The role of ultrasound in differentiating septic arthritis from transient synovitis of the hip in children

Transient synovitis of the hip: Development and validation of a new diagnostic algorithm

AIM

To develop and validate an algorithm to rapidly distinguish transient synovitis (TS) of the hip from differential diagnoses without additional tests.

METHODS

This retrospective cohort study included all children admitted for non-traumatic limping in the emergency department at Lille University-Hospital between 2016 and 2020. The gold standard was a definitive diagnosis at follow-up visit. All variables associated with acute limping in children were analysed in univariate and multivariable analyses. An algorithm was then developed using recursive partitioning and validated internally on a subset of patients.

RESULTS

There were 995 patients included (mean age 5.3 years; males 63%); 337 had a TS including 210 confirmed at follow-up visit and 354 another diagnosis. After multivariable analysis, the relevant variables for distinguishing between TS and differential diagnoses were: age 3-10 years, absence of fever, absence of local inflammation, sudden onset of limping on awakening. An algorithm combining these variables was developed (n = 297) and validated internally (n = 175) for children >12 months with limping for ≤10 days, with a specificity of 98.2% and a positive likelihood ratio of 19.6. No serious differential diagnoses were missed.

CONCLUSION

Use of this algorithm enables the diagnosis of TS without additional tests and without missing serious differential diagnoses.

An economic evaluation of point-of-care ultrasound for children presenting to the emergency department with suspected septic arthritis of the hip

Objective Diagnosing septic arthritis of the hip in children is time-sensitive, with earlier diagnosis improving outcomes. Point-of-care ultrasound (POCUS) requires specialised training and resources in emergency departments (ED) to potentially lower costs through reducing patient time in ED. We aimed to compare the costs of using POCUS for suspected septic arthritis of the hip to current practice. Methods This study is embedded in a retrospective review of 190 cases of suspected cases of septic hip joint collected over 5 years to investigate patient length of stay and time to perform ultrasound. We multiplied time use by cost per bed hour comparing current practice with POCUS. The POCUS arm included training and equipment costs. Scenario, sensitivity, and threshold analyses were conducted. Costs were calculated in Australian dollars for 2022. Results The current practice arm took 507 min from initial patient assessment to ultrasound examination, compared with 96 min for the POCUS arm. Cost per bed hour was estimated at $207 from hospital data. Total cost savings for POCUS compared to current practice were $35 821 per year assuming 38 cases of suspected arthritis of the hip per year, saving 228 bed hours per year. All scenario and sensitivity analyses were cost saving. Threshold analysis indicated that if the cost of a paediatric ED bed was higher than $51 per hour, POCUS would be cost saving. Conclusion There was significant cost saving potential for hospitals by switching to POCUS for suspected septic arthritis of the hip.

Clinical Practice Guideline by the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA): 2023 Guideline on Diagnosis and Management of Acute Bacterial Arthritis in Pediatrics

This clinical practice guideline for the diagnosis and treatment of acute bacterial arthritis (ABA) in children was developed by a multidisciplinary panel representing the Pediatric Infectious Diseases Society (PIDS) and the Infectious Diseases Society of America (IDSA). This guideline is intended for use by healthcare professionals who care for children with ABA, including specialists in pediatric infectious diseases and orthopedics. The panel's recommendations for the diagnosis and treatment of ABA are based upon evidence derived from topic-specific systematic literature reviews. Summarized below are the recommendations for the diagnosis and treatment of ABA in children. The panel followed a systematic process used in the development of other IDSA and PIDS clinical practice guidelines, which included a standardized methodology for rating the certainty of the evidence and strength of recommendation using the GRADE approach (Grading of Recommendations Assessment, Development and Evaluation) (see Figure 1). A detailed description of background, methods, evidence summary and rationale that support each recommendation, and knowledge gaps can be found online in the full text.

Role of ultrasound and inflammatory factors in the management of pediatric hip joint effusion

BACKGROUND

Septic arthritis is an important differential diagnosis of hip joint pain. Joint aspiration analysis is a necessary diagnostic measure for septic arthritis. In order to reduce the need for joint aspiration, we compared the combination of ultrasound findings and laboratory findings to separate septic arthritis from reactive arthritis.

