Subacute osteomyelitis due to Staphylococcus caprae in a teenager: A case report and review of the literature.

BACKGROUND: Staphylococcus caprae (S. caprae) is a human commensal bacterium which can be detected in the nose, nails, and skin. It can be responsible for heterogeneous infections such as bacteremia, endocarditis, pneumonia, acute otitis externa, peritonitis, and urinary tract infections. Bone and joint infections due to S. caprae have also been reported, but most of them resulted from the infection of orthopedic devices, especially joint prostheses and internal osteosynthesis devices. Rare cases of primary osteoarticular infections caused by S. caprae have been described, including osteitis, arthritis, or spondylodiscitis. CASE SUMMARY: We report an unusual case of subacute osteomyelitis in a toe phalanx caused by S. caprae in a 14.5-year-old girl. CONCLUSION: Subacute S. caprae osteomyelitis is a little-known and probably underestimated community-acquired infectious disease. This microorganism's pathogenicity should be seen as more than a classic nosocomial orthopedic device infection.

Transphyseal Hematogenous Osteomyelitis: An Epidemiological, Bacteriological, and Radiological Retrospective Cohort Analysis.

Transphyseal hematogenous osteomyelitis (THO) is a serious condition that can affect the growing physis, yet it is insufficiently recognized in children. The aim of this study was to explore the prevalence and epidemiology of pediatric THO, and to discuss the underlying pathophysiology. All consecutive cases of acute and subacute osteomyelitis admitted to our institution over 17 years were retrospectively studied. Medical records were examined for patient characteristics, bacteriological etiology, and medical and surgical management. Magnetic resonance imaging was reviewed for all patients to identify those with transphyseal spread of infection. For positive cases, the surface area of the transphyseal lesion was estimated relative to the total physeal cross-sectional area. Fifty-four (25.7%) of the 210 patients admitted for acute or subacute osteomyelitis were diagnosed with THO. The study population's ages ranged from 1 month to 14 years old (median age 5.8 years, interquartile range 1-167 months). Fourteen (25.9%) patients were younger than 18 months old; the remaining 40 (74.1%) had a mean age of 8.5 years old. The most common sites of THO were the distal tibia (29.1%), the proximal tibia (16.4%), and the distal fibula (14.5%). Transphyseal lesions were due to acute infection in 41 cases and to subacute osteomyelitis in 14 cases. The two most frequently identified pathogens were Staphylococcus aureus (49.1%) and Kingella kingae (20.0%). An average transphyseal lesion represented 8.9% of the total physeal surface, and lesions comprised more than 7% of the physeal cross-sectional area in 51% of cases. Our study revealed that pediatric THO was more frequent than commonly thought. Transphyseal lesions were frequently above this 7% cut-off, which is of paramount importance since subsequent growth is more likely to be disturbed when more than 7% of the physeal cross-sectional area is injured. THO also affected children older than 18 months, an age at which transphyseal arterial blood supply to the epiphysis is believed to have disconnected. This finding suggests another pathophysiological reason for the transphyseal diffusion of infection, a topic deserving further studies and greater understanding.

Renal peripelvic lymphangiectasia after bilateral renal vein thrombosis.

Renal peripelvic lymphangiectasia (RPL) is one of the rare conditions that mimic renal cysts. Its physiopathology remains unknown, but an association with renal vein thrombosis has been reported. We share the case of a male patient in his 20s suffering from antiphosphlipid syndrome. The patient was hospitalised for thrombosis of the inferior vena cava (IVC) extending from the iliac veins to the level of renal veins. Consecutive CT and clinical follow-up over the course of 14 years showed the development of numerous retroperitoneal venous collaterals and the apparition of several bilateral peripelvic cystic lesions after extensive thrombosis of the IVC and both renal veins. The renal function remained normal throughout the follow-up. We suggest that the development of RPL is secondary to bilateral renal vein thrombosis. The presumed mechanism would be an increased hydrostatic pressure in the kidney capillaries leading to a more important interstitial fluid drainage by the lymphatic system. To our knowledge, this is the first well-documented case of renal vein thrombosis followed by RPL, contrasting with the previous hypothesis that compression by the lymphangiectasia could cause the thrombosis.

Benefits of diffusion-weighted imaging in pediatric acute osteoarticular infections.

