Microbiology and Treatment Outcomes of Community-Acquired Hematogenous Osteoarticular Infections in Infants ≤12 Months of Age

We investigated the microbiology, management, and orthopedic outcomes of osteoarticular infections in infants age ≤1 year at our institution. Among 87 patients, Staphylococcus aureus was the most common pathogen (44.8%), followed by group B Streptococcus. Twenty-nine patients (33%), with a median age of 9.2 months, were transitioned to oral antibiotic therapy after ≤14 days of parenteral therapy; orthopedic outcomes were similar to those with prolonged parenteral therapy.

Management of a Hot Swollen Joint in the Acute Setting

BACKGROUND

The presentation of a hot swollen joint is common in the emergency department, general practice, rheumatology and orthopedic clinics. There is a wide set of differential diagnoses for a hot swollen joint, thus making it difficult to diagnose and manage, especially for junior doctors. Initially, it is pertinent to exclude/diagnose medical and surgical emergencies.

OBJECTIVE

This paper aims to summarize the key indications within the history, examination and investigations in order to quickly and effectively diagnose a hot swollen joint based on the original 2006 management guidelines and the papers discussing other possible indications and management strategies published since.

RESULTS

Currently, the management of crystal and non-infectious arthropathies are well recognized with little disparity. However, the treatment of infectious arthritis is not concrete and there are discrepancies in management between doctors.

CONCLUSION

We have summarized the key indications and provided a diagnostic flow chart to aid with the management.

Factors affecting the occurrence of osseous lesions in septic shoulder arthritis and the recurrence rate after arthroscopic surgery

HYPOTHESIS

The purpose of this study was to determine the incidence of osseous lesions and the recurrence rate after arthroscopic surgery in shoulder septic arthritis patients and evaluate the influencing factors.

MATERIALS AND METHODS

We retrospectively reviewed 44 patients who underwent arthroscopic surgery for septic arthritis of the shoulder between January 2012 and September 2019. The average age of the patients was 65.57 ± 14.2 years, and 56.8% were female patients. The minimum follow-up period was 12 months (average, 32.8 ± 14.2 months; range, 12-72 months). We assessed variables including sex, age, underlying diseases, duration from symptom onset to magnetic resonance imaging (MRI), duration from symptom onset to surgery, radiologic results (radiography and MRI), history of injection therapy, and postoperative infection. The incidence of osseous lesions and the recurrence rate were calculated according to independent variables. In addition, multivariate logistic regression was performed to identify the risk factors for osseous lesions and recurrent infection after adjustment for other variables.

RESULTS

Twenty-one patients had an osseous lesion on MRI, and 12 patients had evidence of bone erosion on radiographs. In univariate analyses, significant (P < .05) risk factors for the presence of osseous lesions were female sex, lower C-reactive protein level, and longer duration from symptom onset to MRI. The overall infection recurrence rate was 22.7% (10 of 44 patients). Culture results and the duration from symptom onset to surgery were significant risk factors for recurrent infection (P < .05). As the duration from symptom onset to MRI increased by 1 day, the probability of osseous lesions increased 1.31-fold (95% confidence interval, 1.08- to 1.59-fold; P = .007), and this probability was significantly higher after correction for other risk factors.

CONCLUSIONS

To reduce the severity of septic shoulder infection, timely diagnosis and treatment are essential. Even if osseous lesions are present, good results can be obtained if meticulous débridement is performed through arthroscopic surgery. However, functional and radiologic long-term follow-up studies are needed in patients with osseous lesions.

Intra-Articular Tenosynovial Giant Cell Tumor Mimicking Septic Arthritis: A Report of Two Cases

Introduction

Intra-articular tenosynovial giant cell tumor (IATGCT) is a type of tenosynovial giant cell tumor that typically occurs in the synovial tissues of large joints. It is also known as pigmented villonodular synovitis. Acute onset of the pain with irritable hip symptoms is very rare. In this paper, we presented two adolescents with acute onset of hip pain mimicking septic arthritis diagnosed with intra-articular tenosynovial giant cell tumor.

