Standard or Fin SIGN® nail? which option is better for the treatment of femoral fractures in low and middle-income countries?

PURPOSE: Femoral fractures are common in low and middle-income countries (LMIC), predominantly caused by high-energy trauma. The surgical implant generation network (SIGN®) program offers two different intramedullary nails in LMIC which are designed to be used without image intensifier free of charge for the patients: the SIGN standard nail (SSN®) and the SIGN Fin nail (SFN®). This study aimed to compare the results of the SSN® and the SFN® for the treatment of middle and distal shaft femoral fractures through a retrograde approach. MATERIAL AND METHODS: This was a retrospective, descriptive, and non-experimental study including all consecutive patients who underwent surgical management of middle or distal shaft femoral fracture between January 2017 and May 2022 in an NGO hospital located in Freetown, Sierra Leone. The duration of surgery, type of reduction, complications like screw loosening, implant migration, anterior knee pain and non-union rate at six months of follow up were evaluated. RESULTS: A total of 122 patients were included in the study. Group A: 60 patients were managed with SSN® and Group B: 62 patients with SFN®. The mean operative time was 104 min with SSN® and 78 with SFN® (p < 0.001). Open reduction of the fracture was necessary in ten (16.7%) patients with SSN® and 12 (19.4%) patients treated with SFN® (p = 0.69). Non-union was observed in one (1.7%) patient with SSN® and two (3.2%) patients with SFN® (p = 0.57). CONCLUSIONS: Both options seem equally effective in treating midshaft and distal femoral shaft fractures. The SFN® reduces the surgical time, due to this fact, in polytraumatized patients, patients with bilateral femur fracture or patients with ipsilateral tibia fracture, it can be considered as the best option to be used. There was no statistical difference in the complications presented by the two groups.

Do Cultures Obtained During Primary THA Predict the Likelihood of Revision?

BACKGROUND: There can be unexpectedly positive culture results during elective hip arthroplasty, but the degree to which these are associated with an increased risk of subsequent premature revision is not known. QUESTION/PURPOSE: Are unexpectedly positive culture results obtained during elective THA associated with an increased likelihood of revision within 5 years of the procedure? METHODS: Between March 2007 and March 2011, the hip unit at our institution performed elective primary THA in 829 patients. We systematically collected three samples in 52% (428 of 829) of the interventions. Of those, 26 patients were excluded because of sampling errors; 94% (402 of 428) had samples that were collected systematically and were eligible for the study. We only considered one hip randomly in bilateral procedures (4% [15 of 428]); patients presenting with acute (< 3 months) periprosthetic joint infection undergoing open debridement (4% [16 of 402]) and patients who died before 5 years of follow-up (2% [seven of 402]) were excluded from the study, leaving 91% (364 of 402) eligible for analysis in this retrospective study of a previous prospective trial. No patient included in the final analysis was lost to follow-up within 5 years from the index surgery. The patient group consisted of 52% (188 of 364) women, with a mean ± SD age of 64.8 ± 13.9 years. RESULTS: Positives culture results were associated with a higher risk of revision within 5 years of the index surgery. The proportion of revision surgery was higher in the group with positive culture results than in those with negative results (10% [eight of 77] versus 2% [seven of 290]; p = 0.01). The difference was mainly attributable to a higher proportion of aseptic loosening in those with positive culture results than in those with negative results (8% [six of 74] versus 1% [four of 290]; p = 0.01). After a multivariable analysis, the only independent variable associated with 5-year revision surgery was the presence of positive results during THA (odds ratio 4.9 [95% confidence interval 1.72 to 13.99]). CONCLUSION: Our findings suggest that bacterial contamination during THA is associated with an increased likelihood of early revision. This higher risk of revision is mainly because of presumed aseptic loosening; thus, efforts should focus on the need to rule out infection. These results not only open new questions that should be answered in new prospective and well-designed studies, but also may help to better select patients to obtain a more favorable outcome after THA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Contribution of the BioballTM head-neck adapter to the restoration of femoral offset in hip revision arthroplasty with retention of a well-fixed cup and stem.

