We have recently shown that waste heat from forced-air
warming blankets can increase the
Patient warming significantly decreases the risk
of surgical site infection. Recently there have been concerns that forced
air warming may interfere with unidirectional airflow, potentially
posing an increased risk of infection. Our null hypothesis was that
forced air and radiant warming devices do not increase the temperature
and the number of particles over the surgical site when compared
with no warming device. A forced air warming device was compared with
a radiant warming device and no warming device as a control. The
temperature and number of particles were measured over the surgical
site. The theatre was prepared as for a routine lower-limb arthroplasty
operation, and the same volunteer was used throughout the study. Forced air warming resulted in a significant mean increase in
the
The aim of this study was to evaluate the diagnostic accuracy of the absolute synovial polymorphonuclear neutrophil cell (PMN) count for the diagnosis or exclusion of periprosthetic joint infection (PJI) after total hip (THA) or knee arthroplasty (TKA). In this retrospective cohort study, 147 consecutive patients with acute or chronic complaints following THA and TKA were included. Diagnosis of PJI was established based on the 2018 International Consensus Meeting criteria. A total of 39 patients diagnosed with PJI (32 chronic and seven acute) and 108 patients with aseptic complications were surgically revised.Aims
Methods
Fungal periprosthetic joint infections (fPJIs) are rare complications, constituting only 1% of all PJIs. Neither a uniform definition for fPJI has been established, nor a standardized treatment regimen. Compared to bacterial PJI, there is little evidence for fPJI in the literature with divergent results. Hence, we implemented a novel treatment algorithm based on three-stage revision arthroplasty, with local and systemic antifungal therapy to optimize treatment for fPJI. From 2015 to 2018, a total of 18 patients with fPJI were included in a prospective, single-centre study (DKRS-ID 00020409). The diagnosis of PJI is based on the European Bone and Joint Infection Society definition of periprosthetic joint infections. The baseline parameters (age, sex, and BMI) and additional data (previous surgeries, pathogen spectrum, and Charlson Comorbidity Index) were recorded. A therapy protocol with three-stage revision, including a scheduled spacer exchange, was implemented. Systemic antifungal medication was administered throughout the entire treatment period and continued for six months after reimplantation. A minimum follow-up of 24 months was defined.Aims
Methods
The COVID-19 pandemic posed significant challenges to healthcare systems across the globe in 2020. There were concerns surrounding early reports of increased mortality among patients undergoing emergency or non-urgent surgery. We report the morbidity and mortality in patients who underwent arthroplasty procedures during the UK first stage of the pandemic. Institutional review board approval was obtained for a review of prospectively collected data on consecutive patients who underwent arthroplasty procedures between March and May 2020 at a specialist orthopaedic centre in the UK. Data included diagnoses, comorbidities, BMI, American Society of Anesthesiologists grade, length of stay, and complications. The primary outcome was 30-day mortality and secondary outcomes were prevalence of SARS-CoV-2 infection, medical and surgical complications, and readmission within 30 days of discharge. The data collated were compared with series from the preceding three months.Aims
Methods
Periprosthetic joint infections (PJIs) are among the most devastating complications after joint arthroplasty. There is limited evidence on the efficacy of different antiseptic solutions on reducing biofilm burden. The purpose of the present study was to test the efficacy of different antiseptic solutions against clinically relevant microorganisms in biofilm. We conducted an in vitro study examining the efficacy of several antiseptic solutions against clinically relevant microorganisms. We tested antiseptic irrigants against nascent (four-hour) and mature (three-day) single-species biofilm created in vitro using a drip-flow reactor model.Aims
Methods
