Current diagnostic tools are not always able to effectively identify periprosthetic joint infections (PJIs). Recent studies suggest that circulating microRNAs (miRNAs) undergo changes under pathological conditions such as infection. The aim of this study was to analyze miRNA expression in hip arthroplasty PJI patients. This was a prospective pilot study, including 24 patients divided into three groups, with eight patients each undergoing revision of their hip arthroplasty due to aseptic reasons, and low- and high-grade PJI, respectively. The number of intraoperative samples and the incidence of positive cultures were recorded for each patient. Additionally, venous blood samples and periarticular tissue samples were collected from each patient to determine miRNA expressions between the groups. MiRNA screening was performed by small RNA-sequencing using the miRNA next generation sequencing (NGS) discovery (miND) pipeline.Aims
Methods
Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients. A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem.Aims
Methods
Antimicrobial suppression has shown to significantly improve treatment success of streptococcal periprosthetic joint infection (PJI) compared to 12-week standard antimicrobial therapy, however, only short-term follow-up was investigated. In this study we assessed the impact of suppression on the long-term outcome of streptococcal PJI. Consecutive patients with streptococcal PJI (defined by EBJIS criteria) treated 2009–2021 were prospectively included and allocated into standard and suppression (> 6 months) treatment group. Infection-free survival was assessed with Kaplan-Meier-method and compared between the groups with log rank test. Rates of infection-free, streptococcal infection-free and relapse-free status as well as tolerability of suppression were assessed.Aim
Method
Antibiotics have limited activity in the treatment of multidrug-resistant or chronic biofilm-associated infections, in particular when implants cannot be removed. Lytic bacteriophages can rapidly and selectively kill bacteria, and can be combined with antibiotics. However, clinical experience in patients with surgical infections is limited. We investigated the outcome and safety of local application of bacteriophages in addition to antimicrobial therapy. 8 patients (2 female and 6 male) with complex orthopedic and cardiovascular infections were included, in whom standard treatment was not feasible or impossible. The treatment was performed in agreement with the Article 37 of the Declaration of Helsinki. Commercial or individually prepared bacteriophages were provided by ELIAVA Institute in Tbilisi, Georgia. Bacteriophages were applied during surgery and continued through drains placed during surgery three times per day for the following 5–14 days. Follow-up ranged from 1 to 28 months.Aim
Method
Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date. Patients treated for IPOS from January 2006 to December 2020 were included. Patient demographics, parameters upon admission and discharge, radiological imaging, and microbiological results were retrieved from medical records. CT and MRI were analyzed for epidural, paravertebral, and intervertebral abscess formation, vertebral destruction, and endplate involvement. Pathogens were identified by CT-guided or intraoperative biopsy, intraoperative tissue sampling, or implant sonication.Aims
Methods
Psychological status may be an important predictor of outcome after periacetabular osteotomy (PAO). The aim of this study was to investigate the influence of psychological distress on postoperative health-related quality of life, joint function, self-assessed pain, and sports ability in patients undergoing PAO. In all, 202 consecutive patients who underwent PAO for developmental dysplasia of the hip (DDH) at our institution from 2015 to 2017 were included and followed up at 63 months (SD 10) postoperatively. Of these, 101 with complete data sets entered final analysis. Patients were assessed by questionnaire. Psychological status was measured by Brief Symptom Inventory (BSI-18), health-related quality of life was raised with 36-Item Short Form Survey (SF-36), hip functionality was measured by the short version 0f the International Hip Outcome Tool (iHOT-12), Subjective Hip Value (SHV), and Hip Disability and Outcome Score (HOS). Surgery satisfaction and pain were assessed. Dependent variables (endpoints) were postoperative quality of life (SF-36, HOS quality of life (QoL)), joint function (iHOT-12, SHV, HOS), patient satisfaction, and pain. Psychological distress was assessed by the Global Severity Index (GSI), somatization (BSI Soma), depression (BSI Depr), and anxiety (BSI Anx). Influence of psychological status was assessed by means of univariate and multiple multivariate regression analysis.Aims
