Aseptic Loosening in Primary Total Hip Arthroplasty

BACKGROUND

Obesity affects millions of patients in the United States and is associated with several complications after total hip arthroplasty (THA). The effect of obesity on the rate and mode of primary THA failure remains poorly understood, especially given other potentially confounding patient characteristics. We hypothesized that, among patients with a failed primary THA, obesity is independently associated with aseptic loosening and a higher rate of early revision.

METHODS

Six hundred eighty-four consecutive cases with failed THA referred to a single academic center for revision during a 10-year period were retrospectively reviewed. Multivariate logistic regression analysis was used to test the independent association between obesity and the timing as well as cause of THA failure.

RESULTS

The rate of primary THA failure before 5 years was 48.8% in obese and 37.1% in nonobese patients (odds ratio [OR] = 1.57, P = .010). Primary THA failure before 5 years was more likely with increasing body mass index (BMI) (BMI: 35-40 kg/m², OR = 2.31, P = .008; BMI >40 kg/m², OR = 2.51, P = .049). The rate of primary THA failure for aseptic loosening before 5 years was 30% in obese and 18% in nonobese patients (OR = 1.88, P = .023). Obesity was not a risk for revision for infection, whereas an American Society of Anesthesiologists class ≥3 was independently associated with primary THA failure for infection (OR = 2.33, P < .001).

CONCLUSION

Among patients with a failed THA, comorbidities may account for the risk of revision due to infection in obese patients. Obesity is independently associated with early primary THA failure for aseptic loosening.

Depression and Patient-Reported Outcomes Following Total Shoulder Arthroplasty

BACKGROUND

Recent studies have found that depression is associated with increased pain and impairment following lower-extremity arthroplasty; however, this association has not been investigated for total shoulder arthroplasty. The objective of this study was to investigate the association between depression and patient-reported outcomes following total shoulder arthroplasty.

METHODS

A prospectively collected institutional registry was queried for consecutive patients who underwent total shoulder arthroplasty for osteoarthritis from 2007 to 2013 with baseline and minimum 2-year postoperative American Shoulder and Elbow Surgeons (ASES) scores. Revision procedures and total shoulder arthroplasty for diagnoses other than osteoarthritis were excluded. Patients with a preoperative diagnosis of depression (n = 88) formed the study cohort; control patients without a diagnosis of depression were matched to the study patients by age and sex in a 2:1 ratio (n = 176). Baseline characteristics and patient-reported outcome measures were compared between groups, as were minimum 2-year patient-reported outcomes and change in patient-reported outcomes. A multivariable regression was performed to investigate the independent effect of depression on improvement in ASES scores.

RESULTS

Except for the Short Form-12 Mental Component Summary (SF-12 MCS) scores, there were no significant differences (p > 0.05) in baseline characteristics between study patients and controls. There was a significant improvement in the ASES score for patients with depression (p < 0.0001) and controls (p < 0.0001). Patients with depression had significantly lower final ASES scores (p = 0.001) and less improvement in ASES scores (p = 0.001) and SF-12 Physical Component Summary scores (p = 0.006) as well as lower satisfaction levels at 2 years; however, the latter difference did not reach clinical importance. Depression (p = 0.018) was an independent predictor of less improvement in ASES scores.

CONCLUSIONS

Patients with a diagnosis of depression should be counseled that they will experience a significant clinical improvement from baseline after total shoulder arthroplasty. A preoperative diagnosis of depression is an independent predictor of significantly less improvement in ASES scores following total shoulder arthroplasty; however, this difference does not reach clinical importance and should not discourage patients with a clinical diagnosis of depression from undergoing total shoulder arthroplasty.

LEVEL OF EVIDENCE

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

Should Preoperative Antibiotics Be Tailored According to Patient's Comorbidities and Susceptibility to Organisms?

BACKGROUND

Preoperative antibiotic prophylaxis remains one of the most important strategies for preventing periprosthetic joint infection (PJI). Current guidelines recommend giving universal antibiotic prophylaxis to all total joint arthroplasty patients regardless of their medical conditions or immune status; however, no studies have evaluated the individualizing of antibiotics. The aims of this study were (1) to determine if comorbidities influence the organism profile of PJIs, and (2) to investigate if the efficacy of two different perioperative antibiotics (cefazolin or vancomycin) for preventing PJI is affected by patient's comorbidities.

