Mortality During Total Hip Periprosthetic Joint Infection

A Human Osteocyte Cell Line Model for Studying Staphylococcus aureus Persistence in Osteomyelitis

Infectious osteomyelitis associated with periprosthetic joint infections is often recalcitrant to treatment and has a high rate of recurrence. In the case of Staphylococcus aureus, the most common pathogen in all forms of osteomyelitis, this may be attributed in part to residual intracellular infection of host cells, yet this is not generally considered in the treatment strategy. Osteocytes represent a unique cell type in this context due to their abundance, their formation of a syncytium throughout the bone that could facilitate bacterial spread and their relative inaccessibility to professional immune cells. As such, there is potential value in studying the host-pathogen interactions in the context of this cell type in a replicable and scalable in vitro model. Here, we examined the utility of the human osteosarcoma cell line SaOS2 differentiated to an osteocyte-like stage (SaOS2-OY) as an intracellular infection model for S. aureus. We demonstrate that S. aureus is capable of generating stable intracellular infections in SaOS2-OY cells but not in undifferentiated, osteoblast-like SaOS2 cells (SaOS2-OB). In SaOS2-OY cells, S. aureus transitioned towards a quasi-dormant small colony variant (SCV) growth phenotype over a 15-day post-infection period. The infected cells exhibited changes in the expression of key immunomodulatory mediators that are consistent with the infection response of primary osteocytes. Thus, SaOS2-OY is an appropriate cell line model that may be predictive of the interactions between S. aureus and human osteocytes, and this will be useful for studying mechanisms of persistence and for testing the efficacy of potential antimicrobial strategies.

The draining surgical wound post total hip and knee arthroplasty: what are my options? A narrative review

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are successful orthopaedic procedures with an ever-increasing demand annually worldwide, and persistent wound drainage (PWD) is a well-known complication following these procedures. Despite many definitions for PWD having been proposed, a validated description remains elusive.

PWD is a risk factor for periprosthetic joint infection (PJI). PJI is a devastating complication of THA and TKA, and a leading cause of revision surgery with dramatic morbidity and mortality and a significant burden on health socioeconomics.

Prevention of PJI has become an essential focus in THA and TKA. Understanding the pathophysiology, risk factors and subsequent management of PWD may aid in decreasing the rate of PJI.

Risk factors of PWD can be divided into modifiable and non-modifiable patient risk factors, pharmacological and surgical risk factors. No gold standard treatment protocol to address PWD exists; however, non-operative options progressing to surgical interventions have been described.

The aim of this study was to review the current literature regarding PWD and consolidate the risk factors and management strategies available.

Cite this article: EFORT Open Rev 2021;6:872-880. DOI: 10.1302/2058-5241.6.200054

Transcriptomic analysis of Streptococcus agalactiae periprosthetic joint infection

Although Streptococcus agalactiae periprosthetic joint infection (PJI) is not as prevalent as staphylococcal PJI, invasive S. agalactiae infection is not uncommon. Here, RNA-seq was used to perform transcriptomic analysis of S. agalactiae PJI using fluid derived from sonication of explanted arthroplasties of subjects with S. agalactiae PJI, with results compared to those of S. agalactiae strain NEM316 grown in vitro. A total of 227 genes with outlier expression were found (164 upregulated and 63 downregulated) between PJI sonicate fluid and in vitro conditions. Functional enrichment analysis showed genes involved in mobilome and inorganic ion transport and metabolism to be most enriched. Genes involved in nickel, copper, and zinc transport, were upregulated. Among known virulence factors, cyl operon genes, encoding β-hemolysin/cytolysin, were consistently highly expressed in PJI versus in vitro. The data presented provide insight into S. agalactiae PJI pathogenesis and may be a resource for identification of novel PJI therapeutics or vaccines against invasive S. agalactiae infections.

The Risk Factor and Outcome of Metachronous Periprosthetic Joint Infections: A Retrospective Analysis With a Minimum Ten-Year Follow-Up

BACKGROUND

Patients with multiple prosthetic joints are at risk of developing periprosthetic joint infections (PJIs). We aimed to determine whether PJI development at one site may lead to infection at another prosthetic joint site and assess the risk factors leading to this subsequent infection.

METHODS

We reviewed all cases (294 patients with first-time PJI [159 hips, 135 knees]) with PJI treated at our institute between January 1994 and December 2020. The average follow-up period was 11.2 years (range 10.1-23.2). Patients were included if they had at least one other prosthetic joint at the time of developing a single PJI (96 patients). Patients with synchronous PJI were excluded from the study. The incidence of metachronous PJI was assessed, and the risk factors were determined by comparing different characteristics between patients without metachronous PJI.

RESULTS

Of the 96 patients, 19.79% developed metachronous PJI. The identified causative pathogen was the same in 63.16% of the patients. The time to developing a second PJI was 789.84 days (range 10-3386). The identified risk factors were PJI with systemic inflammatory response syndrome, ≥3 stages of resection arthroplasty, and PJI caused by methicillin-resistant Staphylococcus aureus.

CONCLUSION

PJI may predispose patients to subsequent PJI in another prosthesis with identified risks. Most causative organisms of metachronous PJI were the same species as those of the first PJI. We believe that bacteremia may be involved in pathogenesis, but further research is required.

What Are the Long-term Outcomes of Mortality, Quality of Life, and Hip Function after Prosthetic Joint Infection of the Hip? A 10-year Follow-up from Sweden

BACKGROUND

Prosthetic joint infection (PJI) is a complication after arthroplasty that negatively affects patient health. However, prior reports have not addressed the long-term consequences of hip PJI in terms of patient mortality, quality of life, and hip function.

QUESTIONS/PURPOSES

At a minimum of 10 years after PJI in patients undergoing primary THA, in the context of several large, national databases in Sweden, we asked: (1) Is mortality increased for patients with PJI after THA compared with patients with a noninfected THA? (2) Does PJI of the hip have a negative influence on quality of life as measured by the Euro-QoL-5D-5L (EQ-5D-5L), ambulatory aids, residential status, and hip function as measured by the Oxford Hip Score (OHS)? (3) Which factors are associated with poor patient-reported outcome measures (PROMs) for patients with PJI after primary THA?