PURPOSE: Failure to restore the femoral offset of the native hip is a potential cause of dysfunctional hip arthroplasty. The aim of this study was to report our experience of using a modular head-neck adapter in revision THA, specifically analyzing its usefulness as a tool to correct a slightly diminished femoral offset. MATERIALS AND METHODS: This was a retrospective single-center study including all hip revisions performed at our institution from January 2017 to March 2022 where the BioBallTM head-neck metal adapter was used. The preoperative and one year follow-up modified Merle d'Aubigné hip score was used to evaluate functional outcomes. RESULTS: Of a total of 34 cases included for revision, the head-neck adapter system was used specifically in six patients (17.6%) to increase femoral offset, retaining both the acetabular and femoral components. In this subgroup of patients, mean offset decrease after primary THA was 6.6 mm (4.0-9.1), equivalent to a mean 16.3% femoral offset reduction. The median modified Merle d'Aubigné score went from 13.3 preoperatively to 16.2 at one year follow-up. CONCLUSION: The use of a head-neck adapter is a safe and reliable procedure that may allow the surgeon to easily correct a slightly diminished femoral offset in a dysfunctional THA without the need to revise well-fixed prosthetic components.

Two novel prehabilitation apps to help patients stop smoking and risky drinking prior to hip and knee arthroplasty.

PURPOSE: Daily smoking or risky drinking increases the risk of complications after surgery by ~50%. Intensive prehabilitation aimed at complete cessation reduces the complication rate but is time-consuming. The purpose of this study was to carry out preoperative pilot tests (randomized design) of the feasibility (1A) and validation (1B) of two novel prehabilitation apps, habeat® (Ha-app) or rehaviour® (Re-app). METHODS: Patients scheduled for hip or knee arthroplasty with daily smoking, risky drinking, or both were randomised to one of the two apps. In part 1A, eight patients and their staff measured feasibility on a visual analog scale (VAS) and were interviewed about what worked well and the challenges requiring improvement. In part 1B, seven patients and their staff tested the improved apps for up to two weeks before validating the understanding, usability, coverage, and empowerment on a VAS and being interviewed. RESULTS: In 1A, all patients and staff returned scores of ≥5 for understanding the apps and mostly suggested technical improvements. In 1B, the scores varied widely for both apps, with no consensus achieved. Two of four patients (Ha-app) and one-third of the patients (Re-app) found the apps helpful for reducing smoking, but without successful quitting. The staff experienced low app competencies among patients and high time consumption. Specifically, patients most often needed help for the Ha-app, and the staff most often for Re-app; however, the staff reported the Re-app dashboard was more user-friendly. Support and follow-up from an addiction specialist staff member were suggested to complement the apps, thereby increasing the time consumption for staff. CONCLUSIONS: This pilot study to test prototype apps generated helpful feedback for the app developers. Based on the patient and staff comments, multiple improvements in functionality seem required before scaling up the evaluation for effect on prehabilitation and postoperative complications.

Can the intra-operative measurement of the diameter of the femoral head help surgeons to choose the best size of the acetabular cup?

PURPOSE: We hypothesized that the intra-operative measurement of the femoral head may increase the accuracy of the acetabular cup size optimal selection in total hip arthroplasty (THA). The purpose of this clinical research was to analyze the correlation between the estimated cup size from intra-operative measurement of the femoral head and the pre-operative templated cup size. METHODS: A prospective observational single-center study was conducted from June 2019 to January 2020 including primary THA (n = 100). All cases were pre-operatively templated. The measurement of the anterior-posterior diameter of the femoral head was routinely intra-operatively performed. Any definitive implanted cup was considered as "oversized" when the size was > 4 mm than the diameter of the native head. RESULTS: The median (interquartile range) size of the implanted cup, pre-operative planned cup size, and diameter of the femoral head were measured 52 (50-54) mm, 50 (48-54) mm and 49 (45-51) mm, respectively. Pre-operative planned size cup accurately predicted the implanted cup or differed in only one size (2 mm) in 77 (78%) cases. Otherwise, intra-operative femoral head measurement method accurately predicted the implanted or differed in only one size (2 mm) in 51 (87%) cases (p = 0.097). CONCLUSION: The intra-operative femoral head measurement is a simple and reliable tool to help the surgeons choose the best size of the acetabular cup and is as reliable as the pre-operative templating in order to avoid cup oversizing in THA. Utmost caution is warranted whenever the cup reamer is > 4 mm than the anterior-posterior diameter of the native head.

