INTRODUCTION. Peri-prosthetic fungal infection is generally considered more difficult to cure than a bacterial infection. Two-stage exchange is considered the gold standard of surgical treatment. A recent study, however, reported a favorable outcome after one stage exchange in selected cases where the fungus was identified prior to surgery. The routine one stage exchange policy for bacterial peri-prosthetic infection involves the risk of identifying a fungal infection mimicking bacterial infection solely on intraoperative samples, i.e. after reimplantation, realizing actually a one stage exchange for fungal infection without pre-operative identification of the responsible fungus, which is considered to have a poor prognosis. We report two such cases of prosthetic hip and knee fungal infection. Despite this negative characteristic, no recurrence of the fungal infection was observed. CASE N°1: A 78 year old patient was referred for loosening of a chronically infected total hip arthroplasty (Staphylococcus aureus and Streptococcus dysgalactiae). One stage exchange was performed. Intraoperative bacterial cultures remained sterile. Two fungal cultures were positive for Candida albicans. Antifungal treatment was initiated for three months. No infection recurrence was observed at three year follow up. CASE N° 2: A 53-year-old patient was referred for loosening of a chronically infected total knee prosthesis (Staphylococcus aureus methicillin susceptible, Klebsiella pneumoniae and Staphylococcus epidermidis). One stage exchange was performed. Intraoperative bacterial cultures remained sterile. Five fungal cultures were positive for Candida albicans. Antifungal treatment was initiated for three months. No infection recurrence was observed at two-year follow-up. DISCUSSION. This experience suggests that eradication of fungal infection of a total hip or knee arthroplasty may be possible after one stage exchange even in cases where the diagnosis of fungal infection was not known before surgery, when the fungus was not identified and its antifungal susceptibility has not been evaluated before surgery. It is however not possible to propose this strategy as a routine procedure. CONCLUSION. We suggest evaluating the results of one stage exchange for peri-prosthetic fungal infection on a larger scale

Introduction

Periprosthetic infection following lower extremity total joint arthroplasty often requires multiple surgical procedures and imposes a marked economic burden on the patient and hospital. The purpose of this study was to evaluate the incidence of surgical site infections in total joint arthroplasty patients who used an advance at-home pre-admission cutaneous preparation protocol and to compare these results to a cohort of patients who underwent standard in-hospital peri-operative preparation only.

Objectives. We wanted to investigate regional variations in the organisms reported to be causing peri-prosthetic infections and to report on prophylaxis regimens currently in use across England. Methods. Analysis of data routinely collected by Public Health England’s (PHE) national surgical site infection database on elective primary hip and knee arthroplasty procedures between April 2010 and March 2013 to investigate regional variations in causative organisms. A separate national survey of 145 hospital Trusts (groups of hospitals under local management) in England routinely performing primary hip and/or knee arthroplasty was carried out by standard email questionnaire. Results. Analysis of 189 858 elective primary hip and knee arthroplasty procedures and 1116 surgical site infections found statistically significant variations for some causative organism between regions. There was a 100% response rate to the prophylaxis questionnaire that showed substantial variation between individual trust guidelines. A number of regimens currently in use are inconsistent with the best available evidence. Conclusions. The approach towards antibiotic prophylaxis in elective arthroplasty nationwide reveals substantial variation without clear justification. Only seven causative organisms are responsible for 89% of infections affecting primary hip and knee arthroplasty, which cannot justify such widespread variation between prophylactic antibiotic policies. Cite this article: Bone Joint Res 2015;4:181–189