Methods
Dual-mobility (DM) bearings are effective to mitigate dislocation in revision total hip arthroplasty (THA). However, data on its use for treating dislocation is scarce. Aim of this study was to compare DM bearings, standard bearings and constrained liner (CL) in revision THA for recurrent dislocation and to identify risk factors for re-dislocation. We reviewed 100 consecutive revision THAs performed for dislocation from 2012 and 2019. 45 hips (45%) received a DM construct, while 44 hips (44%) and 11 hips (11%) had a standard bearing and CL, respectively. Rates of re-dislocation, re-revision for dislocation and overall re-revision were compared. Radiographs were assessed for cup positioning, restoration of centre of rotation, leg length and offset. Risk factors for re-dislocation were determined by cox regression analysis. Modified Harris hip scores (mHHS) were calculated. Mean follow-up was 53 months (1 to 103). DM constructs were used more frequently in elderly patients (p=0.011) and hips with abductor deficiency (p< 0.001). The re-dislocation rate was 11.1% for DM bearings compared with 15.9% for standard bearings and 18.2% for CL (p=0.732). Revision-free survival for DM constructs was 83% (95% CI 0.77 – 0.90) compared to 75% (95% CI 0.68 – 0.82) for standard articulations and 71% (95% CI 0.56 – 0.85) for CL (p=0.455). Younger age (HR 0.91; p=0.020), lower comorbidity (HR 0.42; p=0.031), smaller heads (HR 0.80; p=0.041) and cup retention (HR 8.23; p=0.022) were associated with re-dislocation. Radiological analysis did not reveal a relationship between restoration of hip geometry and re-dislocation. mHHS significantly improved from 43.8 points to 65.7 points (p<0.001) with no differences among bearing types. Our findings suggest that DM bearings do not sufficiently prevent dislocation in revision THA for recurrent dislocation. Reconstruction of the abductor complex may play a key role to reduce the burden in these high-risk patients.
Synovial fluid D-lactate may be useful for diagnosing septic arthritis (SA) as this biomarker is almost exclusively produced by bacteria. We evaluated the performance of synovial fluid D-lactate and determined its optimal cut-off value for diagnosing SA. Consecutive patients with suspicion of septic arthritis were prospectively included. They underwent joint aspiration and synovial fluid was collected for culture, leukocyte count and D-lactate concentration (by spectrophotometry). Youden's J statistic was used for determining optimal D-lactate cut-off value on the receiver operating characteristic (ROC) curve by maximizing sensitivity and specificity.Aim
Method
Special acetabular polyethylene (PE) liners are intended to increase the stability of the artificial hip joint, yet registry studies on them are limited. The pupose of this study was to investigate differences in revision rates for mechanical complications in primary cementless total hip arthroplasty (THA) with standard and special PE acetabular liners in patients with ostheoarthritis. Data from the German Arthroplasty Registry (EPRD) between 2012 until 2020 were analysed. Patients with diagnosed ostheoarthritis of the hip without relevant prior surgeries, who received a primary cementless THA with a ceramic/PE bearing articulation were included. Cumulative incidences of revision for mechanical complications for Standard and 4 special PE liners (Lipped, Increased Offset, Angulated, Angulated|Increased Offset) were determined using the Kaplan-Meier Estimator. Confounding factors were investigated with a Cox proportional-hazards model. In total 151.104 cases were included. 7-year unadjusted revision-free survival for mechanical complications compared to Standard liners (97.7%) was lower for Angulated (97.4%), Lipped (97.2%) and Angulated|Increased Offset liners (94.7%), but higher for Increased Offset liners (98.1%). Risk of revision for mechanical complications was not significantly different between Standard, Lipped and Angulated liners. Increased Offset liners (HR=0.68; 95% CI=0.5–0.92) reduced, while Angulated|Increased Offset liners (HR= 1.81; 95% CI=1.38–2.36) increased the risk. Higher age at admission and an Elixhauser comorbidity index greater zero increased the risk, whereas a larger liner share slightly reduced the risk. Only the use of Increased Offset liners reduced the risk of revision for mechanical complications compared to Standard liners — other special liners did not.