Outcomes of hip arthroplasty with concomitant hardware removal: influence of the type of implant retrieved and impact of positive intraoperative cultures.

INTRODUCTION: The impact of residual internal fixation devices on subsequent procedures about the hip has not been clearly well defined. The objective of the current study is to evaluate the outcome of hip arthroplasty after hardware retrieval as a one-stage replacement, to analyze possible differences related to the type of removed implant, and to assess the impact of unexpected intraoperative cultures during implant retrieval. MATERIALS AND METHODS: We present a retrospective study including all those cases undergoing hip arthroplasty with concomitant hardware removal (cannulated screws, intramedullary nail, or dynamic hip screw) from 2005 to 2018. We evaluated demographics, intraoperative cultures, early infection rate, and other complications. RESULTS: A total of 55 cases were included in the study. The median time between the implant surgery and the hip arthroplasty was 113 days. The removed devices included 6 cannulated screws, 34 intramedullary nails, and 15 dynamic hip screws. Up to 74.5% of the failed osteosynthesis belonged to intertrochanteric femoral fractures. Dislocation rate was 9.1% (1.8% requiring revision surgery), 25.5% of the cases needed further new surgeries after the hip arthroplasty, and 49.1% died during the follow-up period. Any-cause revision surgery and mortality rates were significantly increased after intramedullary nail removal. Intraoperative cultures were performed in 46 cases, and in 9 (16.4%), there was bacterial contamination: 6 cases (10.9%) presented one single positive culture and 3 (5.5%) presented ≥ 2 positive cultures for the same microorganism. A total of five cases (9.1%) presented early prosthetic joint infection that required debridement. None of these five cases had presented positive cultures at the implant removal. CONCLUSION: According to our results, hip arthroplasty with concomitant hardware removal is related to a high 5-year mortality rate, mainly when intramedullary nail is retrieved. Whereas a high risk of early prosthetic joint infection is associated, it seems not to be related to the elevated presence of unexpected positive cultures.

Prevalence and Impact of Positive Intraoperative Cultures in Partial Hip or Knee Revision.

BACKGROUND: Our aim is to investigate the impact of unexpected positive cultures on the outcome of partial prosthetic revisions. METHODS: Data regarding patients who underwent a partial hip or knee revision from 2003 and 2012 with the preoperative diagnosis of aseptic loosening was retrospectively reviewed. The protocol of revision included at least 3 intraoperative cultures. Failure was defined as the need for re-revision due to aseptic or septic loosening at 5 years. RESULTS: A total of 99 hip and 46 knee partial revisions were included. All cases had at least 5 years of follow-up. Ninety-seven cases (66.9%) had all cultures negative, 35 (24.1%) a single positive culture and 13 (9.0%) ≥2 positive cultures for the same microorganism. The median time from primary arthroplasty to partial revision was significantly shorter for patients with ≥2 positive cultures (26 months) than in those with all cultures negative (48 months) or with a single positive culture (51 months). Partial revisions performed within the first 5 years of implantation had a higher 5-year re-revision rate. The presence of a single positive culture during the partial exchange was not associated with a higher re-revision rate (2 of 35, 5.7%) than in those with negative cultures (3 of 97, 3.1%). On the contrary, re-revision rate was significantly higher in cases with ≥2 positive cultures (3 of 13, 23.1%) than in those with negative cultures (P = .02). CONCLUSION: Partial revisions performed within the first 5 years from implantation and ≥2 intraoperative positive cultures were associated with a higher re-revision risk at 5 years.

