A multidisciplinary team approach to two-stage revision for the infected hip replacement

An overview of the current diagnostic approach to Periprosthetic Joint Infections

The diagnosis of periprosthetic joint infections (PJI) presents a formidable challenge to orthopaedic surgeons due to its complex and diverse manifestations. Accurate diagnosis is of utmost importance, as even mild pain following joint replacement surgery may indicate PJI in the absence of a definitive gold standard diagnostic test. Numerous diagnostic modalities have been suggested in the literature, and international societies have continually updated diagnostic criteria for this debilitating complication. This review article aims to comprehensively examine the latest evidence-based approaches for diagnosing PJI. Through a thorough analysis of current literature, we explore promising diagnostic strategies that have demonstrated effectiveness in identifying PJI. These strategies encompass the utilization of laboratory markers, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), alongside imaging techniques such as magnetic resonance imaging (MRI) and leukocyte scintigraphy. Additionally, we highlight the importance of synovial fluid analysis, including the potential role of alpha-defensin as a biomarker, and examine evolving international diagnostic criteria to standardize and improve diagnostic accuracy.

Two-stage revision for periprosthetic joint infection in cemented total hip arthroplasty: an increased risk for failure?

BACKGROUND

The impact of the prior fixation mode on the treatment outcome of chronic periprosthetic joint infection (PJI) of the hip is unclear. Removal of cemented total hip arthroplasty (THA) is particularly challenging and residual cement might be associated with reinfection. This study seeks to compare the results of two-stage revision for PJI in cemented and cementless THA.

METHODS

We reviewed 143 consecutive patients undergoing two-stage revision THA for PJI between 2013 and 2018. Thirty-six patients with a fully cemented (n = 6), hybrid femur (n = 26) or hybrid acetabulum (n = 4) THA (cemented group) were matched 1:2 with a cohort of 72 patients who underwent removal of a cementless THA (cementless group). Groups were matched by sex, age, number of prior surgeries and history of infection treatment. Outcomes included microbiological results, interim re-debridement, reinfection, all-cause revision, and modified Harris hip scores (mHHS). Minimum follow-up was 2 years.

RESULTS

Compared with PJI in cementless THA, patients undergoing removal of cemented THA had increasingly severe femoral bone loss (p = 0.004). Patients in the cemented group had an increased risk for positive cultures during second-stage reimplantation (22% compared to 8%, p = 0.043), higher rates of reinfection (22% compared to 7%, p = 0.021) and all-cause revision (31% compared to 14%, p = 0.039) compared to patients undergoing two-stage revision of cementless THA. Periprosthetic femoral fractures were more frequent in the group of patients with prior cementation (p = .004). Mean mHHS had been 37.5 in the cemented group and 39.1 in the cementless group, and these scores improved significantly in both groups (p < 0.01).

CONCLUSION

This study shows that chronic infection in cemented THA might be associated with increased bone loss, higher rates of reinfection and all-cause revision following two-stage revision. This should be useful to clinicians counselling patients with hip PJI and can guide treatment and estimated outcomes.

Cure rate of infections is not an argument for spacer in two-stage revision arthroplasty of the hip

INTRODUCTION

 A devastating complication after total hip arthroplasty (THA) is chronic periprosthetic joint infection (PJI). Most frequently spacers (Sp) with or without antibiotics are implanted in a two-stage procedure even though not always indicated due to unknown pathogen, femoral and acetabular defects or muscular insufficiency.

MATERIALS AND METHODS

 A retrospective analysis of a prospectively collected database was conducted, analyzing the treatment of 44 consecutive cases with chronic PJI undergoing two-stage revision using a Girdlestone situation (GS) in the interim period between 01/2015 and 12/2018. Diagnostics included intraoperative microbiological cultures, histological analysis, sonication of the initial implant, analysis of hip aspiration, as well as laboratory diagnostics and blood cultures. We analyzed the general and age-group-specific success rate of treatment using GS. Furthermore, we compared our data with the current literature on spacer implantation regarding common complications.

RESULTS

In total, 21 female and 23 male patients at a mean age of 59.3 ± 9.6 years were included. Age groups were divided into young, mid-age, and elderly. In most patients, microbiology revealed Staphylococcus epidermidis in 39.1% of cases, following Staphylococcus lugdunensis and Staphylococcus aureus in 10.9% after THA explantation. For histology, Krenn and Morawietz type 2 (infectious type) was diagnosed in 40.9%, type 3 (infectious and abrade-induced type) in 25.0%. With GS, the total cure rate was 84.1% compared to 90.1% (range 61-100%) using Sp as described in the literature. Among age-groups, cure rate varied between 77.8 and 100%. Other complications, which only occurred in the mid-age and elderly group, included the necessity of transfusion in 31.1%, and in total, one periprosthetic fracture was identified (2.3%).

CONCLUSION

GS shows an acceptable cure rate at a minimum of 2 years when compared to the cure rate reported in the literature for Sp without major complications. For patients with increased risks for treatment failure using spacer, GS seems to be an alternative for chronic PJI when looking at the success rate of treatment.

LEVEL OF EVIDENCE

III, Retrospective trial.

UK consensus definitions for necrotising otitis externa: a Delphi study

OBJECTIVE

To establish consensus definitions for necrotising otitis externa (NOE) to facilitate the diagnosis and exclusion of NOE in clinical practice and expedite future high-quality study of this neglected condition.

DESIGN

The work comprised of a systematic review of the literature, five iterative rounds of consultation via a Delphi process and open discussion within the collaborative. An expert panel analysed the results to produce the final outputs which were shared with and endorsed by national specialty bodies.

SETTING

Secondary care in the UK.

PARTICIPANTS

UK clinical specialists practising in infection, ear nose and throat (ENT) surgery or radiology.

MAIN OUTCOME MEASURES

Definitions and statements meeting the following criteria were accepted: (a) minimum of 70% of respondents in agreement or strong agreement with a definition/statement AND (b) <15% of respondents in disagreement or strong disagreement with a definition/statement.

RESULTS

Seventy-four UK clinicians specialising in ENT, Infection and Radiology with a special interest in NOE took part in the work which was undertaken between 2019 and 2021. The minimum response rate for a Round was 76%. Consensus criteria for all proposed case definitions, outcome definitions and consensus statements were met in the fifth round.

CONCLUSIONS

This work distills the clinical opinion of a large group of multidisciplinary specialists from across the UK to create practical definitions and statements to support clinical practice and research for NOE. This is the first step in an iterative process. Further work will seek to validate and test these definitions and inform their evolution.

Repeat revision TKR for failed management of peri-prosthetic infection has long-term success but often require multiple operations: a case control study

BACKGROUND

Prosthetic joint infection (PJI) is associated with poor outcomes and catastrophic complications. The aim of this study was to present the outcomes of re-revision surgery for PJI of the knee following previous failed two-stage exchange arthroplasty.

MATERIALS AND METHODS

A retrospective analysis was performed of 32 patients who underwent re-revision knee arthroplasty, having already undergone at least one previous two-stage exchange for PJI with a minimum follow-up of two-years for alive patients. Outcomes were compared to a matched control of two-stage revisions for PJI of a primary knee replacement also containing 32 patients. Outcomes investigated were eradication of infection, re-operation, mortality and limb-salvage rate.

RESULTS

Successful eradication of infection was achieved in 50% of patients following re-revision surgery, compared with 91% following two-stage exchange of primary knee replacement for PJI (p < 0.001). Fourteen (44%) patients required further re-operation compared with three (9%) patients in the primary group (p = 0.006). Amputation was performed in one case (3%) with thirteen patients (92%) who had infection controlled by debridement, antibiotics and implant retention (DAIR), further revision surgery or arthrodesis. Two patients died with infection (6%) and the long-term rate for infection control was 91%. The mean number of procedures following surgery for the re-revision group was 2.8 (0-9) compared with 0.13 (0-1) for the primary two-stage group (p < 0.001). Five-year patient survival was 90.6% (95% CI 77.1-100). The limb-salvage rate for the re-revision cohort was 97%.

CONCLUSION

Outcomes for re-revision knee arthroplasty for PJI have higher re-operation and failure rates, but no worse mortality than in revisions of primary knee replacements. Failures can successfully be managed by further operation.