METHODS

Children aged < 14 years who were referred to Akbar pediatric hospital in 2020-2022 with hip pain or limping were included in this longitudinal study. Participants underwent ultrasound examinations of the hip and blood samples were obtained from them. After confirming an effusion, dependent on patient status and clinical diagnosis, one of the following approaches was recommended; the close follow-up, or the ultrasound-guided aspiration of the hip joint effusion, and or arthrotomy. The various ultrasound and laboratory were documented. Data were analyzed and P < 0.001 being considered statistically significant.

RESULTS

Overall, 115 patients with a mean age of 3.43 ± 5.76 years, 46 of whom were girls, were studied. The final diagnosis in 23 cases (20.0%) was septic arthritis and 92 (80.0%) had reactive arthritis. C-reactive protein (CRP) and The erythrocyte sedimentation rate (ESR) unlike aspirate volume, effusion volume measured on ultrasound, capsule thickness, total thickness, and recorded capsule-to-effusion ratio were significantly higher in patients with septic arthritis (P < 0.001). There was a significant agreement between the volume of measured fluid in the anterior recess and the volume of aspirated fluid (2.5 times, P < 0.001). Septic arthritis was not observed in any of the patients with effusion volume in anterior recess less than 0.5 cc and ESR less than 40 mm/hr or CRP less than 15 mg/L.

CONCLUSION

Since septic arthritis was not observed in any of the patients with effusion volume < 0.5 cc and normal inflammatory factors (ESR or CRP), conservative management and close follow-up can be recommended in these patients instead of joint fluid aspiration.

C-reactive protein of ≥ 20 mg/L and ultrasound finding of an effusion ≥ 7 mm has a high specificity and sensitivity in diagnosing paediatric hip septic arthritis

PURPOSE

Differentiating septic arthritis (SA) from transient synovitis (TS) in children remains a diagnostic challenge. Several algorithms have been developed to diagnose SA including Kocher's criteria and its subsequent modifications, but reports show variable efficacy. This study aims to examine the diagnostic utility of a novel method only using C-reactive protein (CRP) and ultrasound (US) findings of effusion in differentiating SA from TS, determine the optimal values for these predictors and validate this method against existing clinical predictors.

METHODS

A 5-year retrospective study was performed including all paediatric patients with acute, non-traumatic hip pain with a suspicion of SA. All patients were evaluated using Kocher's criteria, Caird's criteria, and the novel method. Multivariate logistic regression was performed to identify independent clinical predictors of SA. The degree of agreement between the various methods were assessed using Cohen's kappa (k). Receiver operating characteristics (ROC) curves were used to examine the diagnostic accuracy of this novel method as well as to determine optimal cut-offs for US effusion and CRP in diagnosing SA.

RESULTS

Hundred and one patients were recruited. CRP and effusion on US were found to be independent predictors of SA. Both Kocher's and Caird's method showed good specificity (98.9%) but extremely poor sensitivity for SA (0%). When Kocher's four clinical predictors were present, probability of SA was only 59.16%. The k for both Kocher's and Caird's methods, was -0.017 indicating poor agreement. However the k in the novel method was 0.641, indicating good agreement.

CONCLUSION

Our study showed that the novel method using CRP (≥ 20 mg/L) and US finding of effusion (≥ 7 mm) has a high specificity (97%) and sensitivity (71%) in diagnosing SA.

[Septic arthritis and transient synovitis of the hip]

CLINICAL/METHODICAL ISSUE

Differentiating between septic arthritis and transient synovitis can be challenging but is very important as a late diagnosis of septic arthritis can lead to sepsis and joint damage. For correct diagnosis and prediction of complications, the right combination of physical examination, laboratory and radiological studies is needed.

STANDARD RADIOLOGICAL METHODS

Hip ultrasound is easy to learn and has a high sensitivity for joint effusion. Faster diagnosis and therapy are possible due to increasing use of ultrasound. Magnetic resonance imaging (MRI) is primarily used to rule out co-infections (osteomyelitis, pyomyositis) and differential diagnoses. X‑ray is typically nonremarkable in septic arthritis.

PRACTICAL RECOMMENDATIONS

Routine use of ultrasound in nontraumatic pediatric hip pain. Generous use of MRI in case of elevated inflammatory markers or inconclusive clinical findings. Using only few sequences may be appropriate to avoid sedation, primarily fluid sensitive sequences (fat-saturated T2, TIRM, STIR), in case of positive findings, accompanied by T1-weighted images.

