Aim

The purpose of this study is to evaluate the safety profile and impact on functional results of surgical debridement performed in the early postoperative by comparing them with patients that undergone uncomplicated total joint arthroplasty.

Method

This is a retrospective case-control study. Patients that underwent debridement with prosthesis preservation for suspected acute postoperative infection of total hip or knee arthroplasty between 2010–2014 were included. Controls were randomly selected (1:2 ratio) from a list of primary arthroplasty patients in the same time period matching for articulation, age, gender, ASA score, BMI and follow-up time.

Infection status, success of treatment and medical-surgical complications were investigated and all patients were assessed using Hip disability and Osteoarthritis Outcome Score(HOOS) or Knee injury and Osteoarthritis Outcome Score(KOOS).

Aim

Early prosthetic joint infection (PJI) is a feared complication of hip arthroplasty. Debridement, antibiotics and implant retention (DAIR) is attempted to avoid removal of the implant. The aim of this retrospective cohort study was to evaluate the success rate of DAIR in early PJI.

Method

All patients who were diagnosed with early PJI and treated with DAIR at our center from 2003 to 2013 were included in the study. During the time period, 5176 primary hip arthroplasties and 555 revision hip arthroplasties were performed. Early PJI was diagnosed in 54 patients (43 primary and 11 revisions). Median follow-up was 5.6 years (range 2.0–12.1). Standard postoperative antibiotic treatment at our centre is vancomycin and rifampicin.

Aim

Despite a preoperative workup with no evidence to suspect a prosthetic joint infection (PJI) before revision surgery, routinely obtained intraoperative cultures still can be unexpectedly positive. The purpose of this study was (1) to assess the incidence of unexpected positive intraoperative cultures in presumed aseptic knee and hip revisions and (2) to determine whether a difference exists between the infection-free implant survival rate of patients with and without unexpected positive intraoperative cultures.

Method

We selected patients who underwent a one-stage revision total knee arthroplasty (TKA) or total hip arthroplasty (THA) for different reasons. Three or more separate intraoperative cultures were obtained during each procedure. A negative result was defined as less than two positive cultures with the same microorganism. An unsuspected PJI was defined as having two or more positive cultures with the same microorganism. Patients’ medical records were reviewed to collect demographics, preoperative laboratory results, culture results, and the occurrence of infection during follow-up.

Introduction

The burden of peri-prosthetic joint infection (PJI) following hip and knee surgery is increasing. Endoprosthetic replacement (EPR) is an option for management of massive bone loss resulting from infection around failed lower limb implants.

Aims

To determine clinical outcome of EPRs for treatment of PJI around the hip and knee joint.

Aim

The aim of this study is to evaluate the value of inflammatory parameters normalization and/or increased time between stages necessary in predicting healing and preventing infection recurrence.

Method

We retrospectively studied all cases of total hip and knee arthroplasty that underwent revision for infection in our institution between 2011 and 2014. We revised the clinical and laboratory information from 55 patients (27 hips: 28 knees) with a mean age of 68 years. The average values before the first stage were 88.6 mm/h (15–134) and 59.1 mg/L (2–279) for the erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) serum respectively. In 10 cases (18.2%) it was not possible to perform the second stage. Moreover, in the other 45 cases of re- arthroplasty, the mean follow-up was 32 months (1 year).

Aim

Quantitative assessment of alpha-Defensin offers a promising approach for diagnosing a periprosthetic joint infection (PJI) with sensitivities and specificities ranging from 97% to 100% and 95% to 100%, respectively. However, to the best of our knowledge and after due inquiry little information exists concerning qualitative measurements of alpha-Defensin. The aim of this study was to assess the diagnostic accuracy of the alpha-Defensin test, a lateral flow test for the qualitative detection of alpha-Defensin.

Method

In this study, 50 patient with indicated revision surgery met the inclusion criteria due to septic or aseptic loosening. In addition to clinical standard diagnostics of PJI, the alpha-Defensin test* for the assessment of the qualitative alpha-Defensin in the synovial fluid was performed. The results were compared with the sensitivity and specificity of currently available clinical tests, specifically C-reactive protein (CRP), frozen section, definitive histology, bacteriology and sonication.

Aim

A key of success in the treatment of prosthetic joint infection (PJI) is the proper diagnosis. There is a lack of diagnostic tools able to diagnose a PJI with high accuracy. Alpha-defensin has been proposed as possible solution but the available literature is still limited. This prospective study was carried out in order to determine (1) what is the sensitivity, the specificity, the positive and the negative predictive value of the Alpha-defensin immunoassay test in diagnosing PJI; (2) which clinical features may be responsible for false positive and false negative results?

Method

Preoperative aspiration was performed in patients presenting with a painful hip/knee arthroplasty. Metallosis, other inflammatory comorbidities and previous/concomitant antibiotic therapy were not considered as exclusion criteria. Patients with inadequate amount of synovial fluid for culture were excluded. At time of revision synovial fluid samples were taken in the OR in order to perform Alpha-defensin assay. During surgical debridement tissue samples for cultures were obtained. Prospectively, 156 patients (65 knees and 91 hips) were included. A diagnosis of PJI was confirmed in 29 patients.

Aim

Preoperative joint aspiration cultures (PJACs) are of great value in diagnosing prosthetic joint infections (PJIs). Studies investigating the predictive value of PJACs to identify causative pathogens in PJI, which is off course relevant for the correct initiation of antimicrobial treatment, are limited. The objective of this study was to investigate whether the PJACs are in agreement with causative pathogens in PJIs.

Method

A retrospective monocentric study was conducted at the 40-bed orthopedics department of a tertiary centre. Medical files of patients with proven prosthetic knee or hip infection with PJACs from maximum 6 months prior to the first stage of a two-stage revision admitted between March 2010 and December 2014 were evaluated. A proven PJI was defined as at least two positive preoperative or intraoperative cultures, the presence of purulent synovial fluid or purulence at the implant site or surrounding the prosthesis without other identifiable causes, the presence of acute inflammation upon histopathological examination of the periprosthetic tissue at the time of surgery or the presence of a sinus tract communicating with the prosthesis. In order to identify the causative pathogen(s) per patient, a multidisciplinary team, consisting out of a microbiologist, a septic orthopedic surgeon, two infectious diseases specialists and two clinical pharmacists, assessed the relevance of pathogens cultured in the PJACs and intraoperative deep samples based on the current 2012 IDSA guidelines. Per patient, agreement of PJACs corresponding to the retained causative pathogen(s) was investigated in two ways: 1) on species level and 2) on Gram stain or fungi level.

Aim

The purpose of this work is to study whether there is or not, in the case of an aseptic arthroplasty exchange, a relationship between positive cultures and an early periprosthetic joint infection.

Method

We carried out a retrospective review of our cases of aseptic exchange arthroplasties of hip, knee and shoulder performed between January 2007 and December 2015.

The follow-up period was, in average, from 1 to 9 years, and in all the cases perioperative cultures were evaluated.

Aim

Dissolvable antibiotic-loaded calcium sulphate beads have been utilized for management of periprosthetic joint infection (PJI) and for aseptic revision arthroplasty. However, wound drainage and toxic reactive synovitis have been substantial problems in prior studies. Currently a commercially pure, physiologic product has been introduced that may reduce complications associated with this treatment modality. We aim to answer the question: does a commercially pure, physiologic version of antibiotic-loaded calcium sulfate beads reduce wound drainage and provide efficacious treatment for PJI and aseptic revision arthroplasty?

Method

Starting January 2010, 756 consecutive procedures were performed utilizing a set protocol of Vancomycin and Tobramycin antibiotics in commercially pure dissolvable antibiotic beads. There were 8 designated study groups:

Aim

Compare clinical outcomes following staged revision arthroplasty for periprosthetic joint infection (PJI) secondary to either multidrug resistant (MDR) bacteria or non-MDR (NMDR) bacteria.

Method

Retrospective analysis of a prospectively collected bone infection database. Adult patients diagnosed and treated for hip or knee PJI, between January 2011 and December 2014, with minimum one-year follow-up, were included in the study. Patients were divided into two groups: MDR group (defined as resistance to 3 or more classes) and N-MDR group (defined as acquired resistance to two classes of antibiotic or less).

The Charlson Comorbidity Index was used to stratify patients into low, medium and high risk.

The diagnosis of PJI, and any recurrence following treatment, was made in accordance with the Musculoskeletal Infection Society criteria. Failure was defined as recurrence of infection necessitating implant removal, excision arthroplasty, arthrodesis or amputation.

Aim

This study aimed to identify risk factors for development of deep periprosthetic joint infection (PJI) in patients following surgical treatment of neck of femur fracture.

Method

This study identified a consecutive series of 2,822 (2,052 female, 73%) patients who underwent either hemiarthroplasty (n=1,825, 65%) or fixation (DHS) (n=997, 35%) for fractured neck of femur performed between January 2009 and June 2015 at our institution. Full patient demographics, co-morbidity and peri-operative complication data were determined. The majority of patients were either ASA 2 (n=663, 23%) or ASA 3 (n=1,521, 54%), mean age = 81.3 years (SD 10.3). All patients were followed up post-operatively by a dedicated surgical site infection (SSI) monitoring team in order to identify patients who developed a PJI within 1 year. A stepwise multivariable logistic regression model was used to identify patient and surgical factors associated with increased risk of infection. Predictors with a p-value of <0.20 in the univariate analysis were included in the multivariate analysis.