METHODS

This study included 442 patients with a PJI after primary THA, from a previously published national study, including all patients with a THA performed from 2005 to 2008 in Sweden (n = 45,570) recruited from the Swedish Hip Arthroplasty Registry (SHAR). Possible deep PJIs were identified in the Swedish Dispensed Drug Registry and verified by review of medical records. Mortality in patients with PJI was compared with the remaining cohort of 45,128 patients undergoing primary THA who did not have PJI. Mortality data were retrieved from the SHAR, which in turn is updated daily from the population registry. A subgroup analysis of patients who underwent primary THA in 2008 was performed to adjust for the effect of comorbidities on mortality, as American Society of Anesthesiologists (ASA) scores became available in the SHAR at that time. For the PROM analysis, we identified three controls matched by age, gender, indication for surgery, and year of operation to each living PJI patient. A questionnaire including EQ-5D-5L, ambulatory aids, residential status, and OHS was collected from patients with PJI and controls at a mean of 11 years from the primary procedure. Apart from age and gender, we analyzed reoperation data (such as number of reoperations and surgical approach) and final prosthesis in situ to explore possible factors associated with poor PROM results.

RESULTS

After controlling for differences in sex, age, and indication for surgery, we found the all-cause 10-year mortality higher for patients with PJI (45%) compared with patients undergoing THA without PJI (29%) (odds ratio 1.4 [95% CI 1.2 to 1.6]; p < 0.001). The questionnaire, with a minimum of 10 years of follow-up, revealed a lower EQ-5D-5L index score (0.83 versus 0.94, -0.13 [95% CI -0.18 to -0.08; p < 0.001]), greater proportion of assisted living (21% versus 12%, OR 2.0 [95% CI 1.2 to 3.3]; p = 0.01), greater need of ambulatory aids (65% versus 42%, OR 3.1 [95% 2.1 to 4.8]; p < 0.001), and a lower OHS score (36 versus 44, -5.9 [-7.7 to -4.0]; p < 0.001) for patients with PJI than for matched controls. Factors associated with lower OHS score for patients with PJI were three or more reoperations (-8.0 [95% CI -13.0 to -3.2]; p = 0.01) and a direct lateral approach used at revision surgery compared with a posterior approach (-4.3 [95% CI -7.7 to -0.9]; p = 0.01).

CONCLUSION

In this study, we found that PJI after THA has a negative impact on mortality, long-term health-related quality of life, and hip function. Furthermore, the subgroup analysis showed that modifiable factors such as the number of reoperations and surgical approach are associated with poorer hip function. This emphasizes the importance of prompt, proper initial treatment to reduce repeated surgery to minimize the negative long-term effects of hip PJI.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Synchronous Periprosthetic Joint Infections: High Mortality, Reinfection, and Reoperation

BACKGROUND

Synchronous periprosthetic joint infections (PJIs) are a catastrophic complication with potentially high mortality. We aimed to report mortality, risk of reinfection, revision, reoperation, and implant survivorship after synchronous PJIs.

METHODS

We identified 34 patients treated for PJI in more than one joint within a single 90-day period from 1990 to 2018. PJIs involved bilateral knee arthroplasty (27), bilateral hip arthroplasty (4), 1 knee arthroplasty and 1 elbow arthroplasty (1), 1 knee arthroplasty and 1 shoulder arthroplasty (1), and bilateral hip and knee arthroplasty (1). Irrigation and debridement with component retention was performed in 23 patients, implant resection in 10 patients, and a combination of irrigation and debridement with component retention and implant resection in 1 patient. A competing risk model was used to analyze implant survivorship, and Kaplan-Meier survival was used for patient mortality. Mean follow-up was 6 years.

RESULTS

Mortality was high at 18% at 30 days and 27% at 1 year. The 1-year cumulative incidence of any reinfection was 13% and 27% at 5 years. The 1-year cumulative incidence of any revision or implant removal was 6% and 20% at 5 years. The 1-year cumulative incidence of unplanned reoperation was 25% and 35% at 5 years. Rheumatoid arthritis was associated with increased risk of mortality (HR 7, P < .01), as was liver disease (HR 4, P = .02).

CONCLUSION

In the largest series to date, patients with synchronous PJIs had a high 30-day mortality rate of 18%, and one-fourth underwent unplanned reoperation within the first year.

The natural trends of C-reactive protein after hip arthroplasty for femoral neck fracture without infection

The aim of this study was to estimate the degree of normalization of C-reactive protein (CRP) at 2-weeks and 4-weeks after hip arthroplasty after femoral neck fracture. We also wished to determine whether the degree of CRP normalization differs after total hip arthroplasty (THA) compared to bipolar hemiarthroplasty (BH). We also wanted to analyze the patient factors that may influence CRP normalization.We conducted a retrospective study of 135 patients who had undergone THA (32 cases) or BH (103 cases) for femoral neck fracture by single surgeon from January 2015 to December 2019. We analyzed CRP levels during the preoperative period, the early postoperative period, the 2-week postoperative period, and the 4-week postoperative period.In THA, CRP was normalized in 4 patients (12.5%) and in 15 patients (46.9%) within 2-weeks and 4-weeks after surgery, respectively. In BH, CRP was normalized in 16 patients (15.5%) and in 52 patients (50.5%) within 2-weeks and 4-weeks after surgery, respectively. There were no statistical differences between THA and BH. Compared to women, men were 3.78 (95% confidence interval, 1.05-13.63) times less likely to have normalized CRP at 2-weeks after surgery (P = .042). Compared to women, men were 3.01 (95% confidence interval, 1.44-6.27) times less likely to have normalized CRP at 4-weeks after surgery (P = .003).Only 50% of patient's CRP level was normalized during 4-week postoperative period. In men, CRP levels were significantly higher than women in whole period. In the case of THA, the CRP level was higher only in early postoperative period compared to BH, and there was no difference since then.

Mid-term follow-up results after implementing a new strategy for the diagnosis and management of periprosthetic joint infections

BACKGROUND

Periprosthetic joint infections (PJIs) represent one of the most serious complications associated with joint replacement surgeries, a complication also of modern orthopedic surgery despite the efforts that occurred in this field. Frequently PJIs lead to prolonged morbidity, increased costs and mortality.

METHODS

We are conducting a single-center observational cohort ongoing study in the Academic Emergency Hospital Sibiu, Romania, study in which sonication of the retrieved and as a rapid method of bacteria detection, molecular identification of bacteria by 16S rRNA beacon-based fluorescent in situ hybridization (bbFISH) are used.

RESULTS

A total of 61 patients were enrolled in this study. The diagnosis of aseptic loosening was established in 30 cases (49.1%) and the diagnosis of periprosthetic joint infection was established at 31 patients (50.8%). The mean follow-up period in the subgroup of patients diagnosed with periprosthetic joint infections was 36.06 ± 12.59 months (range: 1-54). The 25-months Kaplan-Meier survival rate as the end point, as a consequence of the period of enrollment and a different follow-up period for each type of surgical procedure, was 75% after debridement and implant retention, 91.7% after one-stage exchange, 92.3% after two-stage exchange, and 100% after three-stage exchange. There were no significant differences in survival percentage.

CONCLUSIONS

Our study has good results similar to previously published data. We cannot recommend one strategy of managing prosthetic joint infections over the other. Definitely, there is a need for prospective randomized controlled trials.