Acute musculoskeletal infection in children: assessment and management

Musculoskeletal infection in children is challenging to treat, and includes septic arthritis, deep tissue infection, osteomyelitis, discitis and pyomyositis. Delays to diagnosis and management, and under-treatment can be life-threatening and result in chronic disability. The British Orthopaedic Association Standards for Trauma include critical steps in the timely diagnosis and management of acute musculoskeletal infection in children, the principles of acute clinical care and the service delivery requirements to appropriately manage this cohort of patients. Orthopaedic and paediatric services are likely to encounter cases of acute musculoskeletal infection in children and thus an awareness and thorough understanding of the British Orthopaedic Association Standards for Trauma guidelines is essential. This article reviews these guidelines and associated published evidence for the management of children with acute musculoskeletal infection.

Advances in Musculoskeletal Imaging in Juvenile Idiopathic Arthritis

Over the past decade, imaging of inflammatory arthritis in juvenile arthropathies has significantly advanced due to technological improvements in the imaging modalities and elaboration of imaging recommendations and protocols through systematic international collaboration. This review presents the latest developments in ultrasound (US) and magnetic resonance imaging (MRI) of the peripheral and axial joints in juvenile idiopathic arthritis. In the field of US, the ultra-wideband and ultra-high-frequency transducers provide outstanding spatial resolution. The more sensitive Doppler options further improve the assessment and quantification of the vascularization of inflamed tissues, and shear wave elastography enables the diagnosis of tissue stiffness. Concerning MRI, substantial progress has been achieved due to technological improvements in combination with the development of semiquantitative scoring systems for the assessment of inflammation and the introduction of new definitions addressing the pediatric population. New solutions, such as superb microflow imaging, shear wave elastography, volume-interpolated breath-hold examination, and MRI-based synthetic computed tomography open new diagnostic possibilities and, at the same time, pose new challenges in terms of clinical applications and the interpretation of findings.

Transient synovitis of the hip: Current practice and risk of misdiagnosis

INTRODUCTION

Transient synovitis (TS) is a common and benign cause of hip pain in children, but must be distinguished from more serious entities such as septic arthritis, osteomyelitis, and pyomyositis. Our objectives were to determine the risk of missed bacterial musculoskeletal infection and rates of diagnostic testing in children diagnosed with TS.

METHODS

We performed a cohort study using the Pediatric Heath Information System of children 1-10 years diagnosed with TS in the ED. We determined rates of missed bacterial musculoskeletal infection (defined as a new diagnosis of septic arthritis, osteomyelitis, or pyomyositis within 14 days of initial ED visit). We described the initial diagnostic evaluation and ED management of children diagnosed with TS and variability between sites.

RESULTS

We analyzed 6419 encounters from 37 hospitals. 62 (1.0%, 95%CI: 0.7-1.2%) children were diagnosed with a missed bacterial musculoskeletal infection. Children with missed infection were younger than those without (median age 2.6 vs. 4.6 years, p < 0.01). Serum laboratory testing was performed in 76% of encounters with minimal variation across sites. There was significant variation in the rates of hip ultrasound by site (2 to 92%), which has increased in use over time (from 42% in 2016 to 62% in 2021).

CONCLUSION

In this large observational study, missed bacterial musculoskeletal infection in children diagnosed with TS was rare but more common in younger children. The optimal combination of bloodwork and radiographic testing, especially ultrasound, to distinguish TS from more serious disease remains unclear.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Point-of-Care Ultrasound-Guided Drainage of Joint Effusions in the Pediatric Emergency Setting: A Case Series

Literature supporting the use of point-of-care ultrasound (POCUS) for both identification and aspiration of effusions in large joints in the pediatric emergency department (PED) is sparse. We collected a case series of five patients who presented to the PED from August 2020 to December 2020 with an effusion in the hip, shoulder, knee, or elbow identified and aspirated under POCUS performed by pediatric emergency medicine (PEM) physicians. POCUS confirms effusion location and size and visualization of a completely evacuated effusion. POCUS can also guide the decision to start antibiotics earlier in the course of illness, can prevent unnecessary transfers for formal sonographic imaging or for potentially unnecessary radiographic imaging. This series supports the role of a PEM physician and POCUS guidance in the identification and aspiration of large-joint effusions.

