Around 1% of total hip replacements are follow by prosthetic joint infection (PJI). There is uncertainty about best treatment method for PJI, and the most recent high quality systematic reviews in unselected patients indicates that re-infection rates following one-stage and two-stage revision arthroplasty are relatively similar. In the absence of evidence randomised controlled trials will help to identify the most clinically and cost-effective treatment for PJI. Before such trials are conducted, there is a need to establish reasons for current practice and to identify whether trials are feasible. This study aimed to deliver research that would inform trial design. Specifically, we aimed to characterise consultant orthopaedic surgeons' decisions about performing either one-stage or two-stage exchange arthroplasty for patients with PJI after hip replacement and to identify whether a randomised trial comparing one-stage with two-stage revision would be possible. Semi-structured interviews were conducted with 12 consultant surgeons from 5 high-volume National Health Service (NHS) orthopaedic departments in the UK. Surgeons were sampled on the basis that they perform revision surgery for PJI after hip arthroplasty and final sample size was justified on the basis of thematic saturation. Surgeons were interviewed face-to-face (n=2) or via telephone (n=10). The interview study took place before design of a multicentre prospective randomised controlled trial comparing patient and clinical outcomes after one-stage or two-stage revision arthroplasty. Data were audio-recorded, transcribed, anonymised and analysed using a thematic approach, with 25% of transcripts independently double-coded. Results: There is no standard surgical response to the treatment of PJI and surgeons manage a complex balance of factors when choosing a surgical strategy. These include multiple patient-related factors, their own knowledge and expertise, available infrastructure and the infecting organism. Surgeons questioned whether evidence supports the emergence of two-stage revision as a method. They described the use of loosely cemented articulating spacers as a way of managing uncertainty about best treatment method. All surgeons were supportive of a randomised trial to compare one-stage and two-stage revision surgery for PJI after hip replacement. Surgeons reported that they would put patients forward for randomisation when there was uncertainty about best treatment. Surgeons highlighted the need for evidence to support their choice of revision. Some surgeons now use revision methods that can better address both clinical outcomes and patients' quality of life, such as loosely cemented articulating spacers. Surgeons thought that a randomised controlled trial comparing one-stage and two-stage exchange joint replacement is needed and that randomisation would be feasible. The next stage of the work was to design a multi-centre randomised controlled trial, this has been achieved and the trial is now ongoing in the UK

Joint replacement is a highly effective intervention to treat osteoarthritis of the hip, relieving pain and improving mobility and quality of life.(1) Periprosthetic joint infection (PJI) is a devastating complication after arthroplasty. Debridement, antibiotics and implant retention are treatment of first choice in case of early infection after total hip arthroplasty (THA).(2) In case of persisting infection, one- or two-stage revision needs to be performed.(3) The use of different kinds of spacers has been widely debated in the past years.(4)

The aim of this study was to determine which type of spacer should be used during the interval of two-stage revision of an infected THA.

A search term with Boolean operators was constructed. We extracted all information regarding study and patient characteristics and baseline clinical and laboratory findings. Data regarding type of spacer and antibiotics used, timing of second stage surgery, tissue culture results, postoperative regimen, functional outcome and patient satisfaction were extracted.

A total of twenty-six studies met our inclusion criteria and were included for data analysis. Ten studies described various preformed spacers, six studies described functional spacers and eleven studies described custom made spacers. See Table 1 for results.

Research should focus on finding the preferred type of treatment and type of spacer to combine a high success rate of infection treatment with a good functional and patient reported outcome. There is a need for a prospective study evaluating patient satisfaction and functional outcome after two-stage revision THA comparing various spacers. Secondly, research should focus on the optimal timing of the second stage procedure.

Functional spacers achieve a comparable rate of infection eradication in the treatment of periprosthetic hip joint infections as compared to preformed spacers. There is insufficient evidence concerning rehabilitation and functional outcome after two-stage revisionTHA to advocate or discourage the use of either kind of interval spacer.

