Infection in total hip replacement: meta-analysis

Estimation of two-year hospital costs of hip and knee periprosthetic joint infection treatments using activity-based costing

Aims

Our aim was to estimate the total costs of all hospitalizations for treating periprosthetic joint infection (PJI) by main management strategy within 24 months post-diagnosis using activity-based costing. Additionally, we investigated the influence of individual PJI treatment pathways on hospital costs within the first 24 months.

Methods

Using admission and procedure data from a prospective observational cohort in Australia and New Zealand, Australian Refined Diagnosis Related Groups were assigned to each admitted patient episode of care for activity-based costing estimates of 273 hip PJI patients and 377 knee PJI patients. Costs were aggregated at 24 months post-diagnosis, and are presented in Australian dollars.

Results

The mean cost per hip and knee PJI patient was $64,585 (SD $53,550). Single-stage revision mean costs were $67,029 (SD $47,116) and $80,063 (SD $42,438) for hip and knee, respectively. Two-stage revision costs were $113,226 (SD $66,724) and $122,425 (SD $60,874) for hip and knee, respectively. Debridement, antibiotics, and implant retention in hips and knees mean costs were $53,537 (SD$ 39,342) and $48,463 (SD $33,179), respectively. Suppressive antibiotic therapy without surgical management mean costs were $20,296 (SD $8,875) for hip patients and $16,481 (SD $6,712) for knee patients. Hip patients had 16 different treatment pathways and knee patients had 18 treatment pathways. Additional treatment, episodes of care, and length of stay contributed to substantially increased costs up to a maximum of $369,948.

Conclusion

Treating PJI incurs a substantial cost burden, which is substantially influenced by management strategy. With an annual PJI incidence of 3,900, the cost burden would be in excess of $250 million to the Australian healthcare system. Treatment pathways with additional surgery, more episodes of care, and a longer length of stay substantially increase the associated hospital costs. Prospectively monitoring individual patient treatment pathways beyond initial management is important when quantifying PJI treatment cost. Our study highlights the importance of optimizing initial surgical treatment, and informs treating hospitals of the resources required to provide care for PJI patients.

Cemented Constrained Liners Used as an Articulating Hip Spacer for the Treatment of Chronic Prosthetic Joint Infection

Background

Two-stage exchange arthroplasty remains the gold standard for treating chronic hip periprosthetic joint infections. However, controversy remains regarding the optimal spacer type, particularly among patients with increased dislocation risk. This study reports on the outcomes of articulating hip spacers utilizing a single constrained-liner design.

Methods

All patients who underwent treatment for hip periprosthetic joint infection at a single institution were screened. Patients were included if they received an articulating spacer utilizing a constrained liner of a single manufacturer design. Indications for constrained liner, demographic variables, and surgical variables were recorded. Patients were assessed for dislocation and component loosening prior to the second stage or at the final follow-up if the second stage was not undertaken. Comparative analysis was performed.

Results

Overall, 26 constrained liners were utilized in 25 patients. Indications for constrained liner included history of dislocation (n = 14), massive proximal femoral bone loss (n = 14), greater trochanteric deficiency (n = 12), and absent abductors (n = 7). Many patients had more than one indication. In total, 9 hips (34.6%) underwent a second stage at an average of 7.4 months, while 17 hips never underwent a second stage with an average follow-up of 27.6 months. One patient experienced failure of their constrained liner prior to the second stage due to pelvic discontinuity and massive acetabular bone loss.

Conclusions

Utilization of a constrained liner as an articulating spacer is a viable option for patients at high risk of instability. Meticulous cement technique, appropriate component position, and implant selection are crucial in achieving successful outcomes.

Efficacy of Commercially Available Irrigation Solutions on Removal of Staphylococcus Aureus and Biofilm From Porous Titanium Implants: An In Vitro Study

BACKGROUND

Periprosthetic joint infection remains a major problem. The bactericidal efficacy of commercial irrigation solutions for the treatment of infection is not well established in the presence of porous titanium (Ti) implants. This study compared the in vitro efficacy of five irrigation solutions on infected three-dimensional-printed porous Ti discs.

METHODS

Titanium discs (2 × 4 mm, 400, 700, and 1,000 μm) were infected with S. aureus (1 × 106 colony-forming unit/mL) and incubated for 3 hours or 3 days to create acute or chronic infection with biofilm. Discs were irrigated with saline, antibiotic, or antiseptic solutions, then repeatedly sonicated. Sonicates were cultured for bacterial quantification. Statistical analyses were performed using one-way analysis of variance (ANOVA), followed by Tukey-Kramer post hoc testing (P < .05 significance). Biofilms were visualized by scanning electron microscopy.

RESULTS

Saline irrigation was ineffective in both groups. In acute infections with 400 μm pores, differences were found with saline versus solution #3 (P = .015) and #4 (P = .015). Solution #4 had the lowest bacterial counts for all pore sizes. For biofilm, irrigation with saline, solutions #1, #2, and #3 inadequately cleared bacteria in all pore sizes. Lower remaining concentrations were observed in #4 with 400μm pores compared to saline (P = .06) and #2 (P = .039). The scanning electron microscopy showed a reduction of biofilm in samples washed with #4.

CONCLUSIONS

Irrigation of infected porous Ti discs with saline, solutions #1 and #2 failed to reduce the bacterial load. The 400 μm discs consistently had more bacteria despite irrigation, highlighting the difficulty of removing bacteria from small pores. Solutions #3 and #4 reduced bacteria acutely, but only #4 demonstrated efficacy in clearing biofilm compared to saline. These results should be considered when treating periprosthetic joint infection in the presence of porous components and the potential presence of biofilm.

Mechanisms and Preventative Strategies for Persistent Pain following Knee and Hip Joint Replacement Surgery: A Narrative Review

Chronic postsurgical pain (CPSP) following total knee arthroplasty (TKA) and total hip arthroplasty (THA) is a prevalent complication of joint replacement surgery which has the potential to decrease patient satisfaction, increase financial burden, and lead to long-term disability. The identification of risk factors for CPSP following TKA and THA is challenging but essential for targeted preventative therapy. Recent meta-analyses and individual studies highlight associations between elevated state anxiety, depression scores, preoperative pain, diabetes, sleep disturbances, and various other factors with an increased risk of CPSP, with differences observed in prevalence between TKA and THA. While the etiology of CPSP is not fully understood, several factors such as chronic inflammation and preoperative central sensitization have been identified. Other potential mechanisms include genetic factors (e.g., catechol-O-methyltransferase (COMT) and potassium inwardly rectifying channel subfamily J member 6 (KCNJ6) genes), lipid markers, and psychological risk factors (anxiety and depression). With regards to therapeutics and prevention, multimodal pharmacological analgesia, emphasizing nonopioid analgesics like acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs), has gained prominence over epidural analgesia. Nerve blocks and local infiltrative anesthesia have shown mixed results in preventing CPSP. Ketamine, an N-methyl-D-aspartate (NMDA)-receptor antagonist, exhibits antihyperalgesic properties, but its efficacy in reducing CPSP is inconclusive. Lidocaine, an amide-type local anesthetic, shows tentative positive effects on CPSP. Selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) have mixed results, while gabapentinoids, like gabapentin and pregabalin, present hopeful data but require further research, especially in the context of TKA and THA, to justify their use for CPSP prevention.

Optimal reimplantation timing in two-stage exchange for periprosthetic joint infection: an observative cohort study in Asian population

BACKGROUND

The optimal timing for reimplantation for periprosthetic joint infection (PJI) has not been established and varies from a few weeks to several months. The aim of this study was to assess the commendable time between implant removal and reimplantation in patients who underwent two-stage exchange arthroplasty for PJI.

METHODS

We retrospectively reviewed 361 patients who were treated with two-stage exchange arthroplasty for hip and knee chronic PJI at our institution between January 2000 and December 2018. Patient characteristics, comorbidities, surgical variables, microbiology data, and time to reimplantation were recorded. All patients were followed for a minimum of one year. Treatment failure was defined by Delphi criteria. Logistic regression analyses were used to calculate survival rates and adjusted odds ratios (ORs) of treatment failure.

RESULTS

In final analysis, 27 (7.5%) had treatment failure. Factors related to treatment failure including interim spacer exchange (OR, 3.13; confidence interval (CI), 1.04-9.09, p = 0.036), higher ESR level at reimplantation (OR, 1.85; CI, 1.05-3.57; p = 0.04), and time to reimplantation (OR, 1.00; CI, 1.003-1.005, p = 0.04). Performing revision arthroplasty surgery from 16 to 20 weeks had highest successful rate. The reimplantation over 24 weeks had a lower successful rate. However, no statistical significance in comparing each interval group.

CONCLUSION

Our study emphasized the importance of timely reimplantation in achieving successful outcomes. Factors such as ESR levels, spacer exchange, and the duration of time to reimplantation influenced the likelihood of treatment failure in two-stage exchange arthroplasty for hip and knee PJI.

