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Septic arthritis remains an orthopaedic emergency that requires prompt diagnosis and management. During the 2020 COVID-19 pandemic, British Orthopaedic Association (BOAST) guidelines dictated that medical treatment (closed-needle aspiration + antibiotic therapy) should be offered to patients as first-line management, and operative treatment (arthroscopic joint washout +/- synovectomy) be reserved for patients exhibiting signs of sepsis. Literature has previously shown that for native joint septic arthritis, operative treatment is not superior to medical treatment. During the COVID-19 ‘lock-down’ period (March 2020 to June 2020), we prospectively followed the presentation, diagnosis, management and outcome of a total of six patients who presented with confirmed native joint septic arthritis. All six patients underwent initial medical management of their septic arthritis following their diagnostic aspiration, which involved serial closed-needle aspirations and antibiotic therapy as advised by our microbiology team. Four patients went on to have an arthroscopic washout at an average of eight days following admission (mean 2.5), prior to a consultant-led decision to proceed to arthroscopic washout. The decision for operative management was the patient’s clinical deterioration based on physiological (fever, tachycardia) and biochemical (C-reactive protein (CRP), white blood cell (WBC)) parameters. All of the four patients that proceeded to operative treatment failed to provide culture yield at the time of arthroscopic washout. The mean time to discharge was 15.6 days, whilst the mean time to discharge following operative intervention was 12 days. One patient passed away during admission and one patient required a second arthroscopic washout. Medical management of septic arthritis may play a role in symptom control in the palliative setting or in patients where a general anaesthetic is undesirable. We found operative management to be therapeutic clinically, haemodynamically and biochemically as well as facilitative of a faster recovery and shorter inpatient stay.

Introduction: D-dimer is a diagnostic criterion for periprosthetic joint infection (PJI) of the Musculoskeletal Infection Society (MSIS) in 2018. The aim of this study was to evaluate the serum D-dimer values in comparison to C-reactive protein (CRP) and interleukin-6 (IL-6) for the diagnosis of PJI. Materials and Methods: We included 119 patients (50 women, 69 men, 71 knees, 48 hips) undergoing revision arthroplasty with preoperative assessment of CRP, IL-6, and serum D-dimer. Cases were classified as infected or aseptic based on the MSIS criteria of 2018. Receiver operating curves and Youden&rsquo, s index were used to define an ideal cut-off value and sensitivity and specificity for the individual parameters, and respective combinations were calculated using cross-tables. Results: The median D-dimer level (2320 vs. 1105 ng/mL, p &lt, 0.001), the median CRP level (4.0 vs. 0.5 mg/dL, 0.001), and the median IL-6 level (21.0 vs. 5.0 pg/mL, 0.001) were significantly higher in the group of PJI compared to the group with aseptic failure. The calculated optimal cut-off values were 2750 ng/mL (AUC 0.767) for D-dimer, 1.2 mg/dL (AUC 0.914) for CRP, and 10.0 pg/mL (AUC 0.849) for IL-6. D-dimer showed a sensitivity of 38% and specificity of 94%, whereas the CRP and IL-6 had sensitivities of 88% and 76%, and specificities of 87% and 92%, respectively. Conclusion: In comparison with CRP and IL-6, serum D-dimer showed low sensitivity and specificity in our cohort. While CRP and IL-6 combination had the highest sensitivity, a combination of Il-6 and D-dimer or CRP and IL-6 had the highest specificity.

Background Diagnosis of persistent infection at reimplantation of 2-stage exchange revision is a challenging problem. The aim of our study is to evaluate the performance of the 2018 new definition and Musculoskeletal Infection Society (MSIS) criteria in determining the persistent infection at reimplantation in patients without synovial fluid. Methods We retrospectively reviewed 150 patients who underwent 2-stage exchange revision from 2014 to 2018. Two models were used to define persistent infection—model 1: identical major criteria of the MSIS criteria and new definition and model 2: identical major criteria of 2 criteria and/or subsequent infection after reimplantation. The predictive accuracy of the new definition and MSIS criteria was compared by using receiver operating characteristic curves. Results The receiver operating characteristic curves showed that the new definition had good performance in determining the persistent infection, with the area under the curve (AUC) of 0.871 in model 1 and 0.835 in model 2. The optimal threshold for aggregate scores in new definition was 4. The MSIS criteria had limited diagnostic value in both model 1 (AUC = 0.708) and model 2 (AUC = 0.664). In model 1, the sensitivity and specificity were 86.96% and 84.25% in new definition, and 47.83% and 93.70% in MSIS criteria in patients without synovial fluid. In model 2, the sensitivity and specificity were 78.57% and 85.25% in new definition, and 39.29% and 93.44% in MSIS criteria. Conclusion The 2018 new definition of PJI is valuable in the diagnosis of persistent infection, which can improve diagnostic accuracy compared with the MSIS criteria in patients without synovial fluid.