A break-even analysis of tranexamic acid for prevention of periprosthetic joint infection following total hip and knee arthroplasty

Purpose

Despite the commonplace use of tranexamic acid in total joint arthroplasty, much of the current data regarding its cost-effectiveness examines savings directly related to its hemostatic properties, without considering its protective effect against periprosthetic joint infections. Using break-even economic modeling, we calculated the cost-effectiveness of routine tranexamic acid administration for infection prevention in total joint arthroplasty.

Materials and methods

The cost of intraoperative intravenous tranexamic acid, the cost of revision arthroplasty for periprosthetic joint infections, and the baseline rates of periprosthetic joint infections in patients who did not receive intraoperative tranexamic acid were obtained from the literature and institutional purchasing records. Break-even economic modeling incorporating these variables was performed to determine the absolute risk reduction in infection rate to make routine intraoperative tranexamic acid use economically justified. The number needed to treat was calculated from the absolute risk reduction.

Results

Routine use of intraoperative tranexamic acid is economically justified if it prevents at least 1 infection out of 3125 total joint arthroplasties (absolute risk reduction = 0.032%). Cost-effectiveness was maintained with varying costs of tranexamic acid, infection rates, and periprosthetic joint infection costs.

Conclusion

The routine use of intraoperative tranexamic acid is a highly cost-effective practice for infection prevention in primary and revision total joint arthroplasty. The use of tranexamic acid is warranted across a wide range of costs of tranexamic acid, initial infection rates, and costs of periprosthetic joint infection treatment.

Inflation-Adjusted Medicare Reimbursement for Revision Hip Arthroplasty: Study Showing Significant Decrease from 2002 to 2019

BACKGROUND

Investigations into reimbursement trends for primary and revision arthroplasty procedures have demonstrated a steady decline over the past several years. Revision total hip arthroplasty (rTHA) due to infection (rTHA-I) has been associated with higher resource utilization and complexity, but long-term inflation-adjusted data have yet to be compared between rTHA-I and rTHA due to aseptic complications (rTHA-A). The present study was performed to analyze temporal reimbursement trends regarding rTHA-I procedures compared with those for rTHA-A procedures.

METHODS

The Centers for Medicare & Medicaid Services (CMS) Physician Fee Schedule Look-Up Tool was used to extract Medicare reimbursements associated with 1-stage and 2-stage rTHA-I as well as 1-stage rTHA-A procedures from 2002 to 2019. Current Procedural Terminology (CPT) codes for rTHA were grouped according to the American Academy of Orthopaedic Surgeons coding reference guide. Monetary values were adjusted for inflation using the consumer price index (U.S. Bureau of Labor Statistics; reported as 2019 U.S. dollars) and used to calculate the cumulative and average annual percent changes in reimbursement.

RESULTS

Following inflation adjustment, the physician fee reimbursement for rTHA-A decreased by a mean [and standard deviation] of 27.26% ± 3.57% (from $2,209.11 in 2002 to $1,603.20 in 2019) for femoral component revision, 27.41% ± 3.57% (from $2,130.55 to $1,542.91) for acetabular component revision, and 27.50% ± 2.56% (from $2,775.53 to $2,007.61) for both-component revision. Similarly, for a 2-stage rTHA-I, the mean reimbursement declined by 18.74% ± 3.87% (from $2,063.36 in 2002 to $1,673.36 in 2019) and 24.45% ± 3.69% (from $2,328.79 to $1,755.45) for the explantation and reimplantation stages, respectively. The total decline in physician fee reimbursement for rTHA-I ($1,020.64 ± $233.72) was significantly greater than that for rTHA-A ($580.72 ± $107.22; p < 0.00001).

CONCLUSIONS

Our study demonstrated a consistent devaluation of both rTHA-I and rTHA-A procedures from 2002 to 2019, with a larger deficit seen for rTHA-I. A continuation of this trend could create substantial disincentives for physicians to perform such procedures and limit access to care at the population level.

LEVEL OF EVIDENCE

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

External Validation Demonstrates Limited Clinical Utility of a Preoperative Prognostic Calculator for Periprosthetic Joint Infection

BACKGROUND

Preoperative calculation of treatment failure risk in patients undergoing surgery for periprosthetic joint infection (PJI) is imperative to allow for medical optimization and targeted prevention. A preoperative prognostic model for PJI treatment failure was previously developed, and this study sought to externally validate the model.

METHODS

A retrospective review was performed of 380 PJIs treated at two institutions. The model was used to calculate the risk of treatment failure, and receiver operating characteristic curves were generated to calculate the area under the curve (AUC) for each institution.

RESULTS

When applying this model to institution 1, an AUC of 0.795 (95% confidence interval [CI]: 0.693-0.897) was found, whereas institution 2 had an AUC of 0.592 (95% CI: 0.502-0.683). Comparing all institutions in which the model had been applied to, we found institution 2 represented a significantly sicker population and different infection profile.

CONCLUSION

In this cohort study, we externally validated the prior published model for institution 1. However, institution 2 had a decreased AUC using the prior model and represented a sicker and less homogenous cohort compared with institution 1. When matching for chronicity of the infection, the AUC of the model was not affected. This study highlights the impact of comorbidities and their distributions on PJI prognosis and brings to question the clinical utility of the algorithm which requires further external validation.

Tolerance and microbiological efficacy of cefepime or piperacillin/tazobactam in combination with vancomycin as empirical antimicrobial therapy of prosthetic joint infection: a propensity-matched cohort study

BACKGROUND

The use of piperacillin/tazobactam with vancomycin as empirical antimicrobial therapy (EAT) for prosthetic joint infection (PJI) has been associated with an increased risk of acute kidney injury (AKI), leading us to propose cefepime as an alternative since 2017 in our reference centre.

OBJECTIVES

To compare microbiological efficacy and tolerance of these two EAT strategies.

METHODS

All adult patients with PJI empirically treated with vancomycin+cefepime (n = 89) were enrolled in a prospective observational study and matched with vancomycin+piperacillin/tazobactam-treated historical controls (n = 89) according to a propensity score including age, baseline renal function and concomitant use of other nephrotoxic agents. The two groups were compared using Kaplan-Meier curve analysis, and non-parametric tests regarding the proportion of efficacious empirical regimen and the incidence of empirical therapy-related adverse events (AE).

RESULTS

Among 146 (82.0%) documented infections, the EAT was considered efficacious in 77 (98.7%) and 65 (98.5%) of the piperacillin/tazobactam- and cefepime-treated patients, respectively (P = 1.000). The rate of AE, particularly AKI, was significantly higher in the vancomycin+piperacillin/tazobactam group [n = 27 (30.3%) for all AE and 23 (25.8%) for AKI] compared with the vancomycin+cefepime [n = 13 (14.6%) and 6 (6.7%)] group (P = 0.019 and <0.001, respectively), leading to premature EAT discontinuation in 20 (22.5%) and 5 (5.6%) patients (P = 0.002). The two groups were not significantly different regarding their comorbidities, and AKI incidence was not related to vancomycin plasma overexposure.