Emergency Department Visits Following Patellofemoral Arthroplasty

BACKGROUND

Readmissions are a typical postoperative metric; however, postoperative emergency department (ED) utilization also negatively affects patient care. Few studies have explored this metric after patellofemoral arthroplasty (PFA); thus, we investigated the incidence, timing, predictive factors, and reasons for ED utilization within 90 days after PFA.

METHODS

Using the 2010 to 2021 PearlDiver M151Ortho data set, a national billing claims database containing information of over 151 million US orthopaedic patients across all payer types, the study examined weekly ED visits up to 90 days after PFA and conducted univariate and multivariate analyses to identify predictive factors.

RESULTS

Of 7765 PFA patients, 11.2% (922) had ED visits within 90 days, with 46.7% (431) occurring in the first 3 weeks. Independent predictors of ED utilization included younger age (OR 1.40 per decade decrease), higher Elixhauser Comorbidity Index (OR 1.44 per 2-point increase), surgery in the South or Midwest (OR 1.27 and 1.31), and Medicaid insurance (OR 1.74). Postoperative pain accounted for 50.6% of visits.

CONCLUSIONS

11.2% of PFA patients visited the ED within 90 days, primarily for postoperative pain. Younger, more comorbid, and Medicaid-insured patients were most likely to use the ED. This study suggests the need for targeted perioperative pain management to reduce ED utilization after PFA.

Interest in the combination of antimicrobial therapy for orthopaedic device-related infections due to Enterococcus spp

INTRODUCTION

The objective of this study was to evaluate the management of orthopaedic device-related infections (ODRIs) due to Enterococcus spp.

MATERIALS AND METHODS

We performed a retrospective cohort study in a French tertiary university hospital. Patients with prosthetic joint- or osteosynthesis-associated infections caused by enterococci from 2013 to 2020 were included. Patients who died within 5 days after surgery; who were in palliative care; or who had osteosynthesis of the hand, foot or vertebra were excluded.

RESULTS

Thirty-six patients were included, with 24 in the arthroplasty group and 12 in the osteosynthesis material group. Most infections were polymicrobial (63.9%, n = 23). Debridement, antibiotics and implant retention (DAIR) was performed in 30.6% (n = 11), withdrawal of material in 16.7% (n = 6), one-stage exchange in 30.6% (n = 11) and two-stage exchange in 22.2% of cases (n = 8). The antibiotic regimen was amoxicillin in 41.6% (n = 15), rifampicin in 27.8% (n = 10), linezolid in 25% (n = 9) and/or fluoroquinolones in 30.6% (n = 11). Clinical success at 1 year was 67% (18/27). The only variable statistically associated with a decreased risk of clinical failure was a duration of antibiotic therapy of 12 weeks (p = 0.04). Patients with a lower body mass index and age tended to decrease the risk of clinical failure (p = 0.05 and 0.06 respectively).

CONCLUSIONS

The management of enterococcal ODRIs is complex, and ODRI patients are at high risk for relapse. In our small study, a better outcome was not demonstrated for patients with combination therapy and rifampicin use. Further studies are needed to improve the medico-surgical strategy for treating these infections.

Femoral Neck Fractures in Elderly Patients With Coxarthrosis and High Dislocation: The Application of Conservative Treatment

OBJECTIVE

In this study, our aim was to evaluate the results obtained by conservative treatment of femoral neck fracture in patients with untreated Crowe type 4 coxarthrosis with high dislocation.

METHODS

This was was a retrospective study done at the Orthopaedics and Traumatology Clinic in a secondary care public hospital between 2002 and 2022, in Türkiye. Femur neck fractures were evaluated in six patients who had untreated Crowe type 4 coxarthrosis with high dislocation.

RESULTS

 In the study, we had six patients with undiagnosed developmental dysplasia of the hip (DDH) who suffered femoral neck fractures. The youngest among these patients was 76 years old. Conservative treatment (bed rest, analgesics, non-steroidal anti-inflammatory drugs, and, if needed, opiates and low molecular weight heparin for antiembolic treatment) was found to reduce Harris Hip Score (HHS) and Visual Analogue Scale (VAS) scores significantly (p<0,05). Stage 1 sacral decubitus ulcer occurred in two (33.3%) patients. Patients acquired daily activity capacity similar to their situations before fracture within five to six months. None of the patients suffered embolisms and there was no union in the fracture line of the patients.  Conclusion: Based on our data, we think that conservative treatment is a remarkable option for these patients, as the complication risks are low and positive results can be obtained. Thus, we may conclude that conservative treatment can be considered in femoral neck fractures of elderly patients with DDH.

Clinical Outcomes After Stage-One Antibiotic Coated Molded Hip Spacer

BACKGROUND

Two-stage exchange remains the gold standard for managing periprosthetic joint infection (PJI). We evaluated the outcomes of patients treated with a specific molded articulating antibiotic hip spacer for PJI at a tertiary referral center.

METHODS

An institutional database was retrospectively queried for patients who underwent implantation of spacer between 2009-2019. Patient demographics and clinical outcomes were collected.

RESULTS

We identified 88 patients at an average age of 60.4 years who received a spacer implant, with an average of 4.2 years follow-up (standard deviation [SD] 2.5 years). A total of 34 patients (38.6%) had a "clean" two-stage course with successful reimplantation and no evidence of infection at 1-year follow-up. The remaining patients (61.4%) required 3.67 (±0.52) additional surgeries. Overall reimplantation rate was 72%. Causative bacterial agents included MSSA (n = 22), MRSA (n = 16), coagulase-negative Staphylococcus (n = 14), and polymicrobial (n = 12). Regarding complications, there were 13 (15%) dislocations, 16 (18%) periprosthetic fractures, 8 (9%) bent/fractured stems, and 16 (18%) patients had clinically significant subsidence. Patients with previous extended trochanteric osteotomy (ETO) experienced higher rates of bent/broken spacer stems (25% vs 3.1%; P = .006) periprosthetic fractures (37.5% vs 10.9%; P = .010), and dislocations (37.5% vs 6.2%; P = .001). The rate of infection clearance was lower in the prior ETO cohort (26.6% vs 54.2%; P = .029).

CONCLUSION

We report outcomes in patients who underwent implantation of a specific molded articulating hip spacer at our institution. Infection eradication was roughly in line with published series of hip PJI treatment. There was a high rate of mechanical complications, especially in those patients who required an ETO.

Social Determinants of Health in Total Hip Arthroplasty: Are They Associated With Costs, Lengths of Stay, and Patient Reported Outcomes?

BACKGROUND

Social determinants of health (SDOH) may play a larger role in predicting patient outcomes as outpatient total hip arthroplasty (THA) expands. We specifically examined the association between SDOH and patient metrics (demographics and comorbidities) for: (1) 30-day post-discharge costs of care; (2) lengths of stay (LOS); and (3) patient-reported outcomes (Hip Disability and Osteoarthritis Outcomes Score for Joints Replacement (HOOS JR)).

METHODS

Medicare patients who underwent primary THA between 2018 and 2019 were identified. Those who had complete social determinant data were included (n = 136). Data elements were drawn from institutional, regional, and government databases, as well as the Social Vulnerability Index (SVI). Multiple regression analyses were performed to determine SDOH and baseline comorbidities associations with costs, LOS, and HOOS JR scores.

RESULTS

Various SDOH factors were associated with higher 30-day costs, including residing in a food desert ($53,695 ± 15,485; P < .001) and the following SVI themes: 'Minority Status and Language' ($24,075 ± 9845; P = .01) and 'Housing and Transportation' ($16,190 ± 8501; P = .06), although the latter did not meet statistical significance. Baseline depression was associated with longer LOS (P = .02), while none of the other SDOH or patient metrics affected LOS. No relationships were observed between SDOH and HOOS JR changes from baseline.

CONCLUSION

Patients who live in food deserts and have minority status had higher costs of care after primary THA. Poor housing and transportation may also increase costs, albeit insignificantly. These results highlight the utility of assessing SDOH-related risk factors to optimize post-operative outcomes, with potential implications for bundled care.

Postoperative Infection Rates After Total Ankle Arthroplasty: A Comparison With and Without the Use of a Surgical Helmet System

Following total joint arthroplasty, surgical site infections (SSI) and periprosthetic joint infections (PJI) are associated with increased patient morbidity and healthcare utilization. Current positive-pressure surgical sterile helmet system (SHS) were developed as a feasible, useful version of the body exhaust system.The use of SHS has not yet been proven to decrease infection rates in the orthopedic literature. The primary purpose of this study is to compare the infection rates between patients who underwent total ankle arthroplasty (TAA) with a surgical team wearing SHS versus without SHS.A retrospective chart review in patients undergoing primary TAA with the surgeon wearing SHS (Group 1) or standard surgical attire (Group 2) was conducted. The primary outcome was postoperative SSI and PJI. The rate of wound complications, revision rates, and associated procedures were also analyzed. We identified 109 patients in Group 1 and 151 patients in Group 2. The rate of SSI was 12.8% in Group 1 and 14.6% in Group 2 (p = .411). The rate of PJI was 0.92% in Group 1 and 2.6% in Group 2 (p = .411). There was no difference in revision rates between the two groups. This study suggests that SHS does not appear to protect against postoperative SSI or PJI after TAA. Conversely, we did not find a higher infection rate compared to standard surgical attire despite recent in-vitro studies suggesting SHS as a source of wound contamination. The utility of SHS does not appear to influence the prevalence of postoperative SSI or PJI.