METHODS

Using an institutional database of 1022 PJIs, the influence of different patient's comorbidities on the organism profile was evaluated. To investigate the influence of perioperative antibiotics (cefazolin or vancomycin monotherapy) on PJI rate, 8575 primary total joint arthroplasties were identified, crossmatched for PJI, and analyzed based on the comorbidities of the cohort. The PJI rate of each antibiotic within each comorbidity was compared.

RESULTS

Although no comorbidities were associated with an increased rate of Gram-positive infections or Gram-negative infections, metastatic disease (odds ratio [OR] 5.71, P = .018), congestive heart failure (OR 2.2, P = .010), chronic pulmonary disease (OR 1.76, P = .015), and diabetes mellitus (OR 1.66, P = .019) were associated with antibiotic resistant organisms. However, there was no difference in the PJI rate between cefazolin and vancomycin monotherapy when stratifying for diabetes mellitus, rheumatoid arthritis, liver disease, and hypothyroidism.

CONCLUSION

The results of the present study support the current recommendations of a universal antibiotic prophylaxis protocol rather than an antibiotic regimen individualized to a patient's comorbidities.

Postoperative Hyperglycemia Can Be Safely and Effectively Controlled in Both Diabetic and Nondiabetic Patients with Use of a Subcutaneous Insulin Protocol

Background:

Postoperative hyperglycemia related to stress has been shown to be an independent risk factor for periprosthetic joint infection. In a non-intensive care, general-surgery setting, a standardized postoperative insulin protocol has been shown to decrease the rate of wound infections. We hypothesized that the use of a similar protocol is both safe and effective for controlling hyperglycemia in patients who have undergone total joint replacement.

Methods:

We performed a retrospective cohort study of 489 consecutive patients who underwent primary or revision total hip or knee arthroplasty between January 2008 and April 2013. All patients were tested with point-of-care (finger-stick) glucose determinations postoperatively and were started on a subcutaneous insulin protocol if they had postoperative stress hyperglycemia of >140 mg/dL when fasting or >180 mg/dL after meals. Insulin was discontinued when blood glucose decreased to <100 mg/dL.

Results:

Of the 489 patients, 301 (62%) qualified for the insulin protocol. Thirty-seven (17%) of the 220 patients for whom the hemoglobin A1c level was available were diabetic, and 21 (11%) of the 187 patients for whom body mass index data were available were morbidly obese (body mass index, ≥40 kg/m²). Diabetes (p < 0.001), revision surgery (p < 0.001), male sex (p = 0.0110), and obesity (including morbid obesity) (p = 0.0051) were independent factors resulting in significant glycemic elevation. A trend toward hyperglycemia occurred in younger patients but did not reach significance (p = 0.063). The glucose levels of patients in all of these groups responded well to insulin. None of the patients who were managed with the insulin experienced a periprosthetic joint infection. There were no injuries related to hypoglycemia.

Conclusions:

The findings of the present study suggest that hyperglycemia is a common link between seemingly disparate factors related to the increased prevalence of periprosthetic joint infection. The standardized subcutaneous insulin protocol was both safe and effective for the treatment of hyperglycemia for nondiabetic as well as diabetic patients. Patients who have undergone total joint replacement, especially those with revision procedures, male sex, morbid obesity, and diabetes, should be evaluated for hyperglycemia starting in the post-anesthesia care unit and should be managed with the insulin protocol when that risk is identified.

Level of Evidence:

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

Rate of Transfusions After Total Knee Arthroplasty in Patients Receiving Lovenox or High-Dose Aspirin

BACKGROUND

Controversy continues regarding the use of powerful anticoagulants for venous thromboembolism prophylaxis in patients undergoing total knee arthroplasty (TKA). To comply with institution-mandated guidelines and pressure from hospitalist intent on complying with conventionally recommended anticoagulation guidelines, we singularly changed our chemoprophylaxis practice from using aspirin to Lovenox and noted that transfusion rates increased substantially.

METHODS

A retrospective case review was performed to evaluate transfusion requirement differences in primary TKA patients receiving Lovenox (unilateral TKA: n = 135, bilateral TKA: n = 44) or aspirin (unilateral TKA: n = 153, bilateral TKA: n = 45) for venous thromboembolism prophylaxis. Pearson's chi-square tests were used to evaluate surgical complications and the rate of transfusions between aspirin and Lovenox groups. Independent t tests were used to evaluate the units of packed red blood cells transfused, hemoglobin drop, and hematocrit drop between aspirin and Lovenox groups.

