Septic versus aseptic hip revision: how different?

Diagnosis and Treatment Influence Hospital Costs of Revision Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis aimed to synthesize the hospital costs of revision total hip arthroplasty (rTHA) by periprosthetic joint infection, periprosthetic fracture (PPF), aseptic loosening, and recurrent dislocation diagnoses. In addition, as several surgical options are available within some diagnoses, this study aimed to synthesize the evidence on hospital costs for septic rTHA between debridement, antibiotics, and implant retention and one-stage and two-stage rTHA, and for PPF, the cost between rTHA and open reduction and internal fixation treatment.

METHODS

A systematic search of PubMed, Embase, and Scopus identified all studies reporting the hospital costs of rTHA. Screening, data extraction, and risk of bias assessment were conducted. Hospital costs of each study cohort by main diagnosis and treatment were adjusted to 2024 United States Dollar and pooled using a random-effects model.

RESULTS

Of 866 publications identified, 24 studies were included in the meta-analysis. Mean pooled costs of rTHA for dislocation, aseptic loosening, PPF, and septic rTHA were $25,256, $34,533, $35,904, and $55,707, respectively. The mean cost of septic rTHA (16 study cohorts) at $57,264 was 87% higher than aseptic rTHA (22 cohorts) at $30,224. A two-stage septic rTHA ($70,311) cost 77% more than one-stage septic rTHAs ($39,676). The cost of rTHA for PPF ($35,904) was 26% more than open reduction and internal fixation for PPF ($28,410).

CONCLUSIONS

The cost of rTHA is progressively higher by diagnosis in the order of dislocation, aseptic loosening, PPF, and infection. Future studies should separately report rTHA costs by diagnosis and treatment type and longitudinally examine the hospital costs of this patient cohort, particularly for septic cases, beyond initial treatment to better understand the burden of rTHA.

Septic Hip Revision Arthroplasty-A Perioperative and Follow-Up Risk Analysis

Background: Septic hip revision arthroplasty is a complex procedure associated with significant perioperative risks. This study aimed to analyze perioperative and follow-up risk factors in patients undergoing septic hip revision arthroplasty. Methods: A retrospective analysis was conducted on 96 patients who underwent septic revision total hip arthroplasty between 2018 and 2021 at a university hospital. Demographic data, surgical details, pathogen analyses, and complication data were collected and analyzed. The first and second hospitalizations were investigated. Data analyses were conducted with SPSS Version 29.0. Results: The mean age of patients was 69.06 ± 11.56 years, with 59.4% being female. On average, 1.3 ± 0.8 pathogens were detected per patient. Staphylococcus species were the most common pathogens. Women experienced significantly more complications during the first revision hospitalization (p = 0.010), including more surgical (p = 0.022) and systemic complications (p = 0.001). Anemia requiring transfusion was more common in women (70.1% vs. 43.5%, p = 0.012). A higher BMI was associated with a higher count of pathogens (p = 0.019). The number of pathogens correlated with increased wound healing disorders (p < 0.001) and the need for further revision surgeries (p < 0.001). Conclusions: This study identifies gender as a significant risk factor for complications in septic hip revision arthroplasty. Female patients may require more intensive perioperative management to mitigate risks. The findings underscore the need for personalized approaches in managing these complex cases to improve outcomes.

Direct Hospital Costs per Case of Periprosthetic Hip and Knee Joint Infections in Europe - A Systematic Review

BACKGROUND

The rise of periprosthetic joint infections (PJIs) due to aging populations is steadily increasing the number of arthroplasties and treatment costs. This study analyzed the direct health care costs of PJI for total hip arthroplasty and total knee arthroplasty (TKA) in Europe.

METHODS

The databases PubMed, Scopus, Embase, Cochrane, and Google Scholar were systematically screened for direct costs of PJI in Europe. Publications that defined the joint site and the procedure performed were further analyzed. Mean direct health care costs were calculated for debridement, antibiotics, and implant retention (DAIR), one-stage, and 2-stage revisions for hip and knee PJI, respectively. Costs were adjusted for inflation rates and reported in US-Dollar (USD).

RESULTS

Of 1,374 eligible publications, 12 manuscripts were included in the final analysis after an abstract and full-text review. Mean direct costs of $32,933 were identified for all types of revision procedures for knee PJI. The mean direct treatment cost including DAIR for TKA after PJI was $19,476. For 2-stage revisions of TKA, the mean total cost was $37,980. For all types of hip PJI procedures, mean direct hospital costs were $28,904. For hip DAIR, one-stage and 2-stage treatment average costs of $7,120, $44,594, and $42,166 were identified, respectively.

CONCLUSIONS

Periprosthetic joint infections are associated with substantial direct health care costs. As detailed reports on the cost of PJI are scarce and of limited quality, more detailed financial data on the cost of PJI treatment are urgently required.

Defining Clinically Meaningful Subgroups for Risk Stratification in Patients Undergoing Revision Total Hip Arthroplasty: A Combined Unsupervised and Supervised Machine Learning Approach

BACKGROUND

Studies developing predictive models from large datasets to risk-stratify patients under going revision total hip arthroplasties (rTHAs) are limited. We used machine learning (ML) to stratify patients undergoing rTHA into risk-based subgroups.

METHODS

We retrospectively identified 7,425 patients who underwent rTHA from a national database. An unsupervised random forest algorithm was used to partition patients into high-risk and low-risk strata based on similarities in rates of mortality, reoperation, and 25 other postoperative complications. A risk calculator was produced using a supervised ML algorithm to identify high-risk patients based on preoperative parameters.

RESULTS

There were 3,135 and 4,290 patients identified in the high-risk and low-risk subgroups, respectively. Each group significantly differed by rate of 30-day mortalities, unplanned reoperations/readmissions, routine discharges, and hospital lengths of stay (P < .05). An Extreme Gradient Boosting algorithm identified preoperative platelets < 200, hematocrit > 35 or < 20, increasing age, albumin < 3, international normalized ratio > 2, body mass index > 35, American Society of Anesthesia class ≥ 3, blood urea nitrogen > 50 or < 30, creatinine > 1.5, diagnosis of hypertension or coagulopathy, and revision for periprosthetic fracture and infection as predictors of high risk.

CONCLUSION

Clinically meaningful risk strata in patients undergoing rTHA were identified using an ML clustering approach. Preoperative labs, demographics, and surgical indications have the greatest impact on differentiating high versus low risk.

LEVEL OF EVIDENCE

III.

Mortality, patient-reported outcome measures, and the health economic burden of prosthetic joint infection

Prosthetic joint infection (PJI) is one of the most devastating complications for a patient following arthroplasty. This scoping review aims to evaluate the burden of PJI on individual patients and the healthcare system regarding the mortality rate, patient-reported quality of life, and healthcare resource utilisation. Patients with PJI have up to a five-fold higher mortality rate than those who have undergone an uninfected primary arthroplasty. There is an increased use of ambulatory aids and reduced joint function scores in patients with PJI. Global quality of life is poorer, specifically measured by the EQ-5D. Direct hospitalisation costs are two- to five-fold higher, attributed to surgery and prostheses, antibiotics, and a prolonged inpatient stay. There is an immense clinical and health economic burden secondary to PJI worldwide. This is expected to rise exponentially due to the increasing number of primary procedures and an ageing population with comorbidities Improving preventative and treatment strategies is imperative for patients and the healthcare system.

Total femoral arthroplasty for non-oncological indications

Aims

Total femoral arthroplasty (TFA) is a rare procedure used in cases of significant femoral bone loss, commonly from cancer, infection, and trauma. Low patient numbers have resulted in limited published work on long-term outcomes, and even less regarding TFA undertaken for non-oncological indications. The aim of this study was to evaluate the long-term clinical outcomes of all TFAs in our unit.

Methods

Data were collected retrospectively from a large tertiary referral revision arthroplasty unit's database. Inclusion criteria included all patients who underwent TFA in our unit. Preoperative demographics, operative factors, and short- and long-term outcomes were collected for analysis. Outcome was defined using the Musculoskeletal Infection Society (MSIS) outcome reporting tool.

Results

Overall, 38 TFAs were identified. The mean age was 73 years (42 to 80). All patients underwent TFA for non-oncological indications, most commonly as a consequence of infection (53%) and periprosthetic fracture (26%). The mean follow-up time was ten years (0 to 26); 63% of TFAs were considered a success based upon the MSIS outcome reporting tool. The mean time between TFA and death was 8.5 years (0.2 to 19.2), with two patients dying within one year of surgery. Within the cohort, 66% suffered at least one complication, dislocation being most common (37%); 55% of the total cohort required at least one subsequent operation. In total, 70% of TFAs undertaken for infection were considered infection-free at time of final follow-up. The percentage of mobile patients improved from 52% to 65% between pre- and postoperation, with all patients being able to at least transfer from bed to chair at time of final review.

Conclusion

This study is the largest in the UK assessing the use of TFA in patients with bone loss secondary to non-oncological conditions. It demonstrates that TFA has a significant complication profile, however it is favourable in terms of mortality and rehabilitation when compared to amputation and disarticulation.

Hepatitis C Is Associated With Higher Short-Term Complication Rates After Initial Aseptic and Septic Revision Total Hip Arthroplasty: A Matched Cohort Study

BACKGROUND

It is unclear if hepatitis C virus (HCV) negatively impacts outcomes of revision total hip arthroplasty (rTHA). The purpose of this study is to trend recent rTHA utilization in patients who have HCV and compare postoperative complication rates versus a matched cohort.

METHODS

All patients who underwent rTHA were retrospectively identified in a national database. Patients who had HCV (n = 1,746) were matched 1:3 with a matching group (n = 5,238) for age, gender, and several comorbidities. Cochran-Armitage tests were used to analyze trends in the annual proportion of rTHA performed in patients who had HCV from 2010 to 2019. Rates of 90-day medical and prosthesis-related complications within 2 years postoperatively were compared with multivariable logistic regressions.

RESULTS

The annual proportion of rTHA performed in patients who had HCV significantly increased from 2010 to 2019 (P < .001). Patients who had HCV exhibited significantly higher rates of acute kidney injuries (7.6% versus 4.4%; odds ratio [OR] 1.50), transfusions (20.6% versus 14.6%; OR 1.38), and re-revisions for prosthetic joint infection (10.9% versus 6.5%; OR 1.73). In subgroup analyses, rates of re-revision for prosthetic joint infection after initial aseptic rTHA (7.1% versus 3.8%; OR 1.82) and periprosthetic fracture after initial septic rTHA (4.5% versus 1.6%; OR 2.77) were significantly higher in the HCV cohort.

CONCLUSION

Similar to primary THA, patients who have HCV exhibit significantly increased complication rates after rTHA. With growing utilization in recent years, these data suggest that this population will comprise an increasingly larger proportion of rTHA procedures performed in the coming years.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Infection after total joint replacement of the hip and knee: research programme including the INFORM RCT

Background

People with severe osteoarthritis, other joint conditions or injury may have joint replacement to reduce pain and disability. In the UK in 2019, over 200,000 hip and knee replacements were performed. About 1 in 100 replacements becomes infected, and most people with infected replacements require further surgery.

Objectives

To investigate why some patients are predisposed to joint infections and how this affects patients and the NHS, and to evaluate treatments.

Design

Systematic reviews, joint registry analyses, qualitative interviews, a randomised controlled trial, health economic analyses and a discrete choice questionnaire.

Setting

Our studies are relevant to the NHS, to the Swedish health system and internationally.

Participants

People with prosthetic joint infection after hip or knee replacement and surgeons.

Interventions

Revision of hip prosthetic joint infection with a single- or two-stage procedure.

Main outcome measures

Long-term patient-reported outcomes and reinfection. Cost-effectiveness of revision strategies over 18 months from two perspectives: health-care provider and Personal Social Services, and societal.

Data sources

National Joint Registry; literature databases; published cohort studies; interviews with 67 patients and 35 surgeons; a patient discrete choice questionnaire; and the INFORM (INFection ORthopaedic Management) randomised trial.

Review methods

Systematic reviews of studies reporting risk factors, diagnosis, treatment outcomes and cost comparisons. Individual patient data meta-analysis.

Results

In registry analyses, about 0.62% and 0.75% of patients with hip and knee replacement, respectively, had joint infection requiring surgery. Rates were four times greater after aseptic revision. The costs of inpatient and day-case admissions in people with hip prosthetic joint infection were about five times higher than those in people with no infection, an additional cost of > £30,000. People described devastating effects of hip and knee prosthetic joint infection and treatment. In the treatment of hip prosthetic joint infection, a two-stage procedure with or without a cement spacer had a greater negative impact on patient well-being than a single- or two-stage procedure with a custom-made articulating spacer. Surgeons described the significant emotional impact of hip and knee prosthetic joint infection and the importance of a supportive multidisciplinary team. In systematic reviews and registry analyses, the risk factors for hip and knee prosthetic joint infection included male sex, diagnoses other than osteoarthritis, high body mass index, poor physical status, diabetes, dementia and liver disease. Evidence linking health-care setting and surgeon experience with prosthetic joint infection was inconsistent. Uncemented fixation, posterior approach and ceramic bearings were associated with lower infection risk after hip replacement. In our systematic review, synovial fluid alpha-defensin and leucocyte esterase showed high diagnostic accuracy for prosthetic joint infection. Systematic reviews and individual patient data meta-analysis showed similar reinfection outcomes in patients with hip or knee prosthetic joint infection treated with single- and two-stage revision. In registry analysis, there was a higher rate of early rerevision after single-stage revision for hip prosthetic joint infection, but, overall, 40% fewer operations are required as part of a single-stage procedure than as part of a two-stage procedure. The treatment of hip or knee prosthetic joint infection with early debridement and implant retention may be effective in > 60% of cases. In the INFORM randomised controlled trial, 140 patients with hip prosthetic joint infection were randomised to single- or two-stage revision. Eighteen months after randomisation, pain, function and stiffness were similar between the randomised groups (p = 0.98), and there were no differences in reinfection rates. Patient outcomes improved earlier in the single-stage than in the two-stage group. Participants randomised to a single-stage procedure had lower costs (mean difference –£10,055, 95% confidence interval –£19,568 to –£542) and higher quality-adjusted life-years (mean difference 0.06, 95% confidence interval –0.07 to 0.18) than those randomised to a two-stage procedure. Single-stage was the more cost-effective option, with an incremental net monetary benefit at a threshold of £20,000 per quality-adjusted life-year of £11,167 (95% confidence interval £638 to £21,696). In a discrete choice questionnaire completed by 57 patients 18 months after surgery to treat hip prosthetic joint infection, the most valued characteristics in decisions about revision were the ability to engage in valued activities and a quick return to normal activity.

Limitations

Some research was specific to people with hip prosthetic joint infection. Study populations in meta-analyses and registry analyses may have been selected for joint replacement and specific treatments. The INFORM trial was not powered to study reinfection and was limited to 18 months’ follow-up. The qualitative study subgroups were small.

Conclusions

We identified risk factors, diagnostic biomarkers, effective treatments and patient preferences for the treatment of hip and knee prosthetic joint infection. The risk factors include male sex, diagnoses other than osteoarthritis, specific comorbidities and surgical factors. Synovial fluid alpha-defensin and leucocyte esterase showed high diagnostic accuracy. Infection is devastating for patients and surgeons, both of whom describe the need for support during treatment. Debridement and implant retention is effective, particularly if performed early. For infected hip replacements, single- and two-stage revision appear equally efficacious, but single-stage has better early results, is cost-effective at 18-month follow-up and is increasingly used. Patients prefer treatments that allow full functional return within 3–9 months.

Future work

For people with infection, develop information, counselling, peer support and care pathways. Develop supportive care and information for patients and health-care professionals to enable the early recognition of infections. Compare alternative and new treatment strategies in hip and knee prosthetic joint infection. Assess diagnostic methods and establish NHS diagnostic criteria.

Study registration

The INFORM randomised controlled trial is registered as ISRCTN10956306. All systematic reviews were registered in PROSPERO (as CRD42017069526, CRD42015023485, CRD42018106503, CRD42018114592, CRD42015023704, CRD42017057513, CRD42015016559, CRD42015017327 and CRD42015016664).

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 10, No. 10. See the NIHR Journals Library website for further project information.

Clinical and cost effectiveness of single stage compared with two stage revision for hip prosthetic joint infection (INFORM): pragmatic, parallel group, open label, randomised controlled trial

OBJECTIVES

To determine whether patient reported outcomes improve after single stage versus two stage revision surgery for prosthetic joint infection of the hip, and to determine the cost effectiveness of these procedures.

DESIGN

Pragmatic, parallel group, open label, randomised controlled trial.

SETTING

High volume tertiary referral centres or orthopaedic units in the UK (n=12) and in Sweden (n=3), recruiting from 1 March 2015 to 19 December 2018.

PARTICIPANTS

140 adults (aged ≥18 years) with a prosthetic joint infection of the hip who required revision (65 randomly assigned to single stage and 75 to two stage revision).

INTERVENTIONS

A computer generated 1:1 randomisation list stratified by hospital was used to allocate participants with prosthetic joint infection of the hip to a single stage or a two stage revision procedure.

MAIN OUTCOME MEASURES

The primary intention-to-treat outcome was pain, stiffness, and functional limitations 18 months after randomisation, measured by the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score. Secondary outcomes included surgical complications and joint infection. The economic evaluation (only assessed in UK participants) compared quality adjusted life years and costs between the randomised groups.

RESULTS

The mean age of participants was 71 years (standard deviation 9) and 51 (36%) were women. WOMAC scores did not differ between groups at 18 months (mean difference 0.13 (95% confidence interval -8.20 to 8.46), P=0.98); however, the single stage procedure was better at three months (11.53 (3.89 to 19.17), P=0.003), but not from six months onwards. Intraoperative events occurred in five (8%) participants in the single stage group and 20 (27%) in the two stage group (P=0.01). At 18 months, nine (14%) participants in the single stage group and eight (11%) in the two stage group had at least one marker of possible ongoing infection (P=0.62). From the perspective of healthcare providers and personal social services, single stage revision was cost effective with an incremental net monetary benefit of £11 167 (95% confidence interval £638 to £21 696) at a £20 000 per quality adjusted life years threshold (£1.0; $1.1; €1.4).

CONCLUSIONS

At 18 months, single stage revision compared with two stage revision for prosthetic joint infection of the hip showed no superiority by patient reported outcome. Single stage revision had a better outcome at three months, fewer intraoperative complications, and was cost effective. Patients prefer early restoration of function, therefore, when deciding treatment, surgeons should consider patient preferences and the cost effectiveness of single stage surgery.

TRIAL REGISTRATION

ISRCTN registry ISRCTN10956306.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Revision arthroplasty with megaprosthesis after Girdlestone procedure for periprosthetic joint infection as an option in massive acetabular and femoral bone defects

BACKGROUND AND AIM

To evaluate the clinical outcomes of patients treated with Girdlestone procedure (GP) or excision arthroplasty (EA) for periprosthetic infection with massive bone defects and undergoing revision arthroplasty.

METHODS

All patients treated with EA or GP for hip periprosthetic infection between 2014 and 2017 and sustaining revision arthroplasty (RA) were included in the study. Patients with less than 24 months of follow-up or less than 12 months between GP or EA and RA were excluded. Any sign of implant mobilization or periprosthetic fracture was assessed through X-ray. Patients were evaluated with D'aubignè-Postel hip score before RA and at the last follow-up. Mann-Whitney U test was used to assess differences between pre-RA surgery and last follow-up. P value was set as <0.05.

RESULTS

Twelve patients meet the inclusion criteria (mean follow-up 58+/-9.72 months). No radiographic sign of implant mobilization or periprosthetic fracture was reported. A significant difference was found for each parameter of the D'Aubigne-Postel score (p < 0.0001); none of the patients reached more than fair results in the absolute hip score. The difference between pre and post-operative global status showed a fair improvement. A significant difference was found for leg length discrepancy between pre and post RA (p<0.0001).

CONCLUSIONS

Conversion from EA or GP to RA in patients suffering from massive acetabular and femur defects is challenging; conversion procedure is able to reduce patients' disability and to improve walking ability. (www.actabiomedica.it).

Addressing the Needs of the Rapidly Aging Society through the Development of Multifunctional Bioactive Coatings for Orthopedic Applications

The unprecedented aging of the world's population will boost the need for orthopedic implants and expose their current limitations to a greater extent due to the medical complexity of elderly patients and longer indwelling times of the implanted materials. Biocompatible metals with multifunctional bioactive coatings promise to provide the means for the controlled and tailorable release of different medications for patient-specific treatment while prolonging the material's lifespan and thus improving the surgical outcome. The objective of this work is to provide a review of several groups of biocompatible materials that might be utilized as constituents for the development of multifunctional bioactive coatings on metal materials with a focus on antimicrobial, pain-relieving, and anticoagulant properties. Moreover, the review presents a summary of medications used in clinical settings, the disadvantages of the commercially available products, and insight into the latest development strategies. For a more successful translation of such research into clinical practice, extensive knowledge of the chemical interactions between the components and a detailed understanding of the properties and mechanisms of biological matter are required. Moreover, the cost-efficiency of the surface treatment should be considered in the development process.

Aseptic and septic prosthetic joint loosening: Impact of biomaterial wear on immune cell function, inflammation, and infection

The success of total joint replacements has led to consistent growth in the use of arthroplasty in progressively younger patients. However, more than 10 percent of patients require revision surgeries due to implant failure caused by osteolytic loosening. These failures are classified as either aseptic or septic and are associated with the presence of particulate wear debris generated by mechanical action between implant components. Aseptic loosening results from chronic inflammation caused by activation of resident immune cells in contact with implant wear debris. In contrast, septic loosening is defined by the presence of chronic infection at the implant site. However, recent findings suggest that subclinical biofilms may be overlooked when evaluating the cause of implant failure, leading to a misdiagnosis of aseptic loosening. Many of the inflammatory pathways contributing to periprosthetic joint infections are also involved in bone remodeling and resorption. In particular, wear debris is increasingly implicated in the inhibition of the innate and adaptive immune response to resolve an infection or prevent hematogenous spread. This review examines the interconnectivity of wear particle- and infection-associated mechanisms of implant loosening, as well as biomaterials-based strategies to combat infection-related osteolysis.

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.

Results at 10-24 years after single-stage revision arthroplasty of infected total hip arthroplasty in patients under 45 years of age

INTRODUCTION

The management of periprosthetic joint infection (PJI) of the hip is a challenging procedure. One-stage exchange is carried out in specialist centres with comparable infection free survival rates. However, there is a paucity of long-term results of this approach in young patients.

METHODS

All patients undergoing one-stage exchange due to PJI with a known causative organism ⩽45 years of age with a minimum of 10-year follow-up (mean 15 years; range 10-24 years) were enrolled in this retrospective study. Patients older than 45 years of age or patients with a two-stage procedure were excluded from the study. The primary outcome measure was failure rate with special focus on reinfection at latest follow-up. Failure was defined as revision surgery for infection. Furthermore, functional outcome using the Harris Hip Score was determined initially and at latest follow-up. 26 patients fulfilled the inclusion criteria and were available for final follow-up.

RESULTS

The study cohort consists of 16 male and 10 female patients with a mean age of 36.8 years (range 20-45 years) and a mean BMI of 29.8 kg/m2 (range 20.7-40.6 kg/m2). Prior to the single-stage procedure, the patients underwent an average of 3.1 previous surgical interventions (range 1-9). The mean hospital stay after septic revision was 19.7 days (11-33 days). Most infections were caused by Staphylococcus epidermidis (n = 8, 30.8%), followed by Staph. aureus (n = 7, 26.9%) and Propionibacterium acnes (n = 6, 23.1%). At latest follow-up, the overall survival rate was 76.9 %, while infection control could be achieved in 96.2%. At final examination, the mean Harris Hip Score improved from 46.2 to 78.9 (range 18.0-99; SD, 22.6).

CONCLUSIONS

Single-stage revision surgery for the management of PJI in patients ⩽45 years is a successful treatment option with high infection control, even after long-term follow-up.

Do Prosthetic Joint Infections Worsen the Functional Ambulatory Outcome of Patients with Joint Replacements? A Retrospective Matched Cohort Study

OBJECTIVES

To assess the effect on the functional ambulatory outcome of postoperative joint infection (PJI) cured at the first treatment attempt versus not developing PJI in patients with hip and knee prostheses.

METHODS

In a single-hospital retrospectively matched cohort study, each patient with PJI between 2007 and 2016 was matched on age, sex, type of prosthesis and year of implantation with two other patients with uninfected arthroplasties. The definition of a PJI cure included infection eradication, no further surgical procedures, no PJI-related mortality and no suppressive antibiotics. Functional ambulatory status evaluated one year after the last surgery was classified into four simple categories: able to walk without assistance, able to walk with one crutch, able to walk with two crutches, and unable to walk. Patients with total hip arthroplasties (THA), total knee arthroplasties (TKA) and partial hip arthroplasty (PHA) were analysed separately.

RESULTS

A total of 109 PJI patients (38 TKA, 41 THA, 30 PHA) and 218 non-PJI patients were included. In a model adjusted for clinically relevant variables, PJI was associated with a higher risk of needing an assistive device for ambulation (vs. walking without aid) among THA (adjusted odds ratio (OR) 3.10, 95% confidence interval (95% CI) 1.26-7.57; p = 0.014) and TKA patients (OR 5.40, 95% CI 2.12-13.67; p < 0.001), and with requiring two crutches to walk or being unable to walk (vs. walking unaided or with one crutch) among PHA patients (OR 3.05, 95% CI 1.01-9.20; p = 0.047).

CONCLUSIONS

Ambulatory outcome in patients with hip and knee prostheses with postoperative PJI is worse than in patients who do not have PJI.

What are the inpatient and day case costs following primary total hip replacement of patients treated for prosthetic joint infection: a matched cohort study using linked data from the National Joint Registry and Hospital Episode Statistics

BACKGROUND

Prosthetic joint infection (PJI) following total hip replacement (THR) surgery is a serious complication that negatively impacts patients' lives and is financially burdensome for healthcare providers. As the number of THRs increases, so does this financial burden. This research estimates the economic burden with respect to inpatient and day case hospital admissions for patients receiving revision surgery for PJI following primary THR.

METHODS

In this matched cohort study, the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR) was used to identify patients. Patients revised for PJI with a one- or two-stage revision following THR and patients not revised for PJI were matched on several characteristics using exact and radius matching. Hospital inpatient and day case healthcare records from the English Hospital Episode Statistics database were obtained for 5 years following the identified patient's primary THR. UK national unit costs were applied to hospital admissions and the 5-year total cost was estimated. A two-part model (Probit and generalised linear model) was employed to estimate the incremental difference in costs between those revised and not revised for PJI.

RESULTS

Between 2006 and 2009, 1914 revisions for PJI were identified in the NJR. The matching resulted in 422 patients revised for PJI and 1923 matches not revised for PJI who were included in the analysis. The average cost of inpatient and day case admissions in the 5 years following primary THR was approximately £42,000 for patients revised for PJI and £8000 for patients not revised for PJI. The difference in costs over the 5 years was £33,452 (95% CI £30,828 to £36,077; p < 0.00).

CONCLUSIONS

In the 5 years following primary THR, patients who develop PJI and have revision surgery cost approximately £33,000 (over 5-fold) more than patients not revised for PJI based on their hospital inpatient and day case admissions alone. The total burden of PJI is likely to be much higher when also considering outpatient, primary and community care costs. This highlights the need to find both ways to reduce the incidence of PJI following THR and cost-effective treatment strategies if PJI occurs.

Patient-reported Outcome Measures of Revision Total Hip Arthroplasty for Prosthetic Joint Infection is not Inferior to Aseptic Revision Total Hip Arthroplasty

Introduction:

This study aims to investigate whether patients undergoing two-stage revision total hip arthroplasty (THA) for prosthetic joint infection (PJI) and one-stage revision THA for aseptic reasons have similar clinical outcomes and patient satisfaction during their post-operative follow-up. We hypothesise that the two-stage revision THA for PJI is associated with poorer outcomes as compared to aseptic revision THA.

Materials and Methods:

We reviewed prospectively collected data in our tertiary hospital arthroplasty registry and identified patients who underwent revision THA between 2001 and 2014, with a minimum of two years follow-up. The study group (two-stage revision THA for PJI) consists of 23 patients and the control group (one-stage revision THA for aseptic reasons) consists of 231 patients. Patient demographics, Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Hip Score (OHS), Short Form-36 (SF-36) scores and patient reported satisfaction were evaluated. Student’s t-test was used to compare continuous variables between the two groups. Statistical significance was defined as p <0.05.

Results:

The pre-operative demographics and clinical scores were relatively similar between the two groups of patients. At two years, patients who underwent revision THA for PJI reported a better WOMAC Pain Score and OHS as compared to aseptic revision THA. A similar proportion of patients were satisfied with their results of surgery in both groups (p=0.093).

Conclusions:

Although patients who underwent revision THA for PJI had poorer pre-operative functional scores (WOMAC function and SF-36 PF), at two years follow-up, these two groups of patients have comparable post-operative outcomes. Interestingly, patients who had revision THA for PJI reported a better clinical outcome in terms of OHS and WOMAC Pain score as compared to the aseptic group. We conclude that the revision THA for PJI is not inferior to aseptic revision THA in terms of patient satisfaction and clinical outcomes.

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.

Survivorship of Megaprostheses in Revision Hip and Knee Arthroplasty for Septic and Aseptic Indications: A Retrospective, Multicenter Study With Minimum 2-Year Follow-Up

Background

The use of megaprostheses in nononcologic patients has been associated with complication rates greater than 50%. In patients with prior periprosthetic joint infection (PJI) with subsequent two-stage reimplantation, this complication rate may be even higher. This study was to investigate the outcomes of megaprostheses in nononcologic patients undergoing revision hip/knee arthroplasty.

Methods

We retrospectively studied patients who underwent megaprosthesis replacements from 1999 to 2017 at 5 hospitals with minimum 24 months of follow-up. Patients were stratified based on history of prior PJI (septic vs aseptic) and location of the megaprosthesis (the hip or knee). Postoperative complications were classified as soft-tissue failure, aseptic loosening, structural failure, and infection.

Results

Of the 42 patients, 19 were in the septic cohort and 23 were in the aseptic cohort. The overall complication rate was 28.6%. Complication rates for the septic and aseptic cohorts were 32% and 26%, respectively (P = .74). By anatomic location, there were 2 of 13 (15%) and 10 of 29 (34%) complications in the hip and knee groups, respectively (P = .28). In the septic cohort, there were no (0%) complications in the hip group and 6 of 14 (43%) complications in the knee group (P = .13), all due to infection. In the aseptic cohort, there were 2 of 8 (25%) and 4 of 15 (27%) complications in the hip and knee groups, respectively (P = 1.0).

Conclusions

There is no difference in the postoperative complication rates between the septic or aseptic cohorts undergoing revision hip or knee megaprosthesis replacements. In patients with prior PJI, proximal femoral replacements have improved short-term survivorship compared with distal femoral or proximal tibial replacements.

Peri-Prosthetic Joint Infection of the Knee Causes High Levels of Psychosocial Distress: A Prospective Cohort Study

Background: Peri-prosthetic joint infection (PJI) is a major complication of knee arthroplasty that can cause long-term disability. In addition to its physical impact, there is a clear psychological burden that has not been measured yet. We hypothesized that the psychosocial burden of PJI can be assessed quantitatively using standardized questionnaires and may be correlated with treatment stage. Methods: Thirty-one patients were enrolled in this longitudinal prospective cohort study from August 2015 to November 2016. Participants had clinically established knee PJI after primary total knee replacement in osteoarthritis according to the Musculoskeletal Infection Society criteria and underwent a standardized two-stage protocol. After explantation of the prosthesis and implantation of a polymethylmethacrylate knee spacer, patients were treated with organism-specific intravenous antibiotics for two weeks, followed by oral antibiotics for four weeks; and then reimplantation was performed in all cases. Psychometrically validated standardized questionnaires were used to measure psychosocial stress via self-assessment at four time points: (1) Before explantation of the prosthesis; (2) after explantation; (3) after the antibiotic treatment before reimplantation; and (4) three months after reimplantation (follow-up). The Patient Health Questionnaire (PHQ)-4, Short Form (SF)-12 (including PSK and KSK), Questions about Life Satisfaction (FLZ^M) and Fear of Progression (PA-F-KF) (titles and abbreviations in German) scores were interpreted according to cut-off values for depression, fear of progression, anxiety, and quality of life. Results: Eighteen patients (58.1%) showed a PHQ-4 score above the cut-off value for depression at least once, with the highest score before reimplantation (time point 3). On the SF-12, the mean subtest mental scale (PSK) score was 42.6 (± 14.5), and the mean subtest physical scale (KSK) score was 26.9 (± 7.5) over the four time points, which was significantly lower than that of the general German population (PSK 53.1, KSK 44.0; p < 0.05). The SF-12 scores did not change significantly over time. On the FLZ, health was least satisfactory, followed by recreational activities and work. On the PA-F-KF, patients had the greatest fear of being dependent on outside help, drastic medical interventions, and infection progression. The mean PA-F-KF value was 31.24 (± 9.60; values ≥34 are regarded as critical). Conclusion: Peri-prosthetic joint infection is a measurable, relevant psychosocial stressor for patients. Their quality of life and fear of the disease progressing are comparable to those of oncology patients. Routine screening should be conducted to identify affected patients early for appropriate treatment, improving long-term outcomes. Orthopaedic surgeons who treat patients with PJI should initiate by psychologists as well in order to maintain the patient's long-term quality of life.

Antibacterial coating of implants: are we missing something?

Implant-related infection is one of the leading reasons for failure in orthopaedics and trauma, and results in high social and economic costs. Various antibacterial coating technologies have proven to be safe and effective both in preclinical and clinical studies, with post-surgical implant-related infections reduced by 90% in some cases, depending on the type of coating and experimental setup used. Economic assessment may enable the cost-to-benefit profile of any given antibacterial coating to be defined, based on the expected infection rate with and without the coating, the cost of the infection management, and the cost of the coating. After reviewing the latest evidence on the available antibacterial coatings, we quantified the impact caused by delaying their large-scale application. Considering only joint arthroplasties, our calculations indicated that for an antibacterial coating, with a final user's cost price of €600 and able to reduce post-surgical infection by 80%, each year of delay to its large-scale application would cause an estimated 35 200 new cases of post-surgical infection in Europe, equating to additional hospital costs of approximately €440 million per year. An adequate reimbursement policy for antibacterial coatings may benefit patients, healthcare systems, and related research, as could faster and more affordable regulatory pathways for the technologies still in the pipeline. This could significantly reduce the social and economic burden of implant-related infections in orthopaedics and trauma. Cite this article: C. L. Romanò, H. Tsuchiya, I. Morelli, A. G. Battaglia, L. Drago. Antibacterial coating of implants: are we missing something? Bone Joint Res 2019;8:199-206. DOI: 10.1302/2046-3758.85.BJR-2018-0316.

One-stage exchange with antibacterial hydrogel coated implants provides similar results to two-stage revision, without the coating, for the treatment of peri-prosthetic infection

PURPOSE

Aim of this study was to verify the hypothesis that a one-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, provides similar infection recurrence rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic joint infection (PJI).

METHODS

In this two-center case-control, study, 22 patients, treated with a one-stage procedure, using implants coated with an antibiotic-loaded hydrogel [defensive antibacterial coating (DAC)], were compared with 22 retrospective matched controls, treated with a two-stage revision procedure, without the coating.

RESULTS

At a mean follow-up of 29.3 ± 5.0 months, two patients (9.1%) in the DAC group showed an infection recurrence, compared to three patients (13.6%) in the two-stage group. Clinical scores were similar between groups, while average hospital stay and antibiotic treatment duration were significantly reduced after one-stage, compared to two-stage (18.9 ± 2.9 versus 35.8 ± 3.4 and 23.5 ± 3.3 versus 53.7 ± 5.6 days, respectively).

CONCLUSIONS

Although in a relatively limited series of patients, our data shows similar infection recurrence rate after one-stage exchange with DAC-coated implants, compared to two-stage revision without coating, with reduced overall hospitalization time and antibiotic treatment duration. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

LEVEL OF EVIDENCE

III.

Femoral revision with primary cementless stems: a systematic review of the literature

The use of primary cementless stems in femoral revision has gained popularity, but no clear consensus about the correct indication is still present. The aim of our systematic review is to: (1) summarize the available literature focused on the use of cementless primary stem in revision total hip arthroplasty (THA); (2) evaluate whether the use of cementless primary stems could represent a feasible option in hip revision; (3) define the proper indication of this surgical approach. A systematic literature review was performed about the use of cementless primary stems in revision THA. The PRISMA 2009 checklist was considered to edit our review. A total of nine articles were included. The current evidence is primarily Level IV. A total of 439 patients (454 hips) underwent THA revision with primary cementless stem. Partial cementless porous coated stems were used in 246 hips (54.2%). The majority of patients were affected by type I or II Paprosky femoral defects. The mean stem-related survival rate is 95.6% ± 3.8 with a mean follow-up of 4.7 years ± 1.3. Poor standardization of methodological analysis was observed. Current literature shows lacking evidence about primary cementless stems in revision THA. Despite these limitations, we can affirm that primary cementless stems in femoral revision surgery represent a viable option in selected patients. The proper indication is a patient with femoral Paprosky defect types I or II, with low number of previous surgeries and a previous cementless stem.

In vitroantibacterial activity of oxide and non-oxide bioceramics for arthroplastic devices: I.In situtime-lapse Raman spectroscopy

Raman spectroscopy proved why the antibacterial response of non-oxide Si₃N₄bioceramic is superior to those of alumina-based oxide bioceramics.

Hyaluronic Acid and Its Composites as a Local Antimicrobial/Antiadhesive Barrier

Living in biofilms is probably the most common condition for bacteria and fungi and biofilm-related infections account for the majority of bacterial infectious diseases worldwide. Among others biofilm-related infections, those associated with implanted biomaterials have an enormous and still largely underestimated impact in orthopaedics and trauma, cardio-surgery and several other surgical disciplines. Given the limited efficacy of existing antibiotics in the prevention and treatment of bacterial biofilms, new strategies are needed to protect implants and host tissues, overcoming the striking ability of the microorganisms to adhere on different surfaces and to immediately protect themselves by forming the biofilm matrix. Adhesion is a necessary first step in microbial colonization and pathogenesis and provides a potential target for new preventive and treatment approach. Among various polymers, tested as antibacterial coatings, hyaluronic acid and some of its composites do offer a well-established long-term safety profile and a proven ability to reduce bacterial adhesion and biofilm formation. Aim of the present review is to summarize the available evidence concerning the antiadhesion/antibiofilm activity of hyaluronic acid and some of its derivatives to reduce/prevent bacterial adhesion and biofilm formation in various experimental and clinical settings.

A Review of Current Regenerative Medicine Strategies that Utilize Nanotechnology to Treat Cartilage Damage

BACKGROUND

Cartilage is an important tissue found in a variety of anatomical locations. Damage to cartilage is particularly detrimental, owing to its intrinsically poor healing capacity. Current reconstructive options for cartilage repair are limited, and alternative approaches are required. Biomaterial science and Tissue engineering are multidisciplinary areas of research that integrate biological and engineering principles for the purpose of restoring premorbid tissue function. Biomaterial science traditionally focuses on the replacement of diseased or damaged tissue with implants. Conversely, tissue engineering utilizes porous biomimetic scaffolds, containing cells and bioactive molecules, to regenerate functional tissue. However, both paradigms feature several disadvantages. Faced with the increasing clinical burden of cartilage defects, attention has shifted towards the incorporation of Nanotechnology into these areas of regenerative medicine.

METHODS

Searches were conducted on Pubmed using the terms "cartilage", "reconstruction", "nanotechnology", "nanomaterials", "tissue engineering" and "biomaterials". Abstracts were examined to identify articles of relevance, and further papers were obtained from the citations within.

RESULTS

The content of 96 articles was ultimately reviewed. The literature yielded no studies that have progressed beyond in vitro and in vivo experimentation. Several limitations to the use of nanomaterials to reconstruct damaged cartilage were identified in both the tissue engineering and biomaterial fields.

CONCLUSION

Nanomaterials have unique physicochemical properties that interact with biological systems in novel ways, potentially opening new avenues for the advancement of constructs used to repair cartilage. However, research into these technologies is in its infancy, and clinical translation remains elusive.

One-stage revision of an infected cementless total hip replacement

A two-year-old, 44 kg dog with a right Helica cementless total hip replacement (THR) was radiographically diagnosed with implant loosening eight months after the index total hip replacement procedure. Subsequent synoviocentesis and synovial fluid culture revealed a methicillin-resistant coagulase-negative Staphylococcus spp infection of the right THR. A one-stage revision using a hybrid BFX cementless acetabular cup and CFX cemented femoral stem was performed. Vancomycin and micro-silver antimicrobial powder impregnated cement were used in the revision. At re-evaluation 27 months following the revision procedure, the patient did not exhibit any signs of lameness. Radiographic images confirmed stable implants, with bone ingrowth into the cup and no signs of implant loosening. Our report demonstrates the success of a one-stage THR revision when faced with a multi-drug resistant periprosthetic infection, when combined with the use of micro-silver antimicrobial powder and culture-based antibiotic impregnated cement therapy.

Pain and Function Recovery Trajectories following Revision Hip Arthroplasty: Short-Term Changes and Comparison with Primary Hip Arthroplasty in the ADAPT Cohort Study

Background and Purpose

Patients report similar or better pain and function before revision hip arthroplasty than before primary arthroplasty but worse results are reported after revision surgery than after primary surgery. The trajectory of post-operative recovery during the first months and any differences by type of surgery have received little attention. We explored the trajectories of change in pain and function after revision hip arthroplasty to 12-months post-operatively and compare them with those observed after primary hip arthroplasty.

Methods

This study is a prospective cohort study of patients undergoing primary (n = 80 with 92% for an indication of osteoarthritis) and revision (n = 43) hip arthroplasties. WOMAC pain and function scores and walking speed were collected pre-operatively, at 3 and 12-months post-operatively. Multilevel regression models were used to chart and compare the trajectories of change (0–3 months and 3–12 months) between types of surgery.

Results

The improvements in pain and function following revision arthroplasty occurred within the first 3-months with no evidence of further change beyond this initial period. While the pattern of recovery was similar to the one observed after primary arthroplasty, improvements in the first 3-months were smaller after revision compared to primary arthroplasty. Patients listed for revision surgery reported lower pre-operative pain levels but similar post-operative levels compared to those undergoing primary surgery. At 12-months post-operation patients who underwent a revision arthroplasty had not reached the same level of function achieved by those who underwent primary arthroplasty.

Conclusion

The post-operative improvements in pain and function are larger following primary hip arthroplasty than following revision hip arthroplasty. Irrespectively of surgery type, most of the improvements occur in the first three post-operative months. More research is required to identify whether the recovery following revision surgery could be improved with specific post-operative interventions.

Quality of life after staged revision for infected total hip arthroplasty: a systematic review

INTRODUCTION

The aim of this review was to assess (health-related) quality of life ([HR]Qol) after 1-stage or 2-stage revision for prosthetic joint infection of the hip (PJI). Additionally, we compared (HR)QoL scores with normative population scores to assess whether QoL is reduced after revision for PJI.

METHODS

A systematic search was performed in Embase, Cochrane and Pubmed. We included articles that reported (HR)QoL questionnaires after staged revision for hip PJI with a minimum follow-up of 24 months. Methodological quality was assessed using the MINORS score.

RESULTS

The search produced 11,195 results. We selected 12 papers describing 2-stage revisions. The mean MINORS score was 9.8. Average WOMAC scores of 185 patients with a mean follow-up of 69.8 months were 73.Average Short Form 36 (SF-36) scores of 159 patients with a mean follow-up of 40.7 months were 40.4 for the physical component score (PCS) and 51.6 for the mental component score (MCS). Average Short Form 12 (SF-12) scores of 154 patients with a mean follow-up of 73.4 months were: a PCS of 35.4 and a MCS of 49.1. The WOMAC, SF-12 (PCS) and SF-36 (PCS) were respectively 12%, 26.7% and 14.8% lower, compared to normative values.

DISCUSSIONS

Patients who underwent 2-stage revision for hip PJI had substantially lower (physical component) (HR)QoL scores, but mental scores were comparable to the general population.

Morbidly Obese vs Nonobese Aseptic Revision Total Hip Arthroplasty: Surprisingly Similar Outcomes

BACKGROUND

We aimed to compare the outcomes between matched morbidly obese (BMI ≥ 40 kg/m(2)) and nonobese (BMI <30 kg/m(2)) patients undergoing first-time aseptic revision THA with at least 4 years of follow-up.

METHODS

Groups were matched 1:1 using sex, age, and date of revision surgery (123 patients in each group).

RESULTS

The overall incidence and risk of complication, reoperation, and re-revision were similar between groups. Morbidly obese patients were more likely to dislocate (odds ratio [OR], 3.3; P = .03), but were less likely to develop polyethylene wear (OR, 0.1; P = .04) and aseptic loosening (OR, 0.3; P = .03).

CONCLUSION

Quality outcome measures such as hospital readmission were not addressed by this study and could be the basis for future studies.

LEVEL OF EVIDENCE

level III, prognostic study.

One-stage or two-stage revision surgery for prosthetic hip joint infection--the INFORM trial: a study protocol for a randomised controlled trial

BACKGROUND

Periprosthetic joint infection (PJI) affects approximately 1% of patients following total hip replacement (THR) and often results in severe physical and emotional suffering. Current surgical treatment options are debridement, antibiotics and implant retention; revision THR; excision of the joint and amputation. Revision surgery can be done as either a one-stage or two-stage operation. Both types of surgery are well-established practice in the NHS and result in similar rates of re-infection, but little is known about the impact of these treatments from the patient's perspective. The main aim of this randomised controlled trial is to determine whether there is a difference in patient-reported outcome measures 18 months after randomisation for one-stage or two-stage revision surgery.

METHODS/DESIGN

INFORM (INFection ORthopaedic Management) is an open, two-arm, multi-centre, randomised, superiority trial. We aim to randomise 148 patients with eligible PJI of the hip from approximately seven secondary care NHS orthopaedic units from across England and Wales. Patients will be randomised via a web-based system to receive either a one-stage revision or a two-stage revision THR. Blinding is not possible due to the nature of the intervention. All patients will be followed up for 18 months. The primary outcome is the WOMAC Index, which assesses hip pain, function and stiffness, collected by questionnaire at 18 months. Secondary outcomes include the following: cost-effectiveness, complications, re-infection rates, objective hip function assessment and quality of life. A nested qualitative study will explore patients' and surgeons' experiences, including their views about trial participation and randomisation.

DISCUSSION

INFORM is the first ever randomised trial to compare two widely accepted surgical interventions for the treatment of PJI: one-stage and two-stage revision THR. The results of the trial will benefit patients in the future as the main focus is on patient-reported outcomes: pain, function and wellbeing in the long term. Patients state that these outcomes are more important than those that are clinically derived (such as re-infection) and have been commonly used in previous non-randomised studies. Results from the INFORM trial will also benefit clinicians and NHS managers by enabling the comparison of these key interventions in terms of patients' complication rates, health and social resource use and their overall cost-effectiveness.

TRIAL REGISTRATION

Current controlled trials ISRCTN10956306 (registered on 29 January 2015); UKCRN ID 18159.

Burden of Surgical Site Infections Associated with Arthroplasty and the Contribution of Staphylococcus aureus

BACKGROUND

Patients undergoing arthroplasty are at considerable risk of experiencing post-operative complications, including surgical site infections (SSIs). In addition to potential economic consequences, SSIs can have a negative impact on patient outcomes and may potentially be life-threatening. Staphylococcus aureus has been consistently shown as the leading cause of SSIs associated with orthopedic surgery, with an important contribution from methicillin-resistant S. aureus (MRSA). This study evaluated the global burden of SSIs among patients undergoing orthopedic surgical procedures, and specifically those undergoing knee and hip arthroplasties.

METHODS

An extensive search of PubMed and recent conference proceedings was conducted. English articles published between 2003 and 2013 pertaining to SSI epidemiology, patient outcomes, and healthcare resource utilization and costs were reviewed.

RESULTS

Overall, 81 studies were included, mainly from North America and Europe. Median SSI and S. aureus SSI rates, calculated as percentage of all arthroplasty procedures, were 1.7% (range: 0.25%-4.4%; 15 studies) and 0.6% (range: 0.1%-23%), respectively. Median SSI rates were 1.3% (range: 0.05%-19%; 22 studies) after knee arthroplasty, and 2.1% (range: 0.05%-28%; 24 studies) after hip arthroplasty. S. aureus SSI rates ranged from 0.2%-2.4% and 0.18%-3.8% for patients undergoing knee and hip arthroplasty, respectively. The percentage of S. aureus SSIs because of MRSA varied widely within each patient category. SSI-related mortality data (14 studies) showed that in-hospital mortality rates were low (1.2%-2.5%), but increased with time after index arthroplasty procedure (up to 56% over 1 y). Studies assessing healthcare resource utilization (n = 21) revealed that developing post-orthopedic SSIs resulted in a two- to three-fold increase in length of hospital stay (LOS) compared with non-infected patients (median LOS: 18.9 d vs. 6 d for non-SSI patients). Patients with SSIs because of methicillin-resistant staphylococci incurred greater mean LOS compared with SSIs because of methicillin-sensitive organisms. Readmission rates reported in 11 studies indicate a greater likelihood in the presence of SSIs; comparison across studies was not feasible because of differences in data reporting. Consistent with increased healthcare resource utilization (LOS and readmission) associated with SSIs, cost studies (n = 23) revealed that the presence of SSIs was associated with up to three-fold cost increase compared with the absence of SSI across all orthopedic patient categories assessed.

CONCLUSIONS

SSIs are associated with increased morbidity, mortality rates, healthcare resource utilization, and costs. Despite the relatively low SSI incidence following orthopedic surgery and specifically arthroplasty, preventive methods, specifically those targeting S. aureus, would serve to minimize costs and improve patient outcomes.

Are Preformed Articulating Spacers Superior To Surgeon-Made Articulating Spacers in the Treatment Of PJI in THA? A Literature Review

Background and Purpose:

Antibiotic-loaded cement spacers are typically manufactured by surgeons in the operating room. However, if the infecting organism is known preoperatively, the cement spacer can be fabricated (Spacer-G^® or the InterSpace^® Hip) in advance. It is unclear if preformed hip spacers are superior to surgeon-made hip spacers in the treatment of periprosthetic joint infection following primary THA.

Methods:

A literature review of the peer-reviewed literature indexed by MEDLINE and Embase was performed to identify studies reporting the outcomes of preformed and surgeon-made hip spacers in the treatment of infection following primary total hip arthroplasty (THA). A total of 43 articles met the inclusion criteria and were included in the analysis to compare the reinfection rate, Harris Hip Score (HHS) and spacer complication rates between surgeon-made and preformed hip spacers.

Results and Interpretation:

The analyzed studies included a total number of 1631 infected THA cases (n=1027 surgeonmade; n=604 preformed spacers). We found similar reinfection rates (6.0% surgeon-made, and 5.5% preformed spacers) and similar mean HHS at latest follow-up after reimplantation (HHS=84.3 surgeon-made, and HHS=81.8 preformed spacers) between both groups. However, patients treated with a surgeon-made articulating spacer had a higher spacer fracture rate compared to preformed articulating spacer. The use of preformed articulating spacers in the treatment of infected THA is not superior to surgeon-made articulating spacers regarding infection control and functional outcomes. However, the use of surgeon-made antibiotic spacers increased the risk of spacer fracture.

Similar outcomes between two-stage revisions for infection and aseptic hip revisions

PURPOSE

Two-stage revision hip arthroplasty using an antibiotic-loaded spacer is the most widely performed procedure for infected hip arthroplasties. The clinical outcome of this type of surgery compared with aseptic joint revision with exchange of femoral and acetabular components is still controversial due to the relative lack of medium- to long-term follow-up. Therefore, we analysed clinical and radiological outcomes of septic two-stage revisions compared with aseptic hip revision surgeries.

METHODS

In this retrospective study we assessed 82 consecutive patients who underwent two-stage revision for septic total hip (45 patients) or one-stage aseptic revision arthroplasty (37 patients). The average follow-up was 53 months for the aseptic group and 55 months for the septic group. For clinical evaluation, we used the Harris Hip Score (HHS) and the Merle d'Aubigné and Postel score. The postoperative pain level was determined with the visual analogue pain scale.

RESULTS

The surgeries were performed 124 months (aseptic group) and 119 months (septic group) after primary total hip arthroplasty on average. The main indications for aseptic revision surgeries were aseptic loosening (96%), dislocation (2.2%), and periprosthetic fracture (2.2%). In the clinical outcome patients achieved 75.5 points in the aseptic group and 73.4 points in the septic group in the Harris Hip Score. The Merle d'Aubigné and Postel Score revealed 12.5 points for the aseptic group and 13.1 points for the septic group. Mean level of persisting pain was 0.8 (aseptic group) and 0.4 (septic group) on the visual analogue scale (VAS). Overall survival in the aseptic group was 85.6% at 9.8 years 82.7% at 10.1 years for the septic group, with a repeat revision rate of 8.1% and 6.7%, respectively.

CONCLUSIONS

Performing aseptic acetabular and femoral revision hip arthroplasty showed equal clinical outcomes in relation to septic two-stage revision hip surgeries. Our results showed a tendency for better outcome in comparison with the information given in the literature for septic and nonseptic exchange arthroplasties, including a lower rate of re-revisions.

Antimicrobial Release From Prefabricated Spacers Is Variable and the Dose Is Low

BACKGROUND

High-dose antimicrobial-loaded bone cement (ALBC) is recommended to treat orthopaedic infections. Elution characteristics from prefabricated ALBC spacers and how they compare with hand-mixed ALBC are not well described.

QUESTIONS/PURPOSES

(1) How does antimicrobial release from prefabricated spacers compare with release from hand-mixed ALBC over time? (2) Is antimicrobial release uniform across the surface of prefabricated ALBC spacers? (3) Do variations exist between different prefabricated spacer components? (4) Do textured surfaces release more antimicrobial than smooth surfaces?

METHODS

Six prefabricated ALBC spacer components, two hip and four knee, and three hand-mixed ALBC formulations were studied in this comparative laboratory study. Gentamicin was eluted from 41 discrete sites over the surfaces of six spacer components and compared with elution from 15 ALBC specimens, five from each of three hand-mixed formulations. Elution was compared between spacer sites, components, and surface texture. Statistical analysis was performed by analysis of variance and Tukey's multiple-comparison test or t-test.

RESULTS

Gentamicin release was highest in the first 24 hours for both prefabricated ALBC spacers and hand-mixed ALBC. Elution decreased over 7 days similarly for both. At Day 7, prefabricated ALBC spacers eluted more than hand-mixed 1 g ALBC (1 g ALBC: 1.49 ± 0.34, prefabricated: 3.59 ± 1.48, mean difference = 2.1 [0.2-4.0], p = 0.04) but eluted less than 5 g ALBC (9.21 ± 1.31, mean difference = -5.6 [-3.5 to -7.7], p < 0.001) and less than 10 g ALBC (35.8 ± 1.69, mean difference = -32.2 [-29.8 to -34.6], p < 0.001). Release varied from 2.7 to 9.9 µg/mm(2) over the surface of the spacers and from 3.5 to 5.5 µg/mm(2) between components with no component different than the others (Tukey). Release from textured surfaces was inconsistent.

CONCLUSIONS

Antimicrobial release from prefabricated ALBC spacers is consistent with low-dose ALBC. Variation across the surface and between components is small compared with changes in antimicrobial load.

CLINICAL RELEVANCE

Antimicrobial release from prefabricated ALBC spacers is consistent with local antimicrobial delivered from other low-dose ALBC formulations.

Financial analysis of revision knee surgery based on NHS tariffs and hospital costs: does it pay to provide a revision service?

Revision total knee arthroplasty (TKA) is a complex procedure which carries both a greater risk for patients and greater cost for the treating hospital than does a primary TKA. As well as the increased cost of peri-operative investigations, blood transfusions, surgical instrumentation, implants and operating time, there is a well-documented increased length of stay which accounts for most of the actual costs associated with surgery. We compared revision surgery for infection with revision for other causes (pain, instability, aseptic loosening and fracture). Complete clinical, demographic and economic data were obtained for 168 consecutive revision TKAs performed at a tertiary referral centre between 2005 and 2012. Revision surgery for infection was associated with a mean length of stay more than double that of aseptic cases (21.5 vs 9.5 days, p < 0.0001). The mean cost of a revision for infection was more than three times that of an aseptic revision (£30 011 (sd 4514) vs £9655 (sd 599.7), p < 0.0001). Current NHS tariffs do not fully reimburse the increased costs of providing a revision knee surgery service. Moreover, especially as greater costs are incurred for infected cases. These losses may adversely affect the provision of revision surgery in the NHS.

Use of a modular tapered fluted femoral component in revision total hip arthroplasty following resection of a previously infected total hip: minimum 5-year follow-up

Femoral reconstruction in the setting of two stage reimplantation can be difficult and substantial reoperation rates due to implant loosening have been reported. We retrospectively reviewed 28 male and 29 female patients who underwent a two-stage reimplantation using a modular, tapered femoral stem. The mean clinical follow-up was 62 months. The mean Harris Hip score at 5-year follow-up was 76. Two stems were revised for aseptic loosening. Reinfection occurred in 16% of patients. Stem survivorship was 87% at 5-years. Use of a modular tapered stem provided a high rate of stable femoral fixation and acceptable rate of reinfection in two stage treatment of infected THA.

Extensively coated non-modular stem used in two-stage revision for infected total hip arthroplasty: mid-term to long-term follow-up

OBJECTIVE

To determine the rate of curing the infection and mid- to long-term outcomes of using extensively coated non-modular stems in two-stage revision for infected total hip arthroplasty (THA).

METHODS

The clinical data of 33 patients (33 hips) in whom extensively coated non-modular stems had been used in two-stage revision THA for deep infection were retrospectively analyzed. All operations received two-stage reimplantation, which included resection arthroplasty, thorough debridement, insertion of a hand-molded antibiotic-impregnated cement spacer with stainless steel reinforcement, a course of intravenous antibiotics, and delayed reimplantation. Microorganism-specific antibiotics had been chosen according to the results of microbiological studies performed postoperatively. All patients received i.v. antimicrobial therapy for 4 weeks and oral antibiotics to which their organisms were sensitive for a further 6 weeks. Harris hip score (HHS) and plain X-ray films were used to perform clinical and radiological evaluations.

RESULTS

During follow-up for a minimum of 5 years, no reinfection or loosening were found. Cultures of samples taken during the second stage were all negative for infection. The mean HHS improved from 42 preoperative to 89 at the final follow-up. All granular bones had fused well with the host bones by 12 months after the surgery.

CONCLUSION

Using extensively coated non-modular stems combined with intramedullary allografts in two-stage revision for treating infected THAs can achieve satisfactory outcomes.

Does PGE₁ vasodilator prevent orthopaedic implant-related infection in diabetes? Preliminary results in a mouse model

BACKGROUND

Implant-related infections are characterized by bacterial colonization and biofilm formation on the prosthesis. Diabetes represents one of the risk factors that increase the chances of prosthetic infections because of related severe peripheral vascular disease. Vasodilatation can be a therapeutic option to overcome diabetic vascular damages and increase the local blood supply. In this study, the effect of a PGE₁ vasodilator on the incidence of surgical infections in diabetic mice was investigated.

METHODOLOGY

A S. aureus implant-related infection was induced in femurs of diabetic mice, then differently treated with a third generation cephalosporin alone or associated with a PGE₁ vasodilator. Variations in mouse body weight were evaluated as index of animal welfare. The femurs were harvested after 28 days and underwent both qualitative and quantitative analysis as micro-CT, histological and microbiological analyses.

RESULTS

The analysis performed in this study demonstrated the increased host response to implant-related infection in diabetic mice treated with the combination of a PGE₁ and antibiotic. In this group, restrained signs of infections were identified by micro-CT and histological analysis. On the other hand, the diabetic mice treated with the antibiotic alone showed a severe infection and inability to successfully respond to the standard antimicrobial treatment.

CONCLUSIONS

The present study revealed interesting preliminary results in the use of a drug combination of antibiotic and vasodilator to prevent implant-related Staphylococcus aureus infections in a diabetic mouse model.

An economic analysis of aseptic revision hip arthroplasty: calculation of partial hospital costs in relation to reimbursement

INTRODUCTION

Aseptic loosening is one of the most common intermediate and long-term complications after total hip replacement (THR). These complications cause suffering and require expensive revision surgery. Little concrete data on direct costs are available from the hospital's, moreover operating department's perspective. We here provide a detailed analysis of the costs of THR revision and relate them to reimbursement underlying the German diagnosis-related groups (DRG) system.

MATERIALS AND METHODS

Major cost parameters were identified using for orientation the cost matrix of the German Institute for Hospital Reimbursement (InEK GmbH). We then retrospectively analysed the major direct costs of aseptic revision THR in terms of contribution margins I and II. The analysis included a total of 114 patients who underwent aseptic revision from 1 January 2009 to 31 March 2012. Data were retrieved from the hospital information system and patient records. All costs of surgery, diagnostic tests, and other treatments were calculated as purchase prices in EUR. The comparative analysis of direct costs and reimbursements was done for DRG I46A and I46B from the hospital's, especially treating department's rather than the society or healthcare insurance's perspective.

RESULTS

The average direct cost incurred by the hospital for a THR revision was <euro>4,380.0. The largest share was accounted for surgical costs (62.7 % of total). Implant and staff costs were identified as the most important factors that can be influenced. The proportion of the daily contribution margin that was left to cover the hospital's indirect cost decreased with the relative cost weight of the DRG to which a patient was assigned.

CONCLUSION

Our study for the first time provides a detailed analysis of the major direct case costs of THR revision for aseptic loosening from the provider's perspective. Our findings suggest that these revision operations could be performed cost-beneficially by the operating unit. From an economic perspective, cases with higher cost weights are more favorable for a hospital. These results need to be confirmed in multicenter studies.

Periprosthetic joint infection--effect on quality of life

PURPOSE

Relatively little is known about the extent to which periprosthetic joint infections (PJI) affect the patient's long-term quality of life (QoL). Our study aim was to assess the effect of a periprosthetic infection on our patients' QoL.

METHODS

We collected data retrospectively of patients who had undergone surgery in our institution between 2006 and 2011. To capture their overall QoL, we telephoned the patients who could be reached and asked them the questions on the SF-12 questionnaire.

RESULTS

In 84 patients (53 male, 31 female, 43 TKA and 41 THA), 88 % of the hip infections and 62 % of the knee infections had been successfully treated. The hip infections' cure rate was significantly higher than that of the knee joint infections. The average SF-12 score was 36.2 points on the physical scale and 52 on the mental scale. The difference in QoL between patients with and without successful infection therapy was not significant, nor did the site of the infection (knee or hip) influence QoL significantly. Comparison of our patients' QoL data to that from the general population revealed a significant difference in the physical scale but not the mental scale.

CONCLUSION

From these results QoL is substantially reduced after a prosthetic infection. We did however observe that post-Girdelstone procedure patients or those with an arthrodesis attained an acceptable QoL, and that those methods remain therapeutic alternatives as far as patient-perceived QoL is concerned.

Diabetic mouse model of orthopaedic implant-related Staphylococcus aureus infection

Background

Periprosthetic bacterial infections represent one of the most challenging orthopaedic complications that often require implant removal and surgical debridement and carry high social and economical costs. Diabetes is one of the most relevant risk factors of implant-related infection and its clinical occurrence is growing worldwide. The aim of the present study was to test a model of implant-related infection in the diabetic mouse, with a view to allow further investigation on the relative efficacy of prevention and treatment options in diabetic and non-diabetic individuals.

Methodology

A cohort of diabetic NOD/ShiLtJ mice was compared with non-diabetic CD1 mice as an in vivo model of S. aureus orthopaedic infection of bone and soft tissues after femur intramedullary pin implantation. We tested control and infected groups with 1×10³ colony-forming units of S. aureus ATCC 25923 strain injected in the implant site. At 4 weeks post-inoculation, host response to infection, microbial biofilm formation, and bone damage were assessed by traditional diagnostic parameters (bacterial culture, C-reactive protein and white blood cell count), histological analysis and imaging techniques (micro computed tomography and scanning electron microscopy).

Results

Unlike the controls and the CD1 mice, all the diabetic mice challenged with a single inoculum of S. aureus displayed severe osteomyelitic changes around the implant.

Conclusions

Our findings demonstrate for the first time that the diabetic mouse can be successfully used in a model of orthopaedic implant-related infection. Furthermore, the same bacteria inoculum induced periprosthetic infection in all the diabetic mice but not in the controls. This animal model of implant-related infection in diabetes may be a useful tool to test in vivo treatments in diabetic and non-diabetic individuals.

Economical analysis on prophylaxis, diagnosis, and treatment of periprosthetic infections

The economic burden of periprosthetic infections is enormous, but the number of economic studies dealing with this issue is very scarce. This review tries to know the economic literature existing, assess the value of current data, and recognize the less costly and more effective procedures for prevention, diagnosis and treatment of periprosthetic infections. Forty five studies meeting the inclusion criteria and adhering to the quality criteria used were carefully analyzed to extract the economic data of relevance in evaluating the magnitude of problem and the more cost-effective solutions. However, because the heterogeneity and the low-quality of most of these studies meta-analytical technique has not been possible. Instead, the studies have been reviewed descriptively. Optimizing the antibiotic use in the prevention and treatment of periprosthetic infection, combined with systemic and behavioral changes in the operating room; detecting and treating the high-risk groups; a quick, simple, reliable, safe, and cost-effective diagnosis, and the rationale management of the instituted infection, specifically using the different procedures according to each particular case, could allow to improve outcomes and produce the highest quality of life for patients and the lowest economic impact. Nevertheless, the cost effectiveness of different interventions to prevent and to treat the periprosthetic infection remains unclear.

Cost-effectiveness analysis of early versus late total hip replacement in Italy

OBJECTIVE

To assess the cost-effectiveness of early primary total hip replacement (THR) for functionally independent older adult patients with osteoarthritis (OA) versus 1) nonsurgical therapy followed by THR once the patient has progressed to a functionally dependent state ("delayed THR") and 2) nonsurgical therapy alone ('medical therapy'), from the Italian National Health Service perspective.

METHODS

Individual patient data and evidence from published literature on disease progression, economic costs and THR outcomes in OA, including utilities, perioperative mortality rates, prosthesis survival, and costs of prostheses, THR, rehabilitation, follow-up, revision, and nonsurgical management, combined with population life tables, were synthesized in a Markov model of OA. The model represents the lifetime experience of a patient cohort following their treatment choice, discounting costs and benefits (quality-adjusted life-years) at 3% annually.

RESULTS

At age 65 years, the incremental cost per quality-adjusted life-year of THR over delayed THR was €987 in men and €466 in women; the figures for delayed THR versus medical therapy were €463 and €82, respectively. Among 80-year-olds, early THR is (extended) dominant. With gradual utility loss after primary THR, delaying surgery may be more appealing in women than in men in their 50s, because longer female life expectancy implies longer latter periods of low health-related quality of life (HRQOL) with early THR.

CONCLUSIONS

THR is cost-effective. Patients' HRQOL benefits forgone with delayed THR are worth more than the costs it saves to the Italian National Health Service. This analysis might help to explain women's consistently lower HRQOL by the time of primary operation.

Management of total femoral bone loss using a hybrid cement spacer surgical technique

Standard treatment for an infected total hip arthroplasty is 2-stage revision. Bone loss in infected total hip arthroplasty presents specific challenges during the first stage. This is especially the case when there is massive or complete loss of the femoral bone stock. We describe a technique successfully used in the setting of total femoral bone loss using a hybrid cement spacer. We describe 2 cases illustrating the technique and perioperative course. This technique is a potential solution for total femoral bone loss that allows the individual to maintain mobility before definitive surgery.

Choice and doses of antibacterial agents for cement spacers in treatment of prosthetic joint infections: review of published studies

BACKGROUND

Addition of antibacterial drugs to interim antibacterial cement spacers (ACSs) is considered to be standard of care for surgical revision in prosthetic joint infections (PJIs). We reviewed published studies evaluating the choice and doses of antibacterials in spacers.

METHODS

We conducted a PubMed search of all clinical study reports evaluating the use of ACSS in a 2-stage hip or knee arthroplasty for treatment of PJI (1988 through August 2011). The trial design, antibacterials used, and end points studied were analyzed.

RESULTS

No randomized trials were found comparing either ACSs with different concentrations of antibacterials or ACSs with or without antibacterials. Most of the studies were uncontrolled and used various time points to evaluate the outcome. Twenty publications that reported doses of antibacterials in spacers and had a follow-up of ≥ 24 months after the second stage were selected for review. Most ACSs included vancomycin and aminoglycosides. The doses of aminoglycosides and vancomycin ranged from 0.25 to 4.8 g and from 1 to 4 g, respectively, per 4 g of cement. No association between reported eradication of the infection and antibacterial load was found.

CONCLUSIONS

Published data do not allow evaluation of whether antibacterials in temporary cement spacers provide additional benefits in the treatment of PJI, compared with systemic antibacterials, and are not sufficient to support recommendations on dosages. Complications of ACSs have not been consistently analyzed. Prospective randomized trials comparing spacers with and without antibacterials or spacers with different loads of antibacterials are needed to evaluate the safety and efficacy of ACSs.