Usefulness of MRI findings in differentiating between septic arthritis and transient synovitis of hip joint in children: A systematic review and meta-analysis

Purpose

Septic arthritis (SA) of the hip joint is a serious infection which can lead to more irreversible complications. Differentiating Septic arthritis from Transient synovitis (which is the most common cause of painful hip in children) is difficult and very important to prevent serious complications which can occur with Septic arthritis. The aim of this study was to find out the MRI findings which can differentiate between these two conditions.

Methods

Systematic literature search was conducted according to the PRISMA guidelines on MEDLINE(PubMed), Google Scholar, ScienceDirect, and world Health Organization Virtual Health Library, up to April 2022. Studies that compared MRI findings between Septic Arthritis and Transient Synovitis of hip joint in children were included. The pooled sensitivity and specificity estimates of these findings were calculated using MetaDTA version 2.0.

Results

Six studies were included in qualitative analysis and five were included in quantitative analysis. Pooled sensitivity and specificity of synovial enhancement were 94.2 % (95 % CI, 45.2–99.7 %) and 60.6 % (95% CI, 6–97.4 %) respectively. Soft tissue changes had pooled sensitivity and specificity of 75 % (95% CI, 57.5–86.9 %) and 69.9 % (95 % CI, 46.5–86.2 %) respectively. Pooled sensitivity and specificity of femoral head changes were 41.5 % (95 % CI, 15.9–72.7 %) and 87.3 % (95 % CI, 75.5–93.8 %) respectively. Bone marrow changes had pooled sensitivity and specificity of 70 % (95 % CI, 26.8–93.7 %) and 99.9 % (95 % CI, 28.7–100 %) respectively.

Conclusion

MRI findings especially bone marrow changes were found to be useful in differentiating septic arthritis from transient synovitis among children presented with painful hip after exclusion of other causes.

False-negative joint aspiration of septic arthritis of the hip in neonates

In neonates, timely detection of septic arthritis of the hip can be challenging. Joint aspiration can be a useful diagnostic procedure, but scanty fluid in a septic joint has been reported, leading false-negative results. This study aimed to investigate clinical course of neonates with septic arthritis of the hip despite initial negative findings on joint aspiration. The neonates who surgically treated for septic arthritis of the hip between 2003 and 2013 for septic arthritis of the hip despite initial negative joint aspiration were retrospectively reviewed. Clinical presentations, MRI, intraoperative findings, functional and radiographic outcomes were evaluated. Six neonates were included with a mean follow-up of 12 years (range 5-15 years). All patients showed negative results on joint aspirations performed with ultrasound guidance or fluoroscopy. The mean duration between the onset of symptoms and initial surgery was 15.2 days (range 4-25 days). Four patients (67%) had extracapsular abscesses that were connected to perforated joint capsules on MRI. Intraoperatively, all patients were found to have hip joint instability with a ruptured capsule. Five (83%) patients experienced a complicated recovery. Four patients required reconstructive hip surgery, or further procedures to correct leg length discrepancy. Neonates with false-negative aspiration typically had a delay in appropriate surgical treatment. These cases suggest that the absence of aspirable fluid contents in the hip joint does not rule out septic arthritis in neonates. Our findings highlight the importance of considering spontaneous hip joint capsular perforation as the cause of extra-articular drainage of pus and instability.

Transient synovitis of the hip : is systematic radiological screening necessary for the detection of Perthes disease?

Current imaging guidelines in Belgium advise a systematic X-ray screening of the hips after an episode of transient synovitis of the hip, in order to detect Perthes disease. The aim of this study was to analyze whether systematic radiological screening is necessary for all children or whether the X-ray indication could be guided by clinical symptoms. A retrospective single center study including all children with the diagnosis of transient synovitis of the hip between 2013 and 2018 was performed. 242 patients with the diagnosis of one or more transient synovitis episodes were included, 102 of whom underwent a follow up X-ray. Persistence or recurrence of symptoms were recorded for all patients, as well as the results of follow-up hip X-rays. 12 children did not remain symptom-free after the episode of transient synovitis. Of these patients 10 had a normal follow-up X-ray and 3 were diagnosed with Perthes disease. 1 patient of those 3 had a normal X-ray but was diagnosed with Perthes disease on MRI. Of the children which remained symptom-free after the episode of transient synovitis, none were diagnosed with Perthes disease afterwards. A follow-up X-ray to exclude Perthes disease after a diagnosis of transient hip synovitis appears to be necessary only in patients with persistent or recurrent symptomatology.

