Microbiology of bone and joint infections in injecting drug abusers

Risk Factors and Characteristics of Recalcitrant Osteomyelitis After Initial Surgical and Antibiotic Treatment

OBJECTIVES

To evaluate the injury, patient, and microbiological characteristics that place patients at risk for recalcitrant fracture-related infection and osteomyelitis despite appropriate initial treatment.

DESIGN

Retrospective chart review.

SETTING

Three level I trauma centers.

PATIENTS AND PARTICIPANTS

Two hundred and fifty-seven patients undergoing surgical debridement and antibiotic therapy for osteomyelitis from 2003 to 2019.

MAIN OUTCOME MEASUREMENTS

Patients were categorized as having undergone serial bone debridement if they had 2 separate procedures a minimum of 6 weeks apart with a full course of appropriate antibiotics in between. Patient records were reviewed for age, injury location, body mass index, smoking status, comorbidities, and culture results including the presence of multidrug-resistant organisms and culture-negative osteomyelitis.

RESULTS

A total of 257 patients were identified; 49% (n = 125) had a successful single course of treatment, and 51% (n = 132) required repeat debridement for recalcitrant osteomyelitis. At the index treatment for osteomyelitis, the most common organisms in both groups were methicillin-resistant (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). There was no significant difference in incidence of polymicrobial infection between the 2 groups (25% vs. 20%, P = 0.49). The most common organisms cultured at the time of repeat saucerization remained MRSA and MSSA; however, the same organism was cultured from both the index and repeat procedures in only 28% (n = 37) of cases. Diabetic patients, intravenous drug use status, delay to diagnosis, and open fractures of the lower leg are independent risk factors for failure of initial treatment of posttraumatic osteomyelitis.

CONCLUSIONS

Successful eradication of fracture-related infection and posttraumatic osteomyelitis is difficult and fails 51% of the time despite standard surgical and antimicrobial therapy. Although MRSA and MSSA remain the most common organisms cultured, patients who fail initial treatment for osteomyelitis often do not culture the same organisms as those obtained at the index procedure.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

How Do Drugs Affect the Skeleton? Implications for Forensic Anthropology

Simple Summary

Forensic anthropologists analyze human remains to assist in the identification of the deceased, predominantly by assessing age-at-death, sex, stature, ancestry and any unique identifying features. Whilst methods have been established to create this biological profile of the skeleton, these may be influenced by a number of factors. This paper, for the first time, provides an overview from a reading of the clinical and pharmacological literature to explore whether the intake of drugs can affect the skeleton and whether these may have implications for forensic anthropology casework. In effect, drugs such as tobacco, heroin, and prescription medications can alter bone mineral density, can increase the risk of fractures, destroy bone and changes to the dentition. By considering how drugs can affect the skeleton, forensic anthropologists can be aware of this when attempting to identify the deceased.

Abstract

Forensic anthropologists rely on a number of parameters when analyzing human skeletal remains to assist in the identification of the deceased, predominantly age-at-death, sex, stature, ancestry or population affinity, and any unique identifying features. During the examination of human remains, it is important to be aware that the skeletal features considered when applying anthropological methods may be influenced and modified by a number of factors, and particular to this article, prescription drugs (including medical and non-medical use) and other commonly used drugs. In view of this, this paper aims to review the medical, clinical and pharmacological literature to enable an assessment of those drug groups that as side effects have the potential to have an adverse effect on the skeleton, and explore whether or not they can influence the estimation of age-at-death, sex and other indicators of the biological profile. Moreover, it may be that the observation of certain alterations or inconsistencies in the skeleton may relate to the use of drugs or medication, and this in turn may help narrow down the list of missing persons to which a set of human remains could belong. The information gathered from the clinical and medical literature has been extracted with a forensic anthropological perspective and provides an awareness on how several drugs, such as opioids, cocaine, corticosteroids, non-steroidal anti-inflammatory drugs, alcohol, tobacco and others have notable effects on bone. Through different mechanisms, drugs can alter bone mineral density, causing osteopenia, osteoporosis, increase the risk of fractures, osteonecrosis, and oral changes. Not much has been written on the influence of drugs on the skeleton from the forensic anthropological practitioner perspective; and this review, in spite of its limitations and the requirement of further research, aims to investigate the current knowledge of the possible effects of both prescription and recreational drugs on bones, contributing to providing a better awareness in forensic anthropological practice and assisting in the identification process of the deceased.