Evaluation of Lipocalin-2 as a Biomarker of Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) remains a major clinical challenge. In this study, we evaluated the diagnostic performance of lipocalin-2 (LCN2), a well-characterized neutrophil protein, in synovial fluid to discriminate PJI and aseptic implant failure. METHODS: Synovial fluid from patients with acute or chronic PJI, aseptic failure, or controls was obtained during surgery. LCN2 was quantified using a modified enzyme immunoassay coupled with chemiluminescence (Architect Urine NGAL; Abbott Laboratories). RESULTS: Synovial fluid was collected from 72 patients: 22 (30.6%) proven infections, 22 (30.6%) aseptic implant failures, and 28 (38.8%) controls. Synovial fluid was obtained from the hip in 18 (25%) and knee in 54 (75%) cases. Among infections, there were 16 (22.2%) acute and 6 (8.3%) chronic PJIs. The median (interquartile range) LCN2 concentration in synovial fluid was 1536.5 ng/mL (261.8-12,923) in the infection group, 87.0 (54.8-135) in the aseptic group, and 55 (45-67.8) in the control group (P < .001). LCN2 discriminated nearly perfectly between controls and confirmed infection (area under the receiver operating characteristic 0.98, 95% confidence interval 0.95-1.00). The optimal cut-off value for maximal sensitivity (86.3%) and specificity (77.2%) to discriminate aseptic failure versus proven infection was 152 ng/mL, with an area under the receiver operating characteristic of 0.92 (95% confidence interval 0.84-0.99). CONCLUSION: LCN2 is a potential novel biomarker that may be helpful to inform surgical teams on the potential risk of PJI and optimize specific surgical interventions as it distinguishes between septic and aseptic failure of prosthesis with high sensitivity and specificity.

Early clinical and radiological outcomes for the Taperloc Complete Microplasty stem.

The use of short stem designs in total hip arthroplasty is not a new concept, but its popularity has increased as a bone-sparing alternative to traditional stems. This study analyzed the midterm clinical and radiological results of the Taperloc Complete Microplasty stem (Zimmer Biomet® Warsaw, IN, USA). A total of 32 patients (20 men and 12 women) were retrospectively documented and received 40 stems (eight bilateral). The median patient age was 50 years (interquartile range 43-58) at the time of surgery. The median follow-up was 36.5 months (interquartile range 26.75-50.25). Indication for total hip arthroplasty was osteoarthritis (62.5% of patients), avascular necrosis (25%), and developmental dysplasia of the hip (12.5%). The Merle d'Aubigné score improved from a mean 11.5 preoperatively to a mean 17.5 at the latest follow-up. During X-ray assessment, we observed one subsidence of the stem (3 mm) and four cases of varus malalignment without clinical consequences. No cases of osteolysis were reported, and no stems were revised. According to our results, this short tapered stem shows a good early-term outcome. Prospective results and a longer follow-up are needed to assess the long-term survival of this stem fully.

One- and two-stage surgical revision of peri-prosthetic joint infection of the hip: a pooled individual participant data analysis of 44 cohort studies.

One-stage and two-stage revision strategies are the two main options for treating established chronic peri-prosthetic joint infection (PJI) of the hip; however, there is uncertainty regarding which is the best treatment option. We aimed to compare the risk of re-infection between the two revision strategies using pooled individual participant data (IPD). Observational cohort studies with PJI of the hip treated exclusively by one- or two-stage revision and reporting re-infection outcomes were retrieved by searching MEDLINE, EMBASE, Web of Science, The Cochrane Library, and the WHO International Clinical Trials Registry Platform; as well as email contact with investigators. We analysed IPD of 1856 participants with PJI of the hip from 44 cohorts across four continents. The primary outcome was re-infection (recurrence of infection by the same organism(s) and/or re-infection with a new organism(s)). Hazard ratios (HRs) for re-infection were calculated using Cox proportional frailty hazards models. After a median follow-up of 3.7 years, 222 re-infections were recorded. Re-infection rates per 1000 person-years of follow-up were 16.8 (95% CI 13.6-20.7) and 32.3 (95% CI 27.3-38.3) for one-stage and two-stage strategies respectively. The age- and sex-adjusted HR of re-infection for two-stage revision was 1.70 (0.58-5.00) when compared with one-stage revision. The association remained consistently absent after further adjustment for potential confounders. The HRs did not vary importantly in clinically relevant subgroups. Analysis of pooled individual patient data suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating PJI of the hip.