Current Concepts in Pediatric Septic Arthritis

Septic arthritis continues to present challenges regarding the clinical diagnosis, workup, and definitive management. Urgent management is essential, so treating surgeons must efficiently work through differential diagnoses, identify concomitant infections, and do a timely irrigation and débridement. The incidence of methicillin-resistant Staphylococcus aureus is increasing, typically resulting in a more rapid progression of symptoms with more severe clinical presentation. The diagnostic utility of MRI has resulted in improved detection of concomitant septic arthritis and osteomyelitis, although MRI must not substantially delay definitive management. Early diagnosis followed by urgent irrigation and débridement and antibiotic therapy are essential for satisfactory long-term outcomes. Antibiotics should not be administered until blood cultures and arthrocentesis fluid are obtained, except in rare cases of a septic or toxic patient. Once cultures are obtained, empiric antibiotic therapy should commence and provide coverage for the most likely pathogens, given the patient's age. Laboratory markers, especially C-reactive protein, should be followed until normalization and correlate with resolution of clinical symptoms. Definitive antibiotic selection should be shared with a pediatric infectious disease specialist, who can help guide the duration of treatment.

Evaluation of Hip Pain and Management of Toxic Synovitis in the Ultrasound Era

ABSTRACT

The cause of acute onset hip pain in children can be difficult to determine. Once trauma is excluded, the workup revolves around determining whether there is a hip effusion and eliminating orthopedic emergencies. Point-of-care-ultrasound can be used as an adjunct in the workup. In this article, we review (1) differential diagnosis of hip pain, with a focus on toxic synovitis; (2) the evaluation of a hip for the presence of effusion, including the point-of-care ultrasound technique; and (3) the management of toxic synovitis.

Test characteristics of history, examination and investigations in the evaluation for septic arthritis in the child presenting with acute non-traumatic limp. A systematic review

BACKGROUND

Septic arthritis is an uncommon but potentially significant diagnosis to be considered when a child presents to the emergency department (ED) with non-traumatic limp. Our objective was to determine the diagnostic accuracy of clinical findings (history and examination) and investigation results (pathology tests and imaging) for the diagnosis of septic arthritis among children presenting with acute non-traumatic limp to the ED.

METHODS

Systematic review of the literature published between 1966 and June 2019 on MEDLINE and EMBASE databases. Studies were included if they evaluated children presenting with lower limb complaints and evaluated diagnostic performance of items from history, physical examination, laboratory testing or radiological examination. Data were independently extracted by two authors, and quality assessment was performed using the Quality Assessment Tool for Diagnostic Accuracy Studies 2 tool.

RESULTS

18 studies were identified, and included 2672 children (560 with a final diagnosis of septic arthritis). There was substantial heterogeneity in inclusion criteria, study setting, definitions of specific variables and the gold standard used to confirm septic arthritis. Clinical and investigation findings were reported using varying definitions and cut-offs, and applied to differing study populations. Spectrum bias and poor-to-moderate study design quality limit their applicability to the ED setting.Single studies suggest that the presence of joint tenderness (n=189; positive likelihood ratio 11.4 (95% CI 5.9 to 22.0); negative likelihood ratio 0.2 (95% CI 0.0 to 1.2)) and joint effusion on ultrasound (n=127; positive likelihood ratio 8.4 (95% CI 4.1 to 17.1); negative likelihood ratio 0.2 (95% CI 0.1 to 0.3)) appear to be useful. Two promising clinical risk prediction tools were identified, however, their performance was notably lower when tested in external validation studies.

DISCUSSION

Differentiating children with septic arthritis from non-emergent disorders of non-traumatic limp remains a key diagnostic challenge for emergency physicians. There is a need for prospectively derived and validated ED-based clinical risk prediction tools.