Aim

The pathogenesis of non-union is multifactorial. Path biological factors, mechanical factors, and low-grade-infection contribute to impaired bone healing. Aim of this study was to determine the rate of low-grade-infection in patients with long bone non-union of the lower extremity without signs of acute infection, the influence of CRP (C-reactive protein), and the outcome.

Method

In a retrospective study (2003–2013), all patients who underwent surgery for treatment of tibial- or femoral-shaft-non-union without any clinical evidence of infection were assessed. Bacterial cultures harvested during non-union revision, the CRP and WBC (white blood cells) values at hospital admission, the outcome, and epidemiological data were analysed.

Aim

Which patients is bone-defect-reconstruction with the Masquelet-technique suitable and which problems did we see?

Method

From 11/2011 to 4/2016 we treated 49 Patients (12f/37m) with bone-defects up to 150mm after septic complications with the Masquelet-technique. We had infected-non-unions of upper and lower extremity, chronic osteomyelitis, infected knee-arthrodesis and upper-ancle-empyema. On average the patients were 48 (8–74) years old. The mean bone-defect-size was 60 mm (25–150). From other hospitals came 47 of the 49 patient, where they had up to 20 (mean 4,9) operations caused by the infection. The time before transfer to our hospital was on average 177days (6–720). 40 patients receaved flaps because of soft tissue-defects (12 free flaps, 28 local flaps). 21 patients suffered a polytrauma. In 8 cases the femur, in 4 cases a knee-arthrodesis, in 34 cases tibia, in 2 cases humerus and in 1 case the ulna were infected resulting in bone defects. Indication for the Masquelet-technique was low-/incompliance in 35 cases due to higher grade of traumatic brain injury and polytrauma and difficult soft-tissue conditions, in 9 times problems with segment-transport and in 5 cases as dead space management. Positive microbial detection succeeded in 32 patients at the first operation. Mainly we found difficult to treat bacteria. After treating the infection with radical sequestrectomy, removal of foreign bodies and filling the defect with antibiotic loaded cement spacer and external fixation we removed the spacer6–8 weeks later and filled the defect with bone graft. In 23 cases we stabilized the defect then with an internal angle stable plate. All patients were examined clinically and radiologically every 4–6 weeks in our outpatient-department until full weight bearing, later every 3 months.

Aim

The induced membrane technique (IMT) or Masquelet technique is a two-step surgical procedure used to treat bony defects (traumatic or resulting from tumoral resections) and pseudo arthroses, even caused by infections. The relatively small case series reported, sometimes with variants to the original technique, make it difficult to assess the real value of the technique. Aim of this study was then to undertake a systematic review of the literature with a particular focus on bone union, infection eradication and complication rates.

Method

A systematic review was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Individual Patient Data (PRISMA-IPD) guidelines. PubMed and other medical databases were searched using “Masquelet technique” and “induced membrane technique” keywords. English, French or Italian written articles were included if dealing with IMT employed to long bones in adults and reporting at least 5 cases with a 12 months minimum follow-up. Clinical and bone defect features, aetiology, surgical data, complications, re-interventions, union and infection eradication rates were recorded into a database. Fischer's exact test and unpaired t-test were used for the statistical analysis on the individual patient's data.

Aim

To evaluate antimicrobial activity of Sb-1 and Pyo-bacteriophage in preventing and eradicating MRSA biofilm in vitro using isothermal micro calorimetry.

Method

Two S. aureus specific bacteriophages, Sb-1 and Pyo-bacteriophage cocktail, were tested against S. aureus MRSA (ATCC 43300). MRSA biofilm was formed on porous glass beads and incubated for 24 h at 37° C in BHI, washed 3 times and exposed to different concentrations of bacteriophages. For biofilm prevention, MRSA (5×10⁶ CFUs/ml) was incubated with different phage titers. Glass beads were placed in the calorimeter and heat flow (µW) and total heat (J) were measured in real-time for 48h (eradication) or 24h (prevention).

Aim

The demand for a synthetic bone substitute that can build bone and at the same time kill bacteria is high. The aim of this study was to compare the elution of gentamicin from a new synthetic bone substitute in vitro with the performance in clinical applications.

Method

Gentamicin release was measured from a synthetic bone graft substitute, comparing in vitro and clinical conditions:

Gentamicin concentrations were analyzed using antibody technique.

Aim

The ultimate diagnostic proof of chronic osteomyelitis (COM) is the association of a compatible clinical presentation with an unequivocal positive deep bone sample culture. Intraoperative deep bone samples cultures has been widely considered the gold standard in this setting but the preoperative identification of the infecting microorganism through a bone biopsy is of paramount importance in the diagnostic and treatment protocol of any COM. Unfortunately, preoperative bone biopsies have proven to have a broad range of sensitivity values and the most useful biopsy technique remains unknown. The correlation of the preoperative and intraoperative microbiological results is a matter of concern. The purpose of this study was to assess the diagnostic accuracy of a percutaneous bone biopsy (PBB) and an open bone biopsy (OBB) in isolating the infecting organism in cases of lower extremity chronic osteomyelitis.

Methods

A retrospective study was done involving 29 patients suspected of COM and where either a PBB or OBB was performed during the preoperative diagnostic workup. Culture results from PBB and OBB were compared with intraoperative tissue cultures at the time of surgery. Epidemiologic data was recorded, Cierny-Mader type, number of samples, susceptibility profile, and technique-related complications. Only tibia and femur osteomyelitis were considered.

Aim

The incidence of posttraumatic osteomyelitis (PTO) is increasing in spite of new surgical techniques and development of new antimicrobial therapies. It has been difficult to assess outcomes of PTO because of the numerous risk factors involving the patients, trauma characteristics, surgical conditions, diversity of etiologic agents and long period of follow-up required to determine the effects of any treatment. We aim to identify factors predisposing to develop recurrence of chronic PTO.

Method

Between August 2007 and August 2012, a single-centre prospective cohort study was carried out among 193 patients with PTO following orthopaedic surgery. Bone and soft tissues were collected for cultures and PTO was defined according to CDC/NHSN criteria. Patient, injury, surgery-associated variables and microbiological records were identified for potential risk factors associated to recurrence of PTO. Univariate and multivariable analyses using logistic regression were performed, and p <0.05 was considered significant.

Aim

North America is facing a rising epidemic involving strains of methicillin-resistant Staphylococcus aureus (MRSA) that, instead of being found almost exclusively in hospitals, are community-associated (CA-MRSA). These strains are aggressive, associated with musculoskeletal manifestations including osteomyelitis (OM), and septic arthritis (SA).

We aimed to establish novel management algorithms for acute OM and SA in children. We investigated S.aureus susceptibilities to current first-line antimicrobials to determine their local efficacy.

Method

The project was conducted at Nemours General Children Hospital in Florida, USA, following approval by the internal review board. A literature review was conducted. An audit of S.aureus antimicrobial sensitivities was completed over three years and compared against national standards. Susceptibilities of clindamycin, trimethoprim/sulfamethoxazole (TMP/SMX) and vancomycin were studied using local resistance ranges.

Aim

Untreated or improperly managed osteomyelitis can lead to several complications, bone loss being one of the most challenging to manage. Bone transport is just one of the surgical options available for filling the bone gaps and promote bone union. This presentation focuses on bone transport for long bones gaps in paediatric age group, highlighting its advantages and disadvantages, its indications and its complications.

Method

Between 2006 and 2014. 71 patients underwent a procedure of bone transport. Out of them, 39 were males and 32 females, with an average age at presentation of 8.7 years. The bone involved were tibia (27 right, 25 left), femur (4 right, 9 left), radius (1 right, 4 left) and ulna (1 right). Clinically speaking, the children presented with one of the following picture:

Bone transport was preceded by one of the following procedure: sequestrectomy, sequestrectomy and external fixation, external fixation with sequestrum in situ. Monolateral fixator was used in 46 patients, ring fixator in 25. Bone transport started 7 days after the osteotomy, at the rhythm of 1 mm per day. Plastic surgery procedures were used in 3 kids

Introduction

In the last couple of years, several synovial biomarkers have been introduced in the diagnostic algorithm for a prosthetic joint infection (PJI). Alpha defensin-1 proved to be one of the most promising, with a high sensitivity and specificity. However, a major disadvantage of this biomarker is the high costs. Calprotectin is a protein that is present in the cytoplasm of neutrophils, and is released upon neutrophil activation. Its value has been established for decades as a (fecal) marker for inflammatory bowel disease.

Aim

To determine the efficacy of synovial calprotectin in the diagnosis of a prosthetic joint infection.

Aim

The optimal surgical approach for patients hospitalized for moderate to severe septic bursitis is not known, and there have been no randomized trials of a one-stage compared with a two-stage (i.e., bursectomy, followed by closure in a second procedure) approach. Thus, we performed a prospective, non-blinded, randomized study of adult patients hospitalized for an open bursectomy.

Method

Patients were randomized 1:1 to a one-stage vs. a two-stage surgical approach. All patients received postsurgical oral antibiotic therapy for 7 days. These are the final results of the prospective study registered at ClinicalTrials (NCT01406652).