BACKGROUND: Contrast-enhanced magnetic resonance imaging (MRI) is recommended for the diagnosis of acute osteoarticular infections in children. Diffusion-weighted imaging (DWI) may be an alternative to the injection of gadolinium. OBJECTIVE: To evaluate unenhanced MRI with DWI in comparison to contrast-enhanced MRI for the diagnostic work-up of acute osteoarticular infections in children. MATERIALS AND METHODS: This retrospective study included 36 children (age range: 7 months-12 years) with extra-spinal osteoarticular infections and MRI performed within 24 h of admission. MRI protocol included short tau inversion recovery (STIR), water-only T2 Dixon, T1, DWI, and gadolinium-enhanced T1 sequences. Two readers reviewed three sets of images: 1) unenhanced sequences, 2) unenhanced sequences with DWI and 3) unenhanced followed by contrast-enhanced sequences (reference standard). Sensitivity and specificity of sets 1 and 2 were compared to set 3 and assessed to identify osteoarticular infections: osteomyelitis (long bones, metaphyseal equivalents), septic arthritis and abscess (soft tissues, bone). RESULTS: All 14 cases of osteomyelitis in the metaphyses and diaphyses of long bones and all 27 cases of septic arthritis were identified by unenhanced sequences, but 4/16 abscesses were missed. For the diagnosis of abscess, DWI increased sensitivity to 100%. Among the 18 osteomyelitis in metaphyseal equivalents, 4 femoral head chondroepiphyses were identified by contrast-enhanced sequences only. CONCLUSION: MRI for suspected pediatric acute osteoarticular infections is the best diagnostic modality to guide patient management. An unenhanced protocol with DWI may be an alternative to a contrast-based protocol, even in the presence of an abscess. However, gadolinium remains necessary to assess for chondroepiphyseal involvement of the femoral head.

Primary Pyomyositis Caused by Kingella kingae in a 21-Month-old Infant: A Case Report.

The authors report a rare case of an unusual primary pyomyositis of the biceps cruralis assigned to Kingella kingae in a 21-month-old girl. The reported case demonstrated that primary pyomyositis may be encountered during invasive infection due to K. kingae even if this manifestation remains rare. This bacterial etiology must, therefore, be evoked when a primary pyomyositis is observed, and this is in particular in children under 4 years of age.

Early arterial pressure monitoring and term-equivalent age MRI findings in very preterm infants.

INTRODUCTION: Variability of arterial blood pressure (ABP) has been associated with intraventricular hemorrhage in very preterm neonates (VPT) and may predict other brain lesions assessed at term-equivalent of age (TEA). METHODS: This was a prospective single-center study including VPT with early invasive continuous ABP monitoring and assessed at TEA using brain magnetic resonance imaging (TEA-MRI). The association between early mean ABP (MABP) and TEA-MRI findings was modeled by multivariate logistic regression analysis using covariates selected by the LASSO method. RESULTS: Among 99 VPT, the LASSO procedure selected consecutive periods of lowest MABP of 30 min on day 1 (d1) and 10 min on day 2 (d2) as the most relevant durations to predict TEA-MRI findings (OR [95% CI], 1.11 [1.02-1.23], p = 0.03 and 1.13 [1.01-1.27], p = 0.03, respectively). ROC curve analysis showed optimal thresholds at 30.25 mmHg on d1 and 33.25 mmHg on d2. This significant association persisted after adjustment with covariates including birthweight, gestational age, sex, and inotrope exposure. Final models selected by LASSO included the decile of the birthweight and lowest MABP for 30 min on d1 and 10 min on d2, for which the areas under the ROC curve were 74% and 75%, respectively. CONCLUSION: Early continuous ABP monitoring may predict brain TEA-MRI findings in VPT. IMPACT: Early arterial blood pressure monitoring may contribute to predicting brain damage upon MRI at term-equivalent of age for infants born very preterm. Careful blood pressure continuous monitoring in very preterm infants may identify infants at risk of long-term brain damage. Umbilical artery catheterization provides the best option for continuously monitoring arterial blood pressure in very preterm infants.

Distal Patellar Tendon Avulsion Associated with an ACL Tear in a Teenager: A Case Report and Review of the Literature.