Efficacy of Common Antiseptic Solutions Against Clinically Relevant Planktonic Microorganisms

Prosthetic joint infections (PJIs) are among the most devastating complications after joint replacement. There is limited evidence regarding the efficacy of different antiseptic solutions in reducing planktonic microorganism burden. The purpose of this study was to test the efficacy of different antiseptic solutions against clinically relevant planktonic microorganisms. We designed an experiment examining the efficacy of several antiseptic solutions against clinically relevant planktonic microorganisms in vitro. Regarding planktonic microorganisms, povidone-iodine had 99.9% or greater reduction for all microorganisms tested except for methicillin-resistant Staphylococcus aureus, which was reduced by 60.44%. Irrisept (Irrimax Corp) had 99.9% or greater reduction for all microorganisms except Staphylococcus epidermidis (98.31%) and Enterococcus faecalis (48.61%). Bactisure (Zimmer Surgical Inc) had 99.9% or greater reduction for all microorganisms tested. Various measures exist for PJI prevention, one of which is intraoperative irrigation. We tested irrigants against clinically relevant planktonic microorganisms in vitro and found significant differences in efficacy among them. Further clinical outcome data are necessary to determine whether these solutions can impact PJI in vivo. [Orthopedics. 2022;45(2):122-127.].

Infected hip prosthesis in patient with suspected Covid-19 infection

Background

Infections following arthroplasty are one of the major risks during this type of surgery. Moreover, the outbreak of coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus Disease 2), has developed into an unprecedented pandemic, posing enormous pressure on health-care providers around the world.

Case presentation

Four and half years after right hip arthroplasty, the patient came back to our attention with pain at the same hip. The instrumental examinations showed signs of cup detachment. After carefully analyzing the case, we decided to perform a sterile aspiration of the hip in the operating room under C-arm fluoroscopy. Microbiological examinations showed positivity for E. coli. The patient underwent surgery by which the prosthesis was removed and a spacer was implanted. A therapy with Cefotaxim 2 g three times a day for 6 weeks was then set, and then a total arthroplasty was performed. During this period, the COVID-19 pandemic occurred and therefore the patient received nasal-throat swabbing two times, and both yielded negative results. However, 1 week after the final surgery, his respiratory conditions deteriorated and chest X-ray and CT scan showed images of ground-glass opacification patterns (GGO). Due to the clinical symptoms and the characteristic images of the instrumental examinations, the patient was transferred to an observation ward. Thereafter, two more swab tests gave negative results. The patient was then transferred to the ward for patients with typical symptoms of COVID-19 but with negative swab tests for 2 weeks and was subsequently discharged home.

Conclusion

The purpose of this case report was to point out the correct treatment of a PJI after the outbreak of COVID-19. Despite the ongoing COVID-19 pandemic, the guidelines in the case of periprosthetic hip infection further confirmed the correct management of the patient.

A Retrospective Observational Cohort Study of Periprosthetic Hip Infection Treated by one-stage Method Including Cases With Bone Graft Reconstruction

Purpose:

Prosthetic joint infection (PJI) is a devastating complication that can affect hip arthroplasty. Its treatment is extremely difficult, and issues regarding the optimal treatment remain unanswered. This study intended to show the effectiveness of the one-stage treatment of PJI.

Materials and Methods:

A retrospective observational cohort study performed from July 2014- August 2018. All patients with suspected PJI were included. Major and minor criteria developed by the International Consensus on Periprosthetic Joint Infection (ICPJI) was used to define infection. Laboratory tests and image exams were performed, and all patients were followed for at least 2 years.

Outcomes:

Success rate (2018 ICPJI definition to success) in treatment of PJI using one-stage revision method. Clinical and functional outcomes defined by Harris Hip Score (HHS).

Results:

Thirty-one patients were screened and 18 analyzed. 69.85 ± 9.76 years was the mean age. Mean follow-up time was 63.84 ± 18.55 months. Ten patients had acetabular defects and required bone graft reconstruction. Sixteen patients were classified as Tier 1, 1 as Tier 3D, and as 1 Tier 3E. Almost 90% of patients submitted to one-stage revision with acetabulum graft reconstruction were free of infection. The overall infection survival rate was 78.31±6.34 months. Candida albicans and sinus tract were statistically significant in univariate Cox’s analysis. The predictor of one-stage revision surgery failure that remained final Cox’s regression model was C. albicans (hazard ratio [HR]: 4.47).

Conclusion:

Treatment through one-stage revision surgery associated with 6 months of antimicrobial is a viable option with acceptable results even when bone graft reconstruction is necessary. C. albicans was a strong predictor of failure in this cohort.

Long-Term Outcomes of Staged Revision Surgery for Chronic Periprosthetic Joint Infection of Total Hip Arthroplasty

Periprosthetic joint infection (PJI) is a serious complication of total hip arthroplasty. Staged revision surgery is considered effective in eradicating PJI. We aimed to determine the rate of infection resolution after each stage of staged revision surgery (first stage, repeat first stage, second stage, excision arthroplasty, and reimplantation) and to assess functional outcomes and the mortality rate at ten years in a consecutive series of 30 chronic PJI of total hip arthroplasties. Infection resolution was defined as no clinical nor laboratory evidence of infection at 24 months after the last surgery and after a minimum of 12 months following cessation of antimicrobial treatment. Four patients died within 24 months of their final surgery. Nineteen patients, 73% (worst-case analysis (wca) 63%), were infection free after 1 surgery; 22 patients, 85% (wca 73%), were infection free after 2 surgeries; and 26 patients, 100% (wca 87%), were infection free after three and four surgeries. The median Harris Hip Score was 41 prior to first revision surgery and improved to 74 at twelve months and 76 at ten years after the final surgery. Thirteen patients died at a mean of 64 months from first revision, giving a mortality rate of 43% at ten years, which is approximately 25% higher than that of an age-matched general population. The results show that with repeated aggressive surgical treatment, most PJIs of the hip are curable. Ten years after successful treatment of PJI, functional outcomes and pain are improved and maintained compared to before initial surgery, but this must be balanced against the high 10-year mortality. Level of evidence: cohort studies.

Perioperative Management of Hepatitis C in Patients Undergoing Total Joint Arthroplasty

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A small yet growing subset of total joint arthroplasty (TJA) candidates are diagnosed with the hepatitis C virus (HCV), which is a known risk factor for periprosthetic joint infections. Given the poor outcomes associated with TJA infection, we recommend that candidates with HCV receive treatment prior to elective TJA.

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Interferon and ribavirin have historically been the standard treatment regimen for the management of HCV; however, adverse events and an inconsistent viral response have limited the efficacy of these therapies. The advent of direct-acting antivirals has resolved many of the issues associated with interferon and ribavirin regimens.

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Despite the success of direct-acting antivirals, there are still barriers to seeking treatment for TJA candidates with HCV. Many patients are faced with financial burdens, as insurance coverage of direct-acting antiviral therapies is inconsistent and varies by the patient's state of residence and specific treatment regimen.

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TJA candidates with HCV present health-care providers with a unique set of challenges, often encompassing economic, psychosocial, and complex medical concerns. Multidisciplinary care teams can be beneficial when caring for and optimizing this patient cohort.

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Management of HCV prior to elective TJA is associated with higher up-front costs but ultimately reduces long-term patient morbidity as well as associated direct and indirect health-care expenditures.

Management strategies for prosthetic joint infection: long-term infection control rates, overall survival rates, functional and quality of life outcomes

DAIR (debridement, antibiotics, and implant retention), one-stage and two-stage revision surgery are the most common management strategies for prosthetic joint infection (PJI) management. Our knowledge concerning their efficacy is based on short to medium-term low-quality studies.

Most studies report infection recurrence rates or infection-free time intervals. However, long-term survival rates of the infection-free joints, functional and quality of life outcome data are of paramount importance.

DAIR, one-stage and two-stage revision strategies are not unique surgical techniques, presenting several variables. Infection control rates for the above strategies vary from 75% to 90%, but comparisons are difficult because different indications and patient selection criteria are used in each strategy.

Recent outcome data show that DAIR and one-stage revision in selected patients (based on host, bacteriological, soft tissue and type of infection criteria) may present improved functional and quality of life outcomes and reduced costs for health systems as compared to those of two-stage revision.

It is expected that health system administrators and providers will apply pressure on surgeons and departments towards the wider use of DAIR and one-stage revision strategies. It is the orthopaedic surgeon’s responsibility to conduct quality studies in order to fully clarify the indications and outcomes of the different revision strategies.

Cite this article: EFORT Open Rev 2021;6:727-734. DOI: 10.1302/2058-5241.6.210008

Early, Mid-Term, and Late-Term Aseptic Femoral Revisions After THA: Comparing Causes, Complications, and Resource Utilization

BACKGROUND

Registry data suggest increasing rates of early revisions after total hip arthroplasty (THA). We sought to analyze modes of failure over time after index THA to identify risk factors for early revision.