Aim & introduction

Infected knee with bone defect resulting from failed total knee arthroplasty (TKA) or destruction of native joint can necessitate restoration of segmental defect and arthrodesis for therapy of infection and maintenance of walking ability. In segmental knee defect external fixators or KAFO are not suitable, not comfortable and poor tolerated by elderly patients. Both custom-made Femoro-Tibial Nail (FTN) combined with acrylic cement spacer and Knee Arthrodesis Nail System (KANS) offer maintenance of supportive function of extremity and avoidance of leg length discrepance after removal of TKA.

Method

The group consists of 13 patients. In 12 cases knee arthrodesis have been performed due to infection with bone defect after removal of infected TKA, and in 1case due to inflammatory destruction of native knee joint. In 7 cases FTN with ALAC spacer and in 6 cases KANS (5 cases Orthopedic Salvage System-OSS; 1 case Link KANS) was used. In cases treated with FTN the gap between distal femur and proximal tibia was filled with hand-made acrylic cement spacer loaded with selected antibiotic (2g per 40 g cement) so that the spacer finally gained cylindrical shape.

Aim

Since July 2013 our group has been using an antibiotic bone substitute, composed of calcium sulphate, hydroxyapatite and gentamicin sulphate (CSH + HA + GS), in the treatment of osteomyelitis (OM) in diabetic foot. The aim of this work was to evaluate the mid-term efficacy of this treatment regime on outcomes. A favourable outcome in diabetic foot includes no recurrence of OM, healed soft tissues and the ability to weight-bear.

Method

To date we have used the CSH + HA + GS bone substitute in 24 diabetic patients with OM. In this study we reviewed patients treated from July 2013 to December 2014, in which we used CSH + HA + GS to treat OM of the forefoot, midfoot and hind foot, and evaluated how many patients are able to walk and fully weight-bear at present. We identified 11 pts treated during this time period; 1 with bilateral 1^St metatarsal-head OM due to plantar ulcers, 5 with midfoot OM secondary to Charcot deformities and ulcers, 5 with hind foot OM due to pressure ulcers or Charcot deformity. We continuously monitored the patients for recurrence of OM, ulcers and soft tissue inflammation in our outpatient department.

Aim

Prosthetic joint infection (PJI) is a major complication in THA. Nasal carriage with S. Aureus is a well-defined risk factor for infection in hospitalized patients. Risk for infection is reduced up to 50% by eradication therapy. Since PJI rates are very low and only 25% of the population are carriers, significant differences are hard to show and reports on PJI have been inconclusive. We analysed the effect of S. Aureus eradication therapy in THA.

Methods

From 2011, patients receiving THA are screened for S. Aureus carriage and carriers are treated. This group was retrospectively compared with a historical THA group in which no screening and eradication therapy was done. We assumed similar carrier rates in both groups and calculated the risk reduction of eradication therapy for PJI in comparison to the historical carriers without treatment. Fisher's Exact test was used to compare outcome.

Aim

Spondylodiscitis and vertebral osteomyelitis can lead to long-term sequelae if not diagnosed and treated promptly and appropriately. The Royal National Orthopaedic Hospital (RNOH) has devised a new spinal infection referral system within the UK that allows cases to be discussed in a specialist multi-disciplinary (MDT) forum. National guidelines were devised in 2013 to help guide treatment, which recommends both tissue biopsies from the affected region and a MRI of the entire spine. The aims of this study were to assess the current treatment and referral practices and compare them with the set guidelines. It is hypothesised that a high percentage of patients are started on antibiotics without a biopsy or a positive set of blood cultures, a low percentage of patients are referred without undergoing a MRI of the full spine and that there is a long delay in referral to the MDT.

Method

A retrospective case study analysis was carried out on all spinal infection referrals received by the Royal National Orthopaedic Hospital over a 2-year period (2014–16), using the standards set by the current national guidelines. Clinical features, haematology results, imaging, biopsy results, treatment and outcome were all reviewed. Three key areas were addressed; whether antibiotics were commenced before positive cultures or biopsy, whether a MRI of the entire spine was performed and the time taken for referral from the onset of symptoms.

Aim

Septic arthritis of the hip is a rare entity among the adult population, but with a potential severe repercussion. The most accepted treatment is the hip debridement, even though a notorious proportion of the cases need further hip replacement owing to the cartilage destruction. The aim of this study is to analyse all our cases of septic arthritis of the hip treated with a 2-stage strategy using an antibiotic-loaded cement spacer.

Method

We present a retrospective review of all our cases of septic arthritis of the hip diagnosed between 2004 and 2016 that were treated with an antibiotic-loaded cement spacer. We analysed age, gender, comorbidities, aetiology, duration of symptoms, C-reactive protein values, erythrocyte sedimentation rate, initial treatment, cultures, definitive treatment and evolution.

Aim

Peri-prosthetic joint infection is a serious and expensive complication of joint arthroplasty. Theatre discipline has infection prevention at its core with multiple studies correlating increased door opening with surgical site infection. The WHO, NICE and Philadelphia Consensus all advocate minimal theatre traffic. The Dutch Health Inspectorate consider >5 door openings per procedure excessive.

Method

This prospective observational study over five weeks observed theatre door traffic during hip and knee arthroplasty within the eight laminar flow theatres at our institution. Two students attached to the department collected data. Half way through the study notices reminding people not to enter during arthroplasty were placed on the theatre doors.

Aim

Bacterial identification in musculoskeletal infection is sometimes difficult and treatment strategy difficult facing unknown pathogen agent. We wonder if the delay of incubation and the preservation conditions of the samples between surgical procurement and subculture on plates have an influence.

Method

25 cm³ bone fragments were obtained from femoral heads retrieved during hip arthroplasty and excluded for bone transplant donation. Informed consent was obtained from the donor for research purpose. The study was approved by the Ethic Committee (N°B403201317725). Bone fragments were immersed for 30 minutes under gently agitation (140 RPM) at 35°C in a physiologic solution (negative control) or two solutions with two concentrations of staphylococcus epidermidis (0.5 Mc Farland or 1.5× 108 bacteria and 7.5×102 bacteria). Bone samples were separated and preserved at room temperature or at 4°C until seeded on Petri Plates to observe the influence of preservation conditions. Samples were plated after different delays (T0, T30min, T1H, T2H, T4H, T6H, T8H, T12H, T16H, T24H et T48H) to observe the influence of delay of culture. Experiments were repeated 5 times. When culture was positive, results were expressed with the number of colony.

Aim

The aim of this study was to define the role of implant material and surface topography on infection susceptibility in a preclinical in vivo model incorporating appropriate fracture biomechanics and bone healing.

Method

The implants included in this experimental study were composed of: standard Electro polished Stainless Steel (EPSS), standard titanium (Ti-S), roughened stainless steel (RSS) and surface polished titanium (Ti-P). In an in vivo study, a rabbit humeral fracture model was used. Each rabbit received one of three Staphylococcus aureus inocula, aimed at determining the infection rate at a low, medium and high dose of bacteria. Outcome measures were quantification of bacteria on the implant and in the surrounding tissues, and determination of the infectious dose 50 (ID50).

Aim

Diagnosing Orthopaedic infection is limited by the sensitivity of culture methods. Next generation sequencing (NGS) offers an alternative approach for detection of microorganisms from clinical specimens. However, the low ratio of pathogen DNA to human DNA often inhibits detection of microorganisms from specimens. Depletion of human DNA may enhance the detection of microbial DNA¹. Our aim was to compare four DNA extraction methods for the recovery of microbial DNA from orthopaedic samples for NGS.

Method

Simulated samples; pooled culture negative sample matrix was spiked with known concentrations of microorganisms, each panel consisting of 7 samples. Broth culture was performed on simulated samples for comparison with NGS*.

DNA Extraction; total nucleic acid extraction was performed on an automated extraction platform** using the viral NA assay. Modifications included: (1) mechanical lysis (glass beads), (2) lysis of human cells (saponin 0.025%), turbo DNase treatment and (3) mechanical lysis and addition of MspJI enzyme post-extraction for methylated DNA digestion.

Detection of human and microbial DNA; human endogenous (HE) gene rtPCR*** was utilised following manufacturer's recommendations. Microbial DNA was detected using SYBR green 16s ribosomal RNA rtPCR with high resolution melt-curve analysis****.

Aim

Implant-related infections, including peri-prosthetic joint infection (PJI) and infected osteosynthesis, are biofilm-related. Intra-operative diagnosis and pathogen identification is currently considered the diagnostic benchmark; however the presence of bacterial biofilm(s) may have a detrimental effect on pathogen detection with traditional microbiological techniques. Sonication and chemical biofilm debonding have been proposed to overcome, at least partially, this issue, however little is known about their possible economical impact. Aim of this study was to examine direct and indirect hospital costs connected with the routine use of anti-biofilm microbiological techniques applied to hip and knee PJIs.

Method

In a first part of the study, the “Turn Around Time (TAT)” and direct costs comparison between a system to find bacteria on removed prosthetic implants*, a closed system for intra-operative tissue and implant sampling, transport and anti-biofilm processing, versus sonication has been performed. An additional analysis of the estimated indirect hospital costs, resulting from the diagnostic accuracy of traditional and anti-biofilm microbiological processing has been conducted.

Aim

To evaluate the ability of different combinations of antibiotic loaded cement to inhibit bacteria growth and biofilm formation.