Septic Arthritis Among Users of Injection Drugs: Clinical Course and Microbial Characteristics

Injection drug use (IDU) is a risk factor for septic arthritis (SA) of native joints. Amid the opioid crisis, IDU rates have increased. This study assessed differences in pre-operative characteristics, microbial characteristics, and postoperative outcomes of 177 cases of SA treated operatively from 2015 to 2019 at 3 US hospitals, by self-reported IDU status. Forty cases (23%) involved patients who reported IDU. Patient characteristics, comorbidities, microbial characteristics, duration of hospital stay, discharge destination, follow-up rates, and rates of persistent/secondary infection were compared by self-reported IDU status. Compared with non-IDU-associated SA (non-IDU-SA), IDU-associated SA (IDU-SA) was associated with female sex (P=.001), younger age (P<.001), lower body mass index (P<.001), tobacco use (P<.001), and psychiatric diagnosis (P=.04) and was more likely to involve methicillin-resistant Staphylococcus aureus (P<.001). The IDU-SA was associated with discharge to a skilled nursing facility or against medical advice (P<.001) and with loss to follow-up (P=.01). The 2 groups did not differ in terms of American Society of Anesthesiologists classification, joint involved, Gram stain positivity, presence of bacteremia, peripherally inserted central catheter placement, return to hospital within 3 months, or persistent/secondary positive results on culture within 3 months. Patients with IDU-SA were younger, were more likely to be female, had lower body mass index, and had fewer medical comorbidities but were more likely to use tobacco and to have a psychiatric diagnosis compared with patients with non-IDU-SA. Methicillin-resistant S aureus was more common in the IDU-SA group, as was discharge to a skilled nursing facility or against medical advice. Patients with IDU-SA were less likely to return for follow-up than patients with non-IDU-SA. [Orthopedics. 2021;44(6):e747-e752.].

Incidence and Predictors of Gram-Negative Bacilli in Hospitalized People Who Inject Drugs with Injection Drug Use-Attributable Infections

The objective of this study was to quantify incidence and determine predictors of Gram-negative bacilli (GNB) in people who inject drugs (PWID) with injection-drug use (IDU)-related infections. The investigation was a retrospective cohort of hospitalized PWID from January 2017 to December 2019. Inclusion criteria were age of ≥18 years, active IDU, treated IDU-attributable infection, and organism growth from microbiology cultures. Infection types included infective endocarditis (IE), acute bacterial skin/skin structure infection (ABSSSI), osteoarticular infection (OAI), and other bloodstream infections (BSI). Primary outcome was GNB identification from microbiologic culture; descriptive statistics were used to describe the cohort. Multivariable regression was used to identify variables associated with GNB infection. A total of 230 PWID were included, 65 (28%) with GNB infections and 165 (72%) with Gram-positive infections. The median (interquartile range [IQR]) population age was 38 (31 to 45) years. Most patients were women (56%); 37% had no insurance. Infection types were as follows: IE, 41%; ABSSSI, 37%; OAI, 20%; and other BSI, 2%. A total of 278 organisms were isolated from 230 patients. The most common organisms were methicillin-resistant Staphylococcus aureus (43%), Streptococcus spp. (19%), methicillin-susceptible S. aureus (17%), and Serratia marcescens (8%); 10% of infections were mixed GNB and Gram-positive infections. A total of 80% of patients received empirical Pseudomonas aeruginosa coverage; only 7% had P. aeruginosa infections. In multivariable regression, age of >50 years (adjusted odds ratio [adjOR], 2.9; 95% confidence interval [CI], 1.2 to 7.2), prior hospitalization within 90 days (adjOR, 2.2; 95% CI, 1.2 to 4.3), and OAI (adjOR, 3.2; 95% CI, 1.5 to 6.6) were associated with GNB infection. GNB in PWID with IDU-attributable infections were more frequently observed in recently hospitalized, older patients with OAI. The majority of patients received empirical antipseudomonal antibiotic coverage, but P. aeruginosa was infrequent. PWID are a potential population to target improved empirical antibiotic use.

Soft Tissue, Bone, and Joint Infections in People Who Inject Drugs

Infections are a common complication among people who inject drugs (PWID). Skin and soft tissue infections (SSTI) as well as bone and joint infections comprise a significant source of morbidity and mortality among this population. The appropriate recognition and management of these infections are critical for providers, as is familiarity with harm-reduction strategies. This review provides an overview of the presentation and management of SSTI and bone and joint infections among PWID, as well as key prevention measures that providers can take.