Peri-prosthetic joint infection (PJI) is one the most devastating complications of joint arthroplasty. Although PJI is an infrequent complication (the reported incidence is 1%-2% in the United States), it is the most common indication for revision total knee arthroplasty in the Medicare population and the third most frequent indication for revision total hip arthroplasty. Moreover, the prevalence of PJI appears to be on the rise, with a projected number exceeding 60,000 to 70,000 cases in the United States by 2020. It is estimated that more than 25% of revision procedures annually are attributed to PJI and this number is expected to increase in the upcoming years. The increase in the prevalence of obesity, diabetes, and other comorbidities among the patient population and the emergence of resistant infecting organisms are some of the reasons for the expected rise in the number of infections that medical community will witness. The challenges that PJI present to the orthopaedic community are on many fronts. Prevention of PJI has proven to be a difficult task indeed. Effective strategies for prevention of PJI are being refined. The Center for Disease Control will be publishing its updated Surgical Site Prevention Guidelines in the next few months that consists of specific recommendations for prevention of PJI. In recent years, strides are made in introducing novel molecular techniques for diagnosis of PJI, which may stand to change our practices. The current surgical technique for management of PJI, besides the immense cost, fall short of delivering high success to the patients. The major problem in eradication of infection relates to formation of biofilm on the implant surface and internalization of the organisms by affected cells. Biofilm is a sophisticated structure comprising of organisms embedded in multiple layers of glycoccalyx that allows the organisms to evade host immunity and is impenetrable to antibiotics. These organisms are capable of communicating through molecular mechanisms such as quorum sensing that affords them advantage for survival in the host environment. In recent years strategies to prevent colonization of the implant surface, an essential first step in formation of biofilm, or biofilm disruption techniques have been introduced. A recent International Consensus meeting on PJI that assembled more than 350 experts identified some of the best practices in this field and identified areas in need of future research. Moving into the future, the field of orthopaedics in general and PJI in particular stand to benefit from the discoveries in the field of molecular diagnostics, metabolomics and epigenetics

To report our experience with the use of local antibiotic co-delivery with a synthetic bone graft substitute during a second stage re-implantation of an infected proximal humeral replacement. A 72 year old man was admitted to our department with a pathological fracture through an osteolytic lesion in the left proximal humerus, due to IgG Myelomatosis. He was initially treated with a cemented proximal humerus replacement hemiarthroplasty. Peri-prosthetic joint infection (PJI) with significant joint distention was evident three weeks post operatively. Revision surgery confirmed presence of a large collection of pus and revealed disruption of the soft tissue reattachment tube, as well as complete retraction of rotator cuff and residual capsule. All modular components were removed and an antibiotic-laden cement spacer (1.8g of Clindamycin and Gentamycin, respectively) was implanted onto the well-fixed cemented humeral stem. Initial treatment with i.v. Amoxicillin/Clavulanic acid was changed to Rifampicin and Fusidic Acid during a further 8 weeks after cultures revealed growth of S. epidermidis. During second stage revision, a hybrid inverse prosthesis with silver coating was implanted, with a total of 20 ml Cerament ™G (injected into the glenoid cavity prior to insertion of the base plate and around the humeral implant-bone interface) and again stabilized with a Trevira tube. Unfortunately, this prosthesis remained unstable, ultimately requiring re-revision to a completely new constrained reverse prosthesis with a custom glenoid shell and silver-coated proximal humeral component. 18 months postoperatively, the patient's shoulder remains pain free and stable, without signs of persistent or reinfection since the initial second stage revision. The function however, unfortunately remains poor. This case report illustrates the application of an antibiotic-eluting bone graft substitute in a specific clinical situation, where co-delivery of an antibiotic together with a bone remodeling agent may be beneficial to simultaneously address PJI as well as poor residual bone quality