Aims. Treatment outcomes for methicillin-resistant Staphylococcus aureus (MRSA) periprosthetic joint infection (PJI) using systemic vancomycin and antibacterial cement spacers during two-stage revision arthroplasty remain unsatisfactory. This study explored the efficacy and safety of intra-articular vancomycin injections for PJI control after debridement and cement spacer implantation in a rat model. Methods. Total knee arthroplasty (TKA), MRSA inoculation, debridement, and vancomycin-spacer implantation were performed successively in rats to mimic first-stage PJI during the two-stage revision arthroplasty procedure. Vancomycin was administered intraperitoneally or intra-articularly for two weeks to control the infection after debridement and spacer implantation. Results. Rats receiving intra-articular vancomycin showed the best outcomes among the four treatment groups, with negative bacterial cultures, increased weight gain, increased capacity for weightbearing activities, increased residual bone volume preservation, and reduced inflammatory reactions in the joint tissues, indicating MRSA eradication in the knee. The vancomycin-spacer and/or systemic vancomycin failed to eliminate the MRSA infections following a two-week antibiotic course. Serum vancomycin levels did not reach nephrotoxic levels in any group. Mild renal histopathological changes, without changes in serum creatinine levels, were observed in the intraperitoneal vancomycin group compared with the intra-articular vancomycin group, but no changes in hepatic structure or serum alanine aminotransferase or aspartate aminotransferase levels were observed. No local complications were observed, such as sinus tract or non-healing surgical incisions. Conclusion. Intra-articular vancomycin injection was effective and safe for PJI control following debridement and spacer implantation in a rat model during two-stage revision arthroplasties, with better outcomes than systemic vancomycin administration. Cite this article: Bone Joint Res 2022;11(6):371–385

Prosthetic joint infection (PJI) is an uncommon but serious complication of hip replacement. Over 1,000 operations are performed annually in the United Kingdom for PJI following hip replacement, using either one- or two-stage revision arthroplasty. It is unclear which is preferred by patients and which has the best long-term outcome. This qualitative study aims to describe patient experiences of treatment and recovery following one- and two-stage revision arthroplasty for PJI within the context of a pragmatic randomised controlled trial comparing these two approaches. Semi-structured interviews were conducted with 32 patients undergoing one- or two-stage revision treatment for PJI as part of a UK multi-centre randomised controlled trial. Patients were recruited from 12 participating National Health Service (NHS) Orthopaedic Departments and were interviewed 2–4 months after their first revision surgery and again approximately 18 months later. Final sample size was justified on the basis of thematic saturation. All patients consented to the interview being audio-recorded, transcribed, anonymised and analysed using an inductive thematic approach. Ethical approval was provided by NRES Committee South-West Frenchay, 14/SW/116. Patients in both the one- and two-stage treatment groups described prolonged hospital stays, with burdensome antibiotics and brief physiotherapy treatment. However, following discharge home and during recovery, participants undergoing two-stage revision with an ‘empty hip' or with a spacer reported being physically restricted in almost every aspect of their daily life, resulting in inactivity and confinement to home. Mobility aids were not sufficiently available through the health service for these patients. A key difference is that those with a spacer reported more pain than those without. Approximately one year following their second-stage revision, participants described being more independent and active, but two directly attributed muscle weakness to the lengthy period without a hip and described resulting falls or dislocations that had complicated their recovery. In contrast, those undergoing one-stage revision and CUMARS appeared to be more alike, reporting better mobility, functionality and independence, although still limited. Participants in these groups also reported minimal or no pain following their revision. A key difference between CUMARS and one-stage revision was the uncertainty of whether a second operation was necessary, which participants described as “hanging over them”, while those in the two-stage empty hip or spacer group described a more positive anticipation of a second definitive operation as it marked an end to what was described as a detachment from life. Our findings highlight the differences between patient experiences of recovery following revision arthroplasty, and how this is influenced by the surgical approach and presence or lack of spacers. An understanding of lived experiences following one- and two-stage surgical interventions will complement knowledge about the clinical effectiveness of these different types of revision surgery