Clinical evaluation of a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties

INTRODUCTION

In septic two-stage revision surgery, success depends on numerous factors. Key steps are the procedure of ex- and reimplantation and the choice of spacer in the interim phase. The latter is still a matter of debate. Recently, we showed the microbial non-inferiority of a spacer technique using prosthetic cemented implants with an individualized antibiotic mixture in the cement applying a mechanically inferior cementation method. The aim of the present study was to evaluate the clinical results of these spacers in view of either an endofemoral or a transfemoral procedure.

MATERIALS AND METHODS

Our collective consisted of 86 patients (45 endofemoral and 41 transfemoral procedures). The collective was analyzed with respect to complications, reinfection rate and clinical status at the end of the interim phase. Results of an endofemoral and transfemoral approach were compared.

RESULTS

With a median Staffelstein-Score of 60 (range 31-81) at the end of the interim phase, the first clinical results are promising. The reinfection-free rate after a median follow-up of 50 months was 90%. Spacer-related complications occurred in 8% of the total collective. Comparing the endo- and transfemoral procedure, there were no statistical differences in complications or regarding the clinical and infectiological outcome.

CONCLUSIONS

In this study, we were able to show good clinical results for the presented spacer technique. With no relevant difference in outcome, the decision for an endofemoral or transfemoral technique can be based on technical deliberations. Further prospective comparative studies are necessary to show the clinical benefit of this procedure.

Is There Harm in Debridement, Antibiotics, and Implant Retention Versus Two-Stage Revision in the Treatment of Periprosthetic Knee Infection? Experiences Within a Large US Health Care System

BACKGROUND

When faced with a periprosthetic joint infection (PJI) following total knee arthroplasty, the treating surgeon must determine whether 2-stage revision or "liner exchange," aka debridement, antibiotics, exchange of the modular polyethylene liner, and retention of fixed implants (DAIR), offers the best balance of infection eradication versus treatment morbidity. We sought to determine septic re-revision risk following DAIR compared to initial 2-stage revision.

METHODS

We conducted a cohort study using data from Kaiser Permanente's total joint replacement registry. Primary total knee arthroplasty patients who went on to have a PJI treated by DAIR or 2-stage revision were included (2005-2018). Propensity score-weighted Cox regression was used to evaluate risk for septic re-revision.

RESULTS

In total, 1,410 PJIs were included, 1,000 (70.9%) treated with DAIR. Applying propensity score weights, patients undergoing DAIR had a higher risk for septic re-revision compared to initial 2-stage procedures (hazard ratio 3.09, 95% CI 2.22-4.42). Of DAIR procedures, 150 failed (15%) and went on to subsequent 2-stage revision (DAIR-F). When compared to patients undergoing an initial 2-stage revision, we failed to observe a difference in septic re-revision risk following DAIR-F (hazard ratio 1.11, 95% CI 0.58-2.12).

CONCLUSION

Although DAIR had a higher risk of septic re-revision, we failed to observe a difference in risk following DAIR-F when compared to those who initially underwent 2-stage revision. Functional outcome, patient, and organism factors are important to consider when discussing PJI management options.

LEVEL OF EVIDENCE

Level III.

Debridement, antibiotics, and implant retention in non-oncological femoral megaprosthesis infections: minimum 5 year follow-up

Purpose

Megaprostheses are increasingly utilised outside of the oncological setting, and remain at significant risk of periprosthetic joint infection (PJI). Debridement, antibiotic, and implant retention (DAIR) is an established treatment for PJI, however its use in non-oncological patients with femoral megaprostheses has not been widely reported. There are significant differences in patient physiology, treatment goals, and associated risks between these patient cohorts.

Methods

We identified 14 patients who underwent DAIR for a PJI of their femoral megaprostheses, between 2000 and 2014, whom had their index procedure secondary to non-oncological indications. Patients were managed as part of a multidisciplinary team, with our standardised surgical technique including exchange of all mobile parts, and subsequent antibiotic therapy for a minimum of 3 months. Patients were followed up for a minimum of 5 years.

Results

Patients included six proximal femoral replacements, five distal femoral replacements, and three total femoral replacements. No patients were lost to follow-up. There were six males and eight females, with a mean age of 67.2 years, and mean ASA of 2.3.

Nine patients (64.3%) successfully cleared their infection following DAIR at a minimum of 5 year follow-up. Five patients (35.7%) required further revision surgery, with four patients cleared of infection. No patients who underwent DAIR alone suffered complications as a result of the procedure.

Conclusions

The use of DAIR in these complex patients can lead to successful outcomes, but the risk of further revision remains high. The success rate (64.3%) remains on par with other studies evaluating DAIR in megaprostheses and in primary arthroplasty. This study indicates judicious use of DAIR can be an appropriate part of the treatment algorithm.

Level of evidence

II

Antibiotic Therapy in 2-Stage Revision for Periprosthetic Joint Infection: A Systematic Review

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) are at risk for developing periprosthetic joint infection (PJI). To treat PJI, orthopaedic surgeons can perform 1-stage or 2-stage revision arthroplasty. Although 2-stage revision yields superior long-term outcomes, the optimal antibiotic therapy duration and route of administration between stages remain uncertain. In this systematic review, we aimed to identify if variations in antibiotic therapy, duration, and administration during 2-stage hip or knee revision arthroplasty affect PJI eradication rates and surgical outcome measures.

METHODS

A literature search was performed using the PubMed and Google Scholar databases to identify all original reports from January 2000 to June 2021 involving 2-stage revision arthroplasty to treat PJI. Studies were included if they specified antibiotic duration, an intravenous (IV) route of antibiotic administration, type of antibiotic, and 2-stage revision PJI eradication rate and had a mean or median follow-up of at least 2 years after the second-stage operation. Included studies were classified into 3 groups based on the length of IV antibiotic therapy after prosthesis explantation: prolonged IV antibiotic therapy of 4 to 6 weeks, shortened IV antibiotic therapy of ≤2 weeks, and shortened course of IV antibiotic therapy followed by 6 to 12 weeks of oral antibiotics.

RESULTS

Nine studies were included. Three studies utilizing a prolonged IV antibiotic therapy had PJI eradication rates of 79% to 96%. Four studies using a shortened IV antibiotic therapy showed PJI eradication rates of 88% to 100%. Finally, 2 studies utilizing a shortened course of IV antibiotic therapy with oral antibiotics had PJI eradication rates of 95% and 97%. There was no significant difference in eradication rates across IV antibiotic duration strategies, despite a diverse array of cultured microorganisms across the studies.

CONCLUSIONS

Although the numbers are small, this systematic review suggests that prolonged IV antibiotic duration, shortened IV antibiotic duration, and shortened IV antibiotic duration supplemented with oral antibiotics confer similar PJI eradication rates after hip or knee arthroplasty.

LEVEL OF EVIDENCE

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

Extended Trochanteric Osteotomy with Intermediate Resection Arthroplasty Is Safe for Use in Two-Stage Revision Total Hip Arthroplasty for Infection

Background: This study sought to compare the results of two-stage revision total hip arthroplasty (THA) for periprosthetic infection (PJI) in patients with and without the use of an extended trochanteric osteotomy (ETO) for removal of a well-fixed femoral stem or cement. Methods: Thirty-two patients who had undergone an ETO as part of a two-stage revision without spacer placement were matched 1:2 with a cohort of sixty-four patients of the same sex and age who had stem removal without any osteotomy. Clinical outcomes including interim revision, reinfection and aseptic failure rates were evaluated. Modified Harris hip scores (mHHS) were calculated. Minimum follow-up was two years. Results: Patients undergoing ETO had a significantly lower rate of interim re-debridement compared to non-ETO patients (0% vs. 14.1%, p = 0.026). Reinfection following reimplantation was similar in both groups (12.5% in ETO patients vs. 9.4% in non-ETO patients, p = 0.365). Revision for aseptic reason was necessary in 12.5% in the ETO group and 14.1% in the non-ETO group (p = 0.833). Periprosthetic femoral fractures were seen in three patients (3.1%), of which all occurred in non-ETO patients. Dislocation was the most common complication, which was equally distributed in both groups (12.5%). The mean mHHS was 37.7 in the ETO group and 37.3 in the non-ETO group, and these scores improved significantly in both groups following reimplantation (p < 0.01). Conclusion: ETO without the use of spacer is a safe and effective method to manage patients with well-fixed femoral stems and for thorough cement removal in two-stage revision THA for PJI. While it might reduce the rate of repeated debridement in the interim period, the use of ETO appears to lead to similar reinfection rates following reimplantation.