CONCLUSIONS

Based on the susceptibility profile of bacterial isolates from included patients, microbiological efficacy of both strategies was expected to be similar, but vancomycin + cefepime was associated with a significantly lower incidence of AKI.

Potential Use of Adjuvant Bacteriophage Therapy With Debridement, Antibiotics, and Implant Retention Surgery to Treat Chronic Prosthetic Joint Infections

The number of arthroplasties conducted annually continues to increase; however, approximately 1%–2% of all knee and hip arthroplasties will become infected. These prosthetic joint infections are costly, difficult to treat, and cause significant morbidity and mortality as a direct result of conventional surgical and medical managements. In this perspective, we discuss factors that make these infections arduous to treat as well as the potential use of adjuvant bacteriophage therapy with debridement, antibiotics, and implant retention surgery to cure these infections without removing the infected prosthesis. We also provide rationale as to why future clinical trials evaluating this novel therapeutic will need to be designed as noninferiority trials, and we compare this approach to 2-stage revision surgery. If bacteriophage therapy continues to show effectiveness, this could revolutionize the treatment of prosthetic joint infections and pioneer new treatments for similar infections.

[Manual addition of antibiotics to industrial bone cement mixes : Investigations of the dry mix in the cement cartridge during manual admixture to polymer-active substance mixtures]

BACKGROUND

Periprosthetic infection (PPI) is a rare but serious complication. An elementary component of the therapy of PPI is the use of bone cement with the addition of antibiotics. For targeted therapy, manual mixing of antibiotics with industrially produced bone cement mixtures is often necessary. Possible problems resulting from manual mixing have not been described sufficiently so far.

OBJECTIVES

Therefore, the aim of the present study was to describe the influence of the additional homogenisation by dry mixing of a polymer-active substance mixture on the quality of manually added cement.

MATERIAL AND METHODS

In the laboratory-based study, four cement samples were prepared using different methods for manual addition and homogenisation of antibiotics (vancomycin). The reference control was Copal® G + V (Heraeus Medical GmbH, Wehrheim, Germany), to which the vancomycin (V) had already been industrially added. The samples were then examined for mechanical, microbiological and microscopic parameters.

RESULTS

In the mechanical and microbiological results, no statistically significant differences were found between the manually added mixtures and the reference. After dry mixing of the polymer powder, the inner surface of the mixing cartridges used showed signs of scratching in the microscopic examination and showed indications of abrasion during mixing.

CONCLUSION

The manual addition of antibiotics to industrially produced bone cement should be reserved for selected indications if the bone cement mixtures produced by industry are not sufficient.

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

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

[Comparison of DRG revenues between fast and slow-track procedures for a two-stage replacement of prostheses for periprosthetic hip infections in the aG-DRG system 2020]

Hintergrund

Die Behandlung periprothetischer Hüftinfektionen ist meist kostenintensiv und gilt im Allgemeinen als nicht kostendeckend für die Kliniken. Bei chronischen Infektionen ist oft ein zweizeitiger Prothesenwechsel indiziert, der als Fast-Track mit kurzem prothesenfreiem Intervall (2–4 Wochen) oder als Slow-Track mit langem prothesenfreiem Intervall (über 4 Wochen) erfolgen kann.

Ziel

Ziel dieser Arbeit war die Erfassung der Erlössituation beider Behandlungsformen im aktuellen aG-DRG-System 2020 unter Berücksichtigung erlösrelevanter Einflussfaktoren.

Methoden

Für Fast-Track und Slow-Track bei zweizeitigem septischem Hüftprothesenwechsel mit Nachweis eines Staphylococcus aureus (MSSA) wurden mittels einer Grouper-Software (3M KODIP Suite) anhand der Diagnosen (ICD-10-GM) und Prozeduren (OPS) Behandlungsfälle simuliert und in DRG eingruppiert. Erlösrelevante Parameter wie Verweildauer (VWD) und Nebendiagnosen (ND) wurden berücksichtigt. Zusätzlich wurden zwei reale Behandlungsfälle mit Fast-Track und Slow-Track miteinander verglichen.

Ergebnisse

Die Gesamterlöse betrugen beim Slow-Track bei einer VWD von 25 Tagen (ohne ND) 27.551 € und bei einer VWD von 42 Tagen (mit ND) 40.699 €. Beim Fast-Track hingegen lag der Gesamterlös bei 23.965 € bei einer VWD von 25 Tagen (ohne ND) und bei 27.283 € bei einer VWD von 42 Tagen (mit ND). Bei den realen Behandlungsfällen zeigte sich ebenfalls eine deutliche Differenz des Gesamterlöses von 12.244 € zugunsten des Slow-Tracks.

Diskussion

Auch im aG-DRG-System 2020 scheint der zweizeitige Hüftprothesenwechsel mit langem Interimsintervall insbesondere bei multimorbiden Patienten aus Krankenhaussicht ökonomisch vorteilhafter zu sein als das Fast-Track-Konzept, wodurch ein finanzielles Hemmnis zur Behandlung solcher Patienten mit kurzem Interimsintervall geschaffen wird.

Novel custom made composite spacer for first-stage revision total hip replacement in the presence of extensive acetabular/femoral bone loss with abductor deficiency

A two-stage revision total hip replacement (THR) remains the gold standard for treating chronic periprosthetic joint infection. The goals for the first stage are twofold: (1) remove infected tissue/implants, obtaining tissue samples for culture; (2) deliver local antibiotics and maintain hip function with a prosthesis with antibiotic-loaded acrylic cement. With extensive bone loss prefabricated spacers are not sufficient, therefore customised spacers are required. The current technique, coating cephalomedually femoral nail in cement, is complex, time consuming, functions poorly and causes wear debris from excessive friction at the femoral/acetabular articulation. We report a technique to create a custom made composite spacer using a short femoral nail, standard Exeter femoral stem (Stryker), Trident acetabular cup (Stryker) and polymethyl methacrylate (PMMA) bone cement with antibiotics. This technique restores hip biomechanics and gives a stable articulation, even in the presence of abductor deficiency, due to dual mobility bearings.

Successful Treatment of a Recalcitrant Staphylococcus epidermidis Prosthetic Knee Infection with Intraoperative Bacteriophage Therapy

Here, we present a case of a 79-year-old female with a recalcitrant Staphylococcal epidermidis prosthetic knee infection that was successfully treated with a single dose of adjuvant intra-articular bacteriophage therapy after debridement and implant retention surgery. The bacteriophage used in this case, PM448, is the first ɛ² bacteriophage to be used in vivo. Currently the patient is without evidence of clinical recurrence and, interestingly, the patient had also suffered from debilitating aplastic anemia for over 2 years, which is recovering since receiving adjuvant bacteriophage therapy.

