General Assembly, Prevention, Host Related General: Proceedings of International Consensus on Orthopedic Infections

Joint replacement and human immunodeficiency virus

The incidence of human immunodeficiency virus (HIV)-infected cases that need total joint replacement (TJR) is generally rising. On the other hand, modern management of HIV-infected cases has enabled them to achieve longevity while increasing the need for arthroplasty procedures due to the augmented dege-nerative joint disease and fragility fractures, and the risk of osteonecrosis. Although initial investigations on joint replacement in HIV-infected cases showed a high risk of complications, the recent ones reported acceptable outcomes. It is a matter of debate whether HIV-infected cases are at advanced risk for adverse TJR consequences; however, the weak immune profile has been associated with an increased probability of complications. Likewise, surgeons and physicians should be aware of the complication rate after TJR in HIV-infected cases and include an honest discussion of the probable unwelcoming complication with their patients contemplating TJR. Therefore, a fundamental review and understanding of the interaction of HIV and arthroplasty are critical.

Effect of bacterium in the malignant wounds of soft tissue sarcoma

Malignant wounds (MWs) are rare skin lesions, which accompany ulceration, necrosis and infection caused by infiltration or damage by malignant tumor. The present study aimed to investigate the bacterial etiology implicated in MW in soft tissue sarcoma (STS), and the effectiveness of culture-guided perioperative antibacterial administration. A retrospective evaluation was conducted on medical records of patients who presented with MW between 2006 and 2020. A total of seven patients were included in the present study, in whom all tumors were relatively large (>5 cm) and high-grade. Subsequently, five patients underwent limb-sparing surgery, and three patients had distant metastases with a 5-year overall survival of 71%. Preoperative microbiological sampling from the wound identified 11 different bacterial strains in five patients. The infections were polymicrobial with an average of 2.6 strains isolated per patient (1 aerobic, 1.6 anaerobic bacteria). They were predominantly methicillin-sensitive Staphylococcus aureus. Patients with MWs from STS reported symptoms, including bleeding (71%), exudation (71%) and malodorous wound (43%) at the initial presentation; these completely resolved after surgery. All but one patient reported pain at the MW site with an average numeric rating scale of 4.4 at presentation that decreased to 1.4 (P=0.14) and 0.6 (P=0.04) one and two weeks after surgery, respectively. The patients had elevated C-reactive protein (71%), anemia (57%), low albumin (86%) and renal/liver dysfunction (14–29%). One patient was diagnosed with sepsis. Surgical resection afforded symptomatic relief and resolution of abnormal laboratory values. Although selected antibiotics were administered in four patients based on the preoperative antibiotic sensitivity test, surgical site infection (SSI) occurred in three patients. Therefore, the effectiveness of the selected antibiotics based on the results of the preoperative culture in preventing SSI needs to be investigated in the future. In conclusion, physicians should keep in mind that although surgical resection can improve the symptoms and abnormal values in laboratory examination form MW, it is accompanied with a high rate of SSI and poor prognosis.

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.

Multidisciplinary Approach to Multiple Multiresistant Agent Infection of Instrumented Spine Surgery: A Case Report

CASE

We report the case of a patient with consecutive infections with several multidrug-resistant agents-including carbapenem-resistant strains of Klebsiella pneumoniae among others-from a surgical wound infection after lumbar spine fusion, only successfully treated after the resort to novel antibiotics (ceftazidime-avibactam) in combination therapy.

CONCLUSIONS

Multidrug resistance has become a major challenge in today's medicine. Care should be taken to avoid their emergence, but when present, a multidisciplinary approach is mandatory to ensure clinically up-to-date treatment choices. Multimodal antibiotic schemes tend to show the most promising results, with which successful infection resolution can still be achieved.

Experiences during Switching from Two-Stage to One-Stage Revision Arthroplasty for Chronic Total Knee Arthroplasty Infection

The objective of this study was to evaluate our preliminary results after changing our surgical strategy from 2-stage revision arthroplasty to 1-stage revision arthroplasty for patients with chronic knee periprosthetic joint infection. We conducted a prospective study of knee arthroplasty patients that had been diagnosed with chronic infection and treated using a 1-stage revision regardless of the traditional criteria applied for indication thereof. We evaluated two main variables: infection control and economic costs. The definitive diagnosis of infection of the revision was determined by using the criteria proposed by the Musculoskeletal Infection Society. The costs were calculated as average costs in USD, as described by Srivastava (2019), for 1-stage or 2-stage revisions. Eighteen patients were included in the study, and infection was controlled in 17 patients. The total economic savings for our hospital from these 18 patients amounted to USD 291,152. This clinical success has led to major changes in how our hospital approaches the treatment of chronically infected knee replacements, in addition to substantial economic advantages for the hospital.