Methicillin-Resistant Staphylococcus aureus Bloodstream Infections and Injection Drug Use, Tennessee, USA, 2015-2017

Rising injection drug use associated with these infections highlights the need for targeted interventions.

Recently, Tennessee, USA, has seen an increase in the use of commonly injected drugs, such as heroin and fentanyl. Injection drug use (IDU) practices can lead to life-threatening methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) and other serious diseases. We matched MRSA BSIs identified through the National Healthcare Safety Network to the Tennessee Hospital Discharge Data System to characterize the prevalence, demographics, and clinical characteristics associated with IDU in this disease population. Of the 7,646 MRSA BSIs identified during 2015–2017, we found that 1,839 (24.1%) were IDU-related. IDU-related BSIs increased by 118.9%; the greatest rise occurred among emergency department–onset infections (197.4%). IDU was more often associated with white, female, 18–49-year-old, and uninsured persons (p<0.001). We found >1 additional IDU-related diagnoses in 84.2% of IDU-related BSIs. Targeted harm reduction strategies for persons at high risk of IDU are necessary to reduce MRSA BSIs in acute care settings.

Microbiological profile of chronic osteomyelitis with special reference to anaerobic osteomyelitis in a tertiary care hospital of coastal Karnataka

Chronic osteomyelitis is a relapsing, persistent, low-grade inflammation of bone caused by various infectious agents. The present study, conducted over a two-year period, on specimens received from cases of chronic osteomyelitis was, to determine the frequency of isolation of aerobic and anaerobic bacteria and to analyse their antimicrobial susceptibility pattern. Specimens were processed for Gram stain, aerobic and anaerobic culture, and were identified according to standard techniques. Significant growth was observed in 102/204 specimens, in which aerobic growth was observed in 62 (60.8%) and anaerobic in 40 (39.2%). Resistance to metronidazole and clindamycin was observed in 6.7% and 30% of the anaerobic isolates, respectively. None of these were resistant to meropenem. A significant proportion of anaerobic isolates were found to be resistant to commonly used empirical drugs, such as clindamycin, thus necessitating a need for routine anaerobic susceptibility testing.

Diagnostic Performance of CT-Guided Bone Biopsies in Patients with Suspected Osteomyelitis of the Appendicular and Axial Skeleton with a Focus on Clinical and Technical Factors Associated with Positive Microbiology Culture Results

PURPOSE

To assess diagnostic performance of CT-guided percutaneous needle bone biopsy (CTNBB) in patients with suspected osteomyelitis and analyze whether certain clinical or technical factors were associated with positive microbiology results.

MATERIALS AND METHODS

All CTNBBs performed in a single center for suspected osteomyelitis of the appendicular and axial skeleton during 2003-2018 were retrospectively reviewed. Specific inclusion criteria were clinical and radiologic suspicion of osteomyelitis. Standard of reference was defined using outcome of surgical histopathology and microbiology culture and clinical and imaging follow-up. Technical and clinical data (needle size, comorbidities, clinical factors, laboratory values, blood cultures) were collected. Logistic regression was performed to assess associations between technical and clinical data and microbiology biopsy outcome.

RESULTS

A total of 142 CTNBBs were included (46.5% female patients; age ± SD 46.10 y ± 22.8), 72 (50.7%) from the appendicular skeleton and 70 (49.3%) from the axial skeleton. CTNBB showed a sensitivity of 42.5% (95% confidence interval [CI], 32.0%-53.6%) in isolating the causative pathogen. A higher rate of positive microbiology results was found in patients with intravenous drug use (odds ratio [OR] = 5.15; 95% CI, 1.2-21.0; P = .022) and elevated white blood cell count ≥ 10 × 10⁹/L (OR = 3.9; 95% CI, 1.62-9.53; P = .002). Fever (≥ 38°C) was another clinical factor associated with positive microbiology results (OR = 3.6; 95% CI, 1.3-9.6; P = .011).

CONCLUSIONS

CTNBB had a low sensitivity of 42.5% for isolating the causative pathogen. Rate of positive microbiology samples was significantly higher in patients with IV drug use, elevated white blood cell count, and fever.