The aim of this study was to develop a single-layer hybrid organic-inorganic sol-gel coating that is capable of a controlled antibiotic release for cementless hydroxyapatite (HA)-coated titanium orthopaedic prostheses. Coatings containing gentamicin at a concentration of 1.25% weight/volume (wt/vol), similar to that found in commercially available antibiotic-loaded bone cement, were prepared and tested in the laboratory for: kinetics of antibiotic release; activity against planktonic and biofilm bacterial cultures; biocompatibility with cultured mammalian cells; and physical bonding to the material (n = 3 in all tests). The sol-gel coatings and controls were then tested in vivo in a small animal healing model (four materials tested; n = 6 per material), and applied to the surface of commercially pure HA-coated titanium rods.Aims
Methods
Arthrofibrosis is a relatively common complication after joint injuries and surgery, particularly in the knee. The present study used a previously described and validated rabbit model to assess the biomechanical, histopathological, and molecular effects of the mast cell stabilizer ketotifen on surgically induced knee joint contractures in female rabbits. A group of 12 skeletally mature rabbits were randomly divided into two groups. One group received subcutaneous (SQ) saline, and a second group received SQ ketotifen injections. Biomechanical data were collected at eight, ten, 16, and 24 weeks. At the time of necropsy, posterior capsule tissue was collected for histopathological and gene expression analyses (messenger RNA (mRNA) and protein).Aims
Methods
The aim of this study was to evaluate the diagnostic accuracy of the synovial alpha-defensin enzyme-linked immunosorbent assay (ELISA) for the diagnosis of prosthetic joint infection (PJI) in the work-up prior to revision of total hip (THA) and knee arthroplasty (TKA). Inclusion criteria for this prospective cohort study were acute or chronic symptoms of the index joint without specific exclusion criteria. Synovial fluid aspirates of 202 patients were analyzed and semiquantitative laboratory alpha-defensin ELISA was performed. Final diagnosis of PJI was established by examination of samples obtained during revision surgery.Aims
Patients and Methods
Aims
Patients and Methods
We investigated whether the indentation of bone
cement spacers used in revision of infected joint arthroplasty with a
MacDonald dissector increased the elution of antibiotic The fluid sampled at 72 hours from the indented discs containing
0.17 g gentamicin (0.88% w/w) contained a mean of 113 mcg/ml (90.12
to 143.5) compared with 44.5 mcg/ml (44.02 to 44.90) in the fluid
sampled from the plain discs (p = 0.012). In discs containing 0.33
g gentamicin (1.75% w/w), the concentration eluted from the indented discs
at 72 hours was a mean of 316 mcg/ml (223 to 421) compared with
a mean of 118 mcg/ml (100 to 140) from the plain discs (p <
0.001). At two weeks, these significant differences persisted. At nine
weeks the indented discs eluted a greater concentration for all
gentamicin doses, but the difference was only significant for the
discs containing 0.17 g (0.88% w/w, p = 0.006). However if the area
under the curve is taken as a measure of the total antibiotic eluted,
the indented discs eluted more gentamicin than the plain discs for
the 0.17 g (0.88% w/w, p = 0.031), the 0.25 g (1.41% w/w, p <
0.001) and the 0.33 g (1.75% w/w, p <
0.001) discs. When preparing antibiotic spacers for use in staged revision
arthroplasty surgery we recommend indenting the spacer with a MacDonald
dissector to increase the elution of antibiotic. Cite this article:
Vancomycin is commonly added to acrylic bone cement during revision
arthroplasty surgery. Proprietary cement preparations containing
vancomycin are available, but are significantly more expensive.
We investigated whether the elution of antibiotic from ‘home-made’
cement containing vancomycin was comparable with more expensive
commercially available vancomycin impregnated cement. A total of 18 cement discs containing either proprietary CopalG+V;
or ‘home-made’ CopalR+G with vancomycin added by hand, were made.
Each disc contained the same amount of antibiotic (0.5 g gentamycin,
2 g vancomycin) and was immersed in ammonium acetate buffer in a
sealed container. Fluid from each container was sampled at eight
time points over a two-week period. The concentrations of gentamicin
and vancomycin in the fluid were analysed using high performance
liquid chromatography mass spectrometry.Aims
Materials and Methods
Tissue responses to debris formed by abrasion of polymethylmethacrylate
(PMMA) spacers at two-stage revision arthroplasty for prosthetic
joint infection are not well described. We hypothesised that PMMA
debris induces immunomodulation in periprosthetic tissues. Samples of tissue were taken during 35 two-stage revision arthroplasties
(nine total hip and 26 total knee arthroplasties) in patients whose
mean age was 67 years (44 to 85). Fourier transform infrared microscopy
was used to confirm the presence of PMMA particles. Histomorphometry
was performed using Sudan Red and Haematoxylin-Eosin staining.