METHODS

We identified 208 aseptic femoral revision THAs performed between February 2011 and July 2019 using an institutional database. We compared demographics, diagnoses, complications, and resource utilization between aseptic femoral revision THA occurring within 90 days (early), 91 days to 2 years (mid), and greater than 2 years (late) after index arthroplasty.

RESULTS

Early revisions were 33% of revisions at our institution in the time period analyzed. Periprosthetic fractures were 81% of early, 27% of mid, and 21% of late femoral revisions (P < .01). Women were more likely to have early revisions than men (75% vs 53% of mid and 48% of late revisions; P < .01). Patients who had early revisions were older (67.97 ± 10.06) at the time of primary surgery than those who had mid and late revisions (64.41 ± 12.10 and 57.63 ± 12.52, respectively, P < .01). Index implants were uncemented in 99% of early, 96% of mid, and 64% of late revisions (P < .01). Early revisions had longer postoperative length of stay (4.4 ± 3.3) than mid and late revisions (3.0 ± 2.2 and 3.7 ± 2.1, respectively, P = .02). In addition, 58% of early revisions were discharged to an inpatient facility compared with 36% of mid and 41% of late revisions (P = .03).

CONCLUSION

Early aseptic femoral revisions largely occur in older women with uncemented primary implants and primarily due to periprosthetic fractures. Reducing the incidence of periprosthetic fractures is critical to decreasing the large health care utilization of early revisions.

Risk factors for mortality following one-stage septic hip arthroplasty - a case-control study

PURPOSE

Despite good clinical outcomes and a high success rate, there is a comparatively high mortality after one stage septic exchange of total hip arthroplasty. The aim of this study was to identify risk factors for mortality in the hospitalization period after one-stage septic exchange of THA.

METHODS

We retrospectively analyzed in our database all patients who had a one-stage septic exchange for periprosthetic infection of THA and died during hospitalization (n = 33). The control group was matched semi-randomly by surgical procedure (n = 121) who did not die during hospitalization. The two groups were analyzed for risk factors such as age, Charlson Comorbidity Index (CCI), and high-/low-virulence bacteria.

RESULTS

In the deceased group, 16 patients were female and 17 were male with a mean age at surgery of 73.2 years. In the control group, there were 55 females and 66 males with an average age at surgery of 68.2 years. Comparing the two groups, the deceased group had a significantly higher proportion of liver disease as well as higher rate of pulmonary embolism, apoplexy, and/or myocardial infarction, an increased CCI with an average of 6.5 and advanced age. Further demographic and surgery-related parameters especially high- or low-virulent germs were not identified as risk factors for mortality during the hospitalization period. The binominal logistic regression analysis showed that the probability of an inpatient death following one-stage septic exchange of THA increases by a factor of 3.079, with each additional point of the CCI.

CONCLUSION

In conclusion, advanced age and high CCI are the main risk factors for mortality after single-stage septic change of THA. However, high-virulence bacteria have no influence on the mortality during the hospitalization period after one-stage septic exchange of THA.

Active rheumatoid arthritis in a mouse model is not an independent risk factor for periprosthetic joint infection

INTRODUCTION

Periprosthetic joint infection (PJI) represents a devastating complication of total joint arthroplasty associated with significant morbidity and mortality. Literature suggests a possible higher incidence of periprosthetic joint infection (PJI) in patients with rheumatoid arthritis (RA). There is, however, no consensus on this purported risk nor a well-defined mechanism. This study investigates how collagen-induced arthritis (CIA), a validated animal model of RA, impacts infectious burden in a well-established model of PJI.

METHODS

Control mice were compared against CIA mice. Whole blood samples were collected to quantify systemic IgG levels via ELISA. Ex vivo respiratory burst function was measured via dihydrorhodamine assay. Ex vivo Staphylococcus aureus Xen36 burden was measured directly via colony forming unit (CFU) counts and crystal violet assay to assess biofilm formation. In vivo, surgical placement of a titanium implant through the knee joint and inoculation with S. aureus Xen36 was performed. Bacterial burden was then quantified by longitudinal bioluminescent imaging.

RESULTS

Mice with CIA demonstrated significantly higher levels of systemic IgG compared with control mice (p = 0.003). Ex vivo, there was no significant difference in respiratory burst function (p = 0.89) or S. aureus bacterial burden as measured by CFU counts (p = 0.91) and crystal violet assay (p = 0.96). In vivo, no significant difference in bacterial bioluminescence between groups was found at all postoperative time points. CFU counts of both the implant and the peri-implant tissue were not significantly different between groups (p = 0.82 and 0.80, respectively).

CONCLUSION

This study demonstrated no significant difference in S. aureus infectious burden between mice with CIA and control mice. These results suggest that untreated, active RA may not represent a significant intrinsic risk factor for PJI, however further mechanistic translational and clinical studies are warranted.

What is the Level of Evidence Substantiating Commercial Payers' Coverage Policies for Total Joint Arthroplasty?

BACKGROUND

The prevalence of total joint arthroplasty (TJA) in the United States has drawn the attention of health care stakeholders. The payers have also used a variety of strategies to regulate the medical necessity of these procedures. The purpose of this study was to examine the level of evidence of the coverage policies being used by commercial payers in the United States.

METHODS

The references of the coverage policies of four commercial insurance companies were reviewed for type of document, level of evidence, applicability to a TJA population, and success of nonoperative treatment in patients with severe degenerative joint disease.

RESULTS

282 documents were reviewed. 45.8% were primary journal articles, 14.2% were level I or II, 41.2% were applicable to patients who were candidates for TJA, and 9.9% discussed the success of nonoperative treatment in patients who would be candidates for TJA.

CONCLUSION

Most of the references cited by commercial payers are of a lower level of scientific evidence and not applicable to patients considered to be candidates for TJA. This is relatively uniform across the reviewed payers. The dearth of high-quality literature cited by commercial payers reflects the lack of evidence and difficulty in conducting high level studies on the outcomes of nonoperative versus operative treatment for patients with severe, symptomatic osteoarthritis. Patients, surgeons, and payers would all benefit from such studies and we encourage professional societies to strive toward that end through multicenter collaboration.

Cement-in-cement technique of the femoral component in aseptic total hip arthroplasty revision: A systematic review of the contemporary literature

Background

Clinical outcomes of cemented femoral stems revisions using the cement-in-cement technique in aseptic conditions after total hip arthroplasty have been widely described.

Methods

The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried.

Results

Twelve articles were included (620 revision THA). Revision rate for complications related to the femoral side was 1.4% at mid-term follow-up (5.4 years). Periprosthetic femoral fracture rate was 1.1%, aseptic loosening of the femoral component 0.3%.

Conclusions

Cement-in-cement revision technique of the femoral component is associated with a high mid-term success rates (98.6%) and is potentially less challenging than other revision techniques.

Sonication fluid culture of antibiotic-loaded bone cement spacer has high accuracy to confirm eradication of infection before reimplantation of new prostheses

BACKGROUND

Sonication fluid culture of antibiotic-loaded bone cement spacer has been used to predict reinfection of two-stage revision, but its value remains disputable. This study aims to evaluate the association between the culture result of the sonicated spacer and the status of patients with periprosthetic joint infection receiving two-stage revision.

MATERIALS AND METHODS

A comprehensive electronic literature search was performed through four databases including PubMed, Embase/Ovid, and EBSCO, and the Cochrane Library to retrieve studies in which sonication fluid culture of the antibiotic spacer was conducted before reimplantation. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were calculated to assess the association between the culture result of sonicated spacer and prognosis of the two-stage revision.

RESULTS

Eleven eligible studies comprising 603 artificial joints with PJI (134 suffering a clinical failure of two-stage revision) were included in the quantitative analysis. The pooled incidences of positive culture of sonicated spacer and intraoperative tissue were 0.14 (95% confidence interval [CI] 0.08-0.21) and 0.14 (95% CI 0.08-0.20), respectively. A positive culture of sonicated antibiotic-loaded bone cement spacer illustrated moderate sensitivity (0.31, 95% CI 0.13-0.58) but high specificity (0.94, 95% CI 0.86-0.98) for the diagnosis of therapeutic failure of two-stage revision; the pooled DOR was 7.67 (95% CI, 3.63-16.22). Meanwhile, the pooled sensitivity, specificity, and DOR of intraoperative tissue culture during the two-stage revision to predict therapeutic failure were 0.32 (95% CI, 0.20-0.47), 0.96 (95% CI, 0.92-0.98), and 10.62 (95% CI, 4.90-23.01), respectively.

CONCLUSIONS

Sonication fluid culture of antibiotic-loaded bone cement spacer revealed high accuracy for confirming eradication of infection before reimplantation of new prostheses and therefore could be used as a supplement for assessing therapeutic effect for PJI. However, both sonication fluid culture and intraoperative tissue culture from antibiotic-loaded bone cement spacer showed restricted yield for the prediction of a septic failure after the two-stage revision of PJI. Large-scale, prospective studies are still needed to testify current findings.

Is systematic 1-stage exchange a valid attitude in chronic infection of total elbow arthroplasty?