Bone and joint infections of the hand

BACKGROUND

Little guidance is currently available for standardized diagnostic protocols and therapeutic recommendations for bone and joint infections (BJIs) of the hand.

OBJECTIVES

To summarize the available data in the scientific English-language literature on the diagnosis and treatment of native BJIs of the hand. To illustrate these concepts from a narrative point of view in areas where there is lack of evidence.

SOURCES

We performed a systematic PubMed and Internet search of studies that investigated hand BJIs in adult patients.

CONTENT

Few studies have systematically investigated and validated diagnostic concepts, classifications or surgical treatment protocols. Most concepts derive from traditional intra-institutional experience, expert opinions and extrapolations from infections in large joints and long bones. Similarly, there is no uniformly accepted infection definition of BJIs of the hand. The best-documented literature is available for microbiological findings and antibiotic treatment duration in uncomplicated native joint arthritis of the fingers. Retrospective studies and one prospective randomized trial suggest that post-surgical targeted antibiotic therapy of 2 weeks results in a microbiological cure rate of ≥88%.

IMPLICATIONS

Studies on diagnostic workup and infection definition and classification are urgently needed to compare inter-institutional outcome results and generate guidelines for the best patient care. For uncomplicated pyogenic arthritis of native joints, current evidence suggests that a 2-week course of antibiotic therapy following surgery cures the infection.

Clinical characteristics of patients with polymicrobial septic arthritis

Little is known about the incidence, risk factors, clinical characteristics, and outcomes of patients with polymicrobial SA (PMSA). We aimed to determine the unique characteristics of patients with PMSA by comparing them to patients with monomicrobial SA (MMSA). We conducted a retrospective cohort study of patients 18 years and older admitted to a single tertiary care medical center, between 1998 and 2015, with surgically treated culture-positive SA affecting one or more joints. Patients were separated into two groups by the presence of one (MMSA) or more organisms (PMSA). A total of 441 patients with MMSA and 47 with PMSA were identified. Prior history of SA was more common among the PMSA group (31.9% vs. 18.6%; p = 0.03) as well as higher rates of prosthetic joint involvement (48.9% vs. 36.1%; p = 0.06). Patients with PMSA were sicker with higher rates of shock at presentation (14.9% vs. 5.5%; p = 0.02), intensive care unit admissions (39.1% vs. 18%; p < 0.001), and longer mean length of stay (16.1 vs. 10.9 days; p < 0.001). The most prevalent pathogens in the PMSA group were coagulase-negative Staphylococcus (31%), followed by methicillin-sensitive Staphylococcus aureus (29%), and Enterococcus (24%). To our knowledge, this is the first study to determine the clinical and microbiologic profiles of patients with PMSA. Important differences were noted such as more frequent involvement of atypical and prosthetic joints in PMSA. PMSA should be suspected in patients with these clinical features, and broad-spectrum antibiotics should be considered as these patients appear to be sicker and have worse outcomes.

A Rare Case of Burkholderia cepacia Complex Septic Arthritis

Bacteria of the Burkholderia cepacia complex have rarely been reported to cause septic arthritis. Cases have been reported in patients who were immunocompromised, at extremes of age or who had history of steroid injection or penetrating trauma. A 67-year-old man with a history of opioid use disorder, osteoarthritis, and gout but no known immunocompromise was admitted to hospital with pain and swelling of his right knee. Cultures of synovial fluid and urine grew Burkholderia cepacia complex. Microscopy of synovial fluid also identified intracellular calcium pyrophosphate crystals. The patient's symptoms improved with joint irrigation and debridement and prolonged antimicrobial therapy. This case highlights the importance of diagnostic aspiration of an acutely inflamed joint to obtain a specific etiological diagnosis.

Clinical usefulness of multiplex PCR-lateral flow for the diagnosis of orthopedic-related infections

Objectives: Polymerase chain reaction (PCR)-based assays are being increasingly used for the diagnosis of orthopedic-related infections. Unfortunately, classical PCR requires imaging devices that are expensive and complex. We previously developed the PCR-lateral flow (PCR-LF) method, which does not require any additional imaging device. In the present study, the objective was to determine whether PCR-LF tests could be used to effectively diagnose orthopedic-related infections. Methods: In this study, we used PCR-LF to diagnose common causes of orthopedic-related infections and compared the results to those from conventional bacterial cultures of the same samples. Results: Notably, for 228 synovial fluid or pus specimens, the sensitivity and specificity of bacterial cultures were 53.5% and 97.7%, respectively, compared to 61.6% and 89.9% for PCR-LF. Although the difference in sensitivity between bacterial cultures and PCR-LF was not significant, when our analysis was limited to cases with suspected periprosthetic joint infection, the sensitivity of PCR-LF (66.1%) was superior to that of bacterial cultures (42.9%). Conclusion: This study indicates that PCR-LF is a useful method for diagnosing orthopedic-related infections.