Objective Adequate resources are required to rapidly diagnose and treat pediatric musculoskeletal infection (MSKI). The workload MSKI consults contribute to pediatric orthopaedic services is unknown as prior epidemiologic studies are variable and negative work-ups are not included in national discharge databases. The hypothesis was tested that MSKI consults constitute a substantial volume of total consultations for pediatric orthopaedic services across the United States. Study design Eighteen institutions from the Children's ORthopaedic Trauma and Infection Consortium for Evidence-based Study (CORTICES) group retrospectively reviewed a minimum of 1 year of hospital data, reporting the total number of surgeons, total consultations, and MSKI-related consultations. Consultations were classified by the location of consultation (emergency department or inpatient). Culture positivity rate and pathogens were also reported. Results 87,449 total orthopaedic consultations and 7,814 MSKI-related consultations performed by 229 pediatric orthopaedic surgeons were reviewed. There was an average of 13 orthopaedic surgeons per site each performing an average of 154 consultations per year. On average, 9% of consultations were MSKI related and 37% of these consults yielded positive cultures. Finally, a weak inverse monotonic relationship was noted between percent culture positivity and percent of total orthopedic consults for MSKI. Conclusion At large, academic pediatric tertiary care centers, pediatric orthopaedic services consult on an average of ~3,000 'rule-out' MSKI cases annually. These patients account for nearly 1 in 10 orthopaedic consultations, of which 1 in 3 are culture positive. Considering that 2 in 3 consultations were culture negative, estimating resources required for pediatric orthopaedic consult services to work up and treat children based on culture positive administrative discharge data underestimates clinical need. Finally, ascertainment bias must be considered when comparing differences in culture rates from different institution's pediatric orthopaedics services, given the variability in when orthopaedic physicians become involved in a MSKI workup.

The use of genetic sequencing modalities in the diagnosis of periprosthetic joint infection (PJI) and the identification of organisms has gained popularity recently. Polymerase chain reaction (PCR) offers timely results for common organisms. The purpose of this study was to compare the accuracy of broad-range PCR, conventional culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al in the diagnosis of PJI. In this retrospective study, aspirate or tissue samples were collected in 104 revision and 86 primary arthroplasties for routine diagnostic workup for PJI and sent to the laboratory for PCR. Concordance along with statistical differences between diagnostic studies were calculated using chi-square test for categorical data. On comparison with the MSIS criteria, concordance was significantly lower for PCR at 64.7% compared with 86.3% for culture ( P P =.706) or sample collection method (tissue swab or synovial fluid) ( P =.316). Of the 87 patients who met MSIS criteria, only 20 (23.0%) PCR samples had an organism identified. In this series, PCR had little utility as a stand-alone test for the diagnosis of PJI, with a sensitivity of only 23.0% when using MSIS criteria as the gold standard. Polymerase chain reaction also appears to be significantly less accurate than culture in the diagnosis of PJI. Currently, several laboratory tests used for either criteria for PJI diagnosis should be obtained along with the overall clinical picture to help guide decision-making for PJI treatment. [ Orthopedics . 2020;43(6):333–338.]