Aim. Advocates of Debridement-Antibiotics-and-Implant-Retention (DAIR) in hip peri-prosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis-bone interface is likely to lead to better survival and functional outcome compared to revision. However, no evidence supports this. This case-control study's aims were to compare outcome of DAIRs for infected 1° total hip arthroplasty (THA) with outcomes following 1° THA and 2-stage revisions of infected 1° THAs. Method. We retrospectively reviewed all DAIRs, performed for confirmed infected 1° THR (DAIR-Group, n=80), in our unit between 1997–2013. Data recorded included patient demographics, medical history, type of surgery and organism identified. Outcome measures included complications, mortality, implant survivorship and functional outcome using the Oxford Hip Score (OHS). Outcome was compared with 2 control groups matched for gender and age; a cohort of 1° THA (1°-THA-Group, n=120) and a cohort of 2-stage revisions for infection (2-Stage-Revision-Group, n=66). Results. The mean age at DAIR was 69 years and mean follow-up was 8 years (SD:5). 60% of DAIRs were for early PJI (< six weeks). Greater infection eradication with DAIR was detected with early-PJI, interval less than a week between onset of symptoms and exchange of modular components with the DAIR procedure. Infection eradication, complications and re-operation rates were similar in the DAIR- and 2-stage-revision Groups (p>0.05). For hips with successful infection eradication with DAIR, the 5-yr survival (98%) was similar to the 1°THA-Group (98%) (p=0.3). The DAIR-Group had inferior OHS (38) compared to the 1°THA-Group (42) (p=0.02) but significantly better OHS compared to the 2-stage-revision-Group (31) (p=0.008). Patients that required only one DAIR for infection eradication had similar OHS (41) to the 1° THA-Group (p=0.2). Conclusions. DAIRs are associated with similar complication and infection eradication to 2-stage revisions. Exchange of modular components is advised for improved chances of infection eradication. Functional outcome following DAIRs was better than a 2-stage revision and as good as that of a 1° THA if a single DAIR was necessary for infection eradication

Periprosthetic joint infection (PJI) is a devastating complication of total hip arthroplasty (THA). According to registry-based studies, some bearing couples are associated with an increased risk of PJI. The recent International Consensus on Periprosthetic Joint Infection stated that metal-on-metal (MOM) bearing surface appeared to be associated with a higher incidence of PJI. Based on emerging reports, the incidence of PJI appears to be different among different bearing surfaces. We conducted a multi-institutional study attempting to study this exact issue. The purpose of the study was to determine whether there was any difference in the incidence of PJI in two commonly used bearing couples (metal- on-polyethylene versus ceramic-on-polyethylene).

Based on a retrospective multi-institutional query all patients who received primary THA with MOP or COP bearing surfaces performed during 2005–2009 in two high-volume arthroplasty centers were identified. Demographic factors, comorbidities, length of hospital stay, complications and other relevant information were extracted. PJI was defined based on the MSIS (International Consensus) criteria. Multivariate analysis was performed to determine whether bearing coupling was independently correlated with PJI.

In our data, 25/2,921 (0.9%) patients with MOP and 11/2,643 (0.4%) patients with COP developed PJI. This difference was statistically significant (p=0.01). After the multivariate analysis, controlling for potential confounders (age, body mass index and length of hospital stay, Charlson comorbidity index), MOP bearing surface was found to be an independent factor correlating with higher incidence of PJI (odds ratio: 2.6, 95% confidence interval: 1.02–6.54, p=0.04).

The finding of this study, and others from centers in Europe, suggest that the bearing surface may have an influence on the incidence of PJI. Although, we had originally thought that ceramic bearing surfaces may be used in younger and healthier patients, the multivariate analyses that controlled for all these variables confirms that use of metal femoral head is an independent risk factor for development of PJI. The finding of this study is compelling and begs for future basic science mechanistic investigations.

There is limited evidence in the literature suggesting that ceramic-on-ceramic (CoC) THA is associated with lower risk of revision for prosthetic joint infection (PJI) than other bearing combinations especially metal-on-poly (MoP) and metal-on-metal (MoM). Pitto and Sedel reported hazard ratios of 1.3 – 2.1 for other bearing surfaces versus CoC. Of interest, the PJI rate was not significantly lower in the first 6 months, when most infections occur, but only became significant in the long term. While factors such as patient age, fixation, mode, OR type, use of body exhaust suits, and surgeon volume were considered in the multivariate analysis, BMI, medical comorbidities, and ASA class were not. This is a major weakness that casts doubt on the conclusion, since those three factors are MAJOR risk factors for PJI AND all three factors are more likely to be unevenly distributed, and much more likely present in groups other than CoC. The data was also limited by the fact that it was drawn from a retrospective review of National Registry data, The New Zealand Joint Registry. While similar findings have recently been reported from the Australian Joint Registry, the danger in attributing differences in outcomes to implants alone is possibly the single greatest danger in interpreting registry results. While device design can impact implant survival, other factors such as surgical technique, surgeon, hospital, and especially patient factors have a far greater likelihood of explaining differences in observed results. A recent report from the same New Zealand joint registry reported that obesity, ASA class, surgical approach, and trainee operations all were associated with higher PJI and all would be more likely in non-CoC THAs. Accuracy of diagnosis is also a major concern. Revision for trunnionosis is more common in non-CoC THA and is frequently misdiagnosed as PJI.