Case Report

Healthy two adolescents, one male (14-year-old) and the other girl (15-year-old) with no history of the previous trauma or significant comorbidities were presented complaining of acute onset of hip pain to our emergency room. Although initial possible diagnosis was septic arthritis for both cases, laboratory findings were unequivocal for septic arthritis and magnetic resonance imaging (MRI) showed an intra-articular nodular mass. An open resection was performed and pathological evaluation revealed the masses to be intra-articular tenosynovial giant cell tumor. After 26 and 17 months follow-up there was no pain neither with activity nor in rest, hip range of motion was within normal ranges. There was no recurrence, avascular necrosis or destruction detected on control MRI for both patients.

Conclusion

IATGCT is a rare disease of the pediatric population involving the hip. Inflammation or infarction of the lesion can trigger irritable hip findings in children. This diagnosis should be kept in mind mainly in cases with serohemorrhagic aspirate and unequivocal laboratory findings.

The Utility of Routine Radiographic Monitoring in Pediatric Osteoarticular Infections

BACKGROUND

Pediatric musculoskeletal (MSK) infections broadly include isolated osteomyelitis (OM), septic arthritis (SA), and combined infections (OM+SA). These diagnoses are often monitored with serum inflammatory markers and serial radiographs to monitor treatment response and development of negative sequelae, despite limited data supporting these practices. The purpose of this study is to evaluate the utility of obtaining serial radiographic follow-up for pediatric osteoarticular infections.

METHODS

An institutional review board-approved retrospective review was completed. Children 18 years and below admitted to a single institution with a culture/biopsy-proven diagnosis of OM, SA, or OM+SA. All postdischarge radiographs were reviewed and retrospectively categorized as either routine (scheduled) or reactive. Routine radiographs were obtained regardless of clinical presentation. Reactive radiographs were obtained in patients presenting with the sign of an altered clinical course. Negative sequelae, defined as growth arrest/disturbance, pathologic fracture, recurrent MSK infection, and underlying neoplastic process, were recorded and tracked. Descriptive statistics were used to summarize demographic and outcome variables. Number needed to screen (NNS) was defined as the inverse of the incidence of negative sequelae detected.

RESULTS

A total of 131 patients were included for analysis, with a mean age of 11.9 years (SD: 4.96 y). Ninety (69%) patients were diagnosed and treated for OM, 25 (19%) for SA, and 16 (12%) for combined infections. A total of 329 radiographs were obtained following discharge. Of those obtained, 287 (88%) were routine, resulting in the detection of 2 (0.7%) negative sequelae and a resultant NNS of 143 radiographs (95% confidence interval: 36-573). The remaining 39 were reactive radiographs, resulting in the detection of 2 (5.1%) negative sequelae with an NNS of 20 radiographs (95% confidence interval: 5-78).

CONCLUSIONS

While radiographs remain a widely utilized tool to screen for the development of negative sequelae in pediatric osteoarticular infections, they rarely alter management in the absence of other concerning clinical signs or symptoms such as recurrent fevers, swelling of the extremity, or limb deformity. Moreover, routine radiographic surveillance should be replaced with a reactive radiographic protocol.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Clinical and Epidemiological Characteristics of Streptococcus suis Infections in Catalonia, Spain

Introduction:Streptococcus suis (S. suis) is a human zoonotic pathogen of occupational origin, with infection acquired through contact with live pigs or pig meat. Pig farming is one of Catalonia's biggest industries and as a result this region of Spain has one of the highest density pig populations per km². The aim of our study was to describe the infections caused by S. suis occurring in that area over a 9-year period.

Materials and Methods: A retrospective, multi-center study was carried out by searching records from 15 hospitals in Catalonia for the period between 2010 and 2019.

Results: Over the study period altogether nine cases of S. suis infection were identified in five hospitals, with five of these cases occurring in the 2018–2019 period. The mean age of patients was 48 ± 8.9 years and all of them were males. Five patients (55.6%) worked in pig farms. The most frequent manifestation of infection was meningitis (5 cases; 55.6%) followed by septic arthritis (3 cases; 33.3%). None of the patients died at 30 days; nonetheless, 4 developed hearing loss as a long-term complication.