Current guidelines consider analyses of joint aspirates, including leucocyte cell count (LC) and polymorphonuclear percentage (PMN%) as a diagnostic mainstay of periprosthetic joint infection (PJI). It is unclear if these parameters are subject to a certain degree of variability over time. Therefore, the aim of this study was to evaluate the variation of LC and PMN% in patients with aseptic revision total knee arthroplasty (TKA). We conducted a prospective, double-centre study of 40 patients with 40 knee joints. Patients underwent joint aspiration at two different time points with a maximum period of 120 days in between these interventions and without any events such as other joint aspirations or surgeries. The main indications for TKA revision surgery were aseptic implant loosening (n = 24) and joint instability (n = 11).Aims
Methods
The follow-up interval of a study represents an important aspect that is frequently mentioned in the title of the manuscript. Authors arbitrarily define whether the follow-up of their study is short-, mid-, or long-term. There is no clear consensus in that regard and definitions show a large range of variation. It was therefore the aim of this study to systematically identify clinical research published in high-impact orthopaedic journals in the last five years and extract follow-up information to deduce corresponding evidence-based definitions of short-, mid-, and long-term follow-up. A systematic literature search was performed to identify papers published in the six highest ranked orthopaedic journals during the years 2015 to 2019. Follow-up intervals were analyzed. Each article was assigned to a corresponding subspecialty field: sports traumatology, knee arthroplasty and reconstruction, hip-preserving surgery, hip arthroplasty, shoulder and elbow arthroplasty, hand and wrist, foot and ankle, paediatric orthopaedics, orthopaedic trauma, spine, and tumour. Mean follow-up data were tabulated for the corresponding subspecialty fields. Comparison between means was conducted using analysis of variance.Aims
Methods
Two stage revision is the most commonly used surgical treatment strategy for periprosthetic hip infections (PHI). The aim of our study was to assess the intra- and postoperative complications during and after two stage revision using resection arthroplasty between ex- and reimplantation. In this retrospective cohort study, all patients treated with a two stage revision using resection arthroplasty for PHI were included from 2008 to 2014. During the first stage, the prosthesis was removed resulting in a resection arthroplasty without the use a PMMA spacer. During second stage, (cemented or uncemented) reimplantation of the hip prosthesis was performed. The cohort was stratified into two groups according to the length of prosthesis-free interval (≤10 weeks and >10 weeks). Data on complications during explantation, prosthesis-free interval, reimplantation, and after reimplantation was collected. The overall complication rate between both groups was compared using the chi-squared test. The revision-free and infection-free survival was estimated using Kaplan-Meier survival analysis.Aim
Method
Treatment of enterococcal periprosthetic joint infections (PJI) is challenging due to heterogeneous pathogenesis, non-standardized management strategies and lack of biofilm-active antibiotics. Previous studies report treatment success from 50–76%. We evaluated the characteristics and outcome of enterococcal PJI, in particular the influence of antimicrobial treatment regimens. Consecutive patients with enterococcal PJI treated at two specialized orthopaedic institutions were retrospectively included from 2010 to 2017. PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Adequate antimicrobial treatment was considered when the antibiotic was appropiate for the treatment of enterococcal bone infections (activity, dose, oral bioavailability, bone penetration). The treatment success (defined as no relapse of enteroccal infection) and clinical success(i.e. infection-free status) was evaluated and compared using Fishers exact test.Aim
Method
We included 26 patients suffering from We conclude that
The aim of the study was to assess the accuracy of the alpha defensin lateral flow test for diagnosis of periprosthetic joint infection (PJI) using an optimized diagnostic algorithm and three classification systems. In addition, we compared the performance with synovial fluid leukocyte count, the most sensitive preoperative test. In this prospective multicenter study we included all consecutive patients with painful prosthetic hip and knee joints undergoing diagnostic joint aspiration. Alpha defensin lateral flow test was used according to manufacturer instructions. The following diagnostic criteria were used to confirm infection: Musculoskeletal Infection Society (MSIS), Infectious Diseases Society of America (IDSA) and Swiss orthopedics and Swiss Society of Infectious Diseases (SOSSID). In the latter, PJI was confirmed when at least one of following criteria applied: macroscopic purulence, sinus tract, positive cytology of joint aspirate (>2000 leukocytes/μl or >70% granulocytes), histological proof of acute inflammation in periprosthetic tissue, positive culture (from aspirate, tissue or sonication fluid). Infection was classified as chronic, if symptom duration was more than 3 weeks or if infection manifested after more than 1 month after surgery. The sensitivity and specificity of the alpha defensin lateral flow test and leukocyte count in synovial fluid were calculated and compared using McNemar Chi-square test.Aim