Pulsed electric fields reduce bacterial attachment to stainless steel plates.

The purpose of this study was to evaluate the capacity of pulsed bilateral electric fields to control bacterial attachment on stainless steel plates. Previously sterilized circular metal plates of stainless steel were submerged in a liquid medium with a known concentration of Staphylococcus epidermidis and incubated for 1 hour at 36oC while a 200 Hz pulsed electric field of 18 V/cm was applied for 2.5 µseg and then sonicated for 5 minutes in 10 ml of saline. Three different models were cultured and compared: 1) negatively-charged plate, 2) positively-charged plate, and 3) control plate without electric current. A total of 39 metal plates were processed. The median adherence in the control group and the electric field group was 312 CFU/mm2 and 16,2 CFU/mm2 respectively (p < 0.001, reduction of 95% of bacterial attachment). Bilateral pulsed electric field is able to reduce bacterial attachment on stainless steel plates in in vitro conditions.

Long-term effectiveness of corticosteroid injections for trigger finger and thumb.

PURPOSE: To analyze the long-term response to corticosteroid injection in the management of trigger digit. METHODS: This was an observational study of a prospectively recruited series of patients with first-time diagnosis of trigger finger. Efficacy of the injections, comorbidities, digit injected, and related complications were compared and statistically analyzed. RESULTS: A total of 71 digits were included in the study. The median (interquartile range) duration of follow-up was 8 years (range, 7.0-8.3 y). At final follow-up, complete remission of symptoms was obtained in 69% of cases. There were 37 trigger thumbs (52%), with a success rate of 81% compared with 56% in the other the digits. There were 11 patients with diabetes mellitus, and 16 fingers developed trigger finger after carpal tunnel syndrome surgery. We found no complications. CONCLUSIONS: Steroid injections were an effective first-line intervention for the treatment of trigger finger. At long-term follow-up, the success incidence may be as high as 69%. In this study, the efficacy of this treatment increases when treating the thumb compared with other digits.

Is asymptomatic bacteriuria a risk factor for prosthetic joint infection?

BACKGROUND: Infection is a major complication after total joint arthroplasty. The urinary tract is a possible source of surgical site contamination, but the role of asymptomatic bacteriuria (ASB) before elective surgery and the subsequent risk of infection is poorly understood. METHODS: Candidates for total hip or total knee arthroplasty were reviewed in a multicenter cohort study. A urine sample was cultured in all patients, and those with ASB were identified. Preoperative antibiotic treatment was decided on an individual basis, and it was not mandatory or randomized. The primary outcome was prosthetic joint infection (PJI) in the first postoperative year. RESULTS: A total of 2497 patients were enrolled. The prevalence of ASB was 12.1% (303 of 2497), 16.3% in women and 5.0% in men (odds ratio, 3.67; 95% confidence interval, 2.65-5.09; P < .001). The overall PJI rate was 1.7%. The infection rate was significantly higher in the ASB group than in the non-ASB group (4.3% vs 1.4%; odds ratio, 3.23; 95% confidence interval, 1.67-6.27; P = .001). In the ASB group, there was no significant difference in PJI rate between treated (3.9%) and untreated (4.7%) patients. The ASB group had a significantly higher proportion of PJI due to gram-negative microorganisms than the non-ASB group, but these did not correlate to isolates from urine cultures. CONCLUSIONS: ASB was an independent risk factor for PJI, particularly that due to gram-negative microorganisms. Preoperative antibiotic treatment did not show any benefit and cannot be recommended.

One-stage revision arthroplasty using cementless stem for infected hip arthroplasties.