BACKGROUND The American Academy of Orthopedic Surgeons clinical practice guideline currently recommends repeat joint aspiration when workup of periprosthetic joint infection (PJI) reveals conflicting data. This guideline is based on a single study of 31 patients published 25 years ago. We sought to determine the correlation between first and second aspirations and factors that may play a role in variability between them. METHODS Sixty patients with less than 90 days between aspirations and no intervening surgery were identified at our institution and classified by Musculoskeletal Infection Society (MSIS) criteria as infected, not infected, or not able to determine after both aspirations. Culture results from both aspirations were recorded. The rates of change and correlation in clinical diagnosis and culture results between aspirations were determined. RESULTS Repeat aspiration changed the diagnosis in 26 cases (43.3%, 95% confidence interval 31.6-55.9, kappa coefficient 0.32, P < .001), and the culture results in 25 cases (41.7%, 95% confidence interval 30.1-54.3, kappa coefficient 0.27, P < .01). Among patients initially MSIS negative, the proportion who changed to MSIS positive was greater for those with a history of prior PJI compared to those without (66.7% vs 0%, P < .05), and the first aspiration mean volume was higher for those changed to MSIS positive compared to those that remained MSIS negative (12.0 vs 3.0 mL, P < .01). Among patients initially MSIS positive, the proportion of patients who changed to MSIS negative was greater for those with a history of adverse local tissue reaction (ALTR) to metal debris compared to patients without suspicion of ALTR (100% vs 7.7%, P

Background There has been recent increased focus on the importance of modifiable risk factors that can affect the risk of potentially avoidable complications such as prosthetic joint infection (PJI). We aimed to assess the relationship between adherence to a preoperative optimization protocol at our institution and its influence on the rate of PJI after primary and revision total knee arthroplasty (TKA). Methods A single-institution, retrospective study was conducted on all elective primary and revision TKAs performed over a 2-year period. PJI was diagnosed using the 2011 Musculoskeletal Infection Society criteria. Surgical outcomes and PJI were assessed relative to adherence to preoperative optimization criteria. Compliance was set as a binary variable with any case that did not meet all criteria deemed noncompliant. Results A total of 669 TKAs met inclusion criteria, including 510 primary and 159 revision TKAs. Overall compliance was 61.3%. There were 26 PJIs (3.9%) in total. The PJI rate was 1.2% (6) among primary and 14.4% (20) among revision TKAs. The rate of PJI among cases that met the preoperative optimization criteria was 2.4% (5), and the rate among cases that did not was 6.2% (21) (P Conclusions Adherence to preoperative optimization criteria may decrease the incidence of PJI after primary and revision TKA, but further study is needed to confirm the findings of this study.

Tissues from a periprosthetic joint infection (PJI) of the knee contain a heavy neutrophil polymorph (NP) infiltrate (> 5 NPs per high-powered field [HPF] by Musculoskeletal Infection Society [MSIS] criteria). PJI of the knee can be treated by a two-stage procedure and our aim was to determine whether the MSIS histological criteria for PJI diagnosis are valid in a second-stage revision knee arthroplasty. Periprosthetic tissues from 45 second-stage revision knee cases were analyzed histologically by hematoxylin–eosin and chloroacetate esterase (CAE) staining for the identification of NPs. The number of NPs was determined semiquantitatively and results correlated with the microbiological and clinical findings. In 9 of the 45 cases, an organism was cultured in two or more samples, meeting MSIS microbiological criteria for a definite diagnosis of PJI; histologically, seven of these cases contained > 5 per NPs per HPF on average, with the remaining two cases containing 1 NP and 2 NPs per HPF. In noninfected second-stage revisions, NPs were not seen in 30 cases with 6 cases showing less than 1 NP per HPF on average. The sensitivity, specificity, accuracy, and positive and negative predictive values of MSIS histological criteria (> 5 NPs per HPF) to diagnose PJI were 78%, 100%, 96%, 100%, and 95%, respectively. MSIS histological criteria for the diagnosis of PJI are valid for most but not all infected second-stage revision knee arthroplasties. Correlation of histology with clinical, microbiology and other laboratory findings is required to establish a diagnosis of PJI in second-stage revision knee arthroplasties.