RESULTS

Lovenox was found to significantly increase (P < .01) the rate of transfusion, units of packed red blood cells, hemoglobin drop, and hematocrit drop compared to aspirin in both unilateral and bilateral TKA patients, without significantly decreasing venous thromboembolism events (aspirin: 3 pulmonary embolisms and 4 deep venous thrombosis; Lovenox: 3 pulmonary embolisms and 2 deep venous thrombosis).

CONCLUSION

Our findings suggest that aspirin is as effective as Lovenox in preventing venous thromboembolism and that the use of Lovenox significantly increases the likelihood of requiring transfusions after surgery.

Morbid Obesity in Total Hip Arthroplasty: Redefining Outcomes for Operative Time, Length of Stay, and Readmission

BACKGROUND

The incidence of obesity among patients presenting for elective total hip arthroplasty (THA) has increased in the last decade, and the relationship between obesity and the need for joint arthroplasty has been demonstrated. This study evaluates the effects of morbid obesity on outcomes after primary THA by comparing short-term outcomes in THA between a morbidly obese (body mass index [BMI] ≥40) and a normal weight (BMI, 18.5 to <25) cohort at our institution between January 2003 and December 2010.

METHODS

Thirty-nine patients included in the morbidly obese group were compared with 186 in the normal weight group. Operative time, length of stay, complications, readmission, and length of readmission were compared.

RESULTS

Operative time was increased in the morbidly obese group at 122 minutes compared with 100 minutes (P = .002). Postoperatively, there was an increased 30-day readmission rate related to surgery of 12.8% associated with BMI ≥40 compared with 2.7% (P = .005) as well as a 5.1-fold increase in surgery-related readmitted bed days-0.32 bed days per patient for normal weight compared with 1.64 bed days per patient for the morbidly obese (P = .026).

CONCLUSION

Morbidly obese patients present a technical challenge and likely this, and the resultant complications are underestimated. More work needs to be performed to enable suitable allocation of resources.

Obesity is Associated With Early Total Hip Revision for Aseptic Loosening

BACKGROUND

Obesity affects more than 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 hip arthroplasty (THA). It remains unknown whether obese patients progress to revision THA faster than nonobese patients.

METHODS

A total of 257 consecutive primary THAs referred to an academic tertiary care center for revision THA were retrospectively stratified according to preoperative body mass index (BMI), reason for revision THA, and time from primary to revision THA.

RESULTS

When examining primary THAs referred for revision THA, increasing BMI adversely affected the mean time to revision THA. The percentage of primary THAs revised at 5 years was 25% for a BMI of 18-25, 38% for a BMI of 25-30, 56% for a BMI of 30-35, 73% for a BMI of 35-40, and 75% for a BMI of greater than 40 (P < .001). The percentage of primary THAs revised at 15 years was 70%, 82%, 87%, 94%, and 100%, respectively (P < .001). A significant increase in early revision THA for aseptic loosening/osteolysis in obese patients (56%, 23/41) when compared with the nonobese patients (12%, 10/83, P < .001, relative risk ratio = 4.7).

CONCLUSION

Preoperative BMI influences the time of failure of primary THAs referred to an academic tertiary care for revision THA as well as the mechanism of failure. Specifically, obesity increased in the relative risk of early revision THA due to aseptic loosening/osteolysis by 4.7 fold.

Preoperative Hip Injections Increase the Rate of Periprosthetic Infection After Total Hip Arthroplasty

BACKGROUND

Intraarticular injections are both diagnostic and therapeutic for patients with osteoarthritis. A potential risk of periprosthetic joint infection (PJI) after total hip arthroplasty (THA) may occur from direct inoculation and/or immune suppression by corticosteroids. Large population-level databases were used to evaluate hip injection on the 1-year rate of PJI in patients undergoing primary THA.

METHODS

State-level ambulatory surgery and inpatient databases for Florida and California (2005-2012) were used to identify primary THA patients with 1-year preoperative and postoperative windows to evaluate possible injections or PJI, respectively. Patients were grouped as no injection or as THA performed 6-12 months, 3-6 months, or 0-3 months after injection. Risk adjustment was performed with multivariable regression.