Revisions for Periprosthetic Hip Infections Do Not Fail More Than Revisions for Aseptic Loosening, but Mortality is Higher

BACKGROUND

The influence of the reasons for revision on the outcomes of revision hip arthroplasties is controversial and poorly described. A registry study was designed to compare the revision hips performed for periprosthetic hip infection (PHI) to the revision hips performed for aseptic loosening. The aims of this study were the long-term assessment and comparison of survival rates, reasons for rerevisions, and mortality rates between these two cohorts.

METHODS

By using an arthroplasty registry, revision hips were stratified according to the reasons for revision (aseptic loosening and PHI). Preoperative and intraoperative, demographic and implant-related features were recorded. Survival rates, reasons for revision and mortality rates were assessed and compared.

RESULTS

The two cohorts were homogenous for preoperative and intraoperative parameters, apart from age at revision, time elapsed between THA and revision, bearing surfaces, and head size. At 10 years, the survival rates were similar between the two groups (P = .51). Half of the rerevisions occurred in the first two years in both the groups. The reasons for rerevision were similar: when rerevision for infection was adopted as an end point, the two cohorts showed nonsignificant differences. The mortality rate was statistically higher in the PHI cohort (P .0015, hazard ratio adjusted for age and gender: 1.42).

CONCLUSION

Aseptic and septic revisions achieved similar outcomes at long-terms, rerevisions tended to fail for the same reason for revision. The mortality rate was significantly higher in the septic cohort. These findings are useful to modify and tune the preoperative, intraoperative, and postoperative managements of revisions.

Good Functional Outcomes and Low Infection Rates in Total Hip Arthroplasty in HIV-Positive Patients, Provided There Is Strict Compliance With Highly Active Antiretroviral Therapy

BACKGROUND

Patients with HIV are more likely to require a total hip arthroplasty (THA) because of an increase in life expectancy and complications with HIV. The purpose of this study is to describe the mid-term outcomes of THA in HIV-positive patients and risk factors for postoperative infections and poor outcomes.

METHODS

This is a single-center retrospective review of nonhemophiliac HIV-positive patients who underwent THA. We reviewed the short- and mid-term readmission and complication rates.

RESULTS

Eighty-seven patients underwent 102 THAs. The average age was 58 years (24-73 years). The average body mass index was 31.6 (18-55). The average CD4+ count was 569 cells per cubic millimeter (mm³) (51-1480), and the mean viral load was <40 copies/mL (undetectable-380 000). The mean follow-up time was 6.7 years (24 months- 8.3 years). Four patients had postoperative complications within 30 days. Seven patients had postoperative complications after 30 days; 5 of which had septic loosening of implants and had either not been initiated on or were noncompliant with their highly active antiretroviral therapy. The average postoperative Harris Hip Score was 81 (41-100) and Oxford Hip Score was 43.43 (34-48). There was no correlation the between CD4+ count and viral load with complications.

CONCLUSION

Low rate of complications and revision is achievable in the HIV-positive, nonhemophilic arthroplasty population contrary to published literature. An important factor ensuring good long-term outcomes in HIV-positive patients undergoing THA was the initiation of highly active antiretroviral therapy before the procedure and ensuring patient compliance with therapy after joint arthroplasty.

Iron Chelation in Local Infection

Iron is an essential element in multiple biochemical pathways in humans and pathogens. As part of the innate immune response in local infection, iron availability is restricted locally in order to reduce overproduction of reactive oxygen species by the host and to attenuate bacterial growth. This physiological regulation represents the rationale for the therapeutic use of iron chelators to support induced iron deprivation and to treat infections. In this review paper we discuss the importance of iron regulation through examples of local infection and the potential of iron chelation in treating infection.

Systematic review of single stage revision for prosthetic joint infection

While advanced technology, increased medical knowledge and improved surgical technique has improved patient outcomes in total joint arthroplasty, prosthetic joint infection still remains one of the leading causes of increased healthcare costs, medical resources and societal burdens in orthopaedic care. Two stage arthroplasty revision remains the gold standard for treatment of prosthetic joint infection. Proponents of single stage revision arthroplasty for infection argue that it results in lower healthcare costs while improving patient reported functional outcomes and with equivalent success rates. Here we review the history of single stage revision arthroplasty, discuss the key principles, highlight the indications and contraindications, and review the reported outcomes with a focus on future developments of single stage revision arthroplasty for hip and knee periprosthetic joint infections.

Contemporary 2-Stage Treatment of Periprosthetic Hip Infection with Evidence-Based Standardized Protocols Yields Excellent Results: Caveats and Recommendations

BACKGROUND

This study quantified the effectiveness of contemporary and evidence-based standardized 2-stage treatment for periprosthetic hip infection. Findings illustrate potential limitations of criticisms of 2-stage protocols and potential consequences of adopting single-stage protocols before definitive data are available.

METHODS

Fifty-four consecutive hips treated with 2-stage resection and reimplantation were retrospectively reviewed. Standardized protocols were adhered to including implant resection, meticulous surgical debridement, antibiotic spacer, 6-week intravenous antibiotics, a 2-week drug holiday, and laboratory assessment of infection eradication before reimplantation. After reimplantation, patients were placed on prophylactic intravenous antibiotics until discharge and discharged on oral antibiotics for a minimum of 7 days until intraoperative cultures were final. Successful treatment was defined per Delphi-based International Multidisciplinary Consensus.

RESULTS

The overall treatment success rate was 95.7% (44 of 46 cases) with mean infection-free survivorship of 67.2 (range, 23.8-106.4) months. Success rates were 100% for early and acute hematogenous infections regardless of host type and 100% for chronic infections in uncompromised hosts. 95% (19/20) of chronic infections in compromised hosts and 83.3% (5/6) of chronic infections in significantly compromised hosts were successfully treated. About 4% of primary hips and 20% of revision hips required repeat debridement and spacer exchange after initial resection. No patients died because of treatment.

CONCLUSION

Details from this consecutive series of patients undergoing 2-stage treatment for hip infection suggest that some criticisms of 2-stage treatment as well as some arguments in support of single-stage treatment may be overstated. Promotion and uncritical adoption of single-stage treatment protocols are discouraged until further and more definitive data exist.

Outcomes Associated With Infection of Chronic Pain Spinal Implantable Electronic Devices: Insights From a Nationwide Inpatient Sample Study

OBJECTIVES

Chronic pain spinal implantable electronic devices (CPSIEDs) include devices that provide spinal cord stimulation and intrathecal drug therapy. In this study, we sought to evaluate the trends of CPSIED infections, related complications, and outcomes following the treatment of infection.