Biofilm properties in relation to treatment outcome in patients with first-time periprosthetic hip or knee joint infection

Background

Periprosthetic joint infections (PJI) are challenging complications following arthroplasty. Staphylococci are a frequent cause of PJI and known biofilm producers. Biofilm formation decreases antimicrobial susceptibility, thereby challenging favourable treatment outcomes. The aims of this study were to characterize the biofilm abilities and antimicrobial susceptibilities of staphylococci causing first-time PJI and correlate them to clinical outcome (infection resolution and recurrence).

Methods

Reoperations for PJI of the hip or knee between 1st January 2012 to 30th June 2015 performed at the Sahlgrenska University Hospital were identified in a local database. Medical records were reviewed and clinical parameters recorded for patients whose intraoperative bacterial isolates had been stored at the clinical laboratory. Staphylococcal strains isolated from reoperations due to first-time PJI were characterised by their ability to form biofilms using the microtiter plate test. Antimicrobial susceptibility of the strains was determined by minimum inhibitory concentration (MIC) when grown planktonically, and by minimum biofilm eradication concentration (MBEC) when grown as biofilms. MBEC determination was conducted using the Calgary biofilm device (CBD) and a custom-made antimicrobial susceptibility plate containing eight clinically relevant antimicrobial agents.

Results

The study group included 49 patients (70 bacterial strains) from first-time PJI, whereof 24 (49%) patients had recurrent infection. Strong biofilm production was significantly associated with recurrent infection. Patients infected with strong biofilm producers had a five-fold increased risk for recurrent infection. Strains grown as biofilms were over 8000 times more resistant to antimicrobial agents compared to planktonic cultures. Biofilms were more susceptible to rifampicin compared to other antimicrobials in the assay. Increased biofilm susceptibility (MBEC ​> ​MIC) was observed for the majority of the bacterial strains and antimicrobial agents.

Conclusions

Strong biofilm production was significantly associated with increased antimicrobial resistance and PJI recurrence. This underscores the importance of determining biofilm production and susceptibility as part of routine diagnostics in PJI. Strong staphylococcal biofilm production may have implications on therapeutic choices and suggest more extensive surgery. Furthermore, despite the increased biofilm resistance to rifampicin, results from this study support its use in staphylococcal PJI.

The Translational Potential of this Article

Like for many biomaterial-associated infections, staphylococci are a common cause of PJI. Their ability to adhere to surfaces and produce biofilms on medical devices is proposed to play a role. However, clinical studies where biofilm properties are directly linked to patient outcome are scarce. This study demonstrates that the majority of staphylococci isolated from first-time PJI were biofilm producers with increased antimicrobial resistance. Patients suffering an infection caused by a staphylococcal strain with strong biofilm production ability had a five-fold greater risk of recurrent infection. This novel finding suggests the importance of evaluating biofilm production as a diagnostic procedure for the guidance of treatment decisions in PJI.

New Technique for Custom-Made Spacers in Septic Two-Stage Revision of Total Hip Arthroplasties

The choice of spacer in the interim phase of two-stage revision hip arthroplasty is crucial. Conventional concepts like a Girdlestone situation, handformed or preformed bone cement spacers show complications like soft-tissue contractions, abrasion of bone cement particles, dislocation, breakage and a low level of mobility in the interim phase. To address these disadvantages, the senior author developed a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties using prosthetic implants with individualized antibiotic mixture in the cement applying a mechanical inferior cementation method. The aim of this study was to evaluate the results of these spacers with respect to their non-inferiority in terms of reinfection and survival-rate of the new implant and to describe the complications associated with this procedure. Our collective consisted of 130 patients with a median follow-up of nearly five years. With a reinfect-free rate of 92% and a spacer-related complication rate of 10% (8% articular dislocation, 1% periprosthetic joint fracture, 1% breakage), this procedure seems to be safe and superior regarding complications compared to conventional concepts. Further studies are necessary to show the clinical benefit of this procedure.

Complications in the treatment of periprosthetic joint infection of the hip: when do they occur?

Prosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty (THA). The common treatment in the USA is a two-stage exchange which can be associated with significant morbidity and mortality. The purpose of this study was to analyze complications in the treatment course of patients undergoing two-stage exchange for PJI THA and determine when they occur. Methods: We analyzed all patients that underwent two-stage exchange arthroplasty for treatment of PJI after THA from January 2005 to January 2018 at a single institution. Complications were categorized as medical or surgical and divided into interstage and post-reimplantation. Minimum follow-up was 1 year. Success was based on the MusculoSkeletal Infection Society (MSIS) definition. Results: 205 hips (203 patients) underwent first stage of planned two-stage exchange. The median age was 68 (interquartile range (IQR) 18). There were 97 males and 106 females. Overall, 73/205 (38 %) patients had at least one complication during treatment: 13.5 % (25/185) of patients experienced a medical complication and 28.1 % (52/185) a surgical complication; 2.4 % died within 1 year of surgery, and 4.9 % (15/203) had mortality at a median of 2.5 years (IQR 4.9); 27 % of patients had complications during the interstage period, most commonly being recurrence of infection requiring additional surgery (63 %); and 14 % of patients experienced a complication following reimplantation, most commonly persistence or recurrence of infection (59 %). While 92 % of patients that initiated treatment were ultimately reimplanted, only 69 % were infection free at 1 year and required no additional treatment. Conclusions: While two-stage exchanges for PJI in THA have been reported as successful, there are few reports of the complications during the process. In our series, significant numbers of patients experienced complications, often during the interstage period, highlighting the morbidity of this method of treatment.

Fixation and Implant Retention of Extracapsular Femoral Neck Periprosthetic Fractures Around Hip Resurfacing Arthroplasty - A Case Series

BACKGROUND

Extracapsular femoral neck fractures in the presence of a resurfacing hip arthroplasty (RHA) appear to be independent of suboptimal technique during the initial implantation of the RHA and present with a similar etiology as native hip fractures - that is, a fragility fracture related to pathological or age-related osteoporosis, as a consequence of trauma. In the presence of a well-fixed and previously well-functioning RHA, the options for management include revision arthroplasty or open reduction and internal fixation (ORIF). In the absence of loosening through mechanisms of wear, infection, metallosis, or suboptimal prosthesis positioning, many authors have advocated ORIF with implant retention. However, there is often debate regarding the use of total hip arthroplasty in these cases.

CASE SERIES

The authors conducted a thorough assessment of the literature followed by a retrospective review of outcomes for three patients treated by ORIF with implant retention for extracapsular femoral neck fractures around a RHA, using a standardized technique. All patients were independently mobile and active with well-fixed and well-functioning RHAs before the date of injury. All patients suffered low-energy trauma resulting in the fracture. There were no intraoperative or perioperative complications. All patients achieved full weight-bearing status and independent mobility. Two patients achieved radiographic union and returned to full range of movement and independent mobilization comparable to their preoperative state. One patient was lost to follow-up.

CONCLUSION

The authors believe that fixation of extracapsular proximal femoral fractures distal to a well-fixed, well-functioning RHA is a good management option in an independent and active patient. A higher level of evidence is needed to investigate the surgical management options of these injuries comparing osteosynthesis with revision arthroplasty.

Improving outcomes in acute and chronic periprosthetic hip and knee joint infection with a multidisciplinary approach

AIMS

Periprosthetic hip and knee infection remains one of the most severe complications following arthroplasty, with an incidence between 0.5% to 1%. This study compares the outcomes of revision surgery for periprosthetic joint infection (PJI) following hip and knee arthroplasty prior to and after implementation of a specialist PJI multidisciplinary team (MDT).