RESULTS

A total of 173,958 patients were included; 5421 (3.1%) underwent THA after an injection: 1395 (1.1%) of patients after 6-12 months, 1863 patients after 3-6 months, and 2163 (1.2%) after 0-3 months. In the 0-3 month group, PJI was significantly increased at 3 months (1.58%, P = .015), 6 months (1.76%, P = .022), and 1 year (2.04%, P = .031) compared with the noninjection control group (1.04%, 1.21%, and 1.47%, respectively). There were no differences in the 3- to 6-month and 6- to 12-month injection groups.

CONCLUSION

There is an increased risk of PJI when THA is performed within 3 months of hip injection. We recommend that patients and their surgeons consider delaying elective THA until 3 months after an injection to avoid this elevated risk of infection.

Risk factors for periprosthetic joint infection following primary total hip or knee arthroplasty: a meta-analysis

To identify risk factors for periprosthetic joint infection following primary total joint arthroplasty, a systematic search was performed in Pubmed, Embase and Cochrane library databases. Pooled odds ratios (ORs) or standardised mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Patient characteristics, surgical-related factors and comorbidities, as potential risk factors, were investigated. The main factors associated with infection after total joint arthroplasty (TJA) were male gender (OR, 1·48; 95% CI, 1.19-1.85), age (SMD, -0·10; 95% CI, -0.17--0.03), obesity (OR, 1·54; 95% CI, 1·25-1·90), alcohol abuse (OR, 1·88; 95% CI, 1·32-2·68), American Society of Anesthesiologists (ASA) scale > 2 (OR, 2·06; 95% CI, 1·77-2·39), operative time (SMD, 0·49; 95% CI, 0·19-0·78), drain usage (OR, 0·36; 95% CI, 0·18-0·74), diabetes mellitus (OR, 1·58; 95% CI, 1·37-1·81), urinary tract infection (OR, 1·53; 95% CI, 1.09-2.16) and rheumatoid arthritis (OR, 1·57; 95% CI, 1·30-1·88). Among these risk factors, ASA score > 2 was a high risk factor, and drain usage was a protective factor. There was positive evidence for some factors that could be used to prevent the onset of infection after TJA.

A Trend for Increased Risk of Revision Surgery due to Deep Infection following Fast-Track Hip Arthroplasty

Rates of revision surgery due to deep infection following total hip arthroplasty (THA) increased at a Norwegian hospital following implementation of fast-track procedures. The purpose of this study was to determine whether selected demographic (age and sex) and clinical (body mass index, American Society of Anesthesiologists (ASA) classification, surgery duration, length of hospital stay, cemented versus uncemented prosthesis, and fast-track procedures) factors were associated with higher risk of revision surgery due to deep infection following THA. In a prospective designed study 4,406 patients undergoing primary THA between January 2001 and January 2013 where included. Rates of infection-related revision surgery within 3 months of THA were higher among males and among patients who received fast-track THA. Adjusting for sex and age, the implemented fast-track elements were significantly associated with increased risk of revision surgery. Risk of infection-related revision surgery was unrelated to body mass index, physical status, surgery duration, length of hospital stay, and prosthesis type. Because local infiltration analgesia, drain cessation, and early mobilization were introduced in combination, it could not be determined which component or combination of components imposed the increased risk. The findings in this small sample raise concern about fast-track THA but require replication in other samples.

Patient-related medical risk factors for periprosthetic joint infection of the hip and knee

Despite advancements and improvements in methods for preventing infection, periprosthetic joint infection (PJI) is a significant complication following total joint arthroplasty (TJA). Prevention is the most important strategy to deal with this disabling complication, and prevention should begin with identifying patient-related risk factors. Medical risk factors, such as morbid obesity, malnutrition, hyperglycemia, uncontrolled diabetes mellitus, rheumatoid arthritis (RA), preoperative anemia, cardiovascular disorders, chronic renal failure, smoking, alcohol abuse and depression, should be evaluated and optimized prior to surgery. Treating patients to get laboratory values under a specified threshold or cessation of certain modifiable risk factors can decrease the risk of PJI. Although significant advances have been made in past decades to identify these risk factors, there remains some uncertainty regarding the risk factors predisposing TJA patients to PJI. Through a review of the current literature, this paper aims to comprehensively evaluate and provide a better understanding of known medical risk factors for PJI after TJA.