Method

Cement beads were aseptically prepared using Palacos R (plain 40g PMMA cement) or Palacos R+G (40g PMMA cement containing industrially added 0.5g of gentamicin), with or without supplementary antibiotics as follows: Palacos R; Palacos R+G; Palacos R plus 1g / 2g daptomycin; Palacos R+G plus 1g / 2g of daptomycin; Palacos R plus 1g / 2g vancomcyin; and Palacos R+G plus 1g / 2g vancomycin. After production, each antibiotic loaded acrylic cement (ALAC) combination was allocated into two groups (group 1 and 2).

The group 2 cement beads were initially eluted in broth at 37^o C for 72hours then transferred to fresh broth containing a known concentration of bacteria. The group 1 samples were not eluted but directly immerse in culture broth containing bacteria. All samples were thereafter incubated at 37^oC for 24 hours. After incubation, group 1 samples were visually assessed for bacterial growth, while for the group 2 samples, biofilm formation were quantified using ultrasonication and viable bacteria counting technique. Three proficient biofilm forming Staphylococcus epidermidis bacterial strains (1457, 1585-RA and 5179-R1) were used for all experiments and the bacteria counts were expressed as colony forming units / ml (CFU/ml).

Aim

When a prosthetic joint infection (PJI) is suspected, guidelines recommend performing periprosthetic samples, at least one for histopathological examination and 3 to 6 for microbiological culture. The diagnosis of infection is based on the presence of neutrophil granulocytes whose number and morphology can be variable, resulting in definition of “acute” inflammation. The acute inflammation of periprosthetic tissue is supportive of infection. Since 2007, in our hospital, for all patients with suspected PJI who underwent surgery, from each sample taken by the surgeon, one part has been sent to the pathologist and the other one to the microbiologist. Our aim was to compare histopathological to microbiological results from samples taken intraoperatively at the same site.

Method

We conducted a retrospective study including all surgeries for which at least one couple “histopathology-culture” was found. Exclusion criterion was a history of antimicrobial treatment 2 weeks prior the surgery.

Aim

This study aimed to define the increased costs incurred by a return to theatre for cases requiring free tissue transfer for surgical treatment of chronic osteomyelitis. We hypothesised that there would be a significantly greater cost when patients required re-exploration of the free flap.

Method

We retrospectively analysed the costs of a consecutive series of sixty patient episodes treated at the Bone Infection Unit in Oxford from 2012 to 2015. Treatment involved excision of osteomyelitis with free tissue transfer for immediate soft tissue cover. We compared the costs of uncomplicated cases with those who returned to theatre and determined the profit/loss for the hospital from remuneration through the UK National Health Service Tariff Structure.

Aim

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 resistance. We reviewed cases of infection in LDSAC and HDDAC bone cement with regard to causative organism and resistance profile.

Method

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 from the trust SSI surveillance database. The infecting organisms and susceptibility patterns were collated for each cement.

Aim

Open fractures with bone loss and skin lesions carry a high risk of infection and complication. Treatment options are usually a two-stage approach (debridement, temporary stabilization with external fixation followed by open reduction and stabilization with plate). We describe an experience for a single stage procedure with an antibiotic eluting bone graft substitute (BGS) for prophylaxis of implant-related infection.

Method

Between December 2014 and January 2016 were analysed the data of twenty-six patients with open fractures (Gustilo and Anderson grade I and II) or with skin lesion and high risk of contamination and bone loss. They where treated with debridement of soft tissue, closed reduction of fracture, placement of a plate augmented with BGS eluting antibiotic (gentamicin (1) and/or Vancomicin (2)).

Ampicillin and sulbactam 3g three times daily was used as systemic antibiotic prophylaxis minimum for one week. Clinical outcome and radiographic bone defect filling were assessed by blinded observers.

Aim

Treatment principles of chronic osteomyelitis include debridement, clean sampling, excision of dead bone, stabilization, dead space management, soft tissue closure and systemic antibiotic therapy. Dead space management becomes very complicated, if the bone infection is caused by multi-resistant bacteria. The aim of this investigation was to evaluate the effect of a new vancomycin-loaded hydroxyapatite / calcium sulfate composite* in the treatment of chronic osteomyelitis (OM) caused by multi-resistant bacteria.

Method

From June 2015 to November 2015, 7 patients (4 males, 3 females, average age 52.6y) were treated according to the above mentioned principles using the new vancomycin-loaded hydroxyapatite / calcium sulfate composite*. Infections were caused by methicillin-resistant Staphylococcus aureus (MRSA), multi-resistant Staphylococcus epidermidis (MRSE) and polymicrobial, vancomycin-sensitive bacteria.

We used a two-stage protocol with debridement, excision of bone and external stabilization in the first stage, followed by bone defect reconstruction. To fill the residual bone defects, in 3 patients the new vancomycin-loaded hydroxyapatite / calcium sulfate composite* (10mL) was used on its own and in 4 patients combined with 18mL of an unloaded calcium sulfate / hydroxyapatite composite**. Post-operative follow-up was evaluated clinically and by radiographs and CT scans at 6, 14 and 24 weeks.

Aim

This study describes and correlates the radiographic and histologic changes which develop in a Gentamicin-eluting synthetic bone graft substitute* in the management of bone defects after resection of chronic osteomyelitis (COM).

Method

100 patients with COM were treated with a single stage procedure, including management of the dead space with insertion of a Gentamicin-eluting synthetic bone graft substitute*. Radiographs of 73 patients with a follow-up of at least 12 months (range 12–33 months) were available for review. Bone defects were diaphyseal in 32, metaphyseal in 34 and combined in 7 patients. In 3 patients, radiographs were not of sufficient quality to allow analysis.

Five patients had subsequent surgery, not related to recurrence of infection, which allowed biopsy of the implanted material. These biopsies were harvested between 12 days and 9 months after implantation. Tissue was fixed in formalin and stained with haematoxylin-eosin and immunohistochemically for bone matrix markers.

Aim

We performed this Institutional Review Board-approved study to evaluate the efficacy of antibiotic-impregnated cement nailing for management of this condition.

Method

The study included 41 patients with infected non-unions of femur (23) and tibia (18) treated from 01.2009 to 09.2014. 32 (78%) patients were male and 9 (22%) patients were female. Mean age was 41.8 (range 20–78) years old. Mean time from the injury to AB-cement nailing was 21.2 (range 6–91) months. Mean follow-up duration was 18 (8–36) month. 6/23 femoral and 9/18 tibial fractures were initially open. Other fractures were closed and infected non-union developed as complication of previous surgeries: IM-nailing, ORIF or Ilizarov external fixation. Sinuses were revealed in all patients, but have closed by the time of AB-cement nailing in 30 cases. Pre- and intraoperative cultures revealed S.aureus in 20, S.epidermidis in 8, Klebsiella Pneumoniae in 3, Enterobacter cloacae in 2, Acinetobacter baumannii in 1 and no grows in 7 cases. We used 9–12 mm nails* for femur and 8–10 mm for tibia with 2 mm cement thickness. Gentamicin-impregnated cement was mixed with thermostable antibiotic according to the predetermined sensitivity (vancomycin or daptomycin). Nails were coated using silicone tube with equal diameter for the entire length. After debridement and preparation of intramedullary cavity with reamers the locked IM-osteosynthesis was performed. In all cases nails were locked proximally and distally to improve bone stability. Patients additionally received intravenous antibiotics according to the sensitivity for two weeks. Full weight-bearing was allowed 3 months after surgery. Follow-up was performed in 6, 12, 24 and 52 weeks.

Aim

Chronic osteomyelitis often requires surgical debridement and local antibiotic treatment. Disadvantages of PMMA carriers include low dose release and the requirement of surgical removal in the case of PMMA-beads. Synthetic nanocrystalline calcium phosphate (nCP) materials, which mimic the chemical structure of the mineral composition of bone, have been well accepted as bone grafting materials due to their consistent osteoconductivity, ease of use, and mechanical properties. Such a material which remodels into native bone is a much more attractive option. The aim of this study is to investigate the release of gentamicin from CaP in vitro and in vivo when implanted in a rabbit femoral condyle defect.

Method

Three formulations of nCP were evaluated in this study: putty, paste and porous. Four cylindrical dowels were made for each group with gentamicin sulphate at a concentration of 20mg/cc of paste. Material was eluted in PBS at 37C and pH 7.0 and elutions were tested every day up to 30 days. Eighteen New Zealand white rabbits will undergo surgeries. Briefly, a drill defect will be created in the metaphyseal bone of the lateral femoral condyle. The formulations will be implanted in the created defect at time of surgery and the wound will be closed. Blood will be collected regularly and analysed for gentamicin titers. Animals will be sacrificed at 6wk, 12wk or 24wk. Explanted femurs will be fixed, sectioned and stained.

Aim

Aim of this study is to present the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating*, in patients undergoing internal osteosynthesis for closed fractures.

Method

In this prospective, multi-centre, randomized, controlled, prospective study, a total of 260 patients were randomly assigned, in five European orthopaedic centres, to receive the antibiotic-loaded DAC coating or to a control group, without coating. Pre- and post-operative assessment of laboratory tests, wound healing, clinical scores and x-rays were performed at fixed time intervals.

