Potential value of a rapid syndromic multiplex PCR for the diagnosis of native and prosthetic joint infections: a real-world evidence study.

Introduction: The BIOFIRE Joint Infection (JI) Panel is a diagnostic tool that uses multiplex-PCR testing to detect microorganisms in synovial fluid specimens from patients suspected of having septic arthritis (SA) on native joints or prosthetic joint infections (PJIs). Methods: A study was conducted across 34 clinical sites in 19 European and Middle Eastern countries from March 2021 to June 2022 to assess the effectiveness of the BIOFIRE JI Panel. Results: A total of 1527 samples were collected from patients suspected of SA or PJI, with an overall agreement of 88.4 % and 85 % respectively between the JI Panel and synovial fluid cultures (SFCs). The JI Panel detected more positive samples and microorganisms than SFC, with a notable difference on Staphylococcus aureus, Streptococcus species, Enterococcus faecalis, Kingella kingae, Neisseria gonorrhoeae, and anaerobic bacteria. The study found that the BIOFIRE JI Panel has a high utility in the real-world clinical setting for suspected SA and PJI, providing diagnostic results in approximately 1 h. The user experience was positive, implying a potential benefit of rapidity of results' turnover in optimising patient management strategies. Conclusion: The study suggests that the BIOFIRE JI Panel could potentially optimise patient management and antimicrobial therapy, thus highlighting its importance in the clinical setting.

Long-term implant survival following hemiarthroplasty for fractured neck of femur.

Aims: Several different designs of hemiarthroplasty are used to treat intracapsular fractures of the proximal femur, with large variations in costs. No clinical benefit of modular over monoblock designs has been reported in the literature. Long-term data are lacking. The aim of this study was to report the ten-year implant survival of commonly used designs of hemiarthroplasty. Methods: Patients recorded by the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) between 1 September 1999 and 31 December 2020 who underwent hemiarthroplasty for the treatment of a hip fracture with the following implants were included: a cemented monoblock Exeter Trauma Stem (ETS), cemented Exeter V40 with a bipolar head, a monoblock Thompsons prosthesis (Cobalt/Chromium or Titanium), and an Exeter V40 with a Unitrax head. Overall and age-defined cumulative revision rates were compared over the ten years following surgery. Results: A total of 41,949 hemiarthroplasties were included. Exeter V40 with a Unitrax head was the most commonly used (n = 20,707, 49.4%). The overall rate of revision was small. A total of 28,201 patients (67.2%) were aged > 80 years. There were no significant differences in revision rates across all designs of hemiarthroplasty in patients of this age at any time. The revision rates for all designs were < 3.5%, three years postoperatively. At subsequent times the ETS and Exeter V40 with a bipolar head performed well in all age groups. The unadjusted ten-year mortality rate for the whole cohort was 82.2%. Conclusion: There was no difference in implant survival between all the designs of hemiarthroplasty in the first three years following surgery, supporting the selection of a cost-effective design of hemiarthroplasty for most patients with an intracapsular fracture of the hip, as determined by local availability and costs. Beyond this, the ETS and Exeter bipolar designs performed well in all age groups.

A multicentre evaluation and expert recommendations of use of the newly developed BioFire Joint Infection polymerase chain reaction panel.

Septic arthritis is a serious condition with significant morbidity and mortality, routinely diagnosed using culture. The FDA has recently approved the rapid molecular BioFire® Joint Infection Panel (BJIP) for synovial fluid. We aimed to evaluate the BJIP compared to culture and its potential use in patient management. A multicentre retrospective evaluation of BJIP was conducted in the UK and Ireland. Positive percent agreement (PPA) and negative percent agreement (NPA) were calculated between the BJIP and routine culture. A multidisciplinary team (MDT) discussion addressing the optimal or potential case use of the assay practice was facilitated. Three hundred ninety-nine surplus synovial fluid samples (~ 70% from native joints) from eight centres were processed using BJIP in addition to routine culture. An increased yield of positive results was detected using BJIP compared to routine culture (98 vs 83), giving an overall PPA of 91.6% and overall NPA of 93% for the BJIP compared to culture results. The BJIP detected resistant markers and additional organisms that could influence antibiotic choices including Neisseria gonorrhoeae and Kingella kingae. The MDT agreed that the assay could be used, in addition to standard methods, in adult and children patients with specialist advice use based on local needs. Rapid results from BJIP were assessed as having potential clinical impact on patient management. Organisms not included in the panel may be clinically significant and may limit the value of this test for PJI.

Trends and developments in hip and knee arthroplasty technology.

The developments in hip and knee arthroplasty over recent years have aimed to improve outcomes, reduce complications and improve implant survival. This review describes some of the most interesting trends and developments in this important and fast-moving field. Notable developments have included ceramic hip resurfacing, mini hip stems, cementless knee replacement and the wider adoption of the dual mobility articulation for hip arthroplasty. Advances in additive manufacturing and the surface modification of joint replacements offer increasing options for more challenging arthroplasty cases. Robotic assisted surgery is one of the most interesting developments in hip and knee surgery. The recent growth in the use of this technology is providing data that will help determine whether this approach should become the standard of care for hip and knee arthroplasty in the future.