Quantifying the Burden of Revision Total Joint Arthroplasty for Periprosthetic Infection

Periprosthetic joint infection (PJI) represents substantial clinical and economic burdens. This study evaluated patient and procedure characteristics and resource utilization associated with revision arthroplasty for PJI. The Nationwide Inpatient Sample (Q4 2005-2010) was analyzed for 235,857 revision THA (RTHA) and 301,718 revision TKA (RTKA) procedures. PJI was the most common indication for RTKA, and the third most common reason for RTHA. PJI was most commonly associated with major severity of illness (SOI) in RTHA, and with moderate SOI in RTKA. RTHA and RTKA for PJI had the longest length of stay. Costs were higher for RTHA/RTKA for PJI than for any other diagnosis except periprosthetic fracture. Epidemiologic differences exist in the rank, severity and populations for RTHA and RTKA for PJI.

Increased Complications in Obese Patients Undergoing Direct Anterior Total Hip Arthroplasty

The direct anterior (DA) approach for total hip arthroplasty (THA) has demonstrated successful short term outcomes in several studies. However, there is no consensus about which patients are appropriate candidates for DA total hip arthroplasty. It is also unclear if short term outcomes in obese patients undergoing THA through a DA approach are elevated in comparison to non-obese patients. The purpose of this study was to evaluate complication rates and short term outcomes of obese, pre-obese, and normal body mass index (BMI) patients undergoing THA with a DA approach in a consecutive group of patients. This study was a retrospective review of 210 consecutive patients who underwent unilateral THA through a DA approach for osteoarthritis or avascular necrosis during the early peri-operative period. The study included 61 patients with normal BMI, 70 pre-obese patients, and 79 obese patients according to World Health Organization (WHO) classification (49 class I obese, 22 class II obese, and 8 class III obese patients). Patient charts were reviewed to determine differences in surgical time, length of stay, disposition, major complications, wound complications, and short term outcome measures. When comparing normal and pre-obese patients (BMI <30) to a combined group of WHO class I, II, and III obese patients (BMI >30), the obese group demonstrated increased surgical times by 12.7 minutes (P<0.0001), as well as increased length of stay (P=0.0303), narcotic use (P=0.0037), and assistive device use at two weeks (P<0.0030). In addition, major complications and wound complications were both significantly increased in the obese group (odds ratio [OR], 8.8; P=0.0493 and OR, 3.6; P=0.0431, respectively). There was also a trend toward increased use of rehabilitation facilities in the obese group at disposition, 15.4% vs 7.6% (P=0.0774). This study demonstrates that obese patients undergoing a DA approach have a 8.8 and 3.6 times increase in major and wound complications, respectively, compared to patients with a BMI <30. Obese patients also demonstrated significant increases in operative time, use of narcotics, use of assistive devices, and length of stay. There was a trend toward higher use of rehabilitation placement. While significant, these findings are similar to complication rates in the literature for other THA operative approaches. This study further defines the risks associated with performing THA on obese patients regardless of approach.

Factors associated with infection following anterior cruciate ligament reconstruction

BACKGROUND

Although rare, infection can be devastating after anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to test the association between infection after ACL reconstruction and potential risk factors such as age, body mass index (BMI), smoking, diabetes, and graft choice.

METHODS

We reviewed the Multicenter Orthopaedic Outcomes Network (MOON) cohort from 2002 to 2005 to identify patients with a postoperative infection. The age, BMI, smoking status, history of diabetes, and graft choice were recorded for each patient. A multivariable regression analysis was constructed to examine which baseline risk factors were independently associated with postoperative infection after ACL reconstruction requiring surgical intervention.

RESULTS

There were 2198 eligible patients in the cohort, with seventeen (0.8%) reporting a postoperative infection. Diabetes was found to be a significant risk factor for infection (odds ratio [OR] = 18.8; 95% confidence interval [CI] = 3.8 to 94.0; p < 0.001). Compared with bone-tendon-bone autograft, both hamstring autograft and other grafts (e.g., the majority of allografts, with some that were both autograft and allograft) also increased the risk of infection (OR = 4.6 [95% CI = 1.2 to 17.9; p = 0.026] for hamstrings and 4.3 [95% CI = 1.0 to 18.1; p = 0.047] for other grafts). Although the OR for infection in smokers was 2.5, this finding did not reach significance.

CONCLUSIONS

Patients with diabetes undergoing ACL reconstruction have a significantly elevated risk of postoperative infection (18.8-times higher odds) compared with that for patients without diabetes. Use of bone-tendon-bone autograft is associated with a lower risk of infection after ACL reconstruction.