Aim. Identification of the causal pathogen is crucial in the management of periprosthetic joint infection (PJI) of the hip. Unfortunately, it was often difficult and negative culture could be a common findings. This situation made the treatment of PJI of the hip became more challenging. The negative culture finding resulted in a doubtful diagnosis of infection, and poses difficulty in choosing the appropriate antibiotics. Here we compared the treatment outcome of two-stage revision arthroplasty for culture-negative versus culture-positive PJI of the hip. Method. We retrospectively reviewed patients who received two-stage revision for PJI of the hip between January 2010 to June 2015. All patients was planned to received articulated antibiotic cement-spacer as the first stage and revision total hip arthroplasty (THA) as the second stage of the procedure. Out of total 94 patients, 10 patients was loss to follow-up and excluded from the study. We devided the rest of 84 patients into two groups: culture-negative group (n: 27) and culture-positive group (n: 57). We compared all relevant medical records and the treatment outcome between the two groups. Results. The mean of follow-up was 29.5 months (range, 12–78) in culture-negative group and 30.9 months (range, 12–71) in culture-positive group (p = 0.74). The overall negative culture finding rate was 30.8%. There was no significant difference on baseline data between the two groups including: age, gender, body mass index, preoperative C-reactive protein (CRP), preoperative erythrocyte sedimentation rate and preoperative white blood count, type of hip arthroplasty, previous history of irrigation and debridement (I & D), and preoperative Harris hip score (HHS). However, culture-negative group has significantly higher number on history of preoperative antibiotic use (p = 0.003). The reimplantation rate was 96.3% and 91.2% in culture-negative and culture-positive group, respectively (p= 0.39). The infection recurrency rate after reimplantation was 7.7% and 15.4% in culture-negative and culture-positive group, respectively (p= 0.33). The overall infection control rate was 92.6% (25/27) and 82.4% (47/57) in culture-negative and culture-positive group, respectively (p = 0.21). We also observed no significant difference on the time interval between stage, time to normal CRP, time to recurrency and complications rate between the two groups. A higher postoperative HHS was obtained in culture-negative group (p = 0.04). Conclusions. Negative culture finding was not resulted in an inferior treatment outcome compared to culture-positive group in periprosthetic joint infection of the hip which treated with two-stage revision arthroplasty

Introduction: The current gold standard for the treatment of the infected total knee arthroplasty is a two-stage revision. The purpose of this study is to present our results with two-stage revision arthroplasty in a series of 48 infected TKAs. Materials and Methods: Over a 10-year period (1996–2005) we have performed 2140 TKAs. Of them 48 (48 patients) were infected and required a two-stage revision arthroplasty (2.2% infection rate). In 43 patients of these patients we used LCCK prostheses (Zimmer, USA) and in 5 (with severe instability) a rotating hinge prosthesis (Waldemar Link, Germany). In 26 occasions antibiotics-loaded cement (Palacos with gentamicine) was used and in 22 we used articulated spacers. The average age of patients was 67 years (range, 59–82) and the average follow-up was 5.5 years (range: 1–10). The results were assessed according to the Knee Society scores. Results: Four knees were re-infected. Results were excellent in 28 knees, good in 13, fair in 3 and poor in 4 (the four re-infected prostheses). The four infected prostheses had been treated by static spacers. The survival rate taking as end-point removal of components for infection is 91.6% (results at average of 5.5 years). Conclusion: Our results confirm that two-stage revision TKA is a reproducible procedure in the infected primary TKA. Also that articulated antibiotic-loaded spacers seem to be better than static spacers

Periprosthetic joint infection (PJI) remains a challenging complication following Total Hip Arthroplasty (THA). It is associated with high levels of morbidity, mortality and is time consuming and expensive to treat. Our management generally relies on identification of the infecting organism(s) in order to define the appropriate treatment strategy. Patients with culture-negative PJI poses a greater challenge to surgeons and to the wider multidisciplinary team. This study compares the outcomes of 50 consecutive complex culture-positive (deemed unsuitable for single stage exchange) and 50 culture-negative THAs managed with two-stage revision arthroplasty with a minimum of five years follow-up. Culture-negative PJIs were associated with older age, smoking, external referral source and greater use of preoperative antibiotics. There was however no significant difference in outcome between these groups of patients with a similar complication rates and reinfection rates of 6% at 5 years. Culture negative periprosthetic sepsis generates concern, and is often considered a poor prognostic indicator. This study suggests that a strict 2 stage protocol is associated with satisfactory outcomes in such cases