MATERIALS AND METHODS

The Nationwide Inpatient Sample database contains data from 48 states, and the District of Columbia was used to identify patients with a primary diagnosis of CPSIED infection during the years 2005-2014. Patients with intrathecal pumps for the treatment of spasticity were excluded to limit the study population to patients with chronic pain disorders. Treatments were categorized as: 1) without device removal, 2) pulse generator or pump only removal, 3) intrathecal pump system removal, and 4) spinal cord stimulation system removal. Complications associated with CPSIED infections were identified using administrative billing codes.

RESULTS

During the study period 2005-2014, a total of 11,041 patients were admitted to the hospital with CPSIED infections. The majority of the patients were treated without surgical intervention (56%), and a smaller proportion underwent complete system explantation (22.7%). In-hospital mortality or permanent disability due to paralysis after CPSIED infection was around 1.83% and 2.77%, respectively. Infectious complications such as meningitis, abscess formation, and osteomyelitis occurred in 4.93%, 5.08%, and 1.5%, respectively. The median cost of hospitalization was around US $14,118.00, and the median length of stay was approximately six days (interquartile range = 4-13 days).

CONCLUSIONS

The complications of CPSIED infection were higher among patients that did not undergo device removal.

Factors affecting outcome in the treatment of streptococcal periprosthetic joint infections: results from a single-centre retrospective cohort study

PURPOSE

To report and analyse factors affecting the outcome of streptococcal periprosthetic joint infections (PJIs).

METHODS

A retrospective analysis of consecutive streptococcal PJIs was performed. Musculoskeletal Infection Society 2013 criteria were used. Outcome was compared with a prospective PJI cohort from the same institution.

RESULTS

The most common isolated streptococcal species was Streptococcus dysgalactiae (9/22, 41%) among 22 patients included. Surgical treatment consisted of DAIR (debridement, antibiotics, irrigation and retention) in 12 (55%), one-stage revision arthroplasty in one (4%), two-stage revision arthroplasty in eight (37%) and implant removal in one (4%) patient. An infection free-outcome was achieved in 15 cases (68%), whilst seven (32%) patients failed initial revision and relapsed with the same pathogen, from which six were treated with DAIR and one with one-stage revision arthroplasty. No failures were observed in patients who received a two-stage revision. Failure rates did not differ in the cases treated with rifampin (1/5) from those without 6/17 (p = 0.55). There was no correlation between the length of antibiotic treatment and relapse (p = 0.723). In all failures, a persistent distant infection focus was identified at the time of relapse. Compared with our prospective PJI cohort, relapse rates were significantly higher 32% vs 12% (p < 0.05).

CONCLUSION

No correlation with the use of rifampin or length of antibiotic treatment was found. No failures were observed in patients who received a two-stage revision, which may be the surgical treatment of choice. A distant persisting infection focus could be the reason for PJI relapse with recurrent hematogenous seeding in the joint.

Prevention of Prosthetic Joint Infection: From Traditional Approaches towards Quality Improvement and Data Mining

A projected increased use of total joint arthroplasties will naturally result in a related increase in the number of prosthetic joint infections (PJIs). Suppression of the local peri-implant immune response counters efforts to eradicate bacteria, allowing the formation of biofilms and compromising preventive measures taken in the operating room. For these reasons, the prevention of PJI should focus concurrently on the following targets: (i) identifying at-risk patients; (ii) reducing “bacterial load” perioperatively; (iii) creating an antibacterial/antibiofilm environment at the site of surgery; and (iv) stimulating the local immune response. Despite considerable recent progress made in experimental and clinical research, a large discrepancy persists between proposed and clinically implemented preventative strategies. The ultimate anti-infective strategy lies in an optimal combination of all preventative approaches into a single “clinical pack”, applied rigorously in all settings involving prosthetic joint implantation. In addition, “anti-infective” implants might be a choice in patients who have an increased risk for PJI. However, further progress in the prevention of PJI is not imaginable without a close commitment to using quality improvement tools in combination with continual data mining, reflecting the efficacy of the preventative strategy in a particular clinical setting.

Thyroid radiation shields: A potential source of intraoperative infection

Introduction

Thyroid radiation shields are often uncovered by the surgical gown and may represent a preventable source of wound contamination. The aims of this study are to define the common pathogens found on thyroid radiation shields and evaluate the effectiveness of a simple cleaning method.

Methods

Samples were obtained from 29 community thyroid shields collected from the operating theatres of 3 teaching hospitals. Each shield was swabbed under strict sterile technique using a separate swab for each of 4 designated zones. After sampling, shields were cleaned with a readily available disinfectant and sampling was repeated after 5 min. All swabs were cultured in ambient air at 37 °C on 5% sheeps blood agar for 48 hrs and subsequent growth was identified by a MALDI-TOF Walkaway mass spectrometer.

Results

Before cleaning, 100% of thyroid shields (29/29) and 68% of shield zones (79/116) grew at least 1 type of bacteria. Coagulase negative staphylococci, including S. epidermidis, S. capitis, S. cohnii, S. haemolyticus and S. hominis, were most commonly isolated. Enterobacteriaceae and S. aureus were also cultured. After cleaning, culturable contamination was reduced by 86.3% and 64.5%, respectively (p < 0.001).

Conclusion

The most common pathogens associated with SSIs can be isolated on thyroid radiation shields. Appropriate cleaning of thyroid shields with readily available disinfectant can significantly reduce the bacterial burden as detectable by culture. Hospitals should facilitate staff education and reinforce their policies on cleaning these shields which may often be overlooked.

Rifabutin Use in Staphylococcus Biofilm Infections: A Case Series

This is a case series of 10 patients who had staphylococcal biofilm infections that were treated with adjuvant rifabutin therapy instead of rifampin therapy. In these cases, rifampin was contraindicated secondary to drug–drug interactions with the patients’ chronic medications. Rifabutin therapy was well tolerated with no side effects. As well, no patients had recurrence of their staphylococcal infections. This case series shows that rifabutin can be a beneficial adjuvant therapy in Staphylococcus biofilm infections when drug–drug interactions limit the use of rifampin.

The Lawrence D. Dorr Surgical Techniques & Technologies Award: Aseptic Reoperations Within One Year of Primary Total Hip Arthroplasty Markedly Increase the Risk of Later Periprosthetic Joint Infection

BACKGROUND

Despite the success of primary total hip arthroplasties (THAs), some patients will require an aseptic reoperation within 1 year of the index THA. The goal of this study is to evaluate the risk of subsequent periprosthetic joint infection (PJI) in patients undergoing an aseptic reoperation within 1 year of a primary THA.