Purpose The aim of this study was to evaluate the pre-operative performance of an automated multiplex PCR (mPCR) system in patients with suspected periprosthetic joint infection (PJI). Methods Under sterile conditions, synovial fluid samples from patients with a suspected PJI were collected pre-operatively. One hundred eighty microliter of the aspirate was used for analysis in the mPCR. The remaining joint fluid was sent for microbiological analysis. PJI was diagnosed by using the Musculoskeletal Infection Society (MSIS) criteria. Total percentage agreement and Cohen’s kappa coefficient were calculated to measure overall agreement. Results Overall, 90 patients with a suspected PJI were included. Using MSIS criteria, 38 (42%) patients were classified as septic. Total percent agreement between mPCR and synovial fluid culture was 86% with a Cohen’s kappa of 0.68. The mPCR and synovial fluid culture showed sensitivities of 71% and 84%, respectively. Combined evaluation provided an even higher sensitivity of 92%. While Cutibacterium spp. were detected five times by mPCR, it could only be cultured once. A higher detection rate of CoNS by mPCR (n = 7) compared to conventional culture (n = 5) was also demonstrated. In comparison to synovial fluid culture, the mPCR missed Staphylococcus aureus five times. Conclusion With a moderate agreement between synovial fluid mPCR and culture, the mPCR system could be a useful adjunct in diagnosing a PJI pre-operatively. Due to faster availability of results and a higher detection rate of low-virulent microorganisms, it can complement conventional culture.

The diagnosis of a periprosthetic joint infection (PJI) remains a clinical challenge, as there is no uniformly accepted gold standard. In 2011, the Musculoskeletal Infection Society (MSIS) convened a work group to create a standardized definition for a PJI that could be universally adopted. Based on the MSIS criteria, the diagnosis of a PJI can be made with 1 of the 2 major criteria, or 3 of the 5 minor criteria. The purpose of this study was to determine the likelihood of having a PJI based on the number of positive minor criteria and thereby develop a prediction algorithm for differentiating between a chronic PJI and a non-PJI based on the number of positive MSIS minor criteria.We retrospectively reviewed 297 patients who presented to a tertiary care center between 2004 and 2014 with a failed total joint arthroplasty and subsequently underwent a PJI workup to exclude chronic PJI. Patients were divided into 2 groups: (1) PJI group and (2) non-PJI group. Patients who had a positive PJI workup and subsequently underwent a 2-stage revision for infection were included in the PJI group. Patients who had a negative clinical and diagnostic workup were included in the non-PJI group. One hundred eighty-two patients met the criteria for inclusion in the study, 91 in each group. Univariate and multiple logistic regression analyses were used to evaluate 21 independent variables in each of the 2 groups. A prediction algorithm for differentiating between a chronic PJI and a non-PJI based on independent multivariate variables was created.Patients who had a PJI differed significantly (P.05) from those who did not have a PJI with regard to 10 independent variables, which included all the MSIS minor criteria we evaluated. Five independent multivariate variables were identified to differentiate between the 2 groups: positive cultures, elevated synovial white blood cell count, elevated synovial polymorphonuclear neutrophil percentage, elevated erythrocyte sedimentation rate, and elevated C-reactive protein. The predictive probability of a PJI for all 32 combinations of these 5 variables was: 3.6% for 1 positive variable, 19.3% for 2, 58.7% for 3, 83.8% for 4, and 97.8% for 5. The chi-squared test for trend and the area under the receiver-operating characteristic curve (0.977) suggest that the model is highly predictive, with an excellent diagnostic performance in identifying a PJI.Diagnosing a PJI remains a clinical challenge as there is no gold standard for diagnosis. The development of the MSIS criteria, which is based on a consensus of over 400 of the world's experts in musculoskeletal infection, was a major step forward in defining the diagnosis of a PJI. However, to our knowledge, the likelihood of having a PJI based on the number of positive minor criteria has yet to be validated or quantified. Of the 20 independent variables that were evaluated, 10 were found to be significantly associated with a PJI, including all the MSIS minor criteria evaluated. In addition, a diagnostic prediction algorithm was constructed to determine the likelihood of a PJI based on 5 binary independent multivariate variables. The relationship was also examined with a receiver-operating characteristic curve analysis. The area under the curve was 0.98, indicating excellent diagnostic performance for the MSIS minor criteria in identifying a PJI.III.