INTRODUCTION

Surgical treatment for chronic infection of total elbow arthroplasty (TEA) generally involves 2-stage exchange. In the lower limb, 1-stage strategies are increasingly implemented, but few cases have been reported for the elbow. We present results in a preliminary series, with the aim of: (1) assessing control of infection in systematic 1-stage exchange for chronic TEA infection, (2) detailing clinical and radiological results, and (3) analyzing intra- and post-operative complications.

HYPOTHESIS

Systematic 1-stage exchange for chronic TEA prosthetic joint infection provides satisfactory control of infection.

MATERIAL AND METHODS

Seven non-selected patients were operated on by 1-stage exchange for chronic infection of TEA during the study period. Two died before the minimum 2 years' follow-up, from causes unrelated to the infection. Thus 5 patients (4 women, 1 man; mean age at surgery, 61 years [range: 48-69 years]) were included for analysis. At a minimum 2 years' follow-up, all underwent clinical examination and elbow X-ray. Infection was monomicrobial in 4 cases and polymicrobial in 1. Isolates comprised Staphylococcus aureus in 40% of cases (2/5), Staphylococcus epidermidis in 60% (3/5) and Staphylococcus Warneri in 20% (1/5). Three patients showed fistula. Three were under immunosuppression/immunomodulation treatment.

RESULTS

At a mean 40 months' follow-up (range: 24-60 months), 4 patients (80%) were free of infection and 1 showed signs of persistent infection. Mean range of flexion-extension was 81° (range: 60-95°) and pronation-supination 128° (range: 80-160°). Mean Mayo Elbow Performance Score was 75 points (range: 65-90). There were 2 intraoperative fractures and 1 neurologic deficit with partial regression.

CONCLUSION

One-stage exchange provided control of infection in 80% of cases, despite cutaneous fistulae or immunosuppression treatment. Clinical results and complications rate were similar to those reported for 2-stage exchange.

LEVEL OF EVIDENCE

IV; retrospective study without control group.

Efficacy of common antiseptic solutions against clinically relevant microorganisms in biofilm

AIMS

Periprosthetic joint infections (PJIs) are among the most devastating complications after joint arthroplasty. There is limited evidence on the efficacy of different antiseptic solutions on reducing biofilm burden. The purpose of the present study was to test the efficacy of different antiseptic solutions against clinically relevant microorganisms in biofilm.

METHODS

We conducted an in vitro study examining the efficacy of several antiseptic solutions against clinically relevant microorganisms. We tested antiseptic irrigants against nascent (four-hour) and mature (three-day) single-species biofilm created in vitro using a drip-flow reactor model.

RESULTS

With regard to irrigant efficacy against biofilms, Povidone-iodine treatment resulted in greater reductions in nascent MRSA biofilms (logarithmic reduction (LR) = 3.12; p < 0.001) compared to other solutions. Bactisure treatment had the greatest reduction of mature Pseudomonas aeruginosa biofilms (LR = 1.94; p = 0.032) and a larger reduction than Vashe or Irrisept for mature Staphylococcus epidermidis biofilms (LR = 2.12; p = 0.025). Pooled data for all biofilms tested resulted in Bactisure and Povidone-iodine with significantly greater reductions compared to Vashe, Prontosan, and Irrisept solutions (p < 0.001).

CONCLUSION

Treatment failure in PJI is often due to failure to clear the biofilm; antiseptics are often used as an adjunct to biofilm clearance. We tested irrigants against clinically relevant microorganisms in biofilm in vitro and showed significant differences in efficacy among the different solutions. Further clinical outcome data is necessary to determine whether these solutions can impact PJI outcome in vivo. Cite this article: Bone Joint J 2021;103-B(5):908-915.

The Cost-Effectiveness of Silver-Impregnated Occlusive Dressings for Infection Prevention After Total Joint Arthroplasty

BACKGROUND

Prosthetic joint infection (PJI) is a catastrophic complication after total joint arthroplasty that exacts a substantial economic burden on the health-care system. This study used break-even analysis to investigate whether the use of silver-impregnated occlusive dressings is a cost-effective measure for preventing PJI after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA).

METHODS

Baseline infection rates after TKA and THA, the cost of revision arthroplasty for PJI, and the cost of a silver-impregnated occlusive dressing were determined based on institutional data and the existing literature. A break-even analysis was then conducted to calculate the minimal absolute risk reduction needed for cost-effectiveness.

RESULTS

The use of silver-impregnated occlusive dressings would be economically viable at an infection rate of 1.10%, treatment costs of $25,692 for TKA PJI, and $31,753 for THA PJI and our institutional dressing price of $38.05 if it reduces infection rates after TKA by 0.15% (the number needed to treat [NNT] = 676) and THA by 0.12% (NNT = 835). The absolute risk reduction needed to maintain cost-effectiveness did not change with varying initial infection rates and remained less than 0.40% (NNT = 263) for infection treatment costs as low as $10,000 and less than 0.80% (NNT = 129) for dressing prices as high as $200.

CONCLUSION

The use of silver-impregnated occlusive dressings is a cost-effective measure for infection prophylaxis after TKA and THA.

Delayed neutrophil recruitment allows nascent Staphylococcus aureus biofilm formation and immune evasion

Biofilms that form on implanted medical devices cause recalcitrant infections. The early events enabling contaminating bacteria to evade immune clearance, before a mature biofilm is established, are poorly understood. Live imaging in vitro demonstrated that Staphylococcus aureus sparsely inoculated on an abiotic surface can go undiscovered by human neutrophils, grow, and form aggregates. Small (~50 μm²) aggregates of attached bacteria resisted killing by human neutrophils, resulting in neutrophil lysis and bacterial persistence. In vivo, neutrophil recruitment to a peritoneal implant was spatially heterogenous, with some bacterial aggregates remaining undiscovered by neutrophils after 24 h. Intravital imaging in mouse skin revealed that attached S. aureus aggregates grew and remained undiscovered by neutrophils for up to 3 h. These results suggest a model in which delayed recruitment of neutrophils to an abiotic implant presents a critical window in which bacteria establish a nascent biofilm and acquire tolerance to neutrophil killing.

Next generation sequencing for pathogen detection in periprosthetic joint infections

Periprosthetic joint infections (PJI) represent one of the most catastrophic complications following total joint arthroplasty (TJA). The lack of standardized diagnostic tests and protocols for PJI is a challenge for arthroplasty surgeons.Next generation sequencing (NGS) is an innovative diagnostic tool that can sequence microbial deoxyribonucleic acids (DNA) from a synovial fluid sample: all DNA present in a specimen is sequenced in parallel, generating millions of reads. It has been shown to be extremely useful in a culture-negative PJI setting.Metagenomic NGS (mNGS) allows for universal pathogen detection, regardless of microbe type, in a 24-48-hour timeframe: in its nanopore-base variation, mNGS also allows for antimicrobial resistance characterization.Cell-free DNA (cfDNA) NGS, characterized by lack of the cell lysis step, has a fast run-time (hours) and, together with a high sensitivity and specificity in microorganism isolation, may provide information on the presence of antimicrobial resistance genes.Metagenomics and cfDNA testing have reduced the time needed to detect infecting bacteria and represent very promising technologies for fast PJI diagnosis.NGS technologies are revolutionary methods that could disrupt the diagnostic paradigm of PJI, but a comprehensive collection of clinical evidence is still needed before they become widely used diagnostic tools. Cite this article: EFORT Open Rev 2021;6:236-244. DOI: 10.1302/2058-5241.6.200099.

Methods and probability of success after early revision of prosthetic joint infections with debridement, antibiotics and implant retention

Prosthetic joint infection (PJI) is a rare-and dreaded-complication of arthroplasty requiring multidisciplinary care. Given the dual goal of treating the infection and maintaining satisfactory function, it is preferable to determine how and when the implanted components can be retained. Bacteria and fungi organize themselves into biofilms that shield them from antibiotics and the immune system. This biofilm is in place after 15 days of active infection. Some antibiotics have a better activity on biofilms. The following factors have a negative impact on the probability of a successful debridement, antibiotics and implant retention (DAIR) intervention: fracture or revision, use of cement, bacteremia, kidney and/or liver failure, immunosuppression and elevated CRP. Hematogenous infections have a worse prognosis than early postoperative infections. Using a decision algorithm increases the chances of DAIR being successful. The KLIC score applies to early postoperative infections (<4 weeks postoperative and<3 weeks from the first signs) while the CRIME-80 score applies to hematogenous infections (<3 weeks from the first signs). Arthroscopic treatments have no role here, whereas DAIR through an arthrotomy is well standardized. Wide spectrum antibiotic therapy, secondarily adapted to the causative microorganism, is indicated for a total of 3 months. The results against the infection are mixed, although following a decision algorithm resolves the infection in about 75% of cases. The functional outcomes and quality of life are close to those of patients who have undergone primary joint replacement. It is not recommended to carry out a second DAIR if the first one fails. It is logical to apply the principles set out for the hip and knee to other joint replacements, and to use the same algorithm. For the upper limb, and especially for reverse shoulder arthroplasty, one must be careful about Cutibacterium acnes infections as they are hard to diagnose. Surgeons should not hesitate to contact a referral center for any PJI, although it is preferable that early infections be treated at the facility that performed the implantation.