Aim

Negative pressure wound treatment (NPWT) has been widely adopted in the management of septic wound complications or prophylactically after large surgeries. Recent publications have indicated the necessity of further investigations to support the use of NPWT with more evidences. Therefore, the purpose of this pilot-study was to investigate the efficacy of VAC-assisted dressing systems in the treatment of septic trauma cases.

Method

We analysed data of 16 retrospective cases following traumas and septic soft tissue surgeries around the hip and knee. The collected data consisted of bacterial cultures, inflammatory markers (WBC, CRP/HCRP) and body temperature, taken periodically during treatment. Also recorded were the time periods the vacuum pump was used during treatment. To increase the number of measurements and to facilitate subsequent data analysis, the measurements were interpolated to regularly sampled curves with a sampling rate of one day. We used cross-plots and linear regression analysis to investigate trends in the data: 1) while the vacuum pump was switched on and 2) while it was switched off.

Aim

The majority of peri-prosthetic joint infection occurring within 1 year of surgery is due to introduction of microbes at the time of surgery. Lavage of total knee replacement leaves a pool of fluid on the surgical drapes. This fluid could be a direct source of wound contamination via suction catheter tip, gloves or instruments.

Method

Twenty patients undergoing total knee arthroplasty had a sample of drape fluid sent, after prosthesis implantation, for standard and enrichment culture. The surgery took place in a laminar low theatre with scrub teams in togas* and drapes**. Normal saline was used as the wash. 20ml fluid was taken via syringe and transferred to blood culture bottles in theatre post-operatively.

Aim

Prosthetic joint infections (PJI) after failed knee arthroplasty, especially in complicated courses with persisting or recurrent infections, may result in a considerable destruction of bone substance, the extensor apparatus and the surrounding soft tissue. In these cases reconstruction of a proper knee function may be impossible and the only solutions are: knee arthrodesis or above-the-knee amputation (AKA). However, both methods are associated with considerable functional deficits and high complication rates. The primary aim of the current study is to analyse the clinical course, outcome and complications in patients with knee arthrodesis and AKA after PJI and to compare these two methods in terms of the analysed parameters.

Method

Patients treated with a knee arthrodesis or AKA after PJI in an 11-year time period were included in this study. Demographic data, comorbidities, infecting characteristics and operative procedures were recorded. Patients were seen in regular intervals and underwent physical and radiographic examination. Major complications such as: re-infection, implant-failure, revision surgeries or stump healing disorders were recorded. Functional outcome with use of the Lower-Extremity-Functional-Score was assessed and the patients reported general health status (SF-12-questionnaire) was recorded.

Aim

In patients with bone sarcoma, placing mega prostheses in the proximal tibia is associated with high rates of infection. In studies with small numbers of patients and short follow-up periods, silver-coated mega prostheses have been reported to lead to reduced infection rates. To the best of our knowledge, this study is the largest one that has compared the infection rates with titanium versus silver-coated mega prostheses in patients treated for sarcomas in the proximal tibia.

Method

The infection rate in 98 patients with sarcoma or giant cell tumour in the proximal tibia who underwent placement of a titanium (n = 42) or silver-coated (n = 56) mega prosthesis* was assessed, along with the treatments administered for any infection.

Aim

Intracellular persistence of S. aureus is believed to be one of the major mechanisms leading to bone and joint infection (BJI) chronicity and relapses. Despite its poor intracellular activity, daptomycin (DAP) is increasingly used in the treatment of staphylococcal BJI. The well-known in vitro synergy of daptomycin with various betalactam antibiotics consequently led us to investigate whether these combinations enhance the activity of daptomycin against the intracellular reservoir of methicillin-susceptible (MSSA) and -resistant (MRSA) S. aureus in an ex-vivo model of human osteoblast infection.

Method

Osteoblastic MG63 cells were infected for 2h with MSSA strain or its isogenic MRSA. After killing the remaining extracellular bacteria with lysostaphin, infected cells were then incubated for 24h with DAP, oxacillin (OXA) or ceftaroline (CPT) alone or in combination, at the intraosseous concentrations reached with standard human therapeutic doses. Intracellular bacteria were then quantified by plating cell lysates. Minimum inhibitory concentrations (MICs) of these molecules alone and in combination were determined using the checkerboard method at pH7, but also at pH5 to mimic intracellular conditions.

Aim

The aim of this study was to gain insight into the in vivo expression of virulence and metabolic genes of Staphylococcus aureus in a prosthetic joint infection in a human subject.

Method

Deep RNA sequencing (RNA-seq) was used for transcriptome profile of joint fluid obtained from a patient undergoing surgery due to acute S. aureus prosthetic joint infection. The S. aureus gene expression in the infection was compared with exponential culture of a S. aureus isolate obtained from the same sample using EdgeR. In addition, the genome of the isolate was sequenced on Miseq, assembled in CLC genomics workbench and annotated by MaGe. Moreover, using nuclear magnetic resonance (NMR) spectroscopy we analysed the metabolites in the joint fluid and in the culture supernatants to determine the biochemical composition of the environments.

Aim

To see what surgical strategy was used in treating infected total hip arthroplasties (THA), relative to bacterial findings, level of inflammation, length of antibiotic treatment (AB) and re-revisions. Further, to assess the results of treatment after three months and one year.

Method

We used our national arthroplasty register (NAR) to identify THA revised for deep infection from 2004–2015 reported from our hospital. We identified the strategy of revision, i.e. one-stage exchange (one-stage), two-stage exchange (two-stage), debridement and implant retention (DAIR), or Girdlestone, and reported re-revisions for infection. We defined cure as no AB, no need for further surgery and joint with prosthesis (not Girdlestone).

From the hospitals’ medical records we retrieved bacterial findings from the revisions, level of C-reactive protein (CRP), type of antibiotics given, duration of antibiotic therapy and clinical data regarding the patients. The information reported to the NAR was also validated.

Aim

To introduce and promote a new technic and a new component using the 3D technology in the extreme acetabular revisions.

Method

Since 2012, 13 patients, nine women and four men, were treated, 12 for a chronic complex PJI and one for an aseptic loosening. The average age was 75 years old (60 -90 years), the average follow-up 18,6 months (7–36 months).

The revisions were bipolar in 12 cases and unipolar in one case for the oldest patient. For the septic cases, we performed 7 one stage procedure and 5 two stages. The femoral components were in 7 cases a modular stem, in 5 cases a massive component and a total femur. All these massive components were combined with a cemented double cup.

The bone loss was evaluated with the AAOS, the Praposky and the Saleh classifications.

A preoperative and postoperative Oxford score was used.

Aim

To describe the epidemiology, clinical features and outcomes of native joint septic arthritis in adults admitted to Middlemore Hospital in Auckland, New Zealand.

Method

Single-centre retrospective cohort study from 2009 to 2014. Patients ≥16 years of age were identified using ICD-10AM coding data. Electronic records were reviewed for demographic, clinical, laboratory, treatment and outcome data. Total and hemi-arthroplasty infections were excluded.

Aim

Aim of the study was to find out whether patients with positive minor criteria but without meeting the MSIS definition have a difference in the outcome after revision-surgery compared to patients without any MSIS-criteria? And does the reason for revision-surgery (eg. loosening) have an additional influence on the outcome parameters in patients with positive minor criteria?

Method

A retrospective matched-pair analysis with 98 patients who had undergone revision-surgery after TJA was performed. Forty-nine patients who showed 1 to 3 positive minor criteria (PMC) whereas 49 patients without any positive minor criteria (aseptic complications control group) were compared regarding re-revision-rate and revision-free survival. Patients were matched regarding sex, age, joint and comorbidities using the classification system by McPherson et al. Reasons for revisions were categorized in loosening, body wear, periprosthetic fracture/mechanical failure and soft-tissue complication. Endpoints were defined as re-revision for any cases.

Aim

A previous Dutch guideline for prophylaxis of hematogenous PJI (HPJI) caused defensive medicine and incorrect own guidelines. There was a need for a better national guideline, developed cooperatively by orthopedic surgeons and dentist.

Method

A committee of Dutch Orthopedic and Dental Society, performed a systematic literature review to answer the question: “Is there a difference in the risk for hematogenous infection between always or never giving antibiotic prophylaxis to patients with a joint prosthesis undergoing a dental procedure”.

We included 9 papers as follows:

The nine papers’ quality was scored according the GRADE method.

In addition we studied in non-included literature on further information about additional questions of pathophysiology, risk factors and risk procedures.

Aim

Advocates of Debridement-Antibiotics-and-Implant-Retention (DAIR) in hip peri-prosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis-bone interface is likely to lead to better survival and functional outcome compared to revision. However, no evidence supports this. This case-control study's aims were to compare outcome of DAIRs for infected 1° total hip arthroplasty (THA) with outcomes following 1° THA and 2-stage revisions of infected 1° THAs.

Method

We retrospectively reviewed all DAIRs, performed for confirmed infected 1° THR (DAIR-Group, n=80), in our unit between 1997–2013. Data recorded included patient demographics, medical history, type of surgery and organism identified. Outcome measures included complications, mortality, implant survivorship and functional outcome using the Oxford Hip Score (OHS). Outcome was compared with 2 control groups matched for gender and age; a cohort of 1° THA (1°-THA-Group, n=120) and a cohort of 2-stage revisions for infection (2-Stage-Revision-Group, n=66).