Antibiotic resistance profiles of deep surgical site infections in hip hemiarthroplasty; comparing low dose single antibiotic versus high dose dual antibiotic impregnated cement.

Objectives: The incidence of fractured neck of femur (FNOF) is increasing yearly. Many of these patients undergo hip hemiarthroplasty. High dose dual-antibiotic cement (HDDAC) has been shown to reduce rates of deep surgical site infection (SSI) when compared to the current standard low dose single-antibiotic cement (LDSAC) in a quasi-randomised controlled trial. Some concerns exist regarding the use of HDDAC and the development of antibiotic resistance. We reviewed cases of infection in LDSAC and HDDAC bone cement with regard to causative organism and resistance profile. Methods: A retrospective analysis was undertaken of all hemiarthroplasties within our trust from April 2008 to December 2014. We identified all patients in this time period who acquired a deep SSI. The infecting organisms and susceptibility patterns were collated for each cement. Results: We identified 1941 hemiarthroplasties. There were 38 deep surgical site infections representing an infection rate of 3.4% in LDSAC patients and 1.2% in HDDAC patients. The majority of infections were polymicrobial. Staphylococcus epidermidis was the most commonly isolated organism. It accounted for a larger proportion of HDDAC than LDSAC infections (p<0.05). Infection with Corynebacterium species and S. aureus, including MRSA, was eradicated completely with the use of HDDAC. There was no significant change in the proportion of Gram negative and Gram positive infections between the two cements. In Gram positive organisms, there was no significant change in resistance to most antibiotics. Although fewer resistant infections overall, there were significant increases in the proportion of resistance to ciprofloxacin and clindamycin with HDDAC. We observed no resistance to daptomycin or linezolid in either cement and levels of resistance remained low to rifampicin and teicoplanin. In Gram negative organisms, no significant change in resistance was observed. Conclusions: We observed a significantly lower infection rate with the use of HDDAC compared to LDSAC. Such was this reduced infection rate that there was a trend to a lower rate of resistance with the use of HDDAC. However, there were increases in the proportion of resistant cases, most notably to clindamycin and ciprofloxacin in Gram positive organisms, possibly reflecting the higher number of S. epidermidis in the HDDAC group. Whilst the differences in our study were not found to be statistically significant, it is reassuring for teams using HDDAC to prevent SSI in hip hemiarthroplasty.

Difference in the acetabular cup orientation in standing and supine radiographs.

Acetabular orientation changes with that of the pelvis during lying and standing. This study was designed to measure these changes. We assessed 17 BHR replacements using EBRA software. The mean acetabular anteversion was more (p = 0.02) on erect than supine radiographs. Linear regression analysis showed that anteversion and inclination increased in some while decreased in others, and Bland and Altman analysis showed wide limits of agreement. The changes in acetabular orientation are thus subject to significant variations between the patients. We suggest studying the factors affecting acetabular orientation in standing to help reduce joint reaction forces and improve outcomes.

Techniques of training in the management of tension pneumothorax: bridging the gap between confidence and competence.

BACKGROUND: Thoracocentesis is a simple procedure with high potential to be life-saving, but is associated with complications if performed incorrectly. The aim of this study was to determine both the ability and confidence of practitioners who would be expected deal with a tension pneumothorax both in and out of hospital. If any shortfall was identified between theoretical and practical knowledge the goal was to develop techniques to overcome that shortfall. METHODS: A total of 51 consenting medical practitioners were recruited to participate in a prospective single-subject crossover applied behavioural analysis study. The primary outcome was the change in accuracy of identification of the correct site for needle thoracocentesis on an anatomical diagram and by verbal description. This was compared before and after the introduction of brief and frequent "life-saving practical skills" training sessions. Participants' confidence was also assessed pre and post intervention. RESULTS: There was a disparity pre-intervention between confidence (79.4% felt able to perform the procedure without assistance) and competence (85.2% of these incorrectly identified the anatomical site). Following intervention, the in-practice correct identification of the site increased from 15.7% to 52.9%. The disparity between confidence and competence still existed by was reduced. CONCLUSIONS: The learning and re-learning of this skill should occur regularly through both theoretical and practical teaching to ensure the adequate ability of practitioners and reduce the danger associated with false confidence.

Catastrophic osteomyelitis following percutaneous wire fixation of a distal radial fracture: a cautionary tale of poor patient selection followed by surgical mishap.

We present a case of distal radius fracture. Several sequential unfortunate events resulted in a poor outcome. The patient was poorly selected because the degree of early dementia was not fully appreciated, due to intermittent periods of lucidity. Having elected to treat this distal radius fracture with Kirschner wires, a wire snapped during the procedure and was deemed safe to leave within the medullary cavity. Subsequently, the patient was left in a cast for 4 weeks without regular pin site inspection. When the cast was removed a gross osteomyelitis had developed. This series of events, led to unnecessary morbidity and extended the immobilisation time with reduced wrist function. This case highlights the importance of careful patient selection, surgical tactics and continuity of care.