The joint is a common site of musculoskeletal infection in adults. Septic arthritis is the most serious, although not the most frequent, cause of a hot swollen joint or joints. The diagnosis rests principally on clinical suspicion. Investigation of suspected joint sepsis is urgent in order to avoid significant morbidity and mortality. This review will cover the aetiology, pathogenesis, clinical features, investigation and management of native joint sepsis in adults, and will highlight the gaps in the evidence base regarding its pharmacological management and suggest some areas for future research. It will briefly cover osteomyelitis, which is much more common in young children than it is in adults.

Although prevention of infection following arthroplasty requires a multifaceted approach, the use of intraoperative irrigation is an important component of any protocol. Recent clinical practice guidelines from the Centers for Disease Control, World Health Organization, and International Consensus Meeting on Musculoskeletal Infection advocate the use of a dilute povidone-iodine solution prior to wound closure. Our experience suggests that this practice is safe, inexpensive, and easily implemented. The present article describes our institutional irrigation protocol and reviews the current literature regarding povidone-iodine solutions. Keywords: Irrigation, Povidone-iodine, Infection prevention, Surgical site infection

We report a novel case of a patient who had a draining sinus soon after a total hip arthroplasty that spontaneously resolved. The patient voluntarily discontinued antibiotic suppressive therapy (AST) after 10 years of treatment and paradoxically experienced full resolution of signs of chronic prosthetic joint infection (PJI), including recovery of his left-sided draining sinus tract. Now 8 years after discontinuing AST, the patient has no pain, good function, and no major or minor criteria of joint infection according to the Musculoskeletal Infection Society (MSIS) workgroup. The authors have not identified literature describing a similar resolution of draining sinus tracts from around a prosthetic joint after discontinuing AST. Despite the resolution of this patient’s sinus tract, the authors do not advocate for discontinuing AST in patients with a draining sinus tract. However, in spite of the fact that the MSIS consensus statement suggests that a draining sinus is a sure sign of PJI and that the assumption is that the infection will not go away until explant, this case was different.

To determine the added value of CT over planar and SPECT-only imaging in the diagnosis of musculoskeletal infection using 99mTc-UBI 29-4. 184 patients with suspected musculoskeletal infection who underwent planar and SPECT/CT imaging with 99mTc-UBI 29-41 were included. Planar, SPECT-only and SPECT/CT images were reviewed by two independent analysts for presence of bone or soft tissue infection. Final diagnosis was confirmed with tissue cultures, surgery/histology or clinical follow-up. 99mTc-UBI 29-41 was true positive in 105/184 patients and true negative in 65/184 patients. When differentiating between soft tissue and bone infection, planar + SPECT-only imaging had a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 95.0, 74.3, 84.8, 91.3 and 86.9%, respectively, versus 99.0, 94.5, 92.5, 98.5 and 94.5% for SPECT/CT. SPECT/CT resulted in a change in reviewers’ confidence in the final diagnosis in 91/184 patients. Inter-observer agreement was better with SPECT/CT compared with planar + SPECT imaging (kappa 0.87, 95% CI 0.71–0.85 versus kappa 0.81, 95% CI 0.58–0.75). Addition of CT to planar and SPECT-only imaging led to an increase in diagnostic performance and an improvement in reviewers’ confidence and inter-observer agreement in differentiating bone from soft tissue infection.

Aims The aim of this paper was to present the clinical features of patients with musculoskeletal sources of methicillin-sensitive Staphylococcus aureus (MSSA) septicaemia. Patients and Methods A total of 137 patients presented with MSSA septicaemia between 2012 and 2015. The primary source of infection was musculoskeletal in 48 patients (35%). Musculoskeletal infection was considered the primary source of septicaemia when endocarditis and other obvious sources were excluded. All patients with an arthroplasty at the time were evaluated for any prosthetic involvement. Results The most common site of infection was the spine, which occurred in 28 patients (58%), and was associated with abscess formation in 16. Back pain was the presenting symptom in these patients, with a positive predictive value of 100%. A total of 24 patients had a total of 42 arthroplasties of the hip or knee in situ. Prosthetic joint infection occurred in six of these patients (25%). In five patients, the infection originated outside the musculoskeletal system. Three patients (6%) with MSSA septicaemia from a musculoskeletal sources died. Conclusion Amongst the musculoskeletal sources of MSSA septicaemia, the spine was the most commonly involved. We recommend an MRI scan of the whole spine and pelvis in patients with MSSA septicaemia with back pain, when the primary source of infection has not been identified or clinical examination is unreliable. Cite this article: Bone Joint J 2017;99-B:1545–51.