Aim

Different perioperative strategies have been implemented to reduce the devastating burden of infection following arthroplasty. The use of iodophor-impregnated adhesive incise drapes is one such strategy. Despite its wide adoption, there is little proof that this practice leads to a reduction of bacterial colonization. The aim of this randomized, prospective study was to evaluate the efficacy of iodophor-impregnated adhesive drapes for reducing bacterial count at the incision site.

Method

A total of 96 patients undergoing open joint preservation procedure of the hip were enrolled in this prospective, randomized clinical trial of iodophor-impregnated adhesive drapes*. One half of patients (n=48) had iodophor-impregnated adhesive drapes* applied to the skin prior to incision and kept on throughout the procedure, while the other half (n=48) underwent the same surgery without the use of iodophor-impregnated adhesive drapes*. Culture swabs were taken from the surgical site at five different time points during surgery (pre-skin preparation, after skin preparation, post-incision, before subcutaneous closure, and prior to dressing application) and sent for culture and colony counts. Mixed-effects and multiple logistic regression analyses were utilized.

Aim

There is a lack of both epidemiological data and of high-quality evidence to guide the management of Prosthetic joint infection (PJI). We hypothesised that there is substantial heterogeneity in the clinical presentation and management of PJI in Australia and New Zealand, and that the proportion with clinical cure at 24 months is independently associated with modifiable variables in surgical and antibiotic management.

Method

Prospective binational multicentre observational study aiming to enrol 400–600 patients with large joint PJI, defined as per IDSA criteria. Following screening and written informed consent, data are collected at baseline and after 3, 12 and 24 months. The main outcome measures are clinical cure, functional status (based on Oxford joint and SF12 scores) and direct health care costs at 24 months.

Aim

Photodynamic therapy (PDT) requires a photosensitiser, a light source of an appropriate wavelength, and the presence of molecular oxygen. Once stimulated to its excited phase by the light, the photosensitiser reacts with oxygen to form free radicals of ‘singlet oxygen’ which is cytotoxic to microorganisms.

We aim to demonstrate the effectiveness of PDT as an in-vitro antimicrobial technique against Staphylococcus aureus, Methicillin resistant Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Acinetobacter bauminii. This will form the scientific basis for further animal and human studies assessing PDT for treatment of periprosthetic infections, septic arthritis, and open fractures.

Method

A PDT treatment protocol was devised using lawns of bacteria on agar plates. PDT was targeted towards the bacteria and the remaining microorganisms were quantified using a serial dilution technique. In order to assess the ability of photodynamic therapy to target biofilms on metallic implants, biofilms were cultured on polished titanium and hydroxyapatite-coated titanium discs and subjected to PDT.

Aim

In our Bone Infection Unit, epidural anaesthesia and sedation (EA+Sed) is the technique of choice for complex orthoplastic surgery involving lower limb free tissue transfer (LLFTT) (1) as it avoids complications of prolonged general anaesthesia (GA). Following our initial reports of successful use of audio-visual distraction (AVD) as an adjunct to regional anaesthesia we wished to evaluate the AVD effect on the patients’ experience during long duration, complex orthoplastic surgery for chronic osteomyelitis under EA+Sed.

Method

Our AVD equipment consists of a WiFi connected tablet and noise reducing head phones, providing access to downloaded music, films and the internet. Patients are also allowed to use their own equipment.

All patients were fully informed about AVD and EA+Sed as a choice of anaesthesia. EA was established in the anaesthetic room and continued perioperatively. Sedation with propofol was titrated to the patients’ requirements to ensure comfort during surgery.

All patients were followed up postoperatively with a structured questionnaire.

Aim

Periprosthetic joint infections (PJI) are rare and require complex multi-disciplinary management. Successful single and two-stage revision procedures have been described. We describe the clinical features of this rare diagnosis from a single institution.

Method

Patients were identified retrospectively from a prospectively collected institutional infection database. Clinical notes were evaluated for demographic, comorbid and clinical outcomes. The diagnosis of PJI, and any recurrence following treatment, was made in accordance with the Musculoskeletal Infection Society criteria. Failure was defined as recurrence of infection necessitating implant removal, excision arthroplasty or amputation.

Aim

Clear differentiation between aseptic failure and prosthetic joint infection remains one of the goals of modern orthopaedic surgery. New diagnostic methods can provide more precise evaluation of the etiology of prosthetic joint failure. With the introduction of sonication an increasing number of culture-negative prosthetic joint infection were detected. The aim of our study was to evaluate culture-negative prosthetic joint infections in patients who were preoperatively evaluated as aseptic failure.

Method

For the purpose of the study we included patients planed for revision surgery for presumed aseptic failure. Intraoperatively acquired samples of periprosthetic tissue and explanted prosthesis were microbiologically evaluated using standard microbiologic methods and sonication. If prosthetic joint infection was discovered, additional therapy was introduced.

Aim

Hospital systems have recently instituted early systemic sepsis recognition systems, where vital signs and laboratory findings are monitored and automatically alert providers to potential sepsis. Although there are very few reports evaluating the use of sepsis alert systems outside of the emergency room or intensive care unit, many hospital systems have made the decision to apply the sepsis alarm protocols to all inpatients. The purpose of this study was to evaluate if an alarm system using systemic inflammatory response syndrome (SIRS) criteria is a valuable tool to predict systemic sepsis in the immediate postoperative period (POD#0–4) after total joint arthroplasty (TJA).

Method

10,791 primary and revision TJA patients at one institution, from 2010–2014, were retrospectively reviewed for positive SIRS criteria on each hospital day from the date of surgery to postoperative day four (POD#4). SIRS criteria included temperature > 38°C or < 36°C, heart rate > 90 beats per minute, respiratory rate > 20 breaths per minute, and white blood cell (WBC) > 12,000/mm3 or < 4,000/mm3. Additionally, hospital coding data was cross-referenced to identify patients who were diagnosed with systemic sepsis within 10 days after having a TJA.

Aim

When treating periprosthetic joint infections with a two-stage procedure, antibiotic-impregnated spacers are used in the interval between removal of prosthesis and reimplantation. The spacer provides local antibiotics; however, it may also act as foreign-body that can be colonized by microorganisms. According to our experience, cultures of sonicated spacers are most often negative.

The objective of our study was to investigate whether PCR analysis would improve the detection of bacteria in the spacer sonication fluid.

Method

A prospective monocentric study was performed at Lausanne University Hospital from September 2014 until January 2016. Inclusion criteria were two-stage procedure for prosthetic infection and agreement of the patient to participate in the study. For a two-stage procedure the interval before reimplantation ranged between 2 and 8 weeks. Spacers were made of cement impregnated with gentamycin, tobramycin and vancomycin. Cultures of intraoperative deep tissues samples from first and second stage procedures, prosthesis sonication and spacer sonication were analyzed. Multiplex-PCR*, pan-bacterial PCR (16S), and a Staphylococcus-specific PCR analysis were performed on the sonicated spacer fluid.

Aim

Diagnosing prosthetic joint infections(PJI) is sometimes difficult. Being able to identify the bacteria involved in intraoperative samples is an essential diagnostic criterion.

There are however some cases in which the traditional cultures are not capable of providing a definitive diagnosis. In this regard, implant sonication has emerged as a complementary test.

The aim of this study was to analyze the results of microbiological studies obtained with and without implants sonication, in order to understand its real contribution to diagnosis.

Method

We retrospectively evaluated all cases of infected total hip or knee arthroplasty surgically treated between January 2009 and December 2013. The definition of infection met the criteria set out recently in the international consensus meeting.

The number and type of bacteria identified in each patient and the type of microbiological study made were registered.

Two different groups were created, with and without sonication, and the results were compared.

Aim

Thermal stability is a key property determining the suitability of an antibiotic agent for local application. Long-term data describing thermal stability without interference from carrier materials are scarce.

Method

In this study, a total of 38 common antibiotic agents have been maintained at 37 °C in saline solution, and degradation and antibacterial activity assessed over 6 weeks. The impact of an initial supplementary heat exposure mimicking exothermically-curing bone cement has also been tested. Antibiotic degradation was assessed by chromatography coupled to mass spectrometry or immunoassays, as appropriate. Antibacterial activity was determined by Kirby-Bauer disk diffusion assay.

Aim

To prevent infections after orthopaedic surgery, intravenous antibiotics are administered perioperatively. Cefazolin is widely used as the prophylactic antibiotic of choice. Systemic antibiotic therapy may however be less effective in longstanding surgery where bone allografts are used. Bone chips have been shown to be an effective carrier for certain types of antibiotics and may provide the necessary local antibiotic levels for prophylaxis. To be efficient a prolonged release is required. In contrast to vancomycin with proven efficient prolonged release from Osteomycin, this has not been described for cefazolin. We developed a protocol to bind cefazolin to bone chips by means of a hydrogel composed of proteins naturally present in the human body.

Method

Three types of bone chips were evaluated: fresh frozen, decellularized frozen and decellularized lyophilized. Bone chips were incubated with 20 mg/ml cefazolin or treated with liquid hydrogel containing either 1 mg/ml fibrin or 1 mg/ml collagen and 20 mg/ml cefazolin. The cefazolin hydrogel was distributed in the porous structure by short vacuum treatment. Bone chips with cefazolin but without hydrogel were either incubated for 20 min- 4h or also treated with vacuum. Cefazolin elution of bone chips was carried out in fetal bovine serum and analysed by Ultra Performance Liquid Chromatography – Diode Array Detection.