Numerous non-registry studies and reviews have compared PJI in CoC vs. other bearings and none have concluded than the incidence of PJI differed significantly.

Aim

Compare clinical outcomes following staged revision arthroplasty for periprosthetic joint infection (PJI) secondary to either multidrug resistant (MDR) bacteria or non-MDR (NMDR) bacteria.

Background: Chronic prosthetic joint infection is a cause of patient morbidity and can be challenging to treat. Surgeons performing revision arthroplasty of the hip and knee are confronted with a growing number of patients with extensive loss of bone stock. The use of a modular endoprosthesis is a possible method of treatment in such patients.

Aim: The purpose of this study was to assess the functional outcomes and the success of a single and two stage revision procedure in eradicating chronic prosthetic joint infection using a femoral endoprosthesis.

Methods: A prospective database was reviewed of 20 patients who underwent a proximal, total or distal femoral endoprosthetic replacement after chronic prosthetic infection. Radiographs performed at the time of latest follow up were evaluated for signs of loosening, osteomyelitis and implant failure. The functional status was assessed using the Short Form (SF)-36 health survey score, Toronto extremity salvage score (TESS) and the Enneking score.

Results: Thirteen patients underwent a single stage revision procedure and seven had been treated with a staged revision. At the latest follow up none of the 13 patients treated with a single stage procedure had evidence of ongoing infection. Of the seven patients who had a staged revision, 3 patients had evidence of ongoing infection. The mean pre operative Enneking score for the entire group was 17.1 points and this improved to 47.5 points post operatively (p< 0.0002). The mean pre operative TESS score for the entire group was 42% and this improved to 59% post operatively (p< 0.005). There was also a statistically significant improvement in all of the components of the SF-36 score.

Conclusion: We believe that the use of a modular endo-prosthesis in the treatment of chronic prosthetic joint infection is a successful and viable option in eradicating infection, preserving the limb and providing a good functional result.

Aim

Dissolvable antibiotic-loaded calcium sulphate beads have been utilized for management of periprosthetic joint infection (PJI) and for aseptic revision arthroplasty. However, wound drainage and toxic reactive synovitis have been substantial problems in prior studies. Currently a commercially pure, physiologic product has been introduced that may reduce complications associated with this treatment modality. We aim to answer the question: does a commercially pure, physiologic version of antibiotic-loaded calcium sulfate beads reduce wound drainage and provide efficacious treatment for PJI and aseptic revision arthroplasty?

Infection remains among the first reasons for failure of joint prosthesis. Currently, the golden standard for treating prosthetic joint infections (PJIs) is two-stage revision. However, two-stage procedures have been reported to be associated with higher costs and possible higher morbidity and mortality, compared to one-stage. Furthermore, recent studies showed the ability of a fast-resorbable, antibacterial-loaded hydrogel coating to reduce surgical site infections after joint replacement, by preventing bacterial colonization of implants. Aim of this study was then to compare the infection recurrence rate after a one-stage, cemenless exchange, performed with an antibacterial coated implant versus a standardized two-stage revision procedure.