METHODS

A retrospective review utilizing our institutional joint registry identified 211 primary THAs requiring aseptic reoperation within 1 year following index arthroplasty. A control group of 15,357 primary THAs not requiring reoperation within 1 year was identified. Patients were divided into groups based on time from primary THA to reoperation: (1) within 90 days (n = 112 THAs; 40% for dislocation, 34% for periprosthetic fracture) or (2) 91-365 days (n = 99 THAs; 37% for dislocation, 29% for periprosthetic fracture). Mean follow-up was 7 years.

RESULTS

Patients undergoing an aseptic reoperation within 90 days had a PJI rate of 4.8% at 2 years, while the 91-365 day group had a PJI rate of 3.2% at 2 years. The control group had a PJI rate of 0.2% at 2 years. Employing a multivariate analysis, reoperation within 90 days of index arthroplasty had an elevated risk of PJI (hazard ratio 8, P < .001) as did a reoperation between 91 and 365 days (hazard ratio 13, P < .001).

CONCLUSION

Aseptic reoperations within 1 year following primary THA resulted in an 8- to 13-fold increased risk of subsequent PJI. The risk was similar whether the aseptic reoperation was early (within 90 days) or later (91-365 days).

LEVEL OF EVIDENCE

Level III (Prognostic).

Is Treatment of Periprosthetic Joint Infection Improving Over Time?

BACKGROUND

It is unknown whether the outcomes of treatment for periprosthetic joint infection (PJI) are improving with time. This study evaluated trends in PJI treatment outcomes in the hip and knee following 2-stage exchange arthroplasty and irrigation and debridement (I&D) over the last 17 years.

METHODS

We reviewed 550 two-stage exchange arthroplasties and 194 I&Ds between 2000 and 2016 at our institution. Treatment success was defined according to the Delphi consensus criteria and Kaplan-Meier survivorship curves were generated. A multivariate Cox proportional hazards regression model was generated to determine time trends in the outcome of PJI treatment with the year of surgery included as both a continuous covariate (per 1-year increase) and a categorical covariate (2000-2010 or 2011-2016).

RESULTS

The survivorship of I&D, 2-stage revision, and the total combined cohort were comparable between 2000-2010 and 2011-2016 groups. Multivariate Cox regression analysis showed that the year of surgery was not associated with treatment failure following an I&D or 2-stage exchange arthroplasty, and neither did it increase the risk of non-reimplantation. When year of surgery was considered as a categorical variable, there remained no significant difference in treatment failure following an I&D or 2-stage exchange arthroplasty between the 2000-2010 cohort and 2011-2016 cohort.

CONCLUSION

Despite the increasing clinical focus, research advances, and growing literature relating to PJI, we were unable to detect any substantial improvement in the treatment success rates of PJI at our institution over the 17 years examined in this study. Novel treatments and techniques are certainly needed as current and prior strategies remain far from optimal.

Salvage Bacteriophage Therapy for a Chronic MRSA Prosthetic Joint Infection

This is a case of a 72 year old male with a chronic methicillin-resistant Staphylococcus aureus prosthetic joint infection. After the third intravenous dose of bacteriophage therapy, an unusual, reversible transaminitis prompted stoppage of bacteriophage therapy. Nevertheless, treatment was successful and the patient’s severe chronic infection was eradicated.

Corynebacterium Total Hip and Knee Arthroplasy Prosthetic Joint Infections

Prosthetic joint infections (PJIs) are typically caused by Staphylococcus aureus and coagulase-negative Staphylococci species. Corynebacterium species are microorganisms of the human skin and mucous membranes that are often considered contaminants when grown in culture. In the past, Corynebacterium species were often classified as diphtheroids based on growing as gram-positive rods in aerobic environments, but with advances in technology, the identification of Corynebacterium species has improved. Corynebacterium can cause infection, but there are few case reports of orthopaedic infection. We present 3 cases of total hip arthroplasty and 3 cases of total knee arthroplasty PJI caused by Corynebacterium species. We found a high failure rate of surgical treatment of Corynebacterium PJI, defined as reoperation for infection. This information adds to the limited literature on these organisms in total joint arthroplasty PJI.

Genomic characterization and outcome of prosthetic joint infections caused by Staphylococcus aureus

Staphylococcus aureus is a commensal colonizing the skin and mucous membranes. It can also act as a pathogen, and is the most common microorganism isolated from prosthetic joint infections (PJIs). The aim of this study was to explore the genomic relatedness between commensal and PJI S. aureus strains as well as microbial traits and host-related risk factors for treatment failure. Whole-genome sequencing (WGS) was performed on S. aureus isolates obtained from PJIs (n = 100) and control isolates from nares (n = 101). Corresponding clinical data for the PJI patients were extracted from medical records. No PJI-specific clusters were found in the WGS phylogeny, and the distribution of the various clonal complexes and prevalence of virulence genes among isolates from PJIs and nares was almost equal. Isolates from patients with treatment success and failure were genetically very similar, while the presence of an antibiotic-resistant phenotype and the use of non-biofilm-active antimicrobial treatment were both associated with failure.In conclusion, commensal and PJI isolates of S. aureus in arthroplasty patients were genetically indistinguishable, suggesting that commensal S. aureus clones are capable of causing PJIs. Furthermore, no association between genetic traits and outcome could be demonstrated, stressing the importance of patient-related factors in the treatment of S. aureus PJIs.

Prevalence of Staphylococcus aureus colonization in patients for total joint arthroplasty in South Africa

BACKGROUND

Periprosthetic joint infections (PJIs) are a major source of morbidity and mortality for patients undergoing total joint arthroplasty (TJA). Staphylococcus aureus (S. aureus) colonization is an independent, modifiable risk factor for periprosthetic joint infections. Post-operative infections are reported to be ten times greater in S. aureus carriers than in non-carriers in developed countries though recorded data is lacking for the developing world. This study aims to determine the prevalence of S. aureus colonization in patients awaiting TJA in South Africa.

METHODS

We prospectively assessed 119 patients awaiting total knee arthroplasty and total hip arthroplasty between May and October 2016. We screened three separate anatomical sites on each patient for S. aureus. Patients with positive cultures were treated with intranasal mupirocin ointment and chlorhexidine body wash. Univariate and comparative statistical analyses to determine risk factors for colonization was conducted using t tests, Fisher's exact tests, and chi-square analyses.

RESULTS

The overall prevalence of methicillin-sensitive S. aureus colonization was 31.9% (n = 38). There were no patients colonized with methicillin-resistant S. aureus. Nasal swabs returned a yield of 81.6% (n = 31), with groin swabs and axillary swabs at 39.5% (n = 15) and 28.9% (n = 11), respectively. Eradication was successful in 94.74% (n = 36) after 5 days treatment. All patients (100%) were decolonized after counseling and repeat eradication treatment. The overall complication rate was 7.6% (n = 9). The 30-day readmission rate in the S. aureus-colonized group was 7.9% (n = 3) as opposed to 7.4% (n = 6) in the non-colonized cohort. There were no 60- and 90-day readmissions and no cases were revised at a mean follow-up of 2.26 years.