Conclusion: The most commonly identified S. suis infection was meningitis. Over 50% of the episodes occurred in the last 2 years and have affected pig farm workers. Further surveillance is needed in order to know its prevalence.

Kingella kingae Osteoarticular Infections Approached through the Prism of the Pediatric Orthopedist

Nowadays, Kingella kingae (K. kingae) is considered as the main bacterial cause of osteoarticular infections (OAI) in children aged less than 48 months. Next to classical acute hematogenous osteomyelitis and septic arthritis, invasive K. kingae infections can also give rise to atypical osteoarticular infections, such as cellulitis, pyomyositis, bursitis, or tendon sheath infections. Clinically, K. kingae OAI are usually characterized by a mild clinical presentation and by a modest biologic inflammatory response to infection. Most of the time, children with skeletal system infections due to K. kingae would not require invasive surgical procedures, except maybe for excluding pyogenic germs' implication. In addition, K. kingae's OAI respond well even to short antibiotics treatments, and, therefore, the management of these infections requires only short hospitalization, and most of the patients can then be treated safely as outpatients.

Septic Arthritis and Bacteremia Due to Infection by Pasteurella canis

Pasteurella canis is a Gram-negative coccobacilli from the Pasteurellaceae family. The most common form of transmission to humans is a bite from a dog or a cat. We report a case of a 90-year-old woman who presented with septic arthritis in the right knee and bacteremia two weeks after a cat bite. The patient was treated with arthrocentesis and directed antimicrobial therapy. Human Pasteurella canis infection is a rare occurrence, making this a case of note.

Osteoarticular melioidosis: a retrospective cohort study of a neglected disease

INTRODUCTION

Patients with melioidosis can present with a combination of fever, respiratory distress and focal involvement. Focal involvement of bone and joint is, however, rare in patients with melioidosis. This study aimed to characterize patients with osteoarticular melioidosis.

PATIENTS AND METHODS

This was a retrospective review of records of all adult patients diagnosed with culture-positive osteoarticular melioidosis over three years. The clinical, laboratory and treatment details were recorded in a predefined case-record form and analyzed.

RESULTS

Of the 11 patients with osteoarticular melioidosis, 55% (n=6) had concurrent pulmonary involvement. The patients were classified as isolated osteomyelitis (n=3), isolated arthritis (n=3), and both osteomyelitis and septic arthritis (n=5). Of eight patients with joint involvement, 87.5% had monoarthritis. A single bone was involved in 75% of the patients with bone involvement (n=8). Concomitant myositis was seen in 36.4% (n=4) of the cases. Local debridement of the involved bone or joint was done in 54.5% (n=6) of the cases. Combination therapy with ceftazidime/meropenem and cotrimoxazole was predominantly used as intensive therapy for a mean of 3+1.3 weeks. Monotherapy with cotrimoxazole was used as eradication therapy for a mean of 4.6+2 months. Except for one patient with recurrent disease and one death, all patients were declared cured at the end of therapy.

CONCLUSION

Osteoarticular melioidosis should be suspected in high-risk individuals from endemic areas with single bone or joint involvement and surrounding myositis. Early diagnosis and prompt initiation of therapy is key to a favourable response.

Pseudoseptic Arthritis in a Patient With Psoriasis

A 42-year-old male with a history of untreated psoriasis and a previous episode of presumed left knee septic arthritis developed sudden onset of left knee pain, swelling, and a moderate effusion. The pathogen could not be isolated despite extensive inflammation seen in synovial fluid (SF) and synovial tissue biopsy. Whether this is culture-negative septic arthritis or pseudo-septic arthritis is the enigma, given the limited sensitivity of current available SF microbiologic testing. We present a challenging and stimulating case with no current guidelines for an optimal empiric antibiotic regimen or anti-inflammatory therapy.

Septic arthritis of the sternoclavicular joint in a patient with human immunodeficiency virus infection

Septic arthritis is an unusual manifestation in patients with human immunodeficiency virus (HIV). The sternoclavicular joint is rarely affected, although it should be considered in immunosuppressed patients and users of intravenous drugs. Staphylococcus aureus is the most common pathogen detected and should be covered by empiric antibiotic therapy.