Method
The incidence of hematogenous periprosthetic joint infections (hPJI) is unknown and the cases probably largely underreported. Unrecognized and untreated primary infectious foci may cause continuous bacteremia, further spread of microorganisms and thus treatment failure or relapse of infection. This study aimed at improving knowledge about primary foci and microbiological characteristics of this entity to establish preventive measures and improve diagnostic and therapeutic strategies to counteract hPJI. We retrospectively analysed all consecutive patients with hPJI, who were treated at our institution from January 2010 until December 2016. Diagnosis of PJI was established if 1 of the following criteria applied:(i) macroscopic purulence, (ii) presence of sinus tract, (iii) positive cytology of joint aspirate (>2000 leukocytes/μl or >70% granulocytes), (iv) significant microbial growth in synovial fluid, periprosthetic tissue or sonication culture of retrieved prosthesis components, (v) positive histopathology. PJI was classified as hematogenous if the following criteria were fulfilled additionally: (1) onset of symptoms more than 1 month after arthroplasty AND (2) i) isolation of the same organism in blood cultures OR ii) evidence of a distant infectious focus consistent with the pathogen.Aim
Method
Periprosthetic joint infections (PJI), caused by pathogens, for which no biofilm-active antibiotics are available, are often referred to as difficult-to-treat (DTT). It is unclear whether DTT PJI has worse outcome due to unavailability of biofilm-active antibiotics. We evaluated the outcome of DTT and non-DTT PJI managed according to a standardized treatment regimen. Patients with hip and knee PJI from 2013 to 2015 were prospectively included and followed-up for ≥2 years. DTT PJI was defined as growth of microorganism(s) resistant to biofilm-active antibiotics. The Kaplan-Meier survival analysis was used to compare the probability of infection-free survival between DTT and non-DTT PJI.Background
Methods
To assess the clinical characteristics, diagnostic tests and treatment strategies in orthopedic implant-associated infections (OIAI) caused by Cutibacterium spp. We retrospectively included consecutive patients with OIAI caused by Cutibacterium spp. treated at our institution from January 2012 to January 2017. OIAI was diagnosed when: (i) macroscopic purulence, sinus tract or exposed implant was present; (ii) acute inflammation in peri-implant-tissue was documented; (iii) Cutibacterium spp. grew in joint aspirate, ≥2 intraoperative peri-implant tissue samples or in sonication fluid of the removed implant (>50 CFU/ml).Aim
Method
The uncertainty of the biological effects of wear and corrosion from Metal-on-metal (MoM) implants has initiated a debate on their safety and use. Generally, the release of wear particles from MoM hip implants can clinically manifest in aseptic osteolysis. In our study, the effect of MoM-wear particles and particle originated Co and Cr ions on mesenchymal stromal cells (MSCs) was investigated [1]. The lead hypotheses were that (1) dissociated Co and Cr, originated from MoM-wear particles, accumulate in the bone marrow and (2) apparently impair the osteogenic function of local MSCs. This impairment could be one element contributing to the manifestation of periprosthetic osteolyses. The study was approved by the local ethical committee (EA1/194/13); all donors gave written informed consent. Blood (B), Synovial fluid (SF) periprosthetic tissue (PT) and bone marrow (BM) were collected from patients with at least one osteolytic lesion, undergoing a revision of a MoM hip implant. Patients undergoing primary THA served as controls. Metal wear particles were isolated from PT by enzymatic digestion and their size and shape characterized by transmission electron microscopy (TEM). Local and systemic levels of Co and Cr were analyzed by graphite furnace atomic absorption spectroscopy. MoM-MSCs and control-MSCs were isolated from BM for INTRODUCTION
METHODS
Despite the lack of data regarding the diagnostic validity of synovial aspiration in Girdlestone hips a Girdlestone-aspiration is often performed before reimplantation to detect a possible persistence of infection during two staged revision total hip arthroplasty (THA). The aim of this study was to assess the diagnostic performance of the synovial aspiration in Girdlestone hips, without a PMMA-Spacer, for the detection of infection persistence prior to THA reimplantation. Seventy four patients undergoing a two staged revision THA surgery between 2006 and 2013 were included in this retrospective cohort study. Both synovial cultures and CRP values were acquired before explantation of the THA and of the Girdlestone hip before reimplantation. An antibiotic holiday of 14 days was observed prior to synovial aspiration. A PJI was defined according to the following criteria: intraarticular presence of pus or a sinus tract, a periprosthetic membrane indicative of infection in the histological analysis, or a positive microbiological isolation in a minimum of two samples.Introduction
Methods