INTRO. Two-stage revision arthroplasty for PJI may make use of an antibiotic-loaded cement spacer (ACS), as successful long- term prevention of reinfection have been reported using this technique.[i] However, there is little data on systemic complications of high-dose antibiotic spacers. Acute kidney injury (AKI) is of clinical significance, as the drugs most commonly utilized, vancomycin and aminoglycosides, can be nephrotoxic. We intended to determine the incidence of AKI in patients that underwent staged revision arthroplasty with an ACS, as well as to identify potential predisposing risk factors for the disease. METHODS. Local databases of six different orthopaedic surgeons were retrospectively reviewed for insertion of either a static or articulating antibiotic cement spacer by from 2007–2017. Dose of antibiotic powder implanted, as well as IV antibiotic used, was collected from operative records. Demographics, comorbidities, and preoperative and postoperative creatinine and hemoglobin values were recorded from the EHR. AKI was defined by a more than 50% rise in serum creatinine from preoperative baseline to at least 1.4 mg/dL, as described by Menge et al.[ii] Variables were analyzed for the primary outcome of AKI within the same hospital stay as insertion of the ACS. Categorical variables were analyzed with Chi-Square test, and continuous variables with univariate logistic regression. RESULTS. 75 patients (39 M, 36 F) receiving an ACS were identified, with a mean age of 70.0 (SD=10.6) and a mean BMI of 31.3 (SD=7.3). Incidence of in-hospital AKI was 13.3%. Patients reached AKI at a mean 6.7 days (SD=4.5), during a median length of stay of 13.5 days (IQR=21.8). No significant correlation was found between AKI and the variables of age (p=.430), BMI (p=.569) or gender (p=.181). AKI was also not associated with increased dose of vancomycin (p=.416), tobramycin (p=.440), or gentamycin (p=.846) within the cement spacer, or the comorbidities of hypertension (p=.094), diabetes (p=.146), coronary artery disease (p=1.00) and renal disease (p=.521). However, decreased baseline hemoglobin showed significantly increased risk for AKI (OR=1.67, p =.049), and increased creatinine showed a trend (OR=2.9, p=.059). Percentage of hemoglobin decrease (preoperative to postoperative) did not increase odds for AKI (p=.700). CONCLUSION. The incidence of acute kidney injury in patients that receive antibiotic cement spacers is relatively high when compared to the data reported in primary TKA. ii,[iii]. Our results suggest that patient related risk factors, such as low preoperative hemoglobin, may be involved in the etiology of AKI in this population. Therefore, it may be clinically appropriate to monitor anemic patients for AKI when implanting an ACS

Two-stage revision arthroplasty is the gold standard for treatment of infection after total hip Arthroplasty and end stage septic arthritis of the hip. In the first stage we used a modified technique to insert an inexpensive modular femoral component coated with antibiotic-impregnated polymethylmethacrylate articulating with a polyethylene liner. The construct was used in 8 patients with infected arthroplasty, and 6 patients with septic arthritis of the hip. Two patients were excluded (no second stage). Of the remaining 12 patients, only one patient had persistent infection after the first stage; 11 patients received a successful re-implantation at the second-stage. The technique provide a construct that can be used safely and successfully in the awaiting period between the two stages of revision arthroplasty

Deep infection following total knee arthroplasty (TKA) is a devastating complication for the patient and a costly one for patients, surgeons, hospitals and payers. The aim of this study is to compare revision TKA for infection, revision TKA for aseptic loosening and primary TKA with respect to their impact on hospital and surgeon resource utilisation. The evaluation of hospital cost was carried out on a microeconomic basis in order to best evaluate the true cost. Demographic, clinical and economic data were obtained for 25 consecutive patients with an infection after TKA who underwent a two-stage revision arthroplasty (Group 1), 25 consecutive patients who underwent revision of both components because of aseptic loosening (Group 2) and 25 consecutive patients who underwent a primary TKA (Group 3), all of which where admitted at our institution between January 2000 and December 2005. The economic evaluation included both surgical treatment and hospitalisation cost. Because fixed charges do not depict accurately real resource consumption, total cost was calculated through direct cost analysis. All direct health sector costs such as medical supplies, drugs, implants, laboratory and radiology tests, salaries and wages and overhead expenses, including equipment and plant depreciation were calculated. All patients were followed up for a twelve-month period. Revision procedures for infection were associated with longer operative time, more blood loss and a higher total number of operations compared with both revisions for aseptic loosening and primary TKA. Furthermore, revisions for infection compared to revisions due to aseptic loosening and primary TKAs were associated with twofold and 2.6 times higher total number of hospitalisations, 2.5 and 5.6 times higher total number of inpatient days, 10.2 and 53.8 times higher cost of inpatient drugs and 1.2 and 2.37 times higher cost of implants, respectively. The costing evaluation of the three operative techniques is still on progress. Patients’ treatment with an infection after TKA is associated with significantly greater hospital and physician resource utilisation compared with that used for patients with a revision due to aseptic loosening or a primary TKA