Background Acute pediatric musculoskeletal infections are common, leading to significant use of resources and antimicrobial exposure. In order to decrease variability and improve the quality of care, Children's Hospital Colorado implemented a clinical care guideline (CCG) for these infections. The purpose of this study is to evaluate clinical and resource outcomes PRE and POST this CCG. Methods Retrospective chart review evaluated patients admitted to a large pediatric quaternary referral center (CHCO) diagnosed with acute osteomyelitis, septic arthritis, pyomyositis, and/or musculoskeletal abscess prior to and after guideline implementation. Primary outcomes included length of stay and overall antibiotic use, with additional secondary clinical, process, and therapeutic outcomes examined. Results 82 patients were identified in both the pre-CCG and post-CCG cohorts. There was a reduction in the median of all primary outcomes, including length of stay (0.6 median days decrease, P = .04), length of IV antibiotic therapy (4.9 median days decrease, P < .0001), and days of IV antibiotic therapy (6.4 median days decrease, P = .0004). Our median length of stay post-CCG was 4.9 days, the shortest reported length of stay for pediatric acute musculoskeletal infections to date. Additionally, there was a 24.5 hour reduction in median length of fever (P = .02), faster CRP normalization (P < .0001), 50% decrease in the number of related readmissions (P = .02), 34% decrease in central venous catheters placed (P < .0001), decreased time to first culture (P = .02), and 79% pathogen identification post-CCG (P = .056). Conclusions Implementation of a CCG for acute musculoskeletal infections improves patient, process and resource outcomes.

Acute hematogenous osteomyelitis (AHO) in children is an ideal condition to study due to its representation of a wide spectrum of disorders that comprise pediatric musculoskeletal infection. Proper care for children with AHO is multidisciplinary and collaborative. AHO continues to present a significant clinical challenge due to evolving epidemiology and complex pathogenesis. A guideline-driven, multidisciplinary approach has been introduced and shown to effectively reduce hospital stay, improve the timing and selection of empirical antibiotic administration, reduce delay to initial MRI, reduce the rate of readmission, and shorten antibiotic duration.

The acute phase response has a crucial role in mounting the body's response to tissue injury. Excessive activation of the acute phase response is responsible for many complications that occur in orthopedic patients. Given that infection may be considered continuous tissue injury that persistently activates the acute phase response, children with musculoskeletal infections are at markedly increased risk for serious complications. Future strategies that modulate the acute phase response have the potential to improve treatment and prevent complications associated with musculoskeletal infection.

We report a case of a patient presenting with fever, right lower leg swelling, and pain who was found to have a fluid collection between muscle planes noted on point-of-care ultrasound. Point-of-care ultrasound raised the clinician's concern for deep musculoskeletal infection, leading to prompt initiation of antibiotics and magnetic resonance imaging.

Introduction Bacillus species are often considered as contaminants when cultured from clinical samples. Bacillus cereus may be a pathogen in certain circumstances and is known to cause musculoskeletal infections. This report aims to educate clinicians and clinical microbiology laboratories on B. cereus musculoskeletal infections and to heighten awareness that Bacillus species should not always be dismissed as contaminants. Case presentation We report the case of a patient who presented to a tertiary hospital in Pretoria, South Africa, in November 2018 with B. cereus septic arthritis and underlying systemic lupus erythematosus (SLE). The isolate would otherwise have been dismissed as a contaminant had it not been for the crucial interaction between the laboratory and the treating clinicians. To our knowledge, this is the first case report of septic arthritis caused by B. cereus in an SLE patient where the organism was cultured from the joint specimen. Identification of the organism was performed using matrix-assisted laser desorption/ionisation mass spectrometry. Management and outcome Definitive treatment was with intravenous vancomycin, continued for four weeks, in addition to arthroscopy and management of the underlying SLE. The patient had a good clinical outcome and regained full mobility. Conclusion Musculoskeletal infections, specifically septic arthritis caused by B. cereus, are exceedingly rare infections. Immune suppression, trauma, prosthetic implants and invasive procedures are important risk factors for B. cereus musculoskeletal infections. Close collaboration with a multi-disciplinary team approach will effect the best outcome for complicated patients with B. cereus infections.