The objective of this retrospective study was to evaluate our results with one-stage revision using cementless femoral stem for infected hip arthroplasties. Twenty-four patients were included in the study. The acetabular component was cemented in 9 cases. In 2 patients a structured bone allograft was necessary to fill an acetabular defect. After a mean follow-up of 44.6 months, 23 patients showed no signs of infection (95.8%), the mean functional response according to the Merle d'Aubigné scale was 13.8 and the mean Harris Hip Score was 65.4. One-stage revision hip arthroplasty using cementless femoral stem was associated with a high success rate.

Preliminary clinical and radiological evaluation of osteosynthesis using the Femoral Neck System (FNS) for subcapital fractures of the femur.

Addressing subcapital fractures of the femur poses a substantial clinical challenge, complicated by the diverse range of available osteosynthesis materials. This study is dedicated to a comprehensive analysis of the clinical and radiological implications linked with the implementation of the Femoral Neck System (FNS) in osteosynthesis procedures. A descriptive study was conducted involving patients who underwent osteosynthesis for subcapital fractures of the femur utilizing the FNS during the period from 2019 to 2022. The investigation encompassed various facets, including the classification of fractures according to the Garden and Pauwells classifications, criteria for achieving precise reduction based on the Garden criteria and Tip Apex Distance (TAD). At the one-year follow-up, factors such as fracture consolidation, loss of reduction, fracture collapse, complications, and functional outcomes were evaluated utilizing the Harris Hip Score (HHS) scale. The study cohort included a total of 26 patients, among whom 22 exhibited non-displaced subcapital femur fractures categorized as Garden I and II. Successful reduction was accomplished in 23 cases, in which 24 cases (92.3%) displayed a TAD measurement below 25 mm. According to the HHS, patients achieved an average score of 90.9 (ranging from 63 to 100) following the surgical intervention, with predominantly "excellent" and "good" outcomes. The outcomes derived from our investigation corroborate the viability of the Femoral Neck System (FNS) as a reliable option for osteosynthesis in femoral neck fractures. The results obtained are comparable to those achieved with other available implants, as highlighted by previous studies.

Usefulness of histology for predicting infection at the time of hip revision for the treatment of Vancouver B2 periprosthetic fractures.

When facing a Vancouver B2 periprosthetic fracture, the most recommended treatment is the prosthesis replacement. Current tests do not provide enough reliability to identify whether the fracture has been produced on a septic or an aseptic loosened prosthesis. Our aim was to evaluate the usefulness of the histology for the diagnosis of infection in these cases. A total of 11 hip revision procedures were performed (mean age: 78.1 years, 8 women and 3 men). Sensitivity, specificity, positive predictive value and negative predictive value of the histology were 100%, 55.5%, 33.3% and 100% respectively. Of the six patients presenting with a positive histology, four of them had negative cultures (66.6% of false positives). Our results suggest that periprosthetic fractures are a cause of false-positive histology results for the diagnosis of infection during revision of a hip prosthesis for the treatment of Vancouver B2 periprosthetic fractures.

Is hip resection arthroplasty a successful definitive treatment?

Purpose: Hip resection arthroplasty as a definitive treatment is an uncommon indication, although still in use selectively. This study evaluates a cohort of patients who have undergone hip resection arthroplasty surgery indicated as a definitive treatment, in order to assess the rate of re-operation, the rate of infection, and the mortality rates. Methods: We conducted a retrospective, observational, descriptive analysis of a cohort of patients who had undergone a hip resection arthroplasty intended as a definitive treatment, in two University Hospitals from 1994 to 2020. The exclusion criteria were the implantation of a hip cement spacer, or a temporary hip resection arthroplasty in patients undergoing a two-staged surgical approach. We found 26 cases of hip resection arthroplasty. We recorded the indications for a definitive hip resection arthroplasty, the outcomes and complications, and analyzed the success of the hip resection arthroplasty as a definitive surgery using a Kaplan-Meier curve. Results: Seven cases (26.9%) required a re-operation after the hip resection arthroplasty, four cases for persistent hip infection, and in the three remaining a conversion to a total hip arthroplasty was re-considered due to a good medical evolution and non-tolerance to the low functional outcome. The mortality rate was 61.5% (27 days-20 years), with a 19.2% mortality rate in the first 5 years. All the cases that required another surgery after the hip resection arthroplasty were re-operated within the first 18 months. Conclusion: Unfortunately, hip resection arthroplasty continues to show elevated re-operation rate and early mortality rate, as well as low functional outcomes. Two-staged hip revision arthroplasty is the surgical treatment of choice in patients suffering from a periprosthetic joint infection, however we believe that hip resection arthroplasty should be considered in fragile patients, who have endured multiple revision surgeries, or their comorbidities make them unfit from further surgeries.