METHODS

Data was retrospectively analyzed from a single centre. In all, 29 consecutive joints prior to the implementation of an infection MDT in November 2016 were compared with 29 consecutive joints subsequent to the MDT conception. All individuals who underwent a debridement antibiotics and implant retention (DAIR) procedure, a one-stage revision, or a two-stage revision for an acute or chronic PJI in this time period were included. The definition of successfully treated PJI was based on the Delphi international multidisciplinary consensus.

RESULTS

There were no statistically significant differences in patient demographics or comorbidities between the groups. There was also no significant difference in length of overall hospital stay (p = 0.530). The time taken for formal microbiology advice was significantly shorter in the post MDT group (p = 0.0001). There was a significant difference in failure rates between the two groups (p = 0.001), with 12 individuals (41.38%) pre-MDT requiring further revision surgery compared with one individual (6.67%) post-MDT inception.

CONCLUSION

Our standardized multidisciplinary approach for periprosthetic knee and hip joint infection shows a significant reduction in failure rates following revision surgery. Following implementation of our MDT, our success rate in treating PJI is 96.55%, higher than what current literature suggests. We advocate the role of a specialist infection MDT in the management of patients with a PJI to allow an individualized patient-centred approach and care plan, thereby reducing postoperative complications and failure rates. Cite this article: Bone Jt Open 2021;2(7):509-514.

Two-Stage Revision Total Hip Arthroplasty Without Spacer Placement: A Viable Option to Manage Infection in Patients With Severe Bone Loss or Abductor Deficiency

BACKGROUND

High rates of spacer-related complications in two-stage exchange total hip arthroplasty (THA) have been reported. Patients with advanced bone defects and abductor deficiency may benefit from a nonspacer two-stage revision. This study reports on the clinical course of a contemporary two-stage exchange for periprosthetic hip infection without spacer insertion.

METHODS

We reviewed 141 infected THAs with extensive bone loss or abductor damage who underwent two-stage exchange without spacer placement. The mean duration from resection arthroplasty to reimplantation was 9 weeks (2-29). Clinical outcomes included interim revision, reinfection, and aseptic revision rates. Restoration of leg-length and offset was assessed radiographically. Modified Harris hip scores were calculated. Mean follow-up was 5 years (3-7). Treatment success was defined using the modified Delphi consensus criteria.

RESULTS

Thirty-four patients (24%) had treatment failure, including 13 reinfections, 16 interim redebridements for persistent infection, 2 antibiotic suppressive therapies, and 3 prosthetic joint infection-related deaths. Aseptic rerevision after reimplantation was necessary in 14 patients (10%). Dislocation accounted for most aseptic complications, with 20 dislocations occurring in 15 patients (11%). Leg-length and offset were restored to preoperative measures. Mean modified Harris hip scores significantly improved from 35 points to 67 points.

CONCLUSION

A nonspacer two-stage exchange is a viable option for managing chronically infected THA with severe bone loss or abductor deficiency, showing comparable rates of interim revision and recurrence of infection. Cementless reimplantation demonstrates good midterm survivorship with comparable functional outcomes and leg-length restoration. However, dislocation continues to be a major concern.

One-stage revision is as effective as two-stage revision for chronic culture-negative periprosthetic joint infection after total hip and knee arthroplasty

AIMS

Removal of infected components and culture-directed antibiotics are important for the successful treatment of chronic periprosthetic joint infection (PJI). However, as many as 27% of chronic PJI patients yield negative culture results. Although culture negativity has been thought of as a contraindication to one-stage revision, data supporting this assertion are limited. The aim of our study was to report on the clinical outcomes for one-stage and two-stage exchange arthroplasty performed in patients with chronic culture-negative PJI.

METHODS

A total of 105 consecutive patients who underwent revision arthroplasty for chronic culture-negative PJI were retrospectively evaluated. One-stage revision arthroplasty was performed in 30 patients, while 75 patients underwent two-stage exchange, with a minimum of one year's follow-up. Reinfection, re-revision for septic and aseptic reasons, amputation, readmission, mortality, and length of stay were compared between the two treatment strategies.

RESULTS

The patient demographic characteristics did not differ significantly between the groups. At a mean follow-up of 4.2 years, the treatment failure for reinfection for one-stage and two-stage revision was five (16.7%) and 15 patients (20.0%) (p = 0.691), and for septic re-revision was four (13.3%) and 11 patients (14.7%) (p = 0.863), respectively. No significant differences were observed between one-stage and two-stage revision for 30- 60- and 90-day readmissions (10.0% vs 8.0%; p = 0.714; 16.7% vs 9.3%; p = 0.325; and 26.7% vs 10.7%; p = 0.074), one-year mortality (3.3% vs 4.0%; p > 0.999), and amputation (3.3% vs 1.3%; p = 0.496).

CONCLUSION

In this non-randomized study, one-stage revision arthroplasty demonstrated similar outcomes including reinfection, re-revision, and readmission rates for the treatment of chronic culture-negative PJI after TKA and THA compared to two-stage revision. This suggests culture negativity may not be a contraindication to one-stage revision arthroplasty for chronic culture-negative PJI in selected patients. Cite this article: Bone Joint J 2021;103-B(3):515-521.

Single-Stage Revision of the Infected Total Knee Arthroplasty Is Associated With Improved Functional Outcomes: A Propensity Score-Matched Cohort Study

BACKGROUND

Single-stage revision is an alternative to the standard 2-stage revision, potentially minimizing morbidities and improving functional outcomes. This study aimed at comparing single-stage and 2-stage revision total knee arthroplasty (TKA) for chronic periprosthetic joint infection (PJI) with regard to patient-reported outcome measures (PROMs) and complication rates.

METHODS

A total of 185 consecutive revision TKA patients for chronic PJI with complete preoperative and postoperative PROMs were investigated. A total of 44 patients with single-stage revision TKA were matched to 88 patients following 2-stage revision TKA using propensity score matching, yielding a total of 132 propensity score-matched patients for analysis. Patient demographics and clinical information including reinfection and readmission rates were evaluated.

RESULTS

There was no significant difference in preoperative PROMs between propensity score-matched single-stage and 2-stage revision TKA cohorts. Postoperatively, significantly higher PROMs for single-stage revision TKA were observed for Knee disability and Osteoarthritis Outcome Score physical function (62.2 vs 51.9, P < .01), physical function short form 10A (42.8 vs 38.1, P < .01), PROMIS SF Physical (44.8 vs 41.0, P = .01), and PROMIS SF Mental (50.5 vs 47.1, P = .02). There was no difference between propensity score-matched single-stage and 2-stage revision TKA cohorts for clinical outcomes including reinfection rates (25.0% vs 27.2%, P = .78) and 90-day readmission rates (22.7% vs 25.0%, P = .77).

CONCLUSION

This study illustrated that single-stage revision TKA for chronic PJI may be associated with superior patient-reported outcomes compared to 2-stage revision for the infected TKA using a variety of PROMs. Improved PROMs were not accompanied by differences in complication rates between both cohorts, suggesting that single-stage revision TKA may provide an effective alternative to 2-stage revision in patients with chronic TKA PJI.

Is There a Role for Spacer Exchange in Two-Stage Exchange Arthroplasty for Periprosthetic Joint Infection?

Periprosthetic joint infection (PJI) continues to be one of the most serious complications after hip and knee arthroplasty. The choice of surgical treatment depends on a multitude of factors like chronicity of infection, host factors, and institutional or surgeon experience. Two-stage exchange remains one of the most commonly used technique for chronic PJI in the United States of America. The intended two-stage revision may involve an additional interim procedure where the initial antibiotic cement spacer is removed and a new spacer is inserted. Mostly, the rationale behind spacer exchange is an additional load of local antibiotics before proceeding to reimplantation. There is no conclusive evidence whether a spacer exchange confers additional benefits, yet it delays reimplantation and exposes already fragile patients to the risks and morbidity of an additional surgery.

The effect of metal artefact on the design of custom 3D printed acetabular implants

BACKGROUND

3D Printed custom-made implants constitute a viable option in patients with acetabular Paprosky III defects. In these patients, needing complex hip revision surgery, the appreciation of the bony defect is crucial to assure stable fixation of the customised implant, often intended to replace a failed one. We aimed to understand the effect of metal artefact on the design of customised implants.