Peripheral Bacterial Septic Arthritis: Review of Diagnosis and Management

Septic arthritis refers to an infection in a joint due to a bacterial, mycobacterial, or fungal cause. Joint infections are a serious cause of morbidity and mortality and constitute a true musculoskeletal emergency. The estimated incidence of septic arthritis in the general population is between 2 and 6 cases per 100,000 people per year. The most common presentation is an acute monoarthritis. Identification of organisms in the synovial fluid is the criterion standard for diagnosis. Synovial fluid aspiration should be performed prior to initiating antibiotics. While no diagnostic cutoff exists for synovial fluid white blood cell count, increasing leukocytosis is associated with a higher likelihood of an infectious cause of arthritis, and patients commonly present with values greater than 50,000/μL. The cornerstones of treating septic bacterial arthritis are adequate drainage and antimicrobials. Joint drainage is always recommended in septic arthritis; however, no clear guidelines or strong evidence exist to guide the preferred method of drainage. Options for joint drainage include daily needle aspiration, arthroscopy, or open surgical drainage via arthrotomy.

A Real Pain: Diagnostic Quandaries and Septic Arthritis

Rapid diagnosis and treatment of an infected joint are paramount in preserving orthopedic function. Here, we present a brief review of the many challenges associated with the diagnosis of both septic arthritis and prosthetic joint infections. We also discuss the many laboratory tests currently available to aid in the accurate diagnosis of joint infection, as well as emerging diagnostics that may have future utility in the diagnosis of these challenging clinical entities.

Intravenous drug abuse is a risk factor in the failure of two-stage treatment for infected total hip arthroplasty

Reinfection after two-stage revision hip arthroplasty (RHA) is still a complex issue. Only few studies revealed the factors affecting the success rate in the treatment of periprosthetic hip infection (PHI), especially risk factors. A retrospective study was conducted using records of 30 patients underwent two-stage RHA for infected total hip arthroplasty (THA). Treatment was defined as successful if a patient did not need any reoperation or invasive procedure such as image-guided drainage during the two years after reimplantation. Treatment was defined as failure if any surgery or invasive procedure or long-term antibiotic suppression was considered necessary to control infection. Four patients had infection recurrence defined as failed and three of them had intravenous drug abuse. Twenty-six patients had no infection recurrence at the end of follow-up and one of them had intravenous drug abuse but quitting after surgery. We suggest that once adequate cleaning up achieved, risk of reinfection may be little even in immunocompromised patients with RHA because of relative less old age than those with revisional total knee arthroplasty. Patients of the reinfection group were younger and non-obese with adequate nutritional status. We may consider intravenous drug abuse could take a great toll on health and lead to reinfection. Finally, we suggest performing the gold-standard two-stage reimplantation technique to manage cases with infection, educating drug abusers regarding the risk of surgical failure, and implementing a quitting program at least 1 year before the index surgery.

Late and Vague Presentation of Septic Arthritis of Hip in a IVDrug Abuser

INTRODUCTION

Septic arthritis of the hip is a rare entity in acute presentation of hip pain in adults. Even though hip is the second most commonly affected joint, adult patients with septic arthritis not related to a surgical procedure represent <0.00001% of total acute admissions.

CASE REPORT

We present a 32-year-old female intravenous drug abuser, positive for Hepatitis B and C who had started to inject her femoral veins 2 years ago. She presented with a 10 weeks history of radiating pain in the leg which was full, constant and diffuse in nature with hip stiffness. She was treated for sciatica by her GP. She had later visited A and E twice (5 and 8 weeks) and was again treated symptomatically. She started to have increasing pain, hip stiffness, reduced mobility, and developed swelling of both legs extending upto groin medially. The patient was apyrexial throughout these visits. She did not have back/buttock pain. X-ray showed loss of joint space with evidence of articular surface destruction. Ultrasound showed no fluid collection inside the joint and deep vein thrombosis was ruled out. Hip joint was aspirated, and cultures grew Staphylococcus aureus from the aspirate. Flucloxacillin and fucidin were started as per hospital protocol. Skin traction was applied for pain relief with active hip movements as possible. Magnetic resonance imaging demonstrated complete joint destruction post- infective septic arthritis. After 8 weeks of antibiotics, inflammatory markers improved. Follow up X-ray showed complete ankylosis of hip joint, severe restriction ofhip movements and was allowed weight bearing as possible.