Aim

A gentamicin-eluting biocomposite consisting of hydroxyapatite and calcium sulfate¹ can provide effective dead space management in chronic osteomyelitis. However, radiographic follow-up after implantation of this novel material has consistently shown evidence of several unique imaging features previously not described with other comparable bone graft substitutes. Conclusive interpretation of these newly described imaging features is difficult as long term follow-up and histological correlation is not yet available. The aim of this study was to establish a large animal model, closely simulating the clinical situation in order to permit further analysis of imaging features in correlation with histological progression of bone remodelling.

Method

Standardised bone defects were created in ten Merino-wool sheep (age: two to four years). Large drill holes (diameter 2.5cm, depth 2cm, volume approx. 10ml) were placed in the medial femoral condyles of both hind legs and filled with a gentamicin antibiotic eluting bone graft substitute*. Initially surgery was carried out on the right hind leg. Three months later, an identical intervention was performed on the contralateral side. With sacrifice planned after six or twelve months, bone voids three, six, nine and twelve months post-implantation are obtained for evaluation. The study was approved by the Animal Care Committee of Thuringia, Germany.

Aim

Acute postoperative infection is reported to occur in 0.3–2% after arthroscopic rotator cuff repair. Few reports have addressed this dreaded complication although the costs are high both for the patient and for society. The aim of this prospective study was to describe incidence, treatment and outcome after acute postoperative infections following arthroscopic rotator cuff repair.

Method

Patients undergoing arthroscopic rotator cuff repair in our department have been prospectively registered since 2009. 11 out of 1072 patients undergoing surgery developed an acute postoperative infection. The patients were examined with an MRI scan and/or functional scores (Constant Murley (CM) and WORC) at final follow-up.

Aim

Propionibacterium acnes is an emerging pathogen especially in orthopedic implant infection. Interestingly, we previously reported a difference in the distribution of the clades involved in spine versus hip or knee prosthetic infection. To date, no study has previously explored the direct impact and close relationship of P. acnes on bone cells according to their own genetic background. The aim of this study was to investigate this interaction of P. acnes clinical strains involved in spine material infections, arthroplasty infections and acne lesions with bone cells.

Method

From a large collection of 88 P. acnes clinical isolates collected between January 2003 and December 2014, a subset of 11 isolates was studied. Four isolates were recovered from spine infections, two from prosthetic infections (knee and hip), three from acne lesions and two reference strains (ATCC11827 and ATCC6919). Implant-associated infections were confirmed according to Infectious Diseases Society of America guidelines for bone and joint infections. Multi-Locus Sequence Typing (MLST) was carried out on all isolates as described by Lomholt et al. PLoS ONE 2010. Bacterial internalization experiments with MG63 osteosarcoma cells were adapted from Crémet et al. Pathog Dis 2015.

Aim

To demonstrate the use of indium-111 white-cell labelled SPECT CT (In111-WC-SPECT-CT) in bone infection.

Method

This novel imaging modality is useful in bone infection. We present three cases of complex osteomyelitis to illustrate this. All were imaged with conventional modalities, but conclusive diagnosis could not be achieved. In111-WC-SPECT-CT was used to provide the definitive imaging that allowed successful treatment.

Aim

Prosthetic joint infection (PJI) is a much feared complication to arthroplasty with significant patient morbidity. Rifampin is increasingly used in staphylococcal PJIs treated with debridement and retention of the prosthesis. The evidence supporting rifampin combination therapy in PJIs is limited due to the lack of controlled studies. The aim of this study is to evaluate the effect of adding rifampin to conventional antimicrobial therapy in early staphylococcal PJIs treated with debridement and retention.

Method

In this multicentre randomized controlled trial, 99 patients with PJI after hip and knee arthroplasties were enrolled. All patients underwent a standardized surgical debridement. 65 patients had PJI caused by staphylococci and further included in the study. They were randomly assigned to receive rifampin or not in addition to standard antimicrobial therapy with cloxacillin, or vancomycin in case of methicillin resistance. They received parenteral antibiotics for two weeks, then oral antibiotics for 4 weeks. In case of methicillin resistance, vancomycin was administered i.v. for 6 weeks. The primary end point was no signs of infection after 2 wears follow-up.

Aim

This study was conducted to investigate the clinical outcome, functional outcome, and quality of life of patients treated for post traumatic osteomyelitis (PTO) of femur and tibia from July 2007 to June 2014.

Method

Forty seven patients consented and participated in this study. The median age of participants was 44 years old, and ranges from 16 to 80 years old. There were 26 tibia and 21 femur osteomyelitis evaluated in this study. Thirty-eight participants (80.9%) had implants inserted. The PTO patients were classified according to Cierny-Mader (CM) classification: 2 CM-I; 8 CM-II; 18 CM III; 19 CM IV and 25 CM-A and 19 CM-B. The participants were follow up for a mean duration of 4.6 years (range 2.3–9.5 years). Interviews were then conducted and clinical assessments were performed to evaluate the clinical outcome. Their functional outcome was evaluated using the Lower Extremity Functional Score (LEFS) and the quality of life was evaluated using the validated SF-36v2 and the results were compared to the general population (GP).

Aim

The incidence of prosthetic joint infections can be severe to monitor, as they are rare events. Recent publications from National registries points toward a significant underestimation of reported infections. The aim of this project was to develop a complication register that could report the “true” and momentaneous incidence of prosthetic infections after total knee and hip arthroplasty.

Method

All patients operated with total hip arthroplasty (THA) or total knee arthroplasty (TKA) at our hospital were included in a local quality registry. All complications were reported at follow-up at 2 and 3 months for total knee and hip arthroplasties respectively, and at 1-year follow up. Both primary and revision surgeries were included. In order to monitor complications of special interest, such as deep postoperative infections, key variables were presented in a g-chart. This chart shows the number of uncomplicated surgeries between each complication (such as infection) in a bar diagram. This diagram is easily read as high bars indicate a low incidence of complications and low bars indicate a high incidence. The diagram is updated and distributed for information every month.

Aim

To investigate the antimicrobial activity of a gentamicin-loaded bone graft substitute (GLBGS) in the prevention and eradication of bacterial biofilms associated with prosthetic joint infections (PJI).

Method

The GLBGS (17,5 mg gentamicin/ml paste) with 40% hydroxyapatite/60% calcium sulfate¹ was tested against biofilms of methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300, methicillin-susceptible S. aureus (MSSA) ATCC 29213, Escherichia coli Bj HDE-1, S. epidermidis ATCC 12228 and Enterococcus faecalis ATCC 19433. For prevention studies, glass beads and different combinations of GLBGS were co-incubated for 24h at 37°C in CAMH broth with 1–5 × 10⁶ CFU/mL of bacteria. For eradication, biofilms were formed on glass beads for 24h at 37°C in CAMH broth. Then, beads were incubated with different combinations of GLBGS in medium at 37°C for 24h. For microcalorimetric measurements, beads were placed in ampoules and heat flow (µW) and total heat (J) were measured at 37°C for 24h. The minimal heat inhibitory concentration (MHIC) was defined as the lowest gentamicin concentration reducing the heat flow peak by ≥90% at 24h.

Aim

The diagnosis of periprosthetic joint infection (PJI) in total joint arthroplasty (TJA) remains a serious clinical challenge. Nowadays, limited biomarkers associated with PJI are available. We investigated therefore the utility of gene expression pattern of Toll-like receptors (TLR) and members of interleukin (IL)1/IL1R family, molecules critically involved in the innate immune response to invading pathogens, for detecting PJI in periprosthetic tissues around TJA.

Method

Periprosthetic tissues were collected from 37 patients presenting with PJI and 39 patients having an aseptic failure of TJA. mRNA expression of known TLR receptors (TLR1–10) and 21 members of IL-1/IL-1R family was investigated using an innovative Smartchip Real-Time RT-PCR System*; the data were normalized relative to the housekeeping gene GAPDH. Statistical tests were performed using GraphPad Prism** and bio-data mining methods.

Aim

A reason for treatment failure, in cases of periprosthetic bone infections and osteomyelitis, may be incomplete or heterogeneous tissue distribution of antimicrobials to the affected bone. Decreased bioavailability has been demonstrated in healthy bones but never in pathological bone tissue. Therefore, the aim was to obtain pharmacokinetic parameters of cefuroxime in infected bone tissue by means of microdialysis in a porcine model of implant associated osteomyelitis

Method

An implant cavity of 4 mm in diameter was drilled 25 mm into the right tibial bone of ten pigs (30 kg/BW). Subsequently, a small steel implant (K-wire 2 × 2 mm) and 10⁴ CFU of Staphylococcus aureus was inserted and injected into the implant cavity. Five days after inoculation, two additional drill holes of 2 × 25 mm were drilled into the trabecular bone tissue adjacent to the implant cavity and into the left uninfected tibia. After intravenous administration of 1500 mg of cefuroxime, the concentration was measured in plasma and in the three tibial drill holes for 8 hours. All measurements were performed with microdialysis. Post mortem, the presence of bone infection was assessed by computed tomography (CT) scans and cultures of swabs.