METHODS

26 patients with massive acetabular defects were referred, between May 2016 and September 2018, to our institution classified as "un-reconstructable" by other hospitals. They all received custom 3D-printed acetabular cups. A subset of them underwent two-stage revision surgery due to infection. We then extended the two-stage procedure to the cases where metal artefacts were significantly affecting the reading of the CT scans. CT scans of patients' pelvises were taken pre and post-implant removal. We assessed for changes in bony shape and volume of the pelvis using 3D imaging software and quantified the effect on implant design with CAD software.

RESULTS

Eight (out of 26) patients (31%) underwent two-stage revision surgery. The CT bony reconstructions between the two timepoints changed in all cases. The changes were mostly associated to the shape and distribution of the acetabular defects. Three of these cases (37.5%) showed a remarkable difference in the remaining bone that led to a change in implant design. So far, there has been no difference in the clinical outcome between the patients who underwent single (n = 18) and two-stage surgery (n = 8).

CONCLUSIONS

The shape of the acetabulum reconstructed from CT data is potentially altered by metal artefact and bone excised during removal of the failed component. For "end-of-road" acetabular reconstruction, we recommend surgeons consider the use of two-stage surgery to enable a reliable fitting of the complex shape of 3D-printed implants.

Reflecting on and managing the emotional impact of prosthetic joint infections on orthopaedic surgeons-a qualitative study

AIMS

To investigate the experience and emotional impact of prosthetic joint infection (PJI) on orthopaedic surgeons and identify holistic strategies to improve the management of PJI and protect surgeons' wellbeing.

METHODS

In total, 18 prosthetic joint surgeons in Sweden were recruited using a purposive sampling strategy. Content analysis was performed on transcripts of individual in-person interviews conducted between December 2017 and February 2018.

RESULTS

PJI had a negative emotional impact on Swedish surgeons. Many felt guilt, stress, and a sense of failure, and several aspects of PJI management were associated with psychosocial challenges. Peer support was reported as the most important coping strategy as was collaborating with infectious disease specialists.

CONCLUSION

Our study affirms that there is a negative emotional impact of PJI on surgeons which can be minimized by improved peer support and working in multidisciplinary teams. Based on the surgeons' experiences we have identified desired improvements that may facilitate the management of PJI. These may also be applicable within other surgical specialties dealing with postoperative infections, but need to be evaluated for their efficacy. Cite this article: Bone Joint J 2020;102-B(6):736-743.

Single vs 2-Stage Revision for the Treatment of Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) is one of the most devastating complications following total joint arthroplasty, accounting for a projected 10,000 revision surgeries per year by 2030. Chronic PJI is complicated by the presence of bacterial biofilm, requiring removal of components, thorough debridement, and administration of antibiotics for effective eradication. Chronic PJI is currently managed with single-stage or 2-stage revision surgery. To date, there are no randomized, prospective studies available evaluating eradication rates and functional outcomes between the 2 techniques. In this review, both treatment options are described with the most current literature to guide effective surgical decision-making that is cost-effective while decreasing patient morbidity.

Do multidisciplinary teams make a difference to the quality of medical care?

One of the major modern advances in the organization and delivery of health care has been the introduction of multidisciplinary team management. This approach has reduced mortality levels in patients suffering with cancer and other complex multiorgan pathologies. Many centres of excellence and teaching hospitals have established multidisciplinary teams in order to streamline treatment pathways and optimize patient care.

This article presents an overview of multidisciplinary teams, their history, their introduction into mainstream medical care and the issues resulting from their introduction to the treating organizations as well as clinicians.

Twenty common errors in the diagnosis and treatment of periprosthetic joint infection

Background

Misconceptions and errors in the management of periprosthetic joint infection (PJI) can compromise the treatment success. The goal of this paper is to systematically describe twenty common mistakes in the diagnosis and management of PJI, to help surgeons avoid these pitfalls.

Materials and methods

Common diagnostic and treatment errors are described, analyzed and interpreted.

Results

Diagnostic errors include the use of serum inflammatory biomarkers (such as C-reactive protein) to rule out PJI, incomplete evaluation of joint aspirate, and suboptimal microbiological procedures (such as using swabs or collection of insufficient number of periprosthetic samples). Further errors are missing possible sources of distant infection in hematogenous PJI or overreliance on suboptimal diagnostic criteria which can hinder or delay the diagnosis of PJI or mislabel infections as aseptic failure. Insufficient surgical treatment or inadequate antibiotic treatment are further reasons for treatment failure and emergence of antimicrobial resistance. Finally, wrong surgical indication, both underdebridement and overdebridement or failure to individualize treatment can jeopardize surgical results.

Conclusion

Multidisciplinary teamwork with infectious disease specialists and microbiologists in collaboration with orthopedic surgeons have a synergistic effect on the management of PJI. An awareness of the possible pitfalls can improve diagnosis and treatment results.

Diagnostic Arthroscopy for Detection of Periprosthetic Infection in Painful Shoulder Arthroplasty

PURPOSE

To analyze the utility of arthroscopic biopsies for detection of periprosthetic infection in painful shoulder arthroplasty without objective signs of infection.

METHODS

A retrospective analysis of all patients who underwent a diagnostic arthroscopy for painful shoulder arthroplasty from June 2012 through July 2018 was performed. Patients with a subsequent revision shoulder arthroplasty after diagnostic arthroscopy were included. Arthroscopic tissue culture results were compared with the culture results of intraoperative tissue samples obtained at the time of open revision surgery. A minimum of 3 tissue samples from synovia and bone-prosthesis interface with signs of synovitis or abnormal appearance was routinely collected. Cases with 2 or more positive cultures for the same microorganism obtained at open revision surgery were considered as true presence of infection. The study protocol was reviewed and approved by the institutional ethics committee.

RESULTS

Twenty-three cases in 22 patients were included in this study. Five of these 23 cases were classified as true infection based on the samples obtained during open revision surgery, and 16 cases had a positive culture in diagnostic arthroscopy. Cutibacterium acnes was isolated in each case. Classifying any microbiologic growth in the arthroscopic biopsies as positive resulted in a sensitivity and negative predictive value of 100%, specificity of 39%, and positive predictive value of 31.3% for the detection of a periprosthetic shoulder infection (PPSI). If at least 2 positive samples with the same microbiologic growth in the arthroscopic biopsies were considered as positive, sensitivity and negative predictive value dropped to 80% and 94.4%, respectively, but the specificity and positive predictive value increased to 94.4% and 80%, respectively.

CONCLUSIONS

Diagnostic arthroscopy is a useful diagnostic tool in patients with suspicion but no clear evidence of PPSI. Arthroscopically obtained tissue biopsies for culture offer a high sensitivity and specificity in the diagnosis of PPSI if at least 2 cultures positive for the same microorganism are considered as infection.

LEVEL OF EVIDENCE

Level III.

Treatment of periprosthetic hip infection with retention of a well-fixed stem: six to 13-year outcomes

Background

Treatment of periprosthetic joint infection (PJI) is challenging, generally requiring complete implant removal. However, recently reported treatments involve partial retention of implants because of the severe local and systemic burden on the patients and difficulties in functional preservation. Long-term results should be evaluated because of the risk of residual biofilm on the retained implant and late infection recurrence. We evaluated 6 to 13-year clinical outcomes of two-stage treatment of chronic PJI retaining well-fixed cementless stems.

Methods

Among 36 surgeries for deep infection following hip arthroplasty performed from 2004 to 2011, six hips had a well-fixed and well-functioning cementless stem. These six hips were all chronic PJI and were treated without stem removal. The first-stage surgery involved acetabular cup removal and reconstruction by filling the acetabular defect with antibiotic-loaded acrylic cement, creating a socket-like hemispherical dent, and reducing the retained femoral head to this dent. After confirming infection eradication the second-stage acetabular reconstruction was performed. One patient died of an unrelated noninfective cause 1 year after the operation. Clinical outcomes of the remaining five patients were followed for 6 to 13 years.