CONCLUSION

Risk of septic arthritis should always be considered in mind when dealing with these cohorts of patients. Threshold for septic arthritis should be much lower especially in patients with complicated history, current or ex-drug abuser and presenting with vague symptoms. Early diagnosis, detection of organisms, specific targeted antibiotics, and joint wash out with a future consideration of total hip arthroplasty when the infection has settled will help patients resume their normal function.

Clinical case report: discitis osteomyelitis complicated by inferior vena cava venous thrombosis and septic pulmonary emboli

Viridans group streptococcus is an infrequent cause of osteomyelitis that is found in association with infective endocarditis. Only a few studies report viridans osteomyelitis in the absence of endocarditis. Vertebral pyogenic osteomyelitis can sometimes be complicated by psoas or paraspinal abscesses. These intra-abdominal and/or pelvic collections can very rarely result in venous thrombosis. A paraspinal abscess resulting in inferior vena cava (IVC) thrombosis has only been reported once in the literature. We report a case of a young female with a history of polysubstance abuse and chronic back pain, who was found to have extensive vertebral osteomyelitis and discitis with epidural, paraspinal, and psoas abscesses caused by viridans streptococci. These abscesses compressed on the IVC causing IVC thrombophlebitis extending to the iliac veins distally. Imaging also demonstrated multifocal bilateral septic pulmonary emboli and pleural effusions secondary to septic IVC thrombus; a transesophageal echocardiogram showed no evidence of infective endocarditis.

The burden of bone, native joint and soft tissue infections on orthopaedic emergency referrals in a city hospital

Introduction Bone, native joint and soft tissue infections are frequently referred to orthopaedic units although their volume as a proportion of the total emergency workload has not been reported previously. Geographic and socioeconomic variation may influence their presentation. The aim of this study was to quantify the burden of such infections on the orthopaedic department in an inner city hospital, determine patient demographics and associated risk factors, and review our current utilisation of specialist services. Methods All cases involving bone, native joint and soft tissue infections admitted under or referred to the orthopaedic team throughout 2012 were reviewed retrospectively. Prosthetic joint infections were excluded. Results Almost 15% of emergency admissions and referrals were associated with bone, native joint or soft tissue infection or suspected infection. The cohort consisted of 169 patients with a mean age of 43 years (range: 1-91 years). The most common diagnosis was cellulitis/other soft tissue infection and the mean length of stay was 13 days. Two-thirds of patients (n=112, 66%) underwent an operation. Fifteen per cent of patients were carrying at least one blood borne virus, eleven per cent were alcohol dependent, fifteen per cent were using or had been using intravenous drugs and nine per cent were homeless or vulnerably housed. Conclusions This study has shown that a significant number of patients are admitted for orthopaedic care as a result of infection. These patients are relatively young, with multiple complex medical and social co-morbidities, and a long length of stay.

Septic arthritis in intravenous drug abusers: a historical comparison of habits and pathogens

BACKGROUND

Intravenous drug abuse (IVDA) is a common problem; there were more than 16 million users worldwide in 2008. Numerous reports highlight the infectious skeletal complication associated with IVDA.

OBJECTIVE

To determine septic arthritis pathogens in IVDA in a U.S. hospital and compare the current causative organisms to a cohort from the 1980s at the same institution.

METHODS

An institutional review board-approved retrospective cohort study compared a consecutive series of IVDA septic arthritis patients over a 10-year period, 1999-2008 (Group B), with an IVDA septic arthritis database that was collected in the 1980s (Group A). Endpoints were: bacterial species and staph species antibiotic susceptibility.