In this two-center prospective study, 22 patients, candidate to revision surgery for PJI, were enrolled to undergo a one-stage revision surgery with cementless implants, coated intra-operatively with a fast-resorbable, antibiotic-loaded hyaluronan and poly-D,L-lactide based hydrogel coating (“Defensive Antibacterial Coating”, DAC, Novagenit, Italy). DAC was reconstructed according to manufacturer indications and loaded with Vancomycin or Vancomycin + Meropenem, according to cultural examinations, and directly spread onto the implant before insertion. This prospective cohort was compared with a retrospective series of 22 consecutive patients, matched for age, sex, host type, site of surgery, that underwent a two stage procedure, using a preformed, antibiotic-loaded spacer (Tecres, Italy) and a cementless implant. The second surgery, for definitive implant placing, was performed only after CRP normalization and no clinical sign of infection. Clinical, laboratory and radiographic evaluation were performed at 3, 6 and 12 months, and every 6 months thereafter. Infection recurrence was defined by the presence of a sinus tract communicating with the joint, or at least two among the following criteria: clinical signs of infections; elevated CRP and ESR; elevated synovial fluid WBC count; elevated synovial fluid leukocyte esterase; a positive cultural examination from synovial fluid; radiographic signs of stem loosening.

The two groups did not differ significantly for age, sex, host type and site of surgery (18 knees and 4 hips, respectively). The DAC hydrogel was loaded intra-operatively, according to cultural examination, with vancomycin (14 patients) or vancomycin and meropenem (8 cases). At a mean follow-up of 20.2 ± 6.3 months, 2 patients (9.1%) in the DAC group showed an infection recurrence, compared to 3 patients (13.6%) in the two-stage group. No adverse events associated with the use of DAC or radiographic loosening of the stem were observed at the latest follow-up months.

This is the first report on one-stage cementless revision surgery for PJI, performed with a fast-resorbable antibacterial hydrogel coating. Our data, although in a limited series of patients and at a relatively short follow-up, show similar infection recurrence rate after one-stage exchange with cementless, coated implants, compared to two-stage revision. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections.

Aim. Despite the availability of numerous tests, the diagnosis of periprosthetic infection (PJI) continues to be complex. Although several studies have suggested that coagulation-related markers, such as D-dimer and fibrinogen, may be promising tools in the diagnosis of prosthetic infections, their role is still controversial. The aim of this study is to evaluate the diagnostic accuracy of serum D-dimer and fibrinogen in patients with painful total knee replacement. Method. 83 patients with painful total knee replacement and suspected peri-prosthetic infection were included. All patients underwent pre-operative blood tests to evaluate inflammation indices (ESR and CRP) and serum D-Dimer and Fibrinogen levels. The diagnostic performance of the tests was assessed using the ICM definition as the gold standard. The diagnostic accuracy of the D-dimer and fibrinogen was measured by assessing sensitivity, specificity and by calculating the area under the ROC curve. Results. The definition of prosthetic infection based on the ICM criteria has made it possible to classify 40 peri-prosthetic infections and 43 aseptic failures. The mean value of fibrinogen, D-Dimer, VES and PCR observed in patients with prosthetic infection was significantly higher than in patients with aseptic failure [fibrinogen 468 mg / dl vs 331 mg / dl, p <0.001; D-Dimero 2177 ng/mL vs. 875 ng / mL, p <0.005], ESR 49 mm / hr vs 24 mm/h, p <0.001; PCR 25.5 mg /L vs 8.9 mg/L, p <0.001]. The optimal threshold value of the fibrinogen indicative of the presence of infection was 418 mg/dl, with a sensitivity of 72% and a specificity of 88%. The serum concentration of d-dimer greater than 945 ng / ml showed a sensitivity of 72.5% and a specificity of 76.7%. Conclusions. Although in this multicenter prospective study we found that serum D-dimer may have significantly higher statistical values in PJI than aseptic failures, its diagnostic power appears however limited when compared with other markers including plasma fibrinogen. Fibrinogen is regularly analyzed before surgery, the evaluation of this marker does not involve additional costs. The diagnostic accuracy appears to be similar to that of classic markers such as the level of PCR and VES. Plasma D-dimer may have a limited value in the diagnosis of PJI unlike plasma fibrinogen which has shown moderate sensitivity and excellent specificity. However, in our limited series of cases, both tests cannot be used alone in the diagnosis of infection but could contribute to the diagnosis if contextualized to ves and pcr