CONCLUSIONS

The rate of S. aureus colonization in patients undergoing elective TJA in a developing country was 31.9% and is equivalent to reported rates in developed countries. Eradication treatment with combined intranasal mupirocin ointment and chlorhexidine body wash is a successful treatment modality. A larger cohort of patients is recommended to determine risk factors and post-operative septic sequelae in this population group.

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

Streamlining Hospital Treatment of Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) is associated with significant morbidity, mortality, and costs. We developed a fast-track PJI care system using an infectious disease physician to work directly with the TJA service and coordinate in the treatment of PJI patients. We hypothesized that streamlined care of patients with hip and knee PJI decreases the length of the acute hospital stay without increasing the risk of complication or incorrect antibiotic selection.

METHODS

A single-center retrospective chart review was performed for all patients treated operatively for PJI. A cohort of 78 fast-track patients was compared to 68 control patients treated before the implementation of the program. Hospital length of stay (LOS) and cases of antibiotic mismatch were primary outcomes. Secondary outcomes, including 90-day readmissions, reoperations, mortality, rate of reimplantation, and 12-month reimplant survival, were compared. Cox regressions were analyzed to assess the effects on LOS of patient demographics and the type of surgery performed.

RESULTS

Average hospital LOS from infection surgery to discharge was significantly lower in the fast-track cohort (3.8 vs 5.7 days; P = .012). There were no episodes of antibiotic mismatch in the fast-track group vs 1 recorded episode in the control group. No significant differences were noted comparing 90-day complications, reimplantation rate, or 12-month reimplant survival rates.

CONCLUSION

Through the utilization of an orthopedic-specific infectious disease physician, a fast-track PJI protocol can significantly shorten hospital LOS while remaining safe. Streamlining care pathways may help decrease the overall healthcare costs associated with treating PJI.

Partial 2-Stage Exchange for Infected Total Hip Arthroplasty: An Updated Report

BACKGROUND

Management of an infected total hip arthroplasty (THA) is challenging. The eradication of infection as well as complications of component removal must all be considered. This study is an update on previous reports of treating periprosthetic infection of the hip with a partial 2-stage exchange with retention of the femoral component.

METHODS

A retrospective review of our practice's arthroplasty registry from 2000 to 2018 revealed 41 hips with 2-year minimum follow-up that were treated with a 2-stage partial exchange for an infected THA. All first-stage procedures allowed an articulating construct with 1 of 3 variations: cemented constrained liner (13 hips), StageOne Hip Cement Spacer Mold (14 hips), or an antibiotic polymethylmethacrylate head molded from a bulb syringe (14 hips). Of 41 cases, 34 were culture positive, with 3 cases having methicillin-resistant Staphylococcus.

RESULTS

Mean follow-up was 5.5 years (range, 1.5-18.5 years). The second-stage reimplantation was accomplished in 39 of the 41 hips (95%) at a mean interval of 9.2 weeks (range, 5-9 weeks). Two patients underwent repeat radical debridement with removal of all components before reimplantation for persistent clinical evidence of infection. Thirty-three of the 41 hips (81%) were infection free at most recent follow-up. The mean postoperative Harris hip score at most recent evaluation was 63.6 (range, 24-100).

CONCLUSION

Eradication of periprosthetic joint infections, while minimizing patient morbidity, continues to be a challenge. Partial 2-stage exchange may be considered in cases where removal of a well-fixed femoral component may result in significant bony destruction.

Prosthetic-joint Infections: Mortality Over The Last 10 Years

Background: There is a constant increase of joint arthroplasties to improve the quality of life of an ever-aging population. Although prosthetic-joint infections are rare, with an incidence of 1-2%, they represent a serious complication in terms of morbidity and mortality. Infection related mortality is known to be approaching 8% at one year. The aim of this retrospective study is to reassess the one and two-year mortality over the last ten years. Methods: Patients treated for prosthetic joint infection at the University Hospital of Lausanne (Switzerland) between 2006 and 2016 were included. The one and two-year cumulative mortality depending on sex, age, type of prosthesis, infecting organism and type of surgical treatment were computed. Results: 363 patients (60% hips, 40% knees) were identified with a median age of 70 years. The one-year cumulative mortality was 5.5% and it was 7.3% after two years. No difference was seen between hip and knee prostheses, but the mortality was higher in men than in women and increased with age. Furthermore, there was a significant difference depending of the germ with enterococci infections associated with a higher risk of death. Finally, patients treated with a one-stage or two-stage exchange had a lower mortality than those treated with debridement and retention. Conclusion: The mortality is still high and differs according to sex, age, infecting organism and type of surgical treatment. There is a need of studies to improve the management of patients at risk of increased mortality.

First results of a uniform regional treatment protocol and registration for acute prosthetic join infection in the South-East of the Netherlands

Introduction: Prosthetic joint infection (PJI) is a relatively uncommon (average incidence 0.5-2%) but devastating complication, with significant morbidity and leading to tremendously increased health care costs. In 2013, delegates from nine hospitals covering a large region in the South-East Netherlands composed one combined treatment protocol for acute PJI of total hip and knee arthroplasty (THA and TKA). This protocol was based on the definition of acute PJI according to Workgroup of the American Musculoskeletal Infection Society (MSIS) and the principles of debridement, antibiotics, irrigation and retention (DAIR).

Methods: Patients with a THA or TKA treated with DAIR because of suspicion of PJI were selected from the online PJI database. PJI was defined as at least two phenotypically identical pathogens, isolated in cultures from at least two separate tissues, obtained from the affected prosthetic joint. Acute PJIs, occurring within 90 days after primary implantation, between January 2014 and December 2016, were analyzed. We analyzed the PJI incidence rate, patient clinical and microbiological characteristics of PJI, outcome of the DAIR treatment and adherence to the regional protocol.

Results: A total of 310 primary THA or TKA with a suspected PJI were registered in the regional PJI database, 236 met the definition of acute PJI, representing overall incidence of 1.12%. Following the regional treatment protocol replacement of exchangeable parts took place in 45% in 2014 to 70% in 2016. After 12 months follow-up, prosthesis retention was achieved in 87% and 3% of the patients died within one year after the primary surgery.

Conclusion: Results of the regional cohort are in line with the available literature. Regional collaboration and regular feedback on registered data resulted in better adherence to the combined treatment protocol. Despite our attempts to improve PJI care, PJI remains a serious complication of THA and TKA with a significant mortality rate and burden for the patient.