Distal patellar tendon avulsions are rare injuries in healthy individuals, and to date, no case affecting skeletally mature teenagers and adolescents has been reported. In the majority of cases, distal patellar tendon avulsions are associated with severe intra-articular knee lesions, signifying a high-energy trauma. We present the case of a 15.5-year-old female who was admitted to the emergency department after a knee injury. The mechanism of injury was a combination of landing after a jump off a scooter and sudden deceleration with a fixed foot. Lateral radiographs revealed a distal patellar tendon avulsion. An MRI was conducted to accurately diagnose concomitant lesions. The MRI revealed a complete tear of the ACL, and associated bone bruises on the lateral femoral condyle, and also on the posterolateral tibial plateau. A knee joint exam under general anesthesia demonstrated good stability during valgus stress testing and only a grade 1 positive Lachman test. Therefore, we decided to only reconstruct the extensor mechanism and to abstain from a primary ACL reconstruction. The presented case and review of the literature demonstrate the clinical relevance of this atypical lesion. In fact, a distal patellar tendon avulsion after physeal fusion of the proximal tibia should raise a strong suspicion of severe associated intra-articular knee lesions and requires prompt MRI investigation. However, controversy still exists regarding the management of these injuries, in particular concerning the question of whether to address both injuries in a single stage or in 2 stages.

Acoustic radiation force impulse imaging: normal values of spleen stiffness in healthy children.

BACKGROUND: Acoustic radiation force impulse (ARFI) imaging is a noninvasive ultrasound elastography technique for evaluating tissue stiffness. The association of liver and spleen stiffness provides additional information in the assessment of portal hypertension. The technique and normal values of spleen stiffness by point shear wave elastography (p-SWE) in pediatrics have not been well documented. OBJECTIVE: Our aim is to describe the feasibility and normal ARFI elastography values in the spleen for healthy children and to compare measurements in two different probe positions (the axial and sagittal planes). MATERIALS AND METHODS: Spleen p-SWE using ARFI values were measured with a 6C1 probe in 102 healthy children (age range: 8 weeks to 17 years) divided into four age groups. An average of nine (standard deviation: two) spleen stiffness measurements were taken during free breathing in each plane (axial and sagittal). The impact of age and measurement plane in the spleen was analyzed using multivariate models. RESULTS: There was no significant difference in spleen stiffness values taken at different ages, with an average of the medians of 2.43±0.31 m/s. There was no significant difference based on probe orientation: sagittal plane (median: 2.46±0.29 m/s) and axial plane (median: 2.43±0.32 m/s) with Student's t-test P=0.18. The mean depth of measurement varied between 2.3 cm and 3.7 cm, according to age. CONCLUSION: Normal spleen stiffness values using ARFI imaging in children do not vary with age and correspond to a median of 2.43 m/s. No significant difference was found when using different probe positions.

Clinical, biological and bacteriological characteristics of osteoarticular infections in infants less than 12 months of age.

Aim: This retrospective study's objective was to evaluate osteoarticular infection in infants less than 12 months of age, with a particular focus on biological features and bacteriological etiology. Material & methods: We retrospectively reviewed the medical records of every infant younger than 12 months old admitted in our institution for a suspected osteoarticular infection between January 1980 and December 2016. Results: Sixty-nine patients records were reviewed, including eight neonates, 16 infants from 1 to 5 months old, and 45 from 6 to 12 months old. Conclusion: Neonates and infants aged from 6 to 12 months old were more exposed to infections. Staphylococcus aureus remained the main pathogen in children <6 months, whereas Kingella kingae has become the most frequently isolated microorganism in infants aged from 6 to 12 months old.

Diffusion-weighted imaging in differentiating mid-course responders to chemotherapy for long-bone osteosarcoma compared to the histologic response: an update.

BACKGROUND: Diffusion-weighted imaging (DWI) has been described to correlate with tumoural necrosis in response to preoperative chemotherapy for osteosarcoma. OBJECTIVE: To assess the accuracy of DWI in evaluating the response to neoadjuvant chemotherapy at the mid-course treatment of long-bone osteosarcoma and in predicting survival. MATERIALS AND METHODS: We conducted a prospective single-centre study over a continuous period of 11 years. Consecutive patients younger than 20 years treated with a neoadjuvant regimen for peripheral conventional osteosarcoma were eligible for inclusion. Magnetic resonance imaging (MRI) with DWI was performed at diagnosis, and mid- and end-course chemotherapy with mean apparent diffusion coefficients (ADC) calculated at each time point. A percentage less than or equal to 10% of the viable residual tissue at the histological analysis of the surgical specimen was defined as a good responder to chemotherapy. Survival comparisons were calculated using the Kaplan-Meier method. Uni- and multivariate analyses with ADC change were performed by Cox modelling. This is an expansion and update of our previous work. RESULTS: Twenty-six patients between the ages of 4.8 and 19.6 years were included, of whom 14 were good responders. At mid-course chemotherapy, good responders had significantly higher mean ADC values (P=0.046) and a higher increase in ADC (P=0.015) than poor responders. The ADC change from diagnosis to mid-course MRI did not appear to be a prognosticator of survival and did not impact survival rates of both groups. CONCLUSION: DWI at mid-course preoperative chemotherapy for osteosarcoma should be considered to evaluate the degree of histological necrosis and to predict survival. The anticipation of a response to neoadjuvant treatment by DWI may have potential implications on preoperative management.