Aim. Whether pre-operative microbiological sampling contributes to the management of chronic peri-prosthetic infection remains controversial. We assessed agreement between the results of pre-operative and intra-operative samples in patients undergoing single-stage prosthesis exchange to treat chronic peri-prosthetic infection. The tested hypothesis was that agreement between pre-operative and intra-operative samples exceeds 75% in patients undergoing single-stage exchange of a hip or knee prosthesis to treat chronic peri-prosthetic infection. Method. This single-centre retrospective study included 85 single-stage prosthesis exchange procedures in 82 patients with chronic peri-prosthetic infection at the hip or knee. Agreement between pre-operative and intra-operative sample results was evaluated. Changes to the initial antibiotic regimen made based on the intra-operative sample results were recorded. Associations between sample agreement and infection-free survival were assessed. Results. Of 149 pre-operative samples, 109 yielded positive cultures, in 75/85 cases. Of 458 intra-operative samples, 354 yielded positive cultures, in 85/85 cases. Agreement was complete in 54 (63%) cases and partial in 9 (11%) cases; there was no agreement in the remaining 22 (26%) cases. The complete agreement rate was significantly lower than 75% (p=0.01). The initial antibiotic regimen was inadequate in a single case. Agreement between pre-operative and intra-operative samples was not significantly associated with infection-free survival. Conclusions. Pre-operative sampling may contribute to the diagnosis of peri-prosthetic infection but is neither necessary nor sufficient to confirm the diagnosis and identify the causative agent. The spectrum of the initial antibiotic regimen cannot be safely narrowed based on the pre-operative sample results. We suggest the routine prescription of a probabilistic broad-spectrum antibiotic regimen immediately after the prosthesis exchange, even when a pathogen was identified before surgery. No funding from any part was received for the purpose of this study

The diagnosis of infection following shoulder arthroplasty is notoriously difficult. The prevalence of prosthetic shoulder infection after arthroplasty ranges from 3.9 – 15.4% and the most common infective organism is Cutibacterium acnes. Current preoperative diagnostic tests fail to provide a reliable means of diagnosis including WBC, ESR, CRP and joint aspiration. Fluoroscopic-guided percutaneous synovial biopsy (PSB) has previously been reported in the context of a pilot study and demonstrated promising results. The purpose of this study was to determine the diagnostic accuracy of percutaneous synovial biopsy compared with open culture results (gold standard). This was a multicenter prospective cohort study involving four sites and 98 patients who underwent revision shoulder arthroplasty. The cohort was 60% female with a mean age was 65 years (range 36-83 years). Enrollment occurred between June 2014 and November 2021. Pre-operative fluoroscopy-guided synovial biopsies were carried out by musculoskeletal radiologists prior to revision surgery. A minimum of five synovial capsular tissue biopsies were obtained from five separate regions in the shoulder. Revision shoulder arthroplasty was performed by fellowship-trained shoulder surgeons. Intraoperative tissue samples were taken from five regions of the joint capsule during revision surgery. Of 98 patients who underwent revision surgery, 71 patients underwent both the synovial biopsy and open biopsy at time of revision surgery. Nineteen percent had positive infection based on PSB, and 22% had confirmed culture positive infections based on intra-operative tissue sampling. The diagnostic accuracy of PSB compared with open biopsy results were as follows: sensitivity 0.37 (95%CI 0.13-0.61), specificity 0.81 (95%CI 0.7-0.91), positive predictive value 0.37 (95%CI 0.13 – 0.61), negative predictive value 0.81 (95%CI 0.70-0.91), positive likelihood ratio 1.98 and negative likelihood ratio 0.77. A patient with a positive pre-operative PSB undergoing revision surgery had an 37% probability of having true positive infection. A patient with a negative pre-operative PSB has an 81% chance of being infection-free. PSB appears to be of value mainly in ruling out the presence of peri-prosthetic infection. However, poor likelihood ratios suggest that other ancillary tests are required in the pre-operative workup of the potentially infected patient