Staged Joint Arthrodesis in the Treatment of Severe Septic Ankle Arthritis Sequelae: A Case Report

Septic ankle arthritis is a devastating clinical entity with high risks of morbidity and mortality. Prompt treatment is necessary because delayed or inadequate treatment can lead to irreversible damage that may occur on the articular surface, resulting in cartilage erosion, infective synovitis, osteomyelitis, joint deformity, and pain and joint dysfunction. An aggressive surgical approach is required when a joint infection causes severe limb-threatening arthritis. A 58-year-old woman visited our clinic with increasing pain in the right ankle, which had been present for the previous 2 months. She complained of discomfort in daily life due to deformity of the ankle; limping; and severe pain in the ankle even after walking a little. The patient reported a history of right-ankle injury while exiting a bus in her early 20s. Plain radiographs of the right ankle joint revealed that the medial malleolus was nearly absent in the right ankle joint on the anteroposterior view, and severe varus deformity was observed with osteoarthritic changes because of joint space destruction. Magnetic resonance imaging revealed diffuse synovial thickening of the destroyed tibiotalar joint with joint effusion. Hybrid 99mTc white blood cell single-photon emission computed tomography/computed tomography showed increased uptake along the soft tissue around the ankle joint; uptake was generally low in the talocrural and subtalar joints. A two-stage operation was performed to remove the infected lesions and correct the deformity, thus enabling limb salvage. The patient was nearly asymptomatic at the 6-month follow-up, with no discomfort in her daily life and nearly normal ability to carry out full functional activities. She had no complications or recurrent symptoms at the 1-year follow-up. We have described a rare case of a staged limb salvage procedure in a patient with chronic septic arthritis sequelae. For patients with severe joint deformity because of septic ankle sequelae, staged arthrodesis is a reliable method to remove infected lesions, solve soft tissue problems, correct deformities, and maintain leg length.

Septic Polyarthritis Caused by Streptobacillus moniliformis

Streptobacillus moniliformis is a pleomorphic, fastidious gram-negative bacillus that colonizes rodent respiratory tracts and causes rat-bite fever in humans. Rat-bite fever is associated with septic arthritis, usually monoarticular or pauciarticular. We report a rare case of polyarticular septic arthritis caused by S. moniliformis; the disease was initially misdiagnosed as inflammatory arthritis.

Risk Factors of Coexisting Septic Spondylitis and Arthritis: A Case-Control Study in a Tertiary Referral Hospital

Introduction: In patients under immunosuppression or severe sepsis, it is sometimes manifested as coexisting septic arthritis and spondylitis. The aim of this study is to evaluate and investigate the risk factors of infectious spondylitis associated with septic arthritis. Methods: The study retrospectively reviewed the patients diagnosed with infectious spondylitis between January 2010 and September 2018 for risk factors of coexisting major joint septic arthritis. Results: A total of 10 patients with infectious spondylitis and coexisting septic arthritis comprised the study group. Fifty matched patients with solely infectious spondylitis were selected as the control group. Major risk factors include preoperative C-reactive protein (p = 0.001), hypoalbuminemia (p = 0.011), history of total joint replacement (p < 0.001), duration of preoperative antibiotics treatment (p = 0.038) and psoas muscle abscess (p < 0.001). Conclusion: Infectious spondylitis and septic arthritis are thought of as medical emergencies due to their high mortality and morbidity. Our study evaluated 5 risk factors as significant major findings: hypoalbuminemia (<3.4 g/dL), higher preoperative CRP (>130 mg/L), psoas muscle abscess, longer preoperative antibiotics treatment (>8 days) and history of total joint replacement. Clinicians should pay attention to the patients with those five factors to detect the coexisting infections as early as possible.