Antibiotic-loaded PMMA spacers are used with increased frequency in two-stage revision arthroplasty. The release of aminoglycosides and vancomycin, the most commonly used antibiotics, is prompt, and concentrations are inhibitory. The release kinetic from PMMA bone cement shows a biphasic profile, consisting in an initially high and rapid drug release followed by a slower but sustained phase. However, this general profile of drug release kinetics from PMMA spacers in vitro may have great variability in terms of drug amount, modality, and duration of elution. Initial drug concentration, cement surface area and porosity are essential and well-known factors in determining the drug release. Moreover, viscosity, vacuum-preparation and the different technical characteristics of commercially available spacers are additional factors of variability. Industrial preformed spacers are considered superior to custom-made devices because of uniform mixing and standardized procedures. Spacers produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement can also affect these properties. Similar bone cements produced by various brands release different amount of drugs. Gentamicin diffuses from Palacos in a larger amount and for a longer period than from Simplex and CMV. Spacers produced in France (Synicem™) and in Argentina (Subiton™) elute less total amount of gentamicin than those produced in Italy (Spacer G™) and show a delayed peak drug release. The low initial release of antibiotic can contribute to unsatisfactory antimicrobial effect and to the risk of selection of resistant bacteria. Some spacers release gentamicin for longtime (months), while others release antibiotic for only two weeks. In the last years an evolution of PMMA spacers production occurred and modifications in the polimerization process of cement can increase cement porosity and antibiotic elution from spacers. The current commercial preformed spacers for 10 days elution (Spacer G™, prepared with Cemex HP) release more gentamicin (34.1 mg) than previous models, which were prepared with Cemex SP (16.4 mg). Furthermore, they maintain a high elution rate (1.4–1.6 mg/day after one month). The combination of Gentamicin and Vancomycin mantains an elution pharmacokinetic profile that is superimposable to that of Gentamicin and Vancomycin alone, with synergistic effects against multiresistant bacteria in prosthetic infection site. In conclusion, the antibiotic release from PMMA spacers of various brands is not equivalent. The old elution data are no longer valid for new preparations. Consequently, this additional factor of variability should be considered in clinical practice and literature data utilisation

In recent years articulating cement spacers have been used to treat infected knee arthroplasty. The aim has been to better maintain tissue planes and joint mobility thereby improving second stage re-implantation surgery. Two groups of patients treated for infected knee arthroplasty were reviewed. Twenty-six patients with articulating and forty patients with static antibiotic-impregnated methyl-methacrylate spacers were compared. The articulating spacers demonstrated easier surgical exposure at second stage and improved range of knee motion after re-implantation. There was no compromise in the rate of infection eradication with articulating spacers. Bone loss at revision was independent of spacer type. To compare the results of patients treated with articulating versus static antibiotic-impregnated spacers for infected knee arthroplasty. Articulating cement spacers facilitate re-implantation surgery by maintaining tissue planes and joint mobility without compromising joint stability or eradication rate of infection. Patients demonstrate better range of motion and less complications related to the extensor mechanism with the articulated spacer. Antibiotic impregnated methyl-methacrylate spacers have become a mainstay in two-stage revision arthroplasty for sepsis. It is thought that articulating cement spacers facilitate prosthesis re-insertion by better maintaining tissue planes and joint mobility between stages. In the articulating group fewer extensile exposure methods were required at second stage prosthesis reimplantation (19% vs 36 %). No tibial tuberosity osteotomies have been required since using the articulating spacer. The articulating group demonstrated a significantly improved range of flexion compared to the static group(106 vs 97 degrees- p=0.045) and had fewer patients with significant loss of extension or quadriceps lag. Eradication of infection was improved in the articulating group (92% vs 82%) but at shorter average follow-up. The need for augments and stabilized prostheses at revision surgery as a measure of bone loss was no different between the groups but was related to the number of prior surgical procedures. Twenty-six patients treated with articulating spacers were compared to a matched consecutive group of forty patients treated with static spacers. Minimum follow-up was twelve months from second stage re-implantation (average twenty-two months articulating, forty months static). Funding: No direct funding from any commercial source has been received for this study. The primary author’s fellowship position is partially funded by Smith and Nephew Richards Inc