Deep peri-prosthetic infection after partial or total knee arthroplasty is a disconcerting problem for patient and surgeon alike. The diagnosis of infection is sometimes obvious but frequently requires that the surgeon maintain a substantial index of suspicion for infection as the cause of pain or poor outcome after any joint arthroplasty. While surgical debridement with component retention is appropriate in a subgroup of patients with an acute peri-prosthetic infection, most delayed and chronic infections are best treated with component resection. With carefully selected patients and very aggressive debridement protocols some success has been demonstrated in Europe with single-stage exchange for infection. Most surgeons in North America, however, are unfamiliar with the very aggressive debridement techniques employed at European centers that promote single stage replant; and few surgeons in North America are currently comfortable in cementing a hinged total knee replacement in place for the typical infected TKA nor do they have the patience to re-prep and drape with an entirely new OR setup after debridement and prior to the insertion of the new implant − 2 steps that are often mentioned as important to the success of single stage exchange. The pre-eminent role of two-stage exchange as the definitive treatment was established over 30 years ago. Two-stage exchange remains the gold-standard in treatment with an established track record from multiple centers and with multiple different types of infecting organisms. Some of the historical problems with two-stage exchange, such as limited mobility during the interval stage, have been mitigated with the development of effective articulating spacer techniques. Further, the emergence of drug resistant bacteria and the possibility of fungal infection make two-stage exchange the best choice for the majority of patients with deep periprosthetic joint infection in 2017

The use of routine sampling for histological analysis during revision hip replacement has been standard practice in our unit for many years. It is used to identify the presence of inflammatory processes that may represent peri-prosthetic infection. This study follows up on a smaller study in the same unit in 2019 where an initial 152 cases were scrutinised. In this follow up study we examined 1,361 consecutive patients over a 16-year period whom had undergone revision hip replacement in a tertiary orthopaedic centre for any reason excluding primary bone tumour or malignant metastasis. All patients had tissue sampling for histopathological analysis performed by consultant histopathologists with a specialist interest in musculoskeletal pathology. The presence of bacteria in greater than 50% of samples sent for microbiological analysis in each patient was used as the gold standard diagnostic comparator for infection. This was then compared with the histology report for each patient. After excluding 219 patients with incomplete data and 1 sample rejection, 1,141 cases were examined. Microbiology confirmed infection in 132 cases (prevalence of infection 11.04%) and histopathology analysis suggested infection in 171 cases. Only 64 cases with confirmed infection in more than 50% of microbiology samples had concurrent diagnosis of infection on histological analysis (5.60% of total; PPV 51.20%). Furthermore, microbiology analysis confirmed infection in 62 cases where histological analysis failed to identify infection (5.43% of total; False negative rate 49.21%). Overall, histopathology analysis was seen to have a good specificity of 93.99% but poor sensitivity of 50.79%. We believe that this is the largest series in the literature and is somewhat unique in that all histology analysis was performed by consultant histopathologists with specialist interest in musculoskeletal pathology. Based on the costs incurred by this additional investigation our experience does not support routine sampling for histological analysis in revision hip arthroplasty. This is a substantial paradigm shift from current practice among revision arthroplasty surgeons in the United Kingdom but would equate to a substantial cost saving