Septic Arthritis Masquerading as a Flare of Rheumatoid Arthritis: A Not So Straightforward Diagnosis

A typical presentation of septic arthritis (SA) includes pain, swelling, and erythema in the affected joint. Often, patients complain of inability to bear weight on the affected limb. However, some patients may present with subtle symptoms of pain and no fever or obvious swelling of the affected limb thus making the initial suspicion of SA low. Especially, patients with rheumatoid arthritis (RA) may present with polyarticular joint pain and initial synovial fluid analysis from an infected joint not consistent with overt septic arthritis. In such situations, the diagnosis of septic arthritis could be missed on delayed. In this case report, we present a 79-year-old female with a history of RA who presents with polyarticular pain, most notably in her right knee. SA was not initially suspected because of her history of RA and her current presentation with polyarticular pain. The initial synovial analysis did not suggest SA as well. However, cultures of synovial fluid from her right knee confirmed SA. Thus, we have highlighted that physicians should have a high suspicion for SA when addressing joint pain in RA patients.

Sternoclavicular Septic Arthritis: Partial Resection is Still an Option - A Case Report

Introduction

Sternoclavicular joint (SCJ) infection is rare. Delayed diagnosis might lead to severe complications. Optimal surgical management is still under debate however extended resection of the joint requiring muscle flap coverage appears to be the favored approach nowadays in the cases with bony involvement.

Case Presentation

A 58-year-old man complained of isolated left shoulder and anterior chest pain for over a month. Careful examination revealed a mass over the SCJ. A Computed tomography scan confirmed joint effusion and adjacent bone erosion, with no retrosternal involvement, consistent with SCJ septic arthritis with significant bony involvement.

Conclusion

This case illustrates how a heightened index of suspicion is essential for diagnosis and prompt treatment, and how partial resection was effective and resulted in complete recovery of range of motion and pain resolution, despite bony involvement. There were no signs of recurrence 1 year after surgery.

Case Report of a Diagnosed Septic Hip Joint Treated with a 2-Stage Hip Arthroplasty

Introduction

Identifying and determining appropriate treatment of adult hip septic arthritis (SA) can be quite challenging. Although rare, the annual incidence of this diagnosis is approximately 8 cases per 100,000 patients. The timing of patient symptoms is wide spread. The presentation may be acute, subacute, or even chronic, and moreover, the disease process may be masked by an underlying etiology. Once diagnosed, SA requires rapid and aggressive treatment.

Case Report

A 67-year-old patient presented with left hip pain. Physical examination shifted the differential diagnosis from osteoarthritis to a possible septic joint. Elevated inflammatory markers were revealed. Joint aspiration was obtained, which demonstrated rare Group G streptococcus. Two-stage hip arthroplasty was performed. Intra-operative cultures still reveal no growth of bacteria, and the patient is progressing well.

Conclusion

Adult septic hip arthritis is a rare diagnosis. Hence, a proper history, physical examination, infectious laboratory workup is important. The treatment of the condition is based on the duration of symptoms and the physician's clinical gestalt.

Acute Eosinophilic Pneumonia Secondary to Daptomycin

Daptomycin is an antimicrobial agent with activity against gram-positive bacteria that is usually reserved for severe infections. Acute eosinophilic pneumonia (AEP) is an increasingly rare side effect that can manifest after its use. Our patient is a 79-year-old male who was admitted for a left total knee arthroplasty infection. After daptomycin was started, he developed AEP. The offending agent was stopped, the appropriate medical treatment was given, and his symptoms significantly improved. This case illustrates an uncommon side effect of daptomycin. Prompt medical recognition is paramount for medication discontinuation and adequate medical care.

Biofilm Formation by Pseudomonas aeruginosa in a Novel Septic Arthritis Model

Background

Bacterial biofilms generally contribute to chronic infections and complicate effective treatment outcomes. To date, there have been no reports describing biofilm formation in animal models of septic arthritis caused by Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa is an opportunistic pathogenic bacterium which can lead to septic arthritis. The purpose of this study was to establish a rabbit model of septic arthritis caused by P. aeruginosa to determine whether it leads to biofilm formation in the knee joint cavity. In addition, we explored the role of cyclic di-GMP (c-di-GMP) concentrations in biofilm formation in rabbit models.