Radiologic Evaluation of the Child with a Limp

A child presenting with a limp can present a diagnostic challenge to pediatricians. Clinical presentation, age, and history all contribute to the initial differential diagnosis; however, imaging plays a key role in the ultimate diagnosis, and the correct imaging study is essential to save time and health care expenses. This article will present a few of the more common causes of a limp and the recently updated imaging recommendations from the American College of Radiology to aid in final diagnosis. [Pediatr Ann. 2020;49(9):e395-e402.].

Ultrasound Evaluation of Pediatric Orthopaedic Patients

Ultrasonography is a valuable tool that can be used in many capacities to evaluate and treat pediatric orthopaedic patient. It has the capability to depict bone, cartilaginous and soft-tissue structures, and provide dynamic information. This technique can be readily applied to a wide range of pediatric conditions, including developmental dysplasia of the hip, congenital limb deficiencies, fracture management, joint effusions, and many other musculoskeletal pathologies. There are many benefits of implementing ultrasonography as a regular tool. It is readily accessible at most centers, and information can be quickly obtained in a minimally invasive way, which limits the need for radiation exposure. Ultrasonography is a safe and reliable tool that pediatric orthopaedic surgeons can incorporate into the diagnosis and management of a broad spectrum of pathology.

Point-of-care hip ultrasound leads to expedited results in emergency department patients with suspected septic arthritis

BACKGROUND

The evaluation of septic hip arthritis often incorporates the utilization of hip ultrasonography to determine the presence of a hip joint effusion, as well as to guide arthrocentesis. Point-of-care (POC) hip ultrasound has previously been demonstrated to be accurate when performed by the emergency physician. Time to diagnosis and subsequent intervention in septic arthritis (SA) is critical to favorable outcomes.

METHODS

Retrospective single-center study of all emergency department (ED) patients who had a POC or radiology hip ultrasound or arthrocentesis as part of their ED evaluation for SA in a 3-year period. We investigated the difference in time to obtain hip ultrasonography results and the time to arthrocentesis between radiology and emergency physician-performed studies in cases of suspected septic hip arthritis.

RESULTS

Seventy-four patients met inclusion criteria. The median time to hip ultrasound completion was 68 (interquartile range [IQR], 38.8-132) minutes in the emergency physician-performed ultrasound group versus 208.5 (IQR, 163.8-301.3) minutes for the radiology group (P < 0.001). A total of 17 patients had a hip arthrocentesis performed. Time to arthrocentesis was 211 (IQR 141.3-321.5) minutes in the emergency physician-performed arthrocentesis group and 602 (IQR 500-692) minutes in the radiology arthrocentesis (P < 0.001).

CONCLUSION

There was a statistically shorter time to ultrasound result and arthrocentesis when POC hip ultrasound was utilized by the emergency physician. Given that unfavorable outcomes in SA are associated with delay in treatment, further study is warranted to determine if emergency physician-performed hip ultrasound and arthrocentesis could lead to improved patient-centered clinical end points.

Differential MRI findings of transient synovitis of the hip in children when septic arthritis is suspected according to symptom duration

We investigated the differential MRI findings in children with transient synovitis of the hip in whom septic arthritis was suspected. Under the hypothesis that disease progression can alter representative MRI findings, we stratified these findings in accordance with symptom duration as this can correlate with disease progression. We analyzed 65 children who underwent MRI for acute hip pain and who were suspected of having a septic condition (i.e. presented with fever or increased inflammatory markers) when the imaging was performed. Symptom duration was defined as the interval from the first presentation of hip pain to the MRI scan. We divided the patients into two subgroups according to symptom duration: patients with short symptom duration (≤2 days, short-term subgroup, n = 30) and those with long symptom duration (≥3 days, long-term subgroup, n = 35). Twenty-eight (43.1%) of the study subjects were diagnosed with septic arthritis. Whereas only a high-grade joint effusion was a significant MRI finding differentiating septic arthritis from transient synovitis in the whole cohort, the presence of contralateral joint effusion in the short-term subgroup (P = 0.024) and the absence of a change/enhancement of the signal intensity of soft tissue in the long-term subgroup (P < 0.001) were significant predictors of transient synovitis. The significances of differential MRI findings for septic arthritis and transient synovitis seem to change according to symptom duration. We suggest that symptom duration, which may correlate with disease progression, should also be considered when interpreting MRIs of children under suspicion of septic arthritis.