Aim. The diagnosis of peri-prosthetic infection is sometimes difficult to assess, and there is no universal diagnostic test. The recommendations currently accepted include several diagnostic criteria, and are based mainly on the results of deep bacteriological samples, which only provide the diagnosis after surgery. A predictive score of the infection might improve the peri-operative management before repeat surgery after total hip arthroplasty (THA). The goal of this study was to attempt defining a composite score using conventional clinical, radiological and biological data that can be used to predict the positive and negative diagnosis of peri-prosthetic infection before repeat surgery after THA. The tested hypothesis was that the score thus defined allowed an accurate differentiation between infected and non-infected cases in more than 75% of the cases. Method. 104 cases of repeat surgery for any cause after THA were analyzed retrospectively: 61 cases of infection and 43 cases without infection. There were 54 men and 50 women, with a mean age of 70 ± 12 years (range, 30 to 90 years). A univariate analysis looked for individual discriminant factors between infected and uninfected case file records. A multivariate analysis integrated these factors concomitantly. A composite score was defined, and its diagnostic effectiveness was assessed by the percentage of correctly classified cases and by sensitivity and specificity. Results. The score was defined with the following items which were individually weighted: body mass index (BMI), presence of diabetes (D, yes = 1, no = 0), mechanical complication (MC, yes = 1, no = 0), scar complication after THA implantation (SC, yes = 1, no = 0), fever (F, yes = 1, no = 0). The score was calculated as (0.09 × BMI) + (0.94 × D) − (1.34 × MC) + (17.55 × SC) + (1.22 × F) − 3.63. This composite score separated the infected (positive score) and non-infected (negative score) patients accurately in 78% of cases, with a sensitivity of 57% and a specificity of 93%. Conclusions. Subject to prospective validation, this score could be a significant help to define the medico-surgical strategy during a reoperation of the hip prosthesis for whatever reason. No funding from any part was received for the purpose of this study

Introduction: The goal of the study was to evaluate our treatment protocols for peri-prosthetic infection after total hip replacement. Méthode: A prospective study carried out between February 2003 and February 2005, included 100 patients treated for peri-prosthetic infection after total hip replacement. Debridement and prosthesis retention was performed in case of duration of symptoms of less than 14 days (11 cases), otherwise a one-stage (42 cases) or a two-stages (41 cases) prosthesis removal and re-implantation were carried out. A two-stage procedure was decided in case of important bone loss or undetermined germ. If general health state did not allow a re-implantation, an isolated prosthesis removal was performed (6 cases). Post-operatively, patients received intravenous antibiotics (6 weeks), then oral antibiotics (6 weeks). The mean follow-up was 2.2 years with no lost to follow-up. The main evaluation criteria was the rate of infection eradication with 2 years minimal follow -up. In case of a suspected new infection, a hip aspiration was performed to determine whether it was a non-eradication (same germ) or a new re-infection (other germ) which was not considered as a failure. Results: Infection eradication rate was 95% and 100% for the one-stage surgical procedure. 5 failures were recorded (2 deaths and 3 non-eradications). However, 3 patients were re-infected with different germs. The rate of non-infected patiens at the last follow-up was 92%. Conclusion: Our protocols were validated with a high success rate of 95%. Peri-prosthetic infection of the hip is severe even if well treated with a mortality rate of 2%

High doses of intra-articular (IA) antibiotics has been shown to effectively achieve a minimal biofilm eradication concentration which could mitigate the need for removal of infected but well-ingrown cementless components of a total hip arthroplasty (THA). However, there are concerns that percutaneous catheters could lead to multi-resistance or multi-organism peri-prosthetic joint infections (PJI) following single stage THA revisions for PJI. Eighteen single-stage revision procedures were performed for acute (N=9) or chronic (N=9) PJI following a primary (N=12) or revision (N=6) cementless THA. Modular and loosened components were replaced. All well ingrown components were retained. Two Hickmann catheters were placed in the joint space. Along with intravenous antibiotics, IA antibiotics were injected twice a day for two weeks, followed by 3 months of oral antibiotics. Per-operative cultures demonstrated 4 multi-bacterial PJIs. None of the patients developed post-operatively an AB related renal or systemic dysfunction. At a mean follow-up of 38 months [range, 8–72] all patients had normal erythrocyte sedimentation rate and white blood cell count. Four had a slightly elevated C-reactive protein but were completely symptom free and did not show any sign of loosening at a mean of 27 months [range, 16–59]. Addition of high doses of IA antibiotics following single-stage revision for PJI in cementless THA, is an effective and safe treatment option that allows for retention of well-ingrown components. We found no evidence for residual implant infection or catheter induced multi-resistance. Total hip arthroplasty, revision surgery, Periprosthetic Joint Infection, Intra-articular antibiotics. Level 4 (Case series)