Aim

The objective of this study was to define hospital-related healthcare costs associated with infection after fracture fixation (IFF) of the tibia and identify the subset of clinical variables relevant in driving these costs within the Belgium's healthcare system.

Method

Between January 1^st 2009 and January 1^st 2014, a total of 358 patients treated operatively for AO type 41, 42 and 43 tibial fractures, were included in this study. The calculated costs were related to the Belgium's healthcare financing context and limited to costs induced by hospital related care. Five main hospital-related cost categories were studied: honoraria, materials, hospitalization, day care admission, and pharmaceuticals. In addition, a total of 19 clinical and process variables were defined.

Aim

Perioperative hyperglycemia has many etiologies including medication, impaired glucose tolerance, uncontrolled diabetes mellitus (DM), or stress, the latter of which is common to post-surgical patients. This acute hyperglycemia may impair the ability of the host to combat infection.¹ Our study aims to investigate if post-operative day 1 (POD1) blood glucose level is associated with complications, including periprosthetic joint infection (PJI), after total joint arthroplasty (TJA) and to determine a threshold for glycemic control that surgeons should strive for during a patient's hospital stay.

Method

A single-institution retrospective review was conducted on 24,857 primary TJAs performed from 2001–2015. Demographics, Elixhauser comorbidities, laboratory values, complications and readmissions were collected. POD1 morning blood glucose levels were utilized and correlated with PJI, as defined by the Musculoskeletal Infection Society criteria. The Wald test was used to determine the influence of covariates on complication rate. An alpha level of 0.05 was used to determine statistical significance.

Aim

Infection remains among the first reasons of failure of joint prosthesis. According to various preclinical reports, antibacterial coatings of implants may prevent bacterial adhesion and biofilm formation. Aim of this study is to present the first clinical trial on an antibiotic-loaded fast-resorbable hydrogel coating*, in patients undergoing hip or knee prosthesis.

Method

In this multi-center, randomized, prospective, study, a total of 380 patients, scheduled to undergo primary or revision total hip or knee joint replacement, using a cementless or a hybrid implant, were randomly assigned, in six European orthopedic centers, to receive the antibiotic-loaded DAC coating or to a control group, without coating. Pre- and post-operative assessment of clinical scores, wound healing, laboratory tests and x-ray were performed at fixed time intervals.

Aim

Very limited information is available regarding health-related quality of life (HRQOL) and patient reported hip function following treatment for chronic periprosthetic hip joint infection (PJI). Several reviews have not found any clear differences in clinical outcome parameters comparing the most commonly applied treatment strategies for chronic hip PJI. Studies describing patients HRQOL of one-stage and two-stage revision could provide important information regarding patient counselling. The purpose of this study was to investigate HRQOL and patient reported hip function after one-stage revision and two-stage revision in chronic hip PJI.

Method

The one-stage group was identified in a prospective clinical study on one-stage revision in chronic hip PJI. Fifty-one patients were followed for two years on an outpatient basis and completed three questionnaires; EuroQol-5D (EQ-5D), Short Form Health Survey 36 (SF-36) and Oxford Hip Score (OHS) at 3, 6, 12 and 24 months follow-up. The two-stage group was identified retrospectively in the National Patient Register and 45 patients completed EQ-5D and OHS. The observed results were compared to normative population data for SF-36 and EQ-5D.

Aim

Recent studies have indicated that the presence of P. acnes in the skin of the shoulder and around the acromion is higher than other body regions like the knee or the hip. The aim of this study was to estimate the presence of P. acnes in a real set of primary shoulder arthroplasty, after skin preparation with chlorhexidine and administration of empirical antibiotic therapy.

Method

A prospective observational study involving 63 patients undergoing primary shoulder arthroplasty was designed. In all patients two skin biopsies with a 3 mm dermal punch and one subcutaneous tissue sample after surgical incision were obtained. Skin biopsies were obtained at the most anterior part of the surgical wound in case of superior approach and at the upper part in the deltopectoral approach. All patients underwent preoperative antibiotic prophylaxis with cefazolin 2g ev and skin preparation with 2% chlorhexidine alcoholic tinted before the start of surgery twice. The aerobic cultures were incubated at 37ºC for 7 days whereas the anaerobic ones incubated for 14 days.

Aim

Eradication of infection in chronic osteomyelitis requires effective dead space management after debridement. Residual bacteria in biofilm may be resistant to normal levels of systemic antibiotic penetrating bone and will contribute to recurrence of osteomyelitis. This study evaluated a new antibiotic-loaded biocomposite in the eradication of chronic infection from bone defects.

Patients and Method

We report a prospective study of 100 patients with Cierny and Mader types III and IV chronic osteomyelitis, in 105 bones. Osteomyelitis followed open fracture or ORIF of closed fractures in 71%. Nine had concomitant septic arthritis. 80% had comorbidities (Cierny-Mader Class B hosts). Ten had infected non-unions.

All patients were treated by a multidisciplinary team with a single-stage protocol including; debridement, multiple sampling, culture-specific systemic antibiotics, stabilisation, dead space filling with Cerament G™ and immediate primary skin closure.

Stabilisation was required in 21 cases and 5 required joint fusion as part of the initial surgery. Plastic surgical skin closure was needed in 23 cases (18 free flaps).

Patients were followed up for a minimum of one year (mean 19.5 months; 12–34).

Aim

Determine the time concentration profile required to achieve vancomycin-mediated eradication of Staphylococcus aureus biofilm. This is critical for the identification of performance targets for local antibiotic delivery, yet has not been described.

Method

Mature S. aureus UAMS-1 biofilms were grown on titanium-aluminum-niobium discs in Mueller Hinton broth (MHB). After 7 days, the discs were incubated in MHB containing vancomycin at 100, 200, 500, 1′000 and 2′000 mg/L. Both static and shaking conditions were tested. Samples were retrieved at intervals for up to 28 days for quantification of residual biofilm by sonication and serial dilution plating. One additional disc was processed per time point for scanning electron microscopy.

Aim

Vancomycin-intermediate Staphylococcus aureus (VISA) was associated with persistent infection and treatment failure. To date, two staphylococcal virulence mechanisms have been associated with persistence secondary to host immune evasion and vancomycin therapeutic failure: i) bacterial internalization in non-phagocytic cells and ii) biofilm formation. The present study aimed to compare clinical pairs of isolates composed by VISA and their Vancomycin-Susceptible (VSSA) progenitors toward these bacterial adaptive mechanisms.

Method

Methods: Three pairs of VSSA/VISA clinical isolates have been isolated from persistent bloodstream infections during prolonged antibiotic therapy. Clinical pairs were compared for different features: i) biofilm formation ability using the crystal violet staining method (mature biofilm) and the Biofilm test based on measurement of superparamagnetic microbeads mobility trapped by biofilm (early biofilm), ii) cytotoxicity and immune response by quantifying lactate dehydrogenase (LDH) and Interleukin(IL)-6 release and iii) intracellular bacterial persistence using in vitro “lysostaphin protection” infection model of human osteoblasts.

Aim

Our goal is to increase diagnostic accuracy of synovial fluid testing in differentiating prosthetic joint infection(PJI) by more exhaustively studying simple and inexpensive biomarkers. For that purpose, we sought to determine: 1) if synovial fluid C-reactive protein(CRP), alpha-2-macrogloblulin(A2M), procalcitonin and adenosine deaminase(ADA) concentrations are different between infected and aseptic cases; 2) performance and optimal cutoff values of each marker; 3) whether any such test may help improve diagnostic performance of traditional leukocyte count.

Method

Between January/2013 and December/2015 total hip or knee arthroplasty revision cases (regardless of preoperative diagnosis) were prospectively included provided enough synovial fluid for biomarker analysis was collected and at least four tissue samples as well as the implant for sonication were gathered for microbiological study. Definitive diagnosis was classified as infection or aseptic on the basis of the recent International Consensus Meeting definition of PJI. Using receiver operating characteristic curves, we determined cutoff values as well as sensitivity and specificity for each marker.

Aim

The aim of this study was to validate the information on operating room ventilation reported to the Norwegian Arthroplasty Register (NAR) and to assess the influence of this ventilation on the risk of revision due to infection after primary total hip arthroplasty (THA).

Method

Current and previous ventilation systems were evaluated together with the hospitals head engineer in 40 orthopaedic hospitals. The ventilation system of each operating room was assessed and confirmed as either conventional ventilation, vertical laminar airflow (LAF) or horizontal LAF. We then identified cases of first revision due to deep infection after primary THA and the type of ventilation system reported to the NAR in the period 1987–2014. The association between revision due to infection and operating room ventilation was estimated by relative risks (RR) in a Cox regression model.

Aim

Spinal infections with and without aSCI represent a severe disease with a high lethality rate of up to 17%. The current treatment recommendations include an antimicrobial therapy and if necessary in combination with operative procedures. Aims of this study are the analysis of risk factors and treatment concepts and to compare the outcome of patients suffering a spinal infection with and without an aSCI.

Method

Monocentric prospective case study from 2013 – 2015. Patients were examined using a diagnostic algorithm (CT-thorax/abdomen, MRI total-spine, blood cultures, dental chart, echocardiogram). A calculated antimicrobial therapy was initially administered and later changed according to the antibiotic resistance. Additional operative procedures were performed with respect to the clinical and radiological findings.