Surgical site infection in hip arthroplasty in a 10-year follow-up prospective study: Risk and factors associated

BACKGROUND

The increased demand for hip arthroplasty means a growing number of postsurgical complications. This study aims to assess the risk of surgical site infection (SSI) in a teaching hospital; develop regional, national and international external comparisons; and evaluate SSI-related risk factors, particularly according to the timing of surgery (urgent/unplanned or elective).

METHODS

Prospective cohort study from January 2008 to December 2018. Patients were followed up to 90 days after surgery. Primary endpoint was SSI incidence according to the Centers for Disease Control and Prevention criteria. Multivariate analysis was conducted to find independently associated SSI risk factors. The association between risk factors and SSI incidence was assessed by reference to odds ratio (OR). Analyses were also performed among urgent/unplanned and elective patients to identify whether SSI risk factors differed between groups.

RESULTS

The study population (n = 1,808) has an overall SSI rate of 3.0% (95% confidence interval [CI]: 2.4-3.9). Timing of surgery caused an effect modification, so surgery duration> 75th percentile (OR: 3.8; 95% CI: 1.5-9.8) and inadequate preparation (OR: 3.3; 95% CI: 1.1-10.0) were independent risk factors in the urgent/unplanned group; National Healthcare Safety Network risk index≥ 2 (OR: 6.3; 95% CI: 0.1-19.2) and transfusion (OR: 3.6; 95% CI: 1.1-11.9) in the elective group.

CONCLUSIONS

Hospital infection surveillance systems allow identifying risk factors susceptible to change. Characterization of factors that caused an effect modification is key to identify areas of quality improvement, including reducing operating times, preventing perioperative blood transfusion, or improving patient preparation before surgery.

Comparison of Postoperative Complications and Survivorship of Total Hip and Knee Arthroplasty in Dialysis and Renal Transplantation Patients

BACKGROUND

Chronic renal failure (CRF) is an established risk factor for surgical site infection (SSI) and periprosthetic joint infection (PJI) after primary total joint arthroplasty. However, there is limited literature comparing outcomes between patients who receive dialysis vs renal transplantation. We examined and compared clinical outcomes of patients receiving dialysis vs those who had a prior renal transplantation.

METHODS

We retrospectively identified 107 patients undergoing primary total joint arthroplasty between 2000 and 2017, who were receiving dialysis (n = 50), or had a prior renal transplantation (n = 57). The cohorts were compared with respect to postoperative complications, including 90-day SSI, PJI, and failure resulting in revision procedure. Multivariate analysis was performed to determine independent risk factors for complications and revision.

RESULTS

A significantly higher rate of postoperative complications was seen in dialysis patients (28.0%) compared with renal transplant (7.1%). In particular, increased SSI and PJI rates were observed in dialysis group compared with the transplant cohort (18.0% vs 3.5%). In addition, increased revision rates (24.0% vs 3.5%) and decreased survivorship for the implant were observed in dialysis patients. Multivariate analysis revealed that patients with renal transplant were less likely to require revision arthroplasty and that total knee arthroplasty (vs total hip arthroplasty) was an independent risk factor for failure in dialysis patients.

CONCLUSION

This study provides further evidence that patients on dialysis who are on transplant list should await arthroplasty until transplant has taken place. In dialysis patients who are not transplant candidates, extreme care should be exercised, and additional strategies used to minimize the high complication rate that may be encountered.

Outcomes, Microbiology and Antimicrobial Usage in Pressure Ulcer-Related Pelvic Osteomyelitis: Messages for Clinical Practice

Introduction: Pressure ulcer-related pelvic osteomyelitis is a relatively under-studied entity in the field of bone infection. We sought to add to the limited evidence base for managing this challenging syndrome.

Methods: Cases were identified retrospectively from a surgical database and hospital discharge codes at a U.K. tertiary centre (2009-2018). Risk factors associated with outcomes were analysed by logistic regression.