Osteoarticular infection in children.

AIMS: We aimed to describe the epidemiological, biological, and bacteriological characteristics of osteoarticular infections (OAIs) caused by Kingella kingae. METHODS: The medical charts of all children presenting with OAIs to our institution over a 13-year period (January 2007 to December 2019) were reviewed. Among these patients, we extracted those which presented an OAI caused by K. kingae and their epidemiological data, biological results, and bacteriological aetiologies were assessed. RESULTS: K. kingae was the main reported microorganism in our paediatric population, being responsible for 48.7% of OAIs confirmed bacteriologically. K. kingae affects primarily children aged between six months and 48 months. The highest prevalence of OAI caused by K. kingae was between seven months and 24 months old. After the patients were 27 months old, its incidence decreased significantly. The incidence though of infection throughout the year showed no significant differences. Three-quarters of patients with an OAI caused by K. kingae were afebrile at hospital admission, 11% had elevated WBCs, and 61.2% had abnormal CRPs, whereas the ESR was increased in 75%, constituting the most significant predictor of an OAI. On MRI, we noted 53% of arthritis affecting mostly the knee and 31% of osteomyelitis located primarily in the foot. CONCLUSION: K. kingae should be recognized currently as the primary pathogen causing OAI in children younger than 48 months old. Diagnosis of an OAI caused by K. kingae is not always obvious, since this infection may occur with a mild-to-moderate clinical and biological inflammatory response. Extensive use of nucleic acid amplification assays improved the detection of fastidious pathogens and has increased the observed incidence of OAI, especially in children aged between six months and 48 months. We propose the incorporation of polymerase chain reaction assays into modern diagnostic algorithms for OAIs to better identify the bacteriological aetiology of OAIs. Cite this article: Bone Joint J 2021;103-B(3):578-583.

Pelvic MRI for Endometriosis: A Diagnostic Challenge for the Inexperienced Radiologist. How Much Experience Is Enough?

PURPOSE: The purpose of this study was to investigate the impact of radiologist experience on diagnostic performance of pelvic magnetic resonance imaging (MRI) for the evaluation of endometriomas and different localisations of deep pelvic endometriosis (DPE). MATERIALS AND METHODS: In this prospective study all pelvic MRI examinations performed for pelvic endometriosis from December 2016 to August 2017 were evaluated by readers with different experience levels; junior resident (0-6 weeks of experience in female imaging), senior resident (7-24 weeks), fellow (6-24 months), and expert (10 years) in female imaging for the presence of endometriomas and DPE. Their evaluations were compared with surgery confirmed with pathology. Diagnostic performances of readers with different levels of experience were studied by the means of receiving operating characteristic curves and areas under the curve (AUC) were compared with the ones of the expert reader. RESULTS: Of 174 patients evaluated, the standard of reference was available for 59, consisting the final population of the study. The AUC for endometriomas, DPE for the posterior and anterior pelvic compartment, for rectosigmoid DPE and for overall evaluation were 0.983, 0.921, 0.615, 0.862, and 0.914 for the expert reader, 0.966 (p = 0.178), 0.805 (p = 0.001), 0.605 (p = 0.91), 0.872 (p = 0.317), and 0.849 (p = 0.0009) for the fellow level, 0.877 (p = 0.002), 0.757 (p < 0.001), 0.585 (p = 0.761), 0.744 (p = 0.239), and 0.787 (p = < 0.001) for the senior resident level and 0.861 (p = 0.177), 0.649 (p < 0.001), 0.648 (p = 0.774), 0.862 (p = 1), and 0.721 (p < 0.001) for the junior resident level. CONCLUSIONS: According to our results, interpretation of pelvic MRI for DPE should be performed by specialists as; even the performance of radiologists with up to 2 years of experience in female imaging was statistically inferior to that of experts.

Osteoarticular Infections of the Chest Wall Due to Kingella Kingae: A Series of 8 Cases.