Various definitions and biomarkers have been developed in an unsuccessful attempt to obtain a "gold standard" for periprosthetic joint infection (PJI) diagnosis. The development of the 2011 Musculoskeletal Infection Society criteria facilitated further research and advances by allowing the use of a consistent PJI definition across studies. The newly proposed 2018 criteria do not rely at all on expert opinions/consensus. In this review, we describe the most relevant definitions developed throughout recent time, their rationale, characteristics, and supportive evidence for their clinical implementation. In the opinion of the authors, the orthopedic community should consider a probability and likelihood paradigm to create a PJI diagnostic definition. Probably not a single definition might be suited for all situations; the inclusion of serological findings could be the next step moving forward.

BACKGROUND Magnetic resonance imaging (MRI) is a heavily utilized resource to evaluate children suspected to have a musculoskeletal infection. Complex interdisciplinary workflows are involved with decision-making with regard to indications, anesthesia, contrast use, and procedural timing relative to the scan. This study assesses the impact of a quality improvement endeavor on MRI workflows at a tertiary pediatric medical center. METHODS A registry of consecutively enrolled children for a multidisciplinary musculoskeletal infection program identified those evaluated with MRI from 2012 to 2018. Annual MRI process improvement feedback was provided to the key stakeholders. Demographic characteristics, laboratory parameters, MRI indications, anesthesia use, MRI findings, final diagnoses, scan duration, imaging protocol, surgical intervention following MRI, and length of stay were retrospectively compared between the 3 cohorts (initial, middle, and final) representing 2-year increments to assess the impact of the initiative. RESULTS There were 526 original MRI scans performed to evaluate 1,845 children with suspected musculoskeletal infection. Anesthesia was used in 401 children (76.2%). When comparing the initial, middle, and final study period cohorts, significant improvement was demonstrated for the number of sequences per scan (7.5 sequences for the initial cohort, 5.8 sequences for the middle cohort, and 4.6 sequences for the final cohort; p < 0.00001), scan duration (73.6 minutes for the initial cohort, 52.1 minutes for the middle cohort, and 34.9 minutes for the final cohort; p < 0.00001), anesthesia duration (94.1 minutes for the initial cohort, 68.9 minutes for the middle cohort, and 53.2 minutes for the final cohort; p < 0.00001), and the rate of contrast use (87.6% for the initial cohort, 67.7% for the middle cohort, and 26.3% for the final cohort; p < 0.00001). There was also a trend toward a higher rate of procedures under continued anesthesia immediately following the MRI (70.2% in the initial cohort, 77.8% in the middle cohort, and 84.6% in the final cohort). During the final 6-month period, the mean scan duration was 24.4 minutes, anesthesia duration was 40.9 minutes, and the rate of contrast administration was 8.5%. CONCLUSIONS Progressive quality improvement through collaborative interdisciplinary communication and workflow redesign led to improved utilization of MRI and minimized contrast use for suspected musculoskeletal infection. There was a high rate of procedural intervention under continued anesthesia for children with confirmed musculoskeletal infection. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Musculoskeletal infection, especially in young children, often presents with non-specific clinical signs and symptoms necessitating early imaging to identify the source of infection. While MRI is the investigation of choice to demonstrate bone infection, it is expensive and often requires a general anaesthetic in the young child. Ultrasound can be a useful tool in the initial assessment due to its easy availability and portable equipment. It does not involve ionising radiation and is used to guide aspiration and drainage procedures. This review explains sonographic features of septic arthritis, osteomyelitis, pyomyositis and soft tissue infection in children and highlights advantages and limitations of sonography when assessing the child with suspected musculoskeletal infection.

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 11 focused on risk factors and prevention questions in spine surgery, for which this article provides the recommendations, voting results, and rationales.