Results

Between the two surgeries (range; 2–5 months), patients underwent active range-of-motion and ambulation exercises. No dislocation was found during the interval. No recurrence of infection was found and good functional outcomes and radiographic findings were observed during the average follow-up of 109 months in all five patients.

Conclusions

Two-stage treatment with retention of a well-fixed stem may minimize local and systemic burden of the patient and enhance functional preservation while obtaining long-term infection control. Although further study could establish the effectiveness and indications for this treatment option, currently used indications should be carefully evaluated considering factors including local and systemic conditions of the patient, implant fixation status, and type of bacteria.

Outcomes of repeat two-stage exchange hip arthroplasty for prosthetic joint infection

Aims

The increasing infection burden after total hip arthroplasty (THA) has seen a rise in the use of two-stage exchange arthroplasty and the use of increasingly powerful antibiotics at the time of this procedure. As a result, there has been an increase in the number of failed two-stage revisions during the past decade. The aim of this study was to clarify the outcome of repeat two-stage revision THA following a failed two-stage exchange due to recurrent prosthetic joint infection (PJI).

Patients and Methods

We identified 42 patients who underwent a two-stage revision THA having already undergone at least one previous two stage procedure for infection, between 2000 and 2015. There were 23 women and 19 men. Their mean age was 69.3 years (48 to 81). The outcome was analyzed at a minimum follow-up of two years.

Results

A satisfactory control of infection and successful outcome was seen in 26 patients (57%). There therefore remained persistent symptoms that either required further surgery or chronic antibiotic suppression in 16 patients (38%). One-third of patients had died by the time of two years’ follow-up.

Conclusion

The rate of failure and complication rate of repeat two-stage exchange THA for PJI is high and new methods of treatment including host optimization, immunomodulation, longer periods between stages, and new and more powerful forms of antimicrobial treatment should be investigated. Cite this article: Bone Joint J 2019;101-B(6 Supple B):110–115.

Obesity and smoking predict the results of two-stage exchange in septic revision hip arthroplasty: A cohort study

BACKGROUND

Prosthetic joint infection (PJI) is deemed to be the most serious complication following total hip arthroplasty. Obesity and smoking are known risk factors for PJI. However, the influence of these variables on infection free survival, of septic revision hip arthroplasty, is yet to be explored. The aim of this study was to determine the effect of obesity and smoking on the outcome of two-stage prosthetic exchange surgery.

PATIENTS AND METHODS

A consecutive series of 97 hips in 94 patients (69 male, 25 female, mean age 66±12 years), undergoing two-stage revision surgery for hip PJI, were investigated retrospectively, after a mean follow-up of 60 (24-170) months. Survival was estimated using Kaplan-Meyer curves. A multivariate cox-regression model was applied to test for the influence of smoking or obesity (BMI≥30) after adjusting 16 potential patient-dependant variables.

HYPOTHESIS

The study hypothesis was that smoking and high BMI are predictors for the failure of septic revision hip arthroplasty. Failure of septic revision hip arthroplasty was defined as failure to eradicate the infection or eradication of the infection but failure to preserve the arthroplasty.

RESULTS

Kaplan-Meier showed a cumulative survival proportion of 80.4%(standard error S.E 4%), of the definitive implant, at 5 years. Obese patients (BMI≥30) and smokers had a significantly lower 5-year survival of 60.9% (S.E 1%) and 50.6% (S.E 1.4%), respectively (p=0.001).

DISCUSSION

Obesity and smoking are both factors determining infection free survival in two-stage revision hip arthroplasty. Clinicians should be aware of potential complications and anticipate a higher likelihood of conversion to a Girdlestone resection or even amputation in this group of patients.

LEVEL OF EVIDENCE

III, retrospective cohort study.

High cure rate of periprosthetic hip joint infection with multidisciplinary team approach using standardized two-stage exchange

Background

Two-stage exchange arthroplasty is still the preferred treatment choice for chronic PJI. However, the results remain unpredictable. We analyzed the treatment success of patients with an infected hip prosthesis, who were treated according to a standardized algorithm with a multidisciplinary team approach and evaluated with a strict definition of failure.

Methods

In this single-center prospective cohort study, all hip PJI episodes from March 2013 to May 2015 were included. Treatment failure was assessed according to the Delphi-based consensus definition. The Kaplan-Meier survival method was used to estimate the probability of infection-free survival. Patients were dichotomized into two groups depending on the number of previous septic revisions, duration of prosthesis-free interval, positive culture with difficult-to-treat microorganisms, microbiology at explantation, and microbiology at reimplantation.

Results

Eighty-four patients with hip PJI were the subject of this study. The most common isolated microorganisms were coagulase-negative staphylococci (CNS) followed by Staphylococcus aureus and Propionibacterium. Almost half of the study cohort (46%) had at least one previous septic revision before admission. The Kaplan-Meier estimated infection-free survival after 3 years was 89.3% (95% CI, 80% to 94%) with 30 patients at risk. The mean follow-up was 33.1 months (range, 24–48 months) with successful treatment of PJI. There were no statistical differences in infect eradication rate among the dichotomized groups.

Conclusions

High infect eradication rates were achieved in a challenging cohort using a standardized two-stage exchange supported by a multidisciplinary approach.

Periprosthetic joint infections after total hip replacement: an algorithmic approach

An algorithm for managing periprosthetic joint infections (PJIs) after total hip replacement (THR) surgery using a multidisciplinary approach and a clearly defined protocol may improve infection eradication rates. In this article, we present an algorithm for the management of different types of PJIs including the acutely infected cemented and cementless THRs where the components are well-fixed postoperatively and when the infection is secondary to haematogenous spread in previously well-functioning and well-fixed implants. For chronic PJIs where the components are often loose, the standard treatment includes a two-stage revision procedure. However, in a highly selected subset of patients, a single-stage approach has been utilised with high rates of eradicating infections.

Long-Term Results of a 2-Stage Exchange Protocol for Periprosthetic Joint Infection Following Total Hip Arthroplasty in 164 Hips

BACKGROUND

Limited data exist that show the long-term risks of reinfection and mechanical failure with a contemporary 2-stage exchange protocol for periprosthetic joint infection following total hip arthroplasty. The purpose of this study was to determine the long-term reinfection and mechanical failure rates of 2-stage exchange for periprosthetic joint infection after total hip arthroplasty.

METHODS

We identified 164 hips (162 patients) with infection after total hip arthroplasty between 1991 and 2006 treated with a 2-stage exchange protocol with no prior treatment for periprosthetic joint infection. With regard to Musculoskeletal Infection Society diagnostic criteria, at least 1 major criterion or 4 of 6 minor criteria were fulfilled in 129 hips (79%). The cumulative incidence with a competing risk of death was calculated for reinfection, aseptic revisions, and all-cause revisions. The risk factors for reinfection were evaluated using Cox proportional hazards regression. Harris hip scores were calculated. The mean age at the time of spacer insertion was 68 years, and 35% of the patients were female. Excluding the patients with <2 years of follow-up, the mean follow-up was 12 years (range, 2 to 21 years).

RESULTS

The cumulative incidence of recurrence of infection was 10% at 1 year, 14% at 5 years, and 15% at 10 and 15 years. Seventeen patients (11%) used chronic antibiotic suppression (>6 months), with 7 (41%) of these having recurrent infection at the time of the latest follow-up. Use of chronic antibiotic suppression was the only predictive factor for reinfection (hazard ratio, 4.5 [95% confidence interval (CI), 1.9 to 10.9]; p = 0.001). The cumulative incidence of aseptic femoral and acetabular revisions was 2.6% at 5 years and 3.3% at 10 and 15 years. The cumulative incidence of all-cause revisions was 15% at 5 years and 16% at 10 and 15 years. Dislocation was the most common complication, with 28 dislocations occurring in 20 patients (12%). The mean Harris hip score improved from 52 points prior to spacer insertion to 70 points at 15 years after reimplantation (p < 0.01).

CONCLUSIONS

The rate of recurrence of infection of 15% for up to 15 years after total hip arthroplasty was similar to previous shorter-term reports of 2-stage exchange for periprosthetic joint infection. Surgeons should anticipate mitigating instability after reimplantation. Implant survivorship free of aseptic loosening and clinical outcomes were preserved for the long term. The role of chronic antibiotic suppression in the long-term treatment of periprosthetic joint infection requires further investigation.