Results: We identified 35 patients (mean age 57.4 years), 69% managed with a combined medical and surgical approach, with mean follow-up of 3.7 years from index admission. Treatment failure (requiring further surgery or intravenous antimicrobials) occurred in 71% and eventual ulcer healing in 36%. One-year mortality was 23%. Lack of formal care support on discharge, post-traumatic (asensate) neurological deficit and index CRP (>184mg/L) were associated with treatment failure (p=0.001). Age (>59.5 years), lack of attempted soft tissue coverage, haemoglobin (<111g/L) and albumin (<25g/L) were associated with non-healing ulcers (p=0.003). Superficial wound swabs had low sensitivity and specificity compared to deep bone microbiology. Infection (based on deep bone microbiology from 46 infection episodes) was usually polymicrobial (87%), commonly involving S. aureus, Enterococci, GNB and anaerobes. Antimicrobial duration ranged from 0-103 days (mean 54) and was not associated with subsequent treatment failure.

Conclusions: Attempted soft tissue coverage after surgical debridement, ensuring appropriate support for personal care after discharge and nutritional optimisation could improve outcomes. Superficial wound swabs are uninformative and deep bone sampling should be pursued. Long antimicrobial courses do not improve outcomes. Clinicians should engage patients in anticipatory care planning.

Human immunodeficiency virus in total hip arthroplasty

Human immunodeficiency virus (HIV) is a pandemic affecting more than 35 million people worldwide. The aim of this review is to describe the association between HIV and total hip arthroplasty (THA) and assess patient risk factors to optimize functional outcomes and decrease rates of revision.

Since the advent of highly active antiretroviral treatment (HAART), HIV-infected patients are living longer, which allows them to develop degenerative joint conditions. HIV and HAART act independently to increase the demand for THA. HIV-positive patients are also more predisposed to developing avascular necrosis (AVN) of the hip and femoral neck fractures due to decreased bone mineral density (BMD).

Prior to the widespread implementation of access to HAART in homogenous cohorts of HIV-infected patients undergoing THA, reports indicated increased rates of complications. However, current literature describes equivocal functional outcomes and survival rates after THA in HIV-positive patients controlled on HAART when compared to HIV-negative controls.

HIV-infected patients eligible for THA should be assessed for medical co-morbidities and serum markers of disease control should be optimized.

Periprosthetic joint infection (PJI) is a leading cause of revision THA, and HIV is a modifiable risk factor. Importantly, the significance is negated once patients are placed on HAART and achieve viral suppression.

THA should not be withheld in HIV-infected patients injudiciously. However, HIV is a burgeoning epidemic and all patients should be identified and started on HAART to avoid preventable peri-operative complications.

Cite this article: EFORT Open Rev 2020;5:164-171. DOI: 10.1302/2058-5241.5.190030

The seroprevalence of HIV in patients undergoing lower limb Total Joint Arthroplasty (TJA) in South Africa

Aim: The aim was to assess the seroprevalence of Human Immunodeficiency Virus (HIV) in non-haemophilic patients undergoing primary Total Joint Arthroplasty (TJA) at an academic hospital in South Africa.

Methods: A retrospective review of all Total Hip Arthroplasty (THA) and Total Knee Arthroplasty (TKA) patients from January 2017 to December 2018 was conducted. All patients awaiting TJA were offered HIV screening and their demographic data were recorded. Consenting patients were tested or the refusal of testing was documented. The CD4+ T-cell count (CD4+) and viral load (VL) was measured for all HIV-positive patients and newly diagnosed patients were initiated on Highly Active Antiretroviral Treatment (HAART).

Results: We included 1007 patients in the study. The TJA population HIV seroprevalence was 10.7% (n = 108). The seroprevalence for THA was 14.9% (n = 78) and that for TKA was 6.2% (n = 30). There were 93 patients (9.2%) who refused screening. There were 12 (15.4%) and 3 patients (10%) that were newly diagnosed in the THA and TKA seropositive populations, respectively. The average CD4+ for THA and TKA was 569 cells/mm³ (105–1320) and 691 cells/mm³ (98–1406), respectively. The VL was undetectable in 75.9% (n = 82) of HIV-positive patients. Overall 12 HIV-positive patients (11.12%) had CD4+ <200 cells/mm³, 8 of these patients (66%) were newly diagnosed. The average age of the seropositive population was 58 ± 6.5 years and 66 ± 8.5 years for THA and TKA, respectively (p = 0.03). Femoral head osteonecrosis was the underlying pathology for 65.38% (n = 51) of seropositive patients for THA.

Conclusion: The seroprevalence of HIV in patients undergoing THA in our South African institution is greater than the seroprevalence in the general population. The seroprevalence of HIV in THA is significantly greater than that in TKA. This may reflect the association between HIV, HAART and hip joint degeneration. Our findings draw attention to the significant burden HIV has on TJA.

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.