Methods

Twenty rabbits were randomly assigned to five groups: PAO1 (n = 4), PAO1ΔwspF (n = 4), PAO1/p_lac-yhjH (n = 4) infection group, Luria–Bertani (LB) broth (n = 4), and magnesium tetrasilicate (talc) (n = 4) control groups. Inoculation in the rabbit knee of P. aeruginosa or with the same volume of sterile LB or talc in suspension (control group) was used to induce septic arthritis in the animal model. In the infection groups, septic arthritis was caused by PAO1, PAO1ΔwspF, and PAO1/p_lac-yhjH strains, respectively. Rabbits were euthanized after 7 days, and pathological examination of synovial membrane was performed. The biofilms on the surface of the synovial membrane were observed by scanning electron microscopy, while the biofilms’ fiber deposition was discriminated using peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH).

Results

A rabbit model for knee septic arthritis induced by P. aeruginosa was successfully established. Scanning electron microscopy revealed that PAO1 strains were surrounded in a self-produced extracellular matrix on the surface of synovial membrane and showed biofilm structures. The biofilms in the fibrous deposition were also observed by PNA-FISH. The PNA-FISH assay revealed that the red fluorescence size in the PAO1ΔwspF group was greater than in PAO1 and PAO1/p_lac-yhjH groups.

Conclusions

This is the first study to provide evidence that P. aeruginosa forms biofilms in a rabbit model for septic knee arthritis. The rabbit model can be used to investigate new approaches to treatment of biofilms in septic arthritis. Furthermore, c-di-GMP is a key signaling molecule which impacts on biofilm formation in rabbit models of knee septic arthritis.

Non-gonococcal septic arthritis of native joints in Western Australia. A longitudinal population-based study of frequency, risk factors and outcome

OBJECTIVE

To describe the incidence and long-term outcome of non-gonococcal septic arthritis (SA) in Western Australia (WA).

METHODS

Newman criteria were applied to define culture-positive SA and suspected SA cases in the state-wide West Australian Rheumatic Diseases Epidemiological Registry with longitudinally linked health data for patients >16 years with a first diagnostic code of pyogenic arthritis (711.xx [ICD-9-CM] and M00.xx [ICD-10-AM]) between 1990-2010. Annual incidence rates/100 000 (AIR) and standardized (against WA population) mortality rates/1000 person-years (SMR) and outcomes during 10.1 years follow-up are reported.

RESULTS

Among 2633 SA patients (68.6% male, age 47.4 years), 1146 (43.5%) had culture-positive SA. The overall AIR for culture-positive (1.6-6.3) and total SA cases (4.3-12.9) increased between 1990 and 2010 as did age at onset (39.5-54 years) and proportion of females (23-35.6%). Knees (33.6.%) were most frequently affected and 37.1% of cultures showed microorganisms other than Gram-positive cocci. Thirty-day rates for readmission and mortality were 25.4% and 3.2.%. During follow-up rates for serious infections (56.4%), osteoarthrosis (5.2%) and osteomyelitis (2.7%) were higher in culture-positive SA. SMR was increased for all SA patients but especially in those 17-40 years of age with culture-positive SA (24.2; 95% CI 2.3-261).

CONCLUSIONS

The incidence of SA in WA has risen steeply over 20 years. SA now occurs at higher age, affects females more often with over a third of cases caused by Gram-negative microorganisms. Not only culture-positive, but also suspected SA led to increased bone/joint complications, in-hospital and late mortality.

Indications and Future Perspectives of a Minimally Invasive Ultrasound-guided Double-needle Joint Lavage

Arthroscopic joint lavage was proposed as a treatment option for different joint conditions such as septic or inflammatory arthritis. Ultrasound (US) is today considered a fundamental tool in musculoskeletal diseases as for diagnostic and guide for interventional procedures such as synovial fluid sampling and drug injections. To enable faster recovery and to have an alternative to surgery, to reduce risks and costs, we performed an US-guided double-needle lavage of the shoulder joint. Here, we present two different clinical cases, the first with septic arthritis and the second with recalcitrant gouty arthritis, successfully treated with this technique.