RESULTS

Group B included 58 patients (35 men, 23 women) with a median age of 46.5 years. Group A included 38 patients (30 men, 8 women), with a median age of 32.5 years. The sets were significantly different in pathogens (p = 0.0443). The most common organisms were Staphylococcus (staph) species (B 74.51%, A 52.63%), followed by Streptococcus (strep) species (B 7.84%, A 31.58%), Pseudomonas (B 13.73%, A 13.16%), and Serratia (B 3.92%, A 2.63%). Of the total number of septic joints, methicillin-resistant Staphylococcus aureus (MRSA) made up 39% of Group B and 34% of Group A. However, within the staph species, MRSA made up 53% of Group B and 65% of Group A. Strep species made up 7.84% (Group B) vs. 31.58% (Group A), and Pseudomonas (13%) and Serratia (3-4%) were similar. In the Group B cohort, methicillin-susceptible Staphylococcus aureus (MSSA) had a predilection to infect the knee (94.4%), whereas MRSA was found more often in the hip (57.1%).

CONCLUSIONS

In IVDAs, MRSA is the most common pathogen causing septic arthritis. The ratio of staph species in septic joints is increasing, and the ratio of MRSA to MSSA remains high (>50%). Strep species are much less common.

Residential addiction treatment for injection drug users requiring intravenous antibiotics: a cost-reduction strategy

OBJECTIVES

Injection drug users (IDUs) are prone to developing infections and complications requiring prolonged intravenous (IV) antibiotic treatment. Our institution's unique multidisciplinary approach provides special consideration and successful management of IDUs in a residential addiction treatment facility with nurse-administered IV antibiotics. Our hypothesis is that hospital costs can be reduced by providing both IV antibiotics and addiction treatment in a community residential treatment setting outside the hospital.

METHODS

A retrospective chart review was performed for inpatients requiring prolonged antibiotic treatment who were admitted to the university teaching hospital between January 2006 and December 2011 and were treated at the residential addiction treatment facility. Data were gathered to characterize this population of patients and estimate cost savings.

RESULTS

A total of 205 patients were sent to the residential addiction treatment facility from 2006 to 2011. The majority were African American, men, and in their early forties. Heroin was the most popular injected substance, but most patients were polysubstance users, including alcohol and tobacco. The most common infections were osteomyelitis and septic arthritis. There was a 73% completion rate of antibiotic treatment in this program. The relapse rate for return to illicit drug use was at least 32%. This program has resulted in a significant cost savings of $2.43 million in a 6-year period.

CONCLUSIONS

The program saved $2.43 million over 6 years for the health care system by reducing hospital length of stay with safe and appropriate discharge planning for IDUs with infections requiring long-term IV antibiotics.

Epidemiology of septic arthritis of the knee at Hospital das Clínicas, Universidade de São Paulo

Background

Septic arthritis is an infrequent disease although very important due to the possibility of disastrous outcomes if treatment is not adequately established. Adequate information concerning the epidemiology of septic arthritis is still lacking due to the uncommon nature of the disease as well as the struggle to establish a correct case-definition.

Objective

To epidemiologically characterize the population seen at Hospital das Clínicas, University of São Paulo with a diagnosis of septic arthritis between 2006 and 2011.

Methods

Sixty-one patients diagnosed with septic arthritis of the knee between 2006 and 2011 were retrospectively evaluated. The patients’ clinical and epidemiological characteristics, the microorganisms that caused the infection and the patients’ treatment and evolution were analyzed.

Results

Septic arthritis of the knee was more common among men, with distribution across a variety of age ranges. Most diagnoses were made through positive synovial fluid cultures. The most prevalent clinical comorbidities were systemic arterial hypertension and diabetes mellitus, and the most commonly reported joint disease was osteoarthritis. Staphylococcus aureus was the prevailing pathogen. Fever was present in 36% of the cases. All patients presented elevation in inflammatory tests. Gram staining was positive in only 50.8% of the synovial fluid samples analyzed. Six patients presented complications and unfavorable evolution of their condition.

Conclusion

S. aureus is still the most common pathogen in acute knee infections in our environment. Gram staining, absence of fever and normal leukocyte count cannot be used to rule out septic arthritis.

Clinical management of septic arthritis

Septic arthritis is a rheumatologic emergency as joint destruction occurs rapidly and can lead to significant morbidity and mortality. Accurate diagnosis can be particularly challenging in patients with underlying inflammatory joint disease. This review outlines the risk factors for septic arthritis and summarizes the causative bacterial organisms. We highlight advances in antibiotic management with a focus on new drugs for methicillin-resistant Staphylococcus aureus (MRSA) and discuss the use of adjunctive therapies for treatment of septic arthritis in adults.