LEVEL OF EVIDENCE

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

Classic Markers for Infection Perform Poorly in Predicting Residual Infection Prior to Reimplantation

Two-stage exchange arthroplasty remains the treatment of choice for chronic periprosthetic joint infections. This retrospective study conducted between 2009 and 2015 examined the diagnostic value of biomarkers for residual infection between stages. The biomarkers evaluated included C-reactive protein prior to reimplantation, preimplantation synovial fluid white blood cell count and percent neutrophils, and the intraoperative histologic synovial white blood cell count per high-power field (×400) on permanent sections. Residual infection was defined as either positive cultures (more than 1) at second stage, any further surgery (eg, amputation, arthrodesis, or another 2-stage revision), or the need for infection suppression with antibiotics. Sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated accordingly. A total of 182 two-stage exchange operations that included 109 (59.9%) prosthetic hips and 73 (40.1%) prosthetic knees met the inclusion criteria. Residual infection was present in 38 (20.9%) of the procedures. The area under the curve-receiver operating characteristic values were 0.677 for C-reactive protein (P=.002), 0.506 for aspiration white blood cell count (P=.944), 0.623 for aspiration percent neutrophils (P=.200), and 0.524 for white blood cell count per high-power field (P=.801). Positive and negative predictive values were poor and ranged between 26% and 57% and 78% and 85%, respectively. Analyses using specific combinations of biomarkers did not significantly improve predictive values. This study showed that classic markers perform poorly in identifying residual infection prior to second-stage revision. Further research is necessary to evaluate the diagnostic utility of other, more recently introduced biomarkers to determine whether infection has been eradicated between stages. [Orthopedics. 2019; 42(1):34-40.].

Indications for a single-stage exchange arthroplasty for chronic prosthetic joint infection

Aims

Prosthetic joint infections (PJIs) of the hip and knee are associated with significant morbidity and socioeconomic burden. We undertook a systematic review of the current literature with the aim of proposing criteria for the selection of patients for a single-stage exchange arthroplasty in the management of a PJI.

Material and Methods

A comprehensive review of the current literature was performed using the OVID-MEDLINE, EMBASE, and Cochrane Library databases and the search terms: infection and knee arthroplasty OR knee revision OR hip arthroplasty OR hip revision, and one stage OR single stage OR direct exchange. All studies involving fewer than ten patients and follow-up of less than two years in the study group were excluded as also were systematic reviews, surgical techniques, and expert opinions.

Results

The initial search revealed 875 potential articles of which 22 fulfilled the inclusion and exclusion criteria. There were 16 case series and six comparative studies; five were prospective and 14 were retrospective. The studies included 962 patients who underwent single stage revision arthroplasty of an infected hip or knee joint. The rate of recurrent infection ranged from 0% to 18%, at a minimum of two years’ follow-up. The rate was lower in patients who were selected on the basis of factors relating to the patient and the local soft-tissue and bony conditions.

Conclusion

We conclude that single-stage revision is an acceptable form of surgical treatment for the management of a PJI in selected patients. The indications for this approach include the absence of severe immunocompromise and significant soft-tissue or bony compromise and concurrent acute sepsis. We suggest that a two-stage approach should be used in patients with multidrug resistant or atypical organisms such as fungus.

Comparison between the Staphylococci aureus and coagulase-negative staphylococci infected total joint arthroplasty treated by two-stage revision: A retrospective study with two year minimum follow-up

BACKGROUND

Staphylococcus species are major pathogens of peri-prosthetic joint infection (PJI). Coagulase-positive staphylococci and coagulase-negative staphylococci have different intrinsic virulences. However, few studies have specifically compared the clinical manifestations and two-stage revision outcomes of PJI caused by these two species.

METHODS

We retrospectively collected 260 arthroplasty patients who underwent a two-stage revision because of PJI from January 2003 to June 2015 in our institute because of PJI. Sixty-four patients (36 hips and 28 knees) and 23 patients (13 hips and 10 knees) were infected by coagulase-negative staphylococci (CoNS) and SA, respectively.

RESULTS

The preoperative mean ESR value of the SA group was higher than that of the CoNS group (median, 60.9 VS 35.9; P < 0.001). Seventeen (73.9%) of the 23 SA infected patients had a sinus tract, while only 12 (18.8%) of the 64 CoNS-infected patients had this symptom (73.9% VS 18.8%; P < 0.001). At the time of follow-up, 58 (90.6%) of the 64 CoNS-infected patients had successfully controlled the infection. In the SA group, 20 (87.0%) patients ultimately acquired successful control (90.6% VS 87.0%; P = 0.923). Surgical history was identified as a potential risk factor (OR = 6.2, 95%CI 1.17-32.4) for prognosis when potential covariates were adjusted.

CONCLUSIONS

SA infection has a higher ESR value and a more frequent occurrence of sinus tract. The infection control rate of the two-stage revision protocol was close to 90% for both SA and CoNS species, and there is no statistically significant difference in the eradication rate of infection between the SA and CoNS groups. Surgical history may be a good predictor of failure for PJI patients treated with two-stage revision.

An often-unrecognized entity as cause of recurrent infection after successfully treated two-stage exchange arthroplasty: hematogenous infection

INTRODUCTION

Reinfection after two-stage exchange arthroplasty is a difficult clinical scenario with limited data on adequate treatment algorithms. Beside the possibility of treatment failure and a new intraoperative infection at the time of reimplantation, hematogenous seeding could play an up to date underestimated crucial role as another cause of an infection after two-stage exchange. The aim of this study was to evaluate its incidence and treatment possibilities in a prospectively followed case series.

METHODS

All consecutive hip and knee periprosthetic joint infection cases (93 hips and 89 knees) treated according to a standardized diagnostic and therapeutic algorithm at our institution with a two-stage exchange arthroplasty from 2013 to 2015 were included and followed prospectively to identify recurrent infections due to hematogenous seeding.

RESULTS

Six percent from our septic revision hip and knee arthroplasties (11 of 182, including 5 hips and 6 knees) were identified with a hematogenous reinfection after a mean follow-up of 31.8 months (range 14-48 months). The mean time to reinfection after reimplantation was 12.2 months (range 3.1-35.1). In all but two cases was the causative microorganism different than isolated at the time of initial two-stage exchange. In 5 of 11 patients, the primary focus of infection was identified.

CONCLUSION

Hematogenous infection after a successful two-stage exchange arthroplasty is a rare but very important cause of a reinfection. With our work, we aim at raising the awareness for this entity and recommend consideration of irrigation and debridement with implant retention in these cases, as well as possibly the identification of a primary infection source.

Selected Heat-Sensitive Antibiotics Are Not Inactivated During Polymethylmethacrylate Curing and Can Be Used in Cement Spacers for Periprosthetic Joint Infection

BACKGROUND

Antibiotic use in polymethylmethacrylate (PMMA) spacers has historically been limited to those which are "heat-stable" and thus retain their antimicrobial properties after exposure to the high temperatures which occur during PMMA curing.

METHODS

This study examines the requirement of "heat stability" by measuring temperatures of Palacos and Simplex PMMA as they cure inside commercial silicone molds of the distal femur and proximal tibia. Temperature probes attached to thermocouples were placed at various depths inside the molds and temperatures were recorded for 20 minutes after PMMA introduced and a temperature curve for each PMMA product was determined. A "heat-stable" antibiotic, vancomycin, and a "heat-sensitive" antibiotic, ceftazidime, were placed in a programmable thermocycler and exposed to the same profile of PMMA curing temperatures. Antimicrobial activity against Staphylococcus aureus was compared for heat-treated antibiotics vs room temperature controls.

RESULTS

Peak PMMA temperatures were significantly higher in tibial (115.2°C) vs femoral (85.1°C; P < .001) spacers. In the hottest spacers, temperatures exceeded 100°C for 3 minutes. Simplex PMMA produced significantly higher temperatures (P < .05) compared with Palacos. Vancomycin bioactivity did not change against S aureus with heat exposure. Ceftazidime bioactivity did not change when exposed to femoral temperature profiles and was reduced only 2-fold with tibial profiles.