Dair approach in 7 infected total hip arthroplasties: our experience and current concepts of the literature

INTRODUCTION

Periprosthetic joint infection (PJI) is one of the most challenging complications following total hip arthroplasty. In early infection, within four to twelve weeks from surgery, debridement, antibiotics and implant retention (DAIR) can be the initial treatment. The aim of this study is to report our case series and review current concepts reported in the literature about this topic.

MATERIALS AND METHODS

This was an observational cohort study that included 7 patients managed with DAIR for PJI following primary total hip replacement (THR) between 2014 and 2020. Inclusion criteria were a primary THR, direct anterior or lateral approach, DAIR procedure, and PJI. Exclusion criteria were a PJI following a revision total hip replacement or hemiarthroplasty, posterolateral approach, 1-stage revision, 2-stage revision, and Girdlestone procedure without prior DAIR. For each patient demographic characteristics, laboratory values, microorganisms involved, antibiotic therapy and outcome at one-year follow-up were registered.

RESULTS

The mean duration between THR and DAIR was 19 days. In all cases only one DAIR procedure was performed. Most infections were caused by Staphylococcus aureus (4 cases) [one methicillin resistant (MRSA)]. The other infections were caused by Streptococcus agalactiae, Staphylococcus coagulase negative and Escherichia coli. At the final follow-up, the procedure was considered as successful in 6 out of 7 patients (85%). The one with unsuccessful outcome underwent to a two-stage revision.

DISCUSSION

Our results were comparable with those of a recent systematic review of the literature. Factors that have been postulated to influence the outcome of DAIR in the management of PJIs include the timing and numbers of debridement, the exchange of components, the responsible microorganism and the duration of antibiotic treatment. In conclusion, the outcomes following DAIR are better as the indications are refined and risk factors identified. PJI prevention remains the key but the current literature still lacks well documented and effective PJI prevention protocols. (www.actabiomedica.it).

Reducing Dislocations of Antibiotic Hip Spacers via Hybrid Cement-screw Constrained Liner Fixation: A Case Series

Purpose

Infection following total hip arthroplasty is a challenging and devastating complication. In two-stage revision arthroplasty, antibiotic spacers, although efficacious, can be associated with an unacceptable rate of mechanical complications (e.g., fracture, dislocation). This series describes 15 patients with infected total hip prostheses treated with hybrid cement-screw fixation constrained liner antibiotic spacers to enhance stability and minimize mechanical complications.

Materials and Methods

All patients with an infected hip prosthesis undergoing two-stage revision arthroplasty at a single academic medical center were identified and screened for inclusion. Clinical and radiographic data including patient demographics and outcome measures were collected and retrospectively analyzed.

Results

Two patients died of unrelated causes at an average of 6-week postoperatively. Infections in the remaining thirteen patients (100%) were successfully eradicated; all underwent uncomplicated revision arthroplasty at a mean duration of 99.5 days after the placement of the antibiotic spacer. No dislocations, fractures, or other mechanical failures of any spacer were observed in this series.

Conclusion

The hybrid cement-screw fixation technique for constrained liner antibiotic spacers is a reliable and effective treatment method for eradicating prosthetic joint infections without mechanical complications.

Antibiotic therapy alone does not have a high success rate in cases of unexpected positive cultures in intraoperative samples from hip and knee prosthesis revision

BACKGROUND

Unexpectedly positive bacterial cultures during prosthesis revision surgery still occur on occasion despite good preoperative diagnostics. In such cases a six-week antibiotic therapy without further surgical intervention is recommended. The aim of this study was to find out how successful this procedure is.

METHODS

In a study of 508 patients, who required revision surgery of total hip (THA, n = 231) or knee arthroplasties (TKA, n = 277) because of component loosening, biopsy was carried out before their surgery. The collected tissue samples (5) from the biopsy and the revision surgery procedure itself were analyzed according the criteria of the International Consensus Meeting (ICM). Tests revealed 11 patients (7 THA, 4 TKA) with unexpectedly positive bacterial cultures from tissue samples obtained during the revision surgery due to false negative preoperative diagnostic results. These 11 patients were treated with 6 weeks antibiotic therapy and examined with a follow-up of at least 2 years (42.2 ± 16.5 months).

RESULTS

Five patients (2 TKA, 3 THA) became reinfected, resulting in a success rate of 54.5%.

CONCLUSION

Antibiotic therapy alone of an unexpected positive intraoperative bacterial culture in prosthesis revision surgery seems to be less successful than previously assumed.

A Treatment Pathway Variation for Chronic Prosthesis-Associated Infections

Periprosthetic joint infections (PJIs) are relatively rare but are on the rise because of the increasing total number of implantations performed. Treatment of PJI remains individualized and involves both surgical and medical treatment, with variations depending on the time of implantation, the duration and severity of the infection, tissue damage, and the underlying microorganism. In this case series study, we investigated clinical and functional outcomes of a variation of the Liestal algorithm in patients with PJI following total hip arthroplasty.

METHODS

This study included 32 patients (33 cases) who were treated for chronic PJI with 2-stage exchange using a cement spacer during the period of 2003 to 2014. In contrast to other treatment pathways, antibiotic therapy was targeted to the causative microorganism as early as possible despite the presence of a cement spacer. Second-look surgery was performed 4 days after removal of the primary implant and a 4-week antibiotic-free window was interposed before definitive reimplantation. Thereafter, antibiotic treatment continued for approximately 6 weeks. All patients were followed for a minimum of 2 years. Parameters investigated were the duration of infection-free survival, functional outcome, and epidemiological data.

RESULTS

At 2 years of follow-up and at the most recent follow-up (on average, 7 years after reimplantation), 100% of the patients were free of signs of infection, and the mean Harris hip score (HHS) was 89 at the latest follow-up.

CONCLUSIONS

A meticulously performed 2-stage exchange for PJI with early targeted antibiotic treatment, second-look surgery, an antibiotic-free window before reimplantation, and antibiotic treatment post-reimplantation of medium duration is associated with excellent infection-related and good functional outcome after ≥2 years of follow-up even in cases of chronic PJI.

LEVEL OF EVIDENCE

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

Debridement, antibiotic pearls, and retention of the implant in the treatment of infected total hip arthroplasty

In this article the authors describe a modified surgical technique developed to enhance the classical irrigation and debridement procedure to improve the possibilities of retaining a total hip arthroplasty (THA) undergoing acute periprosthetic joint infection (PJI). This technique, debridement antibiotic pearls and retention of the implant (DAPRI), aims to remove the intra-articular biofilm allowing a higher and prolonged local antibiotic concentration by using calcium sulphate antibiotic-added beads. The combination of 3 different surgical techniques (tumour-like synovectomy, Argon Beam application and chlorhexidine gluconate brushing) might enhance the disruption and removal of the bacterial biofilm which is the main responsible of antibiotics and antibodies resistance. The timing of the diagnosis (6 weeks from the original surgery or 1 week from clinical symptoms appearance in the case of an hematogenous infection) and the preoperative isolation of the germ are fundamental in order to obtain a satisfactory outcome. A 12-week course of postoperative antibiotic therapy (6 weeks I.V. and 6 weeks oral) complete the postoperative protocol used by the authors.The DAPRI technique might represent a safe and more conservative treatment for acute and early hematogenous PJI.

The stability of carbapenems before and after admixture to PMMA-cement used for replacement surgery caused by Gram-negative bacteria

Background

Prosthetic joint infection (PJI) is a serious complication of orthopedic implant surgery. Treatment often includes the use of an antibiotic-loaded Polymethyl methacrylate (PMMA) bone cement spacer. Several antibiotics are commonly used for the preparation of these spacers, but due to the increasing number of infections with resistant Gram-negative bacteria, there is a need for the use of carbapenem antibiotics such as meropenem and imipenem as drugs of last resort. Unfortunately, the reaction heat generated during the preparation of the bone cement can be a major problem for the stability of these antibiotics. In the present study, the stability of meropenem and imipenem was tested before and after the admixture to PMMA bone cements.

Methods

High-performance liquid chromatography with ion-pairing reversed-phase separation and spectrophotometric detection was used for analysis. Stability tests with meropenem and imipenem were performed with antibiotics in solution and solid form at different temperatures (37 °C, 45 °C, 60 °C, 90 °C) and times (30 min, 60 min, 120 min). To test the stability of both antibiotics in PMMA after exposure to the reaction heat during polymerization, three different bone cements were used to generate specimens that contained defined amounts of antibiotics. Reaction heat was measured. The form bodies were mechanically crushed and aliquots were dissolved in ethyl acetate. Samples were prepared for HPLC DAD analysis.

Results

Meropenem and imipenem showed the highest degradation levels after heat stressed in solution, with maximum levels of 75% and 95%, respectively. In solid form, degradation levels decreased dramatically for meropenem (5%) and imipenem (13%). Stability tests of both carbapenems in bone cement showed that they remained largely stable during PMMA polymerization, with retrieved amounts of about 70% in Palacos^® R and Copal^® G+V, and between 80 and 90% in Copal^® spacem.