Osteoarticular infections of the chest wall are relatively uncommon in pediatric patients and affect primarily infants and toddlers. Clinical presentation is often vague and nonspecific. Laboratory findings may be unremarkable in osteoarticular chest wall infections and not suggestive of an osteoarticular infection. Causative microbes are frequently identified if specific nucleic acid amplification assays are carried out. In the young pediatric population, there is evidence that Kingella kingae is 1 of the main the main causative pathogens of osteoarticular infections of the chest wall.

Radiological findings of complications after lung transplantation.

Complications following lung transplantation may impede allograft function and threaten patient survival. The five main complications after lung transplantation are primary graft dysfunction, post-surgical complications, alloimmune responses, infections, and malignancy. Primary graft dysfunction, a transient ischemic/reperfusion injury, appears as a pulmonary edema in almost every patient during the first three days post-surgery. Post-surgical dysfunction could be depicted on computed tomography (CT), such as bronchial anastomosis dehiscence, bronchial stenosis and bronchomalacia, pulmonary artery stenosis, and size mismatch. Alloimmune responses represent acute rejection or chronic lung allograft dysfunction (CLAD). CLAD has three different forms (bronchiolitis obliterans syndrome, restrictive allograft syndrome, acute fibrinoid organizing pneumonia) that could be differentiated on CT. Infections are different depending on their time of occurrence. The first post-operative month is mostly associated with bacterial and fungal pathogens. From the second to sixth months, viral pneumonias and fungal and parasitic opportunistic infections are more frequent. Different patterns according to the type of infection exist on CT. Malignancy should be depicted and corresponded principally to post-transplantation lymphoproliferative disease (PTLD). In this review, we describe specific CT signs of these five main lung transplantation complications and their time of occurrence to improve diagnosis, follow-up, medical management, and to correlate these findings with pathology results. KEY POINTS: • The five main complications are primary graft dysfunction, surgical, alloimmune, infectious, and malignancy complications. • CT identifies anomalies in the setting of unspecific symptoms of lung transplantation complications. • Knowledge of the specific CT signs can allow a prompt diagnosis. • CT signs maximize the yield of bronchoscopy, transbronchial biopsy, and bronchoalveolar lavage. • Radiopathological correlation helps to understand CT signs after lung transplantation complications.

Ability of a meta-analysis to prevent redundant research: systematic review of studies on pain from propofol injection.

OBJECTIVE: To examine whether, according to the conclusions of a 2000 systematic review with meta-analysis on interventions to prevent pain from propofol injection that provided a research agenda to guide further research on the topic, subsequently published trials were more often optimally blinded, reported on children, and used the most efficacious intervention as comparator; and to check whether the number of new trials published each year had decreased and whether the designs of trials that cited the review differed from those that did not. STUDY DESIGN: Systematic review comparing old trials (published before, and included in, the review) with new trials (published afterwards). DATA SOURCES: Medline, Cochrane, Embase, and bibliographies to January 2013. ELIGIBILITY CRITERIA FOR STUDY SELECTION: Randomised studies testing any intervention to prevent pain from propofol injection in humans. RESULTS: 136 new trials (19,778 patients) were retrieved. Compared with the 56 old trials (6264 patients), the proportion of optimally blinded trials had increased from 10.7% to 38.2% (difference 27.5%, 95% confidence interval 16.0% to 39.0%, P<0.001), and the proportion of trials that used the most efficacious intervention as comparator had increased from 12.5% to 27.9% (difference 15.4%, 4.0% to 26.9%, P=0.022). The proportion of paediatric trials had increased from 5.4% to 12.5%, although this was not significant (difference 7.1%, -1.0% to 15.2%, P=0.141). The number of new trials published each year was significantly higher (median number/year 12 (range 7-20) v 2.5 (0-9), P<0.001) with no obvious decreasing trend. 72.8% (n=99) of the new trials cited the review, with their designs similar to trials not citing the review. Only 36.0% (n=49) of the new trials were considered clinically relevant since they used the most efficacious intervention as comparator or included a paediatric population. CONCLUSIONS: The impact of the systematic review on the design of subsequent research was low. There was an improvement in the reporting of optimal blinding procedures and a tendency towards an increase in the proportion of paediatric trials. The most efficacious intervention was more often chosen as comparator but remained marginally used, and the number of trials published per year had not decreased. The use of systematic reviews should be encouraged to inform rational, and thus ethical, trial design and improve the relevance of new research.