Knee pain in patients with cancer after chemotherapy, radiotherapy, and bone marrow transplantation

The causes of knee pain in patients with cancer with are different from those without cancer, and the purpose of this study was to evaluate these differences. Thirty-six patients with cancer who had knee pain who had undergone 1 or more modalities of treatment, including chemotherapy, radiotherapy, and bone marrow transplant, for a primary diagnosis of cancer were compared with a cohort of 40 patients without cancer who had knee pain. All patients were evaluated clinically and underwent radiographic examination, and some underwent computed tomography or magnetic resonance imaging examination. Among patients with a primary diagnosis of cancer, the most common diagnosis was lymphoma (n=10), and the most common causes of knee pain were avascular necrosis of bone, osteoarthritis, insufficiency fractures, and septic arthritis. In 5 patients, the classical signs of a septic knee were not present. Other causes of knee pain included meniscus tear and anterior cruciate ligament rupture with instability. The most common diagnosis in patients without cancer was osteoarthritis of the knee. No patient without cancer was diagnosed with avascular necrosis, metastatic lesion, or insufficiency fracture. Two patients without cancer were diagnosed with septic arthritis of the knee. This study showed that the causes of knee pain in patients with cancer are different from those without cancer. Septic arthritis may present without the classical clinical signs in patients with cancer, and a high index of suspicion should be maintained for it.

Atraumatic posterior dislocation of the native hip: an unusual presentation of septic arthritis

We present a case of chronic posterior hip dislocation after severe joint destruction following septic arthritis. In the absence of trauma, infection must be considered in the differential diagnosis of a dislocated joint particularly in patients with risk factors such as intravenous drug abuse and immune compromise. Excision arthroplasty of the hip was performed with good pain relief and functional outcomes. This is an excellent temporary or permanent solution in managing such complex cases although alternative management options are discussed.

Successful salvage therapy with Daptomycin for osteomyelitis caused by methicillin-resistant Staphylococcus aureus in a renal transplant recipient with Fabry-Anderson disease

Daptomycin is licensed in adults for the management of Staphylococcus aureus methicillin-resistant infections, including bone and skin complicated infections. We describe for the first time its use in a renal transplant recipient for Fabry-Anderson Disease with right heel osteomyelitis. The patient was unresponsive to first-line Teicoplanin and second-line Tigecycline, whereas he was successfully treated with third-line Daptomycin monotherapy at 4 mg/Kg/qd for 4 weeks. Local debridement was performed in advance of each line of treatment.

What's New in the Management of Bacterial Septic Arthritis?

Septic arthritis is a common rheumatological emergency requiring prompt diagnosis and treatment, since delays in management can lead to high morbidity and mortality. In this review article, we discuss the epidemiology and recent advances in knowledge of the pathogenesis of septic arthritis, with a special emphasis on various bacterial and host factors involved in mediating the inflammatory process and the potential for targeted therapy to modulate the immune response. Recent advances in laboratory and imaging techniques are reviewed along with treatment and potential new therapies.

Osteomyelitis: an update for hospitalists

Osteomyelitis is a common and challenging condition for hospitalists to manage. The 3 main types of osteomyelitis that are commonly seen in the hospital setting are 1) contiguous spread from decubitus or diabetic ulcers, 2) hematogenous spread, such as in vertebral or long bone metaphyses, and 3) infections associated with a prosthetic joint. In patients with diabetes, osteomyelitis is the underlying cause of about 20% of foot infections, and greatly increases the chance that the patient will eventually need an amputation and be subject to perioperative risks. Osteomyelitis from hematogenous spread is increasing. The prevalence of vertebral osteomyelitis is also increasing, particularly in intravenous drug users and patients treated with immune-modulating agents. Prosthetic joint infections are perhaps the most challenging type to treat, and require hospitalists, orthopedic surgeons, and infectious disease specialists to work closely together to plan for effective treatment. Due to increasing antibiotic resistance, the microorganisms involved are also proving more difficult to treat. Emerging resistance to the commonly used antibiotics is resulting in changes in treatment choices. Community-acquired methicillin-resistant Staphylococcus aureus is commonly seen, and there is increasing concern about emerging vancomycin resistance. Treatment of osteomyelitis is still based largely on expert opinion rather than evidence from controlled studies.