Conclusions

In contrast to the results of meropenem and imipenem in solution, both antibiotics remain stable in solid form and mostly stable in the cement after PMMA polymerization. The low degradation levels of both antibiotics after exposure to temperatures > 100 °C allow the conclusion that they can potentially be used for an application in PMMA cements.

Two-stage revision arthroplasty in the treatment of periprosthetic hip infections with severe bone loss: Results from 182 cases

The optimum treatment for periprosthetic joint infection (PJI) of the hip with substantial bone defects remains controversial. A retrospective assessment was performed for 182 patients treated for PJI with a two-stage protocol from 2005 to 2015. Implant removal and debridement were followed by Girdlestone arthroplasty or spacer implantation. The results of the Girdlestone and spacer groups were compared. There were 71 cases that received spacers, and 111 Girdlestone procedures were performed. After the first stage, 26.37% of cultures were negative, and among patients with a detected pathogen, methicillin-sensitive Staphylococcus aureus was the most common organism (41.79%). Acetabular and femoral bone defects, according to the Paprosky classification, were more severe in the Girdlestone group (P<0.05). During the follow-up (mean, 5.95 years), the overall incidence of complications was 21.42%. The mean Harris hip score was significantly lower in the Girdlestone group (68.39 vs 77.79; P<0.0001). The infection recurrence rate reached 8.79%. Despite satisfactory infection control, the number of complications and poor functional outcomes associated with resection arthroplasty indicate the necessity for development of different approaches for patients with advanced bone loss.

The cement-in-cement technique is a reliable option in hip arthroplasty revision surgery: a systematic review

INTRODUCTION

The cement-in-cement technique for revision hip arthroplasty has many potential advantages and has recently gained widespread interest but still lacks evidence to support it. Our aim was to examine the surgical and patient-reported outcomes after cement-in-cement revision hip arthroplasty.

MATERIALS AND METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and EMBASE databases were searched up to February 2019 for original studies reporting the outcomes of revision hip arthroplasty surgeries using the cement-in-cement technique. The methodological quality was assessed using the methodological index for non-randomized studies scale.

RESULTS

Sixteen non-comparative studies met the eligibility criteria, comprising 1899 hips in 1856 patients (72.2 mean age, 37% male), with a mean follow-up of 7.2 years. Most studies reported only primary revisions and focused on the stem component. Intraoperative complications such as femoral or acetabular fractures (5.3%) were low and easily manageable with no relevant sequelae, as were dislocation rates (2.8% of uncomplicated events and 1.6% of cases requiring re-revision). Failure (considered if there was aseptic loosening of the cement-in-cement revised component, 2%), re-revision (9.3%), implant survival and late complication rates were favourable. Functional patient-reported outcomes showed an overall improvement above the minimal clinically important difference at final follow-up.

CONCLUSION

The cement-in-cement technique is a viable option for hip arthroplasty revision surgery with low intraoperative and late complication rates, dislocations and immediate post-operative morbidity, resulting in good functional patient-reported outcomes and favourable medium-term implant survival.

Unintended Retention of Temporary Articulating Spacers in the Treatment of Periprosthetic Hip Joint Infection

A considerable number of patients who underwent a 2-stage exchange protocol for periprosthetic hip joint infection could not complete the second-stage reimplantation. The aim of this study was to evaluate the results of unintended retention of temporary articulating spacers for the treatment of periprosthetic hip joint infection. Ninety-four patients with infection after total hip arthroplasty were treated by using a 2-stage exchange protocol with temporary articulating spacers. Of the 94 patients, 35 did not complete the 2-stage exchange protocol and retained spacers for more than 12 months. The authors retrospectively investigated the clinical and radiographic results after a mean follow-up of 36.1 months. Thirty-one patients had well-healed wounds without recurrent infection and did not receive further surgery for any reason (success group). Spacers were revised in 2 patients, and the other 2 patients underwent incision and debridement because of recurrent infection (failure group). There were no statistical differences between the 2 groups in terms of demographics or presence of resistant organisms. After 3 years of follow-up, temporary articulating spacers functioned well in 89% of the patients who retained them. These results support that retention of temporary articulating spacers could be considered an alternative treatment option for select patients. [Orthopedics. 2020;43(4):e251-e257.].

Difficult-to-treat pathogens significantly reduce infection resolution in periprosthetic joint infections

Periprosthetic joint infection (PJI) is a feared complication after arthroplasty. Our hypothesis was that PJI caused by difficult-to-treat (DTT) pathogens has a worse outcome compared with non-DTT PJI. Routine clinical data on 77 consecutive patients with confirmed PJI treated with 2-stage exchange arthroplasty were placed in DTT and non-DTT PJI groups and analyzed. The main outcome variable was that the patient was definitively free of infection after 2 years. We found definitive infection resolution in 31 patients in the DTT group (68.9%) and 28 patients (87.5%) in the non-DTT group (P < 0.05). The necessity for revision surgery until assumed resolution of infection was significantly more frequent in the DTT group with 4.72 ± 3.03 operations versus 2.41 ± 3.02 operations in the non-DTT group (P < 0.05). PJI caused by DTT bacteria is associated with significantly higher numbers of revision operations and significantly inferior definitive infection resolution.

Increased periprosthetic hip and knee infection projected from 2014 to 2035 in Taiwan

BACKGROUND

Periprosthetic joint infection (PJI) is a disastrous complication associated with hip and knee arthroplasty. The literature suggests that the economic consequences associated with treating PJI are substantial. Our study aimed to investigate the past trends of PJI rates, and to estimate the projected number of PJI cases, consequent bed-day requirements, and medical expenses in Taiwan up to year 2035.

METHODS

A nationwide epidemiological study was conducted using the inpatient database of the Bureau of National Health Insurance from 2004 through 2013. Patients with the International Classification of Disease-Clinical Modification, ninth revision (ICD9-CM) code 99,666 (PJI) who had received surgical treatment including debridement, removal of hip or knee prosthesis, or revision of total hip/knee arthroplasty (THA/TKA) were identified. Projections were performed with Poisson regression on historical incidence rates in combination with projections of arthroplasty numbers from 2014 to 2035.

RESULTS

A total of 4935 hip (1871) and knee (3064) PJIs were identified between 2004 and 2013. The rates of PJI were 2.46% for hip arthroplasty and 1.63% for knee arthroplasty. The number of PJIs was expected to increase markedly with time from 728 in 2013 to 3542 in 2035 (a 4.87-fold increase). The bed-day requirements for treating PJI was 17,205 in 2013 and is expected to be 82,509 bed-days in 2035 (a 4.79-fold increase). The total hospitalization cost will increase 4.86-fold by 2035.

CONCLUSIONS

The number of PJI cases is increasing rapidly due to the increasing numbers of arthroplasty surgery and the cumulative number of latent infection. This may place a large economic burden on the health care system.

The economic impact of periprosthetic infection in total hip arthroplasty

Background

Periprosthetic joint infection (PJI) is the third leading cause of total hip arthroplasty (THA) failure. Although controversial, 2-stage revision remains the gold standard treatment for PJI in most situations. To date, there have been few studies describing the economic impact of PJI in today’s health care environment. The purpose of the current study was to obtain an accurate estimate of the institutional cost associated with the management of PJI in THA and to assess the economic burden of PJI compared with primary uncomplicated THA.

Methods

We conducted a review of primary THA cases and 2-stage revision THA for PJI at our institution. Patients were matched for age and body mass index. All costs associated with each procedure were recorded. Descriptive statistics were used to summarize the collected data. Mean costs, length of stay, clinic visits and readmission rates associated with the 2 cohorts were compared.

Results

Fifty consecutive cases of revision THA were matched with 50 cases of uncomplicated primary THA between 2006 and 2014. Compared with the primary THA cohort, PJI was associated with a significant increase in mean length of hospital stay (26.5 v. 2.0 d, p < 0.001), mean number of clinic visits (9.2 v. 3.8, p < 0.001), number of readmissions (12 v. 1, p < 0.001) and average overall cost (Can$38 107 v. Can$6764, t = 8.3, p < 0.001).

Conclusion

Treatment of PJI is a tremendous economic burden. Our data suggest a 5-fold increase in hospital expenditure in the management of PJI compared with primary uncomplicated THA.

Risk factors, diagnosis and management of prosthetic joint infection after total hip arthroplasty

Introduction: Although a relatively rare complication, the incidence and prevalence of prosthetic joint infection (PJI) is certainly rising. This is mainly due to the number of arthroplasties performed each year and our ability to capture more cases. There is currently no consensus in the optimal diagnosis and management of the infected total hip arthroplasty. Various management techniques have been described in literature.Areas covered: We discuss and summarize the literature in diagnosing prosthetic joint infection (PJI) including next-generation sequencing. An in-depth critical analysis of the biomarkers and the novel tests available in the market is reviewed including the evolving nature of the diagnostic criteria for PJI. The key issues in managing infected THA are identified.Expert commentary: The senior authors' expert opinion on diagnostic criteria is discussed. We also stress the importance of tissue/fluid analysis of microbiology and histology being key to diagnosis of PJI. The indications of one-stage versus two-stage revision arthroplasty is examined, including techniques for successful one-stage revision.