CD-68, CD-20, CD-11(c), CD-3 and IL-17 antibodies were used to immunophenotype
the inflammatory cells. All slides were scored semi-quantitatively
using the modified Willert scoring system.Aims
Patients and Methods
Hips with metal-on-metal total hip arthroplasty (MoM THA) have a high rate of adverse local tissue reactions (ALTR), often associated with hypersensitivity reactions. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) measures tissue perfusion with the parameter Ktrans (volume transfer constant of contrast agent). Our purpose was 1) to evaluate the feasibility of DCE-MRI in patients with THA and 2) to compare DCE-MRI in patients with MoM bearings with metal-on-polyethylene (MoP) bearings, hypothesising that the perfusion index Ktrans in hips with MoM THA is higher than in hips with MoP THA. In this pilot study, 16 patients with primary THA were recruited (eight MoM, eight MoP). DCE-MRI of the hip was performed at 1.5 Tesla (T). For each patient, Ktrans was computed voxel-by-voxel in all tissue lateral to the bladder. The mean Ktrans for all voxels was then calculated. These values were compared with respect to implant type and gender, and further correlated with clinical parameters.Objectives
Methods
The purpose of this study was to compare the
diagnostic accuracy for the detection of infection between the culture of
fluid obtained by sonication (SFC) and the culture of peri-implant
tissues (PITC) in patients with early and delayed implant failure,
and those with unsuspected and suspected septic failure. It was
hypothesised that SFC increases the diagnostic accuracy for infection
in delayed, but not early, implant failure, and in unsuspected septic
failure. The diagnostic accuracy for infection of all consecutive
implants (hardware or prostheses) that were removed for failure was
compared between SFC and PITC. This prospective study included 317
patients with a mean age of 62.7 years (9 to 97). The sensitivity
for detection of infection using SFC was higher than using PITC
in an overall comparison (89.9% Sonication is mainly recommended when there is implant failure
with no clear signs of infection and in patients with delayed implant
failure. In early failure, SFC is not superior to PITC for the diagnosis
of infection and, therefore, is not recommended as a routine diagnostic
test in these patients. Cite this article:
Bone cements produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement, which may not be apparent to surgeons, can also affect these properties. The supplier of Palacos bone cement with added gentamicin changed in 2005. We carried out a study to examine the mechanical characteristics and antibiotic elution of Schering-Plough Palacos, Heraeus Palacos and Depuy CMW Smartset bone cements. Both Heraeus Palacos and Smartset bone cements performed significantly better than Schering-Plough Palacos in terms of mechanical characteristics, with and without additional vancomycin (p <
0.001). All cements show a deterioration in flexural strength with increasing addition of vancomycin, albeit staying above ISO minimum levels. Both Heraeus Palacos and Smartset elute significantly more gentamicin cumulatively than Schering-Plough Palacos. Smartset elutes significantly more vancomycin cumulatively than Heraeus Palacos. The improved antibiotic elution characteristics of Smartset and Heraeus Palacos are not associated with a deterioration in mechanical properties. Although marketed as the ‘original’ Palacos, Heraeus Palacos has significantly altered mechanical and antibiotic elution characteristics compared with the most commonly-used previous version.
Implantation of allograft bone is an integral part of revision surgery of the hip. One major concern with its use is the risk of transmission of infective agents. There are a number of methods of processing allograft bone in order to reduce this risk. One method requires washing the tissue using pulsed irrigation immediately before implantation. We report the incidence of deep bacterial infection in 138 patients (144 revision hip arthroplasties) who had undergone implantation of allograft bone. The bone used was fresh-frozen, non-irradiated and pulse-washed with normal saline before implantation. The deep infection rate at a minimum follow-up of one year was 0.7%. This method of processing appears to be associated with a very low risk of allograft-related bacterial infection.
Allografts of bone from the femoral head are often used in orthopaedic procedures. Although the donated heads are thoroughly tested microscopically before release by the bone bank, some surgeons take additional cultures in the operating theatre before implantation. There is no consensus about the need to take these cultures. We retrospectively assessed the clinical significance of the implantation of positive-cultured bone allografts. The contamination rate at retrieval of the allografts was 6.4% in our bone bank. Intra-operative cultures were taken from 426 femoral head allografts before implantation; 48 (11.3%) had a positive culture. The most frequently encountered micro-organism was coagulase-negative staphylococcus. Deep infection occurred in two of the 48 patients (4.2%). In only one was it likely that the same micro-organism caused the contamination and the subsequent infection. In our study, the rate of infection in patients receiving positive-cultured allografts at implantation was not higher than the overall rate of infection in allograft surgery suggesting that the positive cultures at implantation probably represent contamination and that the taking of additional cultures is not useful.
This prospective study evaluates the role of new laboratory markers in the diagnosis of deep implant infection in 78 patients (41 men and 37 women) with a revision total knee or hip replacement. The mean age at the time of operation was 64.0 years (19 to 90). Intra-operative cultures showed that 21 patients had a septic and 57 an aseptic total joint replacement. The white blood cell count, the erythrocyte sedimentation rate and levels of C-reactive protein, interleukin-6, procalcitonin and tumour necrosis factor (TNF)-α were measured in blood samples before operation. The diagnostic cut-off values were determined by Received Operating Characteristic curve analysis. C-reactive protein (>
3.2 md/dl) and interleukin-6 (>
12 pg/ml) have the highest sensitivity (0.95). Interleukin-6 is less specific than C-reactive protein (0.87 The combination of C-reactive protein and interleukin-6 measurement provide excellent screening tests for infection of a deep implant. A highly specific marker such as procalcitonin and pre-operative aspiration of the joint might be useful in identifying patients with true positive C-reactive protein and/or interleukin-6 levels.