In July of 2018, the Second International Consensus Meeting (ICM) on Musculoskeletal Infection convened in Philadelphia, PA was held to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 9 focused on implants questions in spine surgery, for which this article provides the recommendations, voting results, and rationales.

Introduction Arthroplasty has always been associated with complications, such as the possibility of periprosthetic infection. The presence of an active infection at the site of the planned surgery is considered a contraindication for the new implant. However, it is unclear whether there is an association between the presence of remote musculoskeletal infection and the development of infection in the prosthetic joint itself. We report six cases involving patients with active ongoing musculoskeletal infections at a remote site who underwent arthroplasty. Presentation of cases Four male and two female patients were included in this review. Three patients underwent total hip arthroplasty, one underwent hip hemiarthroplasty, and two underwent total knee arthroplasty. All surgeries were performed in the presence of different stages of infection at a remote site; two had active infections with pus-discharging sinus, one was being treated with long-term oral antibiotic suppression, and three patients were diagnosed with remote prosthetic joint infections on the basis of joint aspiration or intraoperative cultures. Clinical assessments of pain, wound erythema or drainage, and soft tissue swelling were performed at follow-up. Radiography and analysis of inflammatory marker levels were performed preoperatively and 6 weeks postoperatively. Discussion All six patients were followed-up for at least 18 months (mean, 4.6 years; range, 18 months to 9 years). No evidence of superficial surgical-site infection or deep prosthetic joint infection was observed. Conclusion The presence of an active infection at a remote site might not be a contributing factor to periprosthetic joint infection.

Unexpected positive intraoperative culture (UPIC) in revision hip and knee arthroplasty has a prevalence of 10.5%, there is no consensus in the literature on how to interpret them and how to treat them. Our literature review showed that most authors would consider two or more positive cultures as significant and usually treat them with culture specific antibiotics for 4-6 weeks. A single positive intraoperative culture can or cannot be significant depending on the virulence of the organism, hence taking multiple tissue samples in and around the joint is recommended. All failed arthroplasty cases must be evaluated preoperatively according to musculoskeletal infection society criteria (MSIS) to rule out the possibility of infection as an etiology for failure of the arthroplasty. Most authors reported that large majority of these UPIC were from a low virulence organism. Our review showed that the implant survival is more than 85% with 4-6 weeks of antibiotic treatment.

In July of 2018, the Second International Consensus Meeting on Musculoskeletal Infection convened in Philadelphia, PA to discuss issues regarding infection in orthopedic patients and to provide consensus recommendations on these issues to practicing orthopedic surgeons. During this meeting, attending delegates divided into subspecialty groups to discuss topics specifics to their respective fields, which included the spine. At the spine subspecialty group meeting, delegates discussed and voted upon the recommendations for 63 questions regarding the prevention, diagnosis, and treatment of infection in spinal surgery. Of the 63 questions, 7 focused on wound care, for which this article provides the recommendations, voting results, and rationales.

Background Periprosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty (TJA). Now, the definition of PJI traditionally used in clinical practice was set out by the International Consensus Meeting (ICM) and Infectious Diseases Society (IDSA). There was a new definition proposed in May 2018 on a paper published in the Journal of Arthroplasty. The new scoring system for PJI demonstrated a higher sensitivity and specificity than Musculoskeletal Infection Society and IDSA criteria. Therefore, we wanted to find further evidence to support the new definition in the Chinese population. Methods The patients who were included in our study were divided into PJI group and aseptic group. Medical records of patients (98 in PJI group and 165 in aseptic group) were reviewed, and the score of every patient was aggregated based on the new definition and collected data. The sensitivity and specificity were compared between new definition and classical criteria. Results For patients in our hospital, the overall sensitivity and specificity of the new criteria were respectively 94.9% (95% confidence interval [CI] 87.9–98.1%) and 95.2% (95% CI 90.3–97.7%). The new definition demonstrated a higher sensitivity than traditional criteria in Chinese population, and the specificity was similar to existing criteria. Conclusion We believe the new scoring system about periprosthetic joint infection could also apply to Chinese population for diagnosing PJI following TJA. It can obviously improve diagnostic efficiency for PJI compared with traditional criteria.