In recent years articulating cement spacers have been used to treat infected knee arthroplasty. The aim has been to better maintain tissue planes and joint mobility thereby improving second stage re-implantation surgery. Two groups of patients treated for infected knee arthroplasty were reviewed. Twenty-six patients with articulating and forty patients with static antibiotic-impregnated methyl-methacrylate spacers were compared. The articulating spacers demonstrated easier surgical exposure at second stage and improved range of knee motion after re-implantation. There was no compromise in the rate of infection eradication with articulating spacers. Bone loss at revision was independent of spacer type. To compare the results of patients treated with articulating versus static antibiotic-impregnated spacers for infected knee arthroplasty. Articulating cement spacers facilitate re-implantation surgery by maintaining tissue planes and joint mobility without compromising joint stability or eradication rate of infection. Patients demonstrate better range of motion and less complications related to the extensor mechanism with the articulated spacer. Antibiotic impregnated methyl-methacrylate spacers have become a mainstay in two-stage revision arthroplasty for sepsis. It is thought that articulating cement spacers facilitate prosthesis re-insertion by better maintaining tissue planes and joint mobility between stages. In the articulating group fewer extensile exposure methods were required at second stage prosthesis reimplantation (19% vs 36 %). No tibial tuberosity osteotomies have been required since using the articulating spacer. The articulating group demonstrated a significantly improved range of flexion compared to the static group(106 vs 97 degrees- p=0.045) and had fewer patients with significant loss of extension or quadriceps lag. Eradication of infection was improved in the articulating group (92% vs 82%) but at shorter average follow-up. The need for augments and stabilized prostheses at revision surgery as a measure of bone loss was no different between the groups but was related to the number of prior surgical procedures. Twenty-six patients treated with articulating spacers were compared to a matched consecutive group of forty patients treated with static spacers. Minimum follow-up was twelve months from second stage re-implantation (average twenty-two months articulating, forty months static). Funding: No direct funding from any commercial source has been received for this study. The primary author’s fellowship position is partially funded by Smith and Nephew Richards Inc

Aims

The purpose of this study was to compare the clinical outcomes, mortalities, implant survival rates, and complications of total knee arthroplasty (TKA) in patients with or without hepatitis B virus (HBV) infection over at least ten years of follow-up.

Aims

Achievement of accurate microbiological diagnosis prior to revision is key to reducing the high rates of persistent infection after revision knee surgery. The effect of change in the microorganism between the first- and second-stage revision of total knee arthroplasty for periprosthetic joint infection (PJI) on the success of management is not clear.

Aims

We aimed to evaluate the utility of ⁶⁸Ga-citrate positron emission tomography (PET)/CT in the differentiation of periprosthetic joint infection (PJI) and aseptic loosening (AL), and compare it with ^99mTc-methylene bisphosphonates (^99mTc-MDP) bone scan.

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).