General Pediatric Clinical Applications of POCUS: Part 2

The use of point-of-care ultrasound (POCUS) performed by non-radiologists has become more widespread and is entering new arenas of clinical care, particularly in the world of pediatrics. Children are prime candidates for ultrasound because they are more at risk to the harmful effects of ionizing radiation than adults. This is the second part of a two-part article reviewing 10 uses of POCUS that pediatricians can apply to their practice in both inpatient and outpatient settings. [Pediatr Ann. 2020;49(4):e196-e200.].

Septic Arthritis of the Hip in Children: A Critical Analysis Review

Septic arthritis of the hip is a common and potentially devastating condition in children. Septic arthritis is most commonly caused by Staphylococcus aureus, but other pathogens should be considered on the basis of patient age and presence of risk factors. Diagnosis of septic arthritis is based on history and physical examination, laboratory tests, radiographs, ultrasound, and arthrocentesis. Treatment comprises empiric antibiotics and joint debridement, and antibiotics are subsequently tailored on the basis of culture data, local resistance patterns, and clinical response. Late sequelae of septic arthritis include osteonecrosis, chondrolysis, growth disturbance, subluxation or dislocation, and progressive ankylosis. Surgical treatments to address these issues have been described.

Ultrasonography as a Diagnostic, Therapeutic, and Research Tool in Orthopaedic Surgery

Ultrasonography is an imaging modality that facilitates the diagnosis of pathology and injection therapy without exposing the patient to radiation. In addition, ultrasonography has become popular because of its portability, low cost, and production of real-time tomographic images that provide a cross-sectional view of anatomic structures. Despite its benefits and widespread adoption in general medicine and other specialties, however, ultrasonography is not as well adapted as a diagnostic and research tool in orthopaedic surgery. An understanding of the basic principles of ultrasonography and the evidence supporting its use can aid the orthopaedic surgeon in applying this modality appropriately in clinical practice.

Definitive Diagnosis of Children Presenting to A Pediatric Emergency Department With Fever and Extremity Pain

BACKGROUND

Children who present to the emergency department (ED) with complaint of fever and new-onset joint or extremity pain can be a diagnostic dilemma for many emergency and consulting physicians.

OBJECTIVES

The purpose of our study was to identify the etiologies of pediatric fever and extremity pain presenting to a tertiary care pediatric ED and to define factors that were associated with advanced imaging, admission, and surgical intervention.

METHODS

The electronic medical records of children presenting to our institution's pediatric ED with fever and extremity pain were retrospectively reviewed. Data collected included demographic characteristics, laboratory studies, diagnostic imaging, need for admission, and surgical procedures.

RESULTS

The initial ED diagnosis was consistent with the definitive diagnosis 42% of the time. Children with the inability to bear weight on the affected limb were more likely to have a bacterial infection, such as osteomyelitis, septic arthritis, or intramuscular abscess (p = 0.016). An erythrocyte sedimentation rate >36 mm/hour and C-reactive protein levels >60 mg/L were found in children with osteomyelitis or septic arthritis (p = 0.043 and <0.001, respectively). Magnetic resonance imaging was ordered in 63% of children with multiple visits compared to 34% of children with a single visit (p = 0.05).

CONCLUSIONS

In addition to a thorough history and physical examination, a complete set of laboratory studies and diagnostic imaging is necessary to reach an accurate diagnosis. The inability to bear weight, elevated C-reactive protein levels, and an elevated erythrocyte sedimentation rate are associated with bacterial infection. Magnetic resonance imaging is a useful imaging modality in determining an accurate diagnosis.

Paediatric bone and joint infection

Despite advances in understanding and management, paediatric osteoarticular infections continue to pose diagnostic difficulties for clinicians. Delays in diagnosis can lead to potentially devastating morbidity.No single investigation, including joint aspiration, is sufficiently reliable to diagnose conclusively paediatric bone and joint infection. Diagnosis should be based on a combination of clinical signs, imaging and laboratory investigations. Algorithms should supplement, and not replace, clinical decision making in all cases.The roles of aspiration, arthrotomy and arthroscopy in the treatment of septic arthritis are not clearly defined. There is a very limited role for surgery in the management of acute haematogenous osteomyelitis.The ideal duration and mode of administration of antibiotic therapy for osteoarticular paediatric infection is not yet fully defined but there is increasing evidence that shorter courses (three weeks) and early conversion (day four) to oral administration is safe and effective in appropriate cases. Clear and concise antibiotic guidelines should be available based on local population characteristics, pathogens and their sensitivities.Kingella kingae is increasingly identified through polymerase chain reaction and is now recognised as the commonest pathogen in children aged under four years. Methicillin-resistant Staphylococcus aureus and Panton-Valentine leukocidin-producing strains of Staph. aureus are being increasingly reported.A multidisciplinary integrated evidence-based approach is required to optimise outcomes.Further large-scale, multicentre studies are needed to delineate the optimal management of paediatric osteoarticular infection. Cite this article: EFORT Open Rev 2017;1:7-12. DOI: 10.1302/2058-5241.2.160027.