Efficacy and Cost-effectiveness of Topical Vancomycin Powder in Primary Cementless Total Hip Arthroplasty

Topical vancomycin has been shown to effectively reduce infections after spinal surgery while remaining safe and cost-effective; however, there are few studies evaluating topical vancomycin in total hip arthroplasty. The authors hypothesized that the incidence of periprosthetic joint infection would decrease with the use of topical vancomycin in total hip arthroplasty and that topical vancomycin would be cost-effective. A retrospective patient chart review was performed to evaluate consecutive primary cementless total hip arthroplasties performed in the authors' hospital system between April 2015 and December 2016. Demographic data were collected. Periprosthetic joint infection was defined by Musculoskeletal Infection Society criteria. Statistical analysis included t test, Fisher's exact test, and logistic regression. The costs of vancomycin and postoperative infection were used to determine the absolute risk reduction (1/number needed to treat) threshold needed for topical vancomycin to be cost-effective. In this study, 309 patients (55.7%) undergoing total hip arthroplasty were treated with topical vancomycin, and 246 patients (44.3%) did not receive treatment. There were 2 infections in the vancomycin group (0.6% incidence), and 4 in the no vancomycin group (1.6% incidence). There was no statistical difference in infection rate between the 2 cohorts (P=.414). The absolute risk reduction was 0.98%, and the number needed to treat with topical vancomycin was 102 patients to prevent 1 periprosthetic joint infection. Topical vancomycin ($12 per vial) resulted in an expected cost savings of $904 per patient. Topical vancomycin is inexpensive and cost-effective. Although not statistically significant, the topical vancomycin group had a 60% lower incidence of infection. Further research regarding appropriate prophylactic topical and intravenous antibiotic use is needed prior to widespread adoption. [Orthopedics. 2019; 42(5):e430-e436.].

Health state utilities associated with post-surgical Staphylococcus aureus infections

INTRODUCTION

Surgical site infections (SSIs) are among the most common and potentially serious complications after surgery. Staphylococcus aureus is a virulent pathogen frequently identified as a cause of SSI. As vaccines and other infection control measures are developed to reduce SSI risk, cost-utility analyses (CUA) of these interventions are needed to inform resource allocation decisions. A recent systematic review found that available SSI utilities are of "questionable quality." Therefore, the purpose of this study was to estimate the disutility (i.e., utility decrease) associated with SSIs.

METHODS

In time trade-off interviews, general population participants in the UK (London, Edinburgh) valued health states drafted based on literature and clinician interviews. Health states described either joint or spine surgery, with or without an SSI. The utility difference between otherwise identical health states with and without the SSI represented the disutility associated with the SSI.

RESULTS

A total of 201 participants completed interviews (50.2% female; mean age = 46.2 years). Mean (SD) utilities of health states describing joint and spine surgery without infections were 0.79 (0.23) and 0.78 (0.23). Disutilities of SSIs ranged from - 0.03 to - 0.32, depending on severity of the infection and subsequent medical interventions. All differences between corresponding health with and without SSIs were statistically significant (all p < 0.001).

CONCLUSION

The preference-based SSI disutilities derived in this study may be used to represent mild and serious SSIs in CUAs assessing and comparing the value of vaccinations that may reduce the risk of SSIs.

What Are the Indications for One-Stage Versus Two-Stage Exchange Arthroplasty in Management of the Infected Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

Two-stage exchange arthroplasty is recommended in the majority of cases following infected TAA. One-stage arthroplasty is only indicated in a limited patient population with acute infection, preoperatively identified low-virulence organisms, and low-risk patient factors.

LEVEL OF EVIDENCE

Consensus.

DELEGATE VOTE

Agree: 92%, Disagree: 8%, Abstain: 0% (Super Majority, Strong Consensus).

Enhancing biology and providing structural support for acetabular reconstruction in single-stage revision for infection

Background

Reconstruction of combined segmental and cavitary defects of the acetabulum is a challenge to the hip surgeon. One question regards the efficacy of reconstruction of acetabular defects using a combination of tantalum metal augments (TMAs) and impaction graft in single-stage revision for periprosthetic infection.

Materials and methods

In the period between July 2009 and August 2014, 24 patients with combined segmental and cavitary acetabular defects and Paprosky classification grade IIB, IIC, and IIIA had hips reconstructed using the combination of TMAs and antibiotic-loaded impaction grafting. A similar group of 30 patients who received single-stage revision without metal augments were identified and taken as control. All patients received a polyethylene cemented cup and long cementless (Wagner SL) stem. Patients were prospectively evaluated using the modified Harris Hip Score (HHS) in addition to radiological evaluation at 3, 6, and 12 months then annually thereafter.

Results

At an average follow-up period of 4 years (range 2–7 years), all but one patient in the study group were free of infection, indicating a 96% success rate. This rate of eradicating infection was comparable to the 97% success rate in the control group. All metal augments were stable, and good incorporation of the impacted bone graft was observed. The HHS improved significantly from 27 preoperatively to 83 postoperatively (P < 0.001).

Conclusion

Metal augments can convert massive acetabular defects to a more contained defect suitable for grafting. The combination of tantalum augments that provide strong structural support and antibiotic-loaded allograft is successful in the mid-term in single-stage revisions for infection.

Level of evidence

Level IV (prospective case series).

Zirconium Nitride Coating Reduced Staphylococcus epidermidis Biofilm Formation on Orthopaedic Implant Surfaces: An In Vitro Study

BACKGROUND

One of the most commonly identified pathogens responsible for orthopaedic implant infection is Staphylococcus epidermidis, which can form biofilms on surfaces. Currently, orthopaedic implants made of various surface materials are available, each with features influencing osseointegration, biocompatibility, and adherence of bacteria to the surface, which is the first step in biofilm formation. The aim of this experimental study was to investigate the effect of a high tribologic-resistant 2.5-µm zirconium nitride top coat on an antiallergic multilayer ceramic-covered cobalt-chromium-molybdenum surface on the formation of S. epidermidis biofilm compared with other commonly used smooth and rough orthopaedic implant surface materials.

QUESTIONS/PURPOSES

(1) When evaluating the surfaces of a cobalt-chromium-molybdenum (CoCrMo) alloy with a zirconium (Zr) nitride coating, a CoCrMo alloy without a coating, titanium alloy, a titanium alloy with a corundum-blasted rough surface, and stainless steel with a corundum-blasted rough surface, does a Zr coating reduce the number of colony-forming units of S. epidermidis in an in vitro setting? (2) Is there quantitatively less biofilm surface area on Zr-coated surfaces than on the other surfaces tested in this in vitro model?

METHODS

To determine bacterial adhesion, five different experimental implant surface discs were incubated separately with one of 31 different S. epidermidis strains each and subsequently sonicated. Twenty test strains were obtained from orthopaedic patients undergoing emergency hip prosthesis surgeries or revision of implant infection and 10 further strains were obtained from the skin of healthy individuals. Additionally, one reference strain, S. epidermidis DSM 3269, was tested. After serial dilutions, the number of bacteria was counted and expressed as colony-forming units (CFUs)/mL. For biofilm detection, discs were stained with 0.1% Safranin-O for 15 minutes, photographed, and analyzed with computer imaging software.

RESULTS

The lowest bacterial count was found in the CoCrMo + Zr surface disc (6.6 x 10 CFU/mL ± 4.6 x 10 SD) followed by the CoCrMo surface (1.1 x 10 CFU/mL ± 1.9 x 10 SD), the titanium surface (1.36 x 10 CFU/mL ± 1.8 x 10 SD), the rough stainless steel surface (2.65 x 10 CFU/mL ± 3.8 x 10 SD), and the rough titanium surface (2.1 x 10 CFU/mL ± 3.0 x 10 SD). The mean CFU count was lower for CoCrMo + Zr discs compared with the rough stainless steel surface (mean difference: 2.0 x 10, p = 0.021), the rough titanium alloy surface (mean difference: 1.4 x 10, p = 0.002), and the smooth titanium surface (mean difference: 7.0 x 10, p = 0.016). The results of biofilm formation quantification show that the mean covered area of the surface of the CoCrMo + Zr discs was 19% (± 16 SD), which was lower than CoCrMo surfaces (35% ± 23 SD), titanium alloy surface (46% ± 20 SD), rough titanium alloy surface (66% ± 23 SD), and rough stainless steel surface (58% ± 18 SD).

CONCLUSIONS

These results demonstrate that a multilayer, ceramic-covered, CoCrMo surface with a 2.5-µm zirconium nitride top coat showed less S. epidermidis biofilm formation compared with other surface materials used for orthopaedic implants.

CLINICAL RELEVANCE

CoCrMo with a 2.5-µm zirconium nitride top coat seems to be a promising surface modification technology able to reduce bacterial attachment on the surface of an implant and, hence, may further prevent implant infection with S. epidermidis biofilm formation.