Despite of improved operative technique, ultra-clean air in the operating theater and systemically administered as well as in bone cement loaded antibiotics, septic complications after replacement arthroplasty of the knee still exist. Depending of the follow-up time in different reported series insidence vary from 0.5 to 5 per cent. Classic clinical symptoms, painful, swollen knee joint, possibly fever, indicate to more accurate examinations. Lesson to learn: . No treatment before adequate diagnosis !. No “homeostatic” antibiotics before accurate examinations. If the very first contact with physician or surgeon happens in such conditions, that adequate diagnostic methods are not available, patient has to be referred to hospital or institution with capable facilities. Prosthetic infection can be classified in many ways. The following classification is useful for the treatment purposes. Classification of infection:. 1. Early postoperative infection less than 4 weeks after surgery. superficial. deep. extensive soft tissue defects due to skin necrosis. 2. Originally patient is operated for aseptic loosening, but intraoperative cultures are positive. 3. Late chronic infection. 4. Acute hematogenous infection. Diagnostic methods:. 1. Clinical examination:. - symptoms can be suppressed by painkillers or immunomodulant drugs. - wound healing problems. - sinuses. - swelling, redness. - pain. - temperature increased. 2. Blood chemistry:. ESR, C-reactive protein and blood white cell count/ differentiation are helpful. Be ware if the patient has such a general disease, which increases fex CRP. 3. Routine x-rays. In early cases no significant signs, in late cases might appear erosions or cysts. 4. Isotope scintigraphy. Technetium- or indium labeled leucosytes are given intravenously. The patient is scanned 24 hours. Extended scintigraphy seems to be more sensitive than routine 6 to 8 hours‘ scintigraphy. 5. Joint aspiration. One has to sure, that the patient is not on antibiotics. If she/he is, antibiotics has to be stopped for two to four weeks, and aspiration performed after that, unless infection is not clinically obvious or situation is not life-threatening. White cell count/differentiation can be for some help. When the cell count is less than 2000/ml, and majority of cells are mononuclear, the result is indicative negative for infection. White cell count over 10000/ml, and majority polymorphonuclear, speaks for infection. When the aspiration has been carried in aseptic condition, positive culture is strong evidence for infection. Adequate handling of sample is important: as little as possible air in the syringe and as short as possible time used for transportation to lab. Treatment protocols. Treatment protocols can rather straight forward: if any sample culture is positive,. Two-stage revision arthroplasty is carried out. But also more conservative opinions are reported. 1.a. Early postoperative, superficial infection:. Surgical débridement of the wound. Careful examination of retinaculum layer. Lavage and wound closure if possible. Systemic antibiotics. Joint puncture and aspiration through healthy skin area, never through open wound. b. Early postoperative, deep infection:. Open débridement and careful lavage with retention of prosthesis. Additional peroperative samples for culture in order to confirm earlier pathogene definition. Systemic antibiotics regarding sensitivity estimation. Arthroscopic debridement and lavage has not proved to be better or neither as good as open. New aspiration 4–6 days after. If white cell count clearly over 10000/ml and possibly culture positive, new debridement and lavage. If third debridement comes necessary, even without bony changes, removal of prosthesis and antibiotics- loaded spacer has to be considered. c. Dehiscense of wound or soft tissue defect due to the necrosis:. Wound débridenent, antibiotics and depending on the extend of defect either partial closure, skin grafting or pedicled gastrocnemius muscle flap is performed. 2. In some cases there is no signs of infection, and the is operated as an aseptic loosening. In all revision, routineously 4 to 5 tissue samples should be taken for culture. If preoperatively there is any doubts about infection, histological examination of frozen sections should be carried out. If there are high count of polymorphonuclear cells, results of culture has to be waited. If later on in minimum two samples same pathogen is growing, the case has to be considered as infected. Two-stage revision protocol is recommended. One positive sample cannot be regarded as a concluding proof. Long term antibiotics is recommended. 3. Late chronic infection has insidious , slowly progressing onset. Symptoms can be confusing mild, and can lead to misdiagnosis. Method of choice is débridement, removal of the prosthesis and all bone cement, and placement of an antibiotics-loaded cement spacer. No dead space is left , but has to be filled with antibiotic-loaded collagen or antibiotic-cement beads. The patient is put on systemic antibiotics, preferably combination of two. Antibiotic therapy is continued six- to eight weeks. Healing process is controlled with ESR and CRP tests. If the blood test normal and clinical situation is normal, delayed revision arthroplasty is performed. Antibiotic loaded-cement is always used. 4. Acute hematogenous infection. Onset is usually acute and symptoms dramatic. Sometimes distant focus can be found. If the history is rather short( less than 14 days) open débridement, retainment of prosthesis, antibiotics-loaded collagen filling of the joint as well systemic antibiotics is recommended. Recovering is monitored by blood chemistry and repeated joint aspiration and cultures. If in aspiration sample there is high polymorphonueclear count and culture possibly positive, new débridemand is carried out. If signs of infection still continue, two-stage exchange to be considered. Pathogenes. Gram-positive. staphylococci are most frequent patogene in total knee replacement infections (95%). Gram-negative. bacilli cover the rest (5%). Coagulase-negative staphylococci has grown up the most important bacteria, and it‘s resistance against antibiotics has turned frightening. Spacers. In cases with short history retainment of prosthesis can be considered. Many authors change of polyethylene bearing. In two-stage revisions static antibiotic-loaded cement spacer was used during. The six to eight weeks‘ interval. Static spacer is connected with extensive bone loss as well as stiff causing problems in secondary revision. Molded cement spacer is used in order to avoid complications and to achieve better functional results. Failure. In some cases treatment of infection is unsuccessful. Arthodesis with method of Ilizarov or intramedullary nail or sometimes above-knee amputation comes necessary

Objectives

The diagnosis of periprosthetic joint infection (PJI) is difficult and requires a battery of tests and clinical findings. The purpose of this review is to summarize all current evidence for common and new serum biomarkers utilized in the diagnosis of PJI.