Septic arthritis in children in resource limited and non-resource limited countries: an update on diagnosis and treatment

INTRODUCTION

Septic arthritis (SA) is an orthopedic emergency in childhood. It is uncommon in high resource settings. However, an incidence of 5-20 per 100,000 children has been reported in low-income countries. Area covered: The predictive value of serum markers is still under debate and the proposed diagnostic algorithms for SA are not sufficiently validated in children. Recent data suggest that short-course intravenous treatment, followed by oral therapy, is as effective as traditional long-term treatment. Results from three randomized controlled trials suggest that the addition of systemic steroids may accelerate clinical improvement. Minimally invasive surgical techniques have been proposed for treatment in recent years. Expert commentary: The causes and the epidemiology of septic arthritis will continue to mutate according to the changes in immunization practices, bacterial resistance patterns and the implementation of PCR techniques. Future research should focus on the assessment of appropriate antibiotic regimens and surgical procedures.

Emergency Department Point-of-Care Hip Ultrasound and Its Role in the Diagnosis of Septic Hip Arthritis: A Case Report

We present a case of an 11-year-old girl with eye swelling and hip pain and the use of point-of-care hip ultrasound (US) to facilitate diagnosis of a septic hip. We review the US technique, sonographic findings, and relevant literature regarding point-of-care hip US.

A guideline for differential diagnosis between septic arthritis and transient synovitis in the ED: a Delphi survey

OBJECTIVE

Among the causes of limping gait in children, septic arthritis (SA) and transient synovitis (TS) are the 2 most likely etiologies. The aim of this study was to determine the medical histories, physical examinations, and other studies to use to create a clinical guideline for differential diagnosis between SA and TS in children in the emergency department (ED). The pediatric orthopedic emergency committee of our institution addressed the issue of developing a guideline for differential diagnosis.

METHODS

Two rounds of the modified Delphi survey were conducted, and a face-to-face committee meeting was held after each survey round. Delphi survey panelists included 10 pediatric orthopedic surgeons and 8 emergency physicians including 3 pediatric emergency physicians.

RESULTS

Response rates were 100% in each round. The panelists used a 6-point Likert scale to rate the clinical diagnostic guideline contents as having high (5 or 6), moderate (3 or 4), or low importance (1 or 2). Twenty-eight questionnaire items were included in the first round; and 18 items, in the second round. Factors for concern were selected, and a flowchart of the diagnostic guideline development process was based on the results of the survey.

CONCLUSION

A diagnostic guideline for evaluating SA and TS in children in the ED was achieved using combined empirical evidence together with expert opinion, potentially resulting in a diagnostic strategy to be incorporated into existing guidelines or used on its own.

Imaging of Hip Pain: From Radiography to Cross-Sectional Imaging Techniques

Hip pain can have multiple causes, including intra-articular, juxta-articular, and referred pain, mainly from spine or sacroiliac joints. In this review, we discuss the causes of intra-articular hip pain from childhood to adulthood and the role of the appropriate imaging techniques according to clinical suspicion and age of the patient. Stress is put on the findings of radiographs, currently considered the first imaging technique, not only in older people with degenerative disease but also in young people without osteoarthritis. In this case plain radiography allows categorization of the hip as normal or dysplastic or with impingement signs, pincer, cam, or a combination of both.

Surgical treatment options for septic arthritis of the hip in children

Septic arthritis is the result of bacterial infection of the hip joint and is often found in infants and toddlers. It is the most common septic joint condition during growth and may cause the most devastating complications without prompt and proper treatment. Early diagnosis and intervention are