Antimicrobials in polymethylmethacrylate: from prevention to prosthetic joint infection treatment: basic principles and risk of resistance.

BACKGROUND: Excellent revisions about antibiotic-loaded bone cement (ALBC) have been recently published. In the present article, we review the principles and limitations of local antibiotic delivery in the context of recent advances in the pathogenesis of prosthetic joint infections (PJI), with particular attention paid to the potential association between ALBC and antimicrobial resistance. MAIN BODY: Recalcitrance of PJI is related to the ability of pathogens to adapt to particular environments present in bone tissue and protect themselves from host immunity in different ways. Accordingly, delivery of high local antimicrobial concentrations using ALBC is needed. Most relevant clinical data showing the efficacy of ALBC for PJI prophylaxis and treatment are reviewed, and we dissected the limitations on the basis of the recent findings from animal models and suggested that aminoglycosides, in particular, could not be the best option. One of the major concerns associated with ALBC is the emergence of resistance because of theoretical prolonged exposure to low antibiotic concentrations. We summarize the mechanisms for the selection of resistant microorganisms, and we critically reviewed the evidence from animal models and clinical data from observational and registry studies and concluded that there is no evidence to support this association. CONCLUSION: While waiting for better evidence from well-designed clinical trials, ALBC shows a beneficial effect as a prophylaxis in arthroplasty, and to avoid the colonization of spacers used for two-stage revision in patients with PJI. Experimental models and clinical evidence suggest the need to achieve high local antimicrobial concentrations to obtain the highest prophylactic and therapeutic effect. The current evidence does not support the risk of increasing resistance with use of ALBC. In the future, it is necessary to evaluate new carriers and different antimicrobials to improve clinical outcomes.

Usefulness of serum D-dimer and platelet count to mean platelet volume ratio to rule out chronic periprosthetic joint infection.

Background: Diagnosing periprosthetic joint infection (PJI) is challenging and usually requires the evaluation of several biomarkers. Our main aim was to evaluate the usefulness of D-dimer levels as well as the platelet count (PC) to mean platelet volume (MPV) ratio serum as biomarkers to rule out chronic knee and hip infection. Methods: The study enrolled a prospective cohort of 93 patients undergoing hip or knee revision. D-dimer values, PC to MPV ratio, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were preoperatively determined and evaluated as a predictor of PJI. The definitive diagnosis of PJI was established according to the 2018 International Consensus Meeting criteria. Results: A total of 24 (25.8 %) cases were postoperatively diagnosed with PJI. The median D-dimer value was significantly higher ( p   <  0.001) for patients with PJI (1950 ng mL - 1 ) than for patients with aseptic failure (700 ng mL - 1 ). The area under the receiver operating characteristic curves for D-dimer, CRP and ESR was 0.820, 0.793 and 0.791 respectively. D-dimer  ≥  950 ng mL - 1 (91 % sensitivity, 64 % specificity), CRP  ≥  1.95 mg dL - 1 (61 % sensitivity, 90 % specificity) and ESR  >  20 (74 % sensitivity, 82 % specificity) were identified as the values with the best balance between sensitivity and specificity. The mean PC to MPV ratio was 37.0 for PJI patients and 29.8 for patients in the aseptic revision cohort ( p = 0 .067). Conclusions: Serum D-dimer levels appear very unlikely to remain normal in the presence of chronic PJI. The 91 % sensitivity when considering 950 ng mL - 1 as the threshold highlights D-dimer as the most accurate initial test to rule out chronic PJI. Conversely, the PC to MPV ratio may be of limited value for accurately diagnosing PJI.