CONCLUSION

The curing temperatures of PMMA in knee spacers are not high enough or maintained long enough to significantly affect the antimicrobial efficacy of ceftazidime, a known "heat-sensitive" antibiotic. Future studies should investigate if more "heat-sensitive" antibiotics could be used clinically in PMMA spacers.

Custom-made, antibiotic-loaded, acrylic cement spacers using a dental silicone template for treatment of infected hip prostheses

PURPOSE

Antibiotic-loaded acrylic cement (ALAC) spacers are useful for treatment of infected prostheses in the course of a two-stage revision. Spacers are handmade or are made using a commercial template, with reportedly good treatment outcomes. This study aimed to confirm the usefulness of custom-made ALAC spacers shaped like bipolar hip prostheses using a dental silicone template for treatment of infected hip prostheses, and described their manufacture.

METHODS

This study evaluated 10 patients who underwent two-stage revision for treatment of infected hip prostheses. Custom-made ALAC spacers were used in all patients. Templates were made with dental silicone. We investigated the following in treatment of the infected hip prostheses: bacterial pathogens; antibiotic-cement mixtures; waiting time to revision; dislocation, breakage, and migration of custom-made ALAC spacers; current hip status; progress during follow-up; presence or absence of recurrence; and walking ability.

RESULTS

Dislocation, breakage, and migration were not observed in custom-made ALAC spacers. All patients recovered after two-stage revision without additional surgery and showed no recurrence during the follow-up period.

CONCLUSION

Custom-made ALAC spacers shaped like bipolar hip prostheses using a template made of dental silicone may be useful for treatment of infected hip prostheses.

Two-stage revision for the culture-negative infected total hip arthroplasty : A comparative study

Aims

Periprosthetic joint infection (PJI) remains a challenging complication following total hip arthroplasty (THA). It is associated with high levels of morbidity, mortality and expense. Guidelines and protocols exist for the management of culture-positive patients. Managing culture-negative patients with a PJI poses a greater challenge to surgeons and the wider multidisciplinary team as clear guidance is lacking.

Patients and Methods

We aimed to compare the outcomes of treatment for 50 consecutive culture-negative and 50 consecutive culture-positive patients who underwent two-stage revision THA for chronic infection with a minimum follow-up of five years.

Results

There was no significant difference in the outcomes between the two groups of patients, with a similar rate of re-infection of 6%, five years post-operatively. Culture-negative PJIs were associated with older age, smoking, referral from elsewhere and pre-operative antibiotic treatment. The samples in the culture-negative patients were negative before the first stage (aspiration), during the first-stage (implant removal) and second-stage procedures (re-implantation).

Conclusion

Adherence to strict protocols for selecting and treating culture-negative patients with a PJI using the same two-stage revision approach that we employ for complex culture-positive PJIs is important in order to achieve control of the infection in this difficult group of patients.

Cite this article: Bone Joint J 2018;(1 Supple A)100-B:3–8.

One-Stage Exchange Arthroplasty: A Surgical Technique Update

BACKGROUND

Standard surgical treatment for a periprosthetic knee infection has been based on a staged surgical technique, in order to assure infection eradication prior to implantation of a new prosthesis.

METHODS

In this article, we discuss our surgical technique in undertaking a single-stage exchange of a chronic knee periprosthetic infection.

RESULTS

This technique, which is based on the fundamental principles of controlling infection, preventing recurrence, and restoring function, has been shown to deliver high success rates.

CONCLUSION

As demonstrated, when undertaken under appropriate circumstances, a single-stage exchange combined with local and systemic antibiotic delivery can result in infection eradication comparable to a 2-staged exchange.

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients

BACKGROUND

The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before.

QUESTIONS/PURPOSES

(1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation?

METHODS

Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All patients were assessed before surgery, between stages, every 3 months during the first year after surgery, every 6 months during the second year postoperative, and at latest followup, and were retrospectively drawn from a longitudinally maintained institutional database.

RESULTS

Thirty-four of 35 patients (97.2%; 95% CI, 85.4%-99.5%) appeared free of infection by criteria of Masri et al. and Zimmerli et al. at latest followup. The Harris hip score was 61 ± 13 points after the first operation and 82 ± 16 points 2 years after the second operation.

CONCLUSIONS

This technique is a promising treatment option for periprosthetic infections of the hip in which substantial acetabular defects exclude implantation of a normal spacer and a two-stage revision of the femoral component is favored.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Single-Stage Revision Arthroplasty for Infection-An Underutilized Treatment Strategy

BACKGROUND

The burden of revision arthroplasty surgery for infection is rising as the rate of primary arthroplasty surgery increases. Infected arthroplasty rates are now relatively low, but the sheer increase in volume is leading to considerable patient morbidity and significant increases in costs to the health care system. Single-stage revision for infection is one of the several accepted treatment options, but the indications and results are debated. This review aims to clarify the current evidence.

METHODS

MEDLINE/PubMed databases were reviewed for studies that looked at single- or one-stage revision knee or hip arthroplasty for infection.

RESULTS

There is increasing evidence that single-stage revision for infection can control infection and with decreased morbidity, mortality, and health care costs compared with a staged approach. However, the indications are still debated. Recently, there has been a determined effort to define an infected arthroplasty in a manner that will allow for standardization of reporting in the literature. The evidence supporting single stage for knee arthroplasty is catching up with the result with hip arthroplasty. High-quality data from randomized controlled trials are now pending.

CONCLUSION

After the gradual evolution of using the single-stage approach, with the widespread acceptance of this definition, we can now standardize comparisons across the world and move toward a refined definition of the ideal patient population for single-stage arthroplasty revision in both the hip and the knee population.

Current treatment of infected non-union after intramedullary nailing

Non-union is a devastating consequence of a fracture. Non-unions cause substantial patient morbidity with patients suffering from loss of function of the affected extremity, increased pain, and a substantial decrease in the quality of life. The management is often associated with repeated, unsuccessful operations resulting in prolonged hospital stays, which has social and economic consequences to both the patient and the healthcare system. The rates of non-union following intramedullary (IM) nailing vary according to anatomical location. There is currently no consensus regarding the treatment of infected non-unions following IM nailing, but the most common procedures reported are; exchange IM nail with antibiotic suppression or excision of the non-union, (stabilisation with external fixation or less commonly plate or IM nail) and then reconstruction of the bone defect with distraction osteogenesis or the Masquelet technique. This article explores the general principles of treatment, fixation modalities and proposes a treatment strategy for the management of infected non-unions following intramedullary nailing.

Distribution characteristics of Staphylococcus spp. in different phases of periprosthetic joint infection: A review

Periprosthetic joint infection (PJI) is a devastating condition and Staphylococcus spp. are the predominant pathogens responsible, particularly coagulase-negative staphylococci (CoNS) and Staphylococcus aureus. The aim of the present systematic review was to evaluate the distribution characteristics of specific Staphylococcus spp. in different PJI phases, reveal the effect of pathogens' feature on their distribution and suggest recommendations for antibiotic treatment of Staphylococcal PJI. The present systematic review was performed using PubMed and EMBASE databases with the aim to identify existing literature that presented the spectrum of Staphylococcus spp. that occur in PJI. Once inclusion and exclusion criteria were applied, 20 cohort studies involving 3,344 cases in 3,199 patients were included. The predominant pathogen involved in PJI was indicated to be CoNS (31.2%), followed by S. aureus (28.8%). This trend was more apparent in hip replacement procedures. In addition, almost equal proportions of CoNS and S. aureus (28.6 and 30.0%, respectively) were indicated in the delayed phase. CoNS (36.6%) were the predominant identified organism in the early phase, whereas S. aureus (38.3%) occurred primarily in the late phase. In PJI caused by S. aureus, the number of cases of methicillin-sensitive Staphylococcus aureus (MSSA) was ~2.5-fold greater than that of methicillin-resistant Staphylococcus aureus (MRSA). MRSA occurred predominantly in the early phase, whereas MSSA was largely observed in the delayed and late phases. With regards to antibiotic treatment, the feature of various pathogens and the phases of PJI were the primary considerations. The present review provides useful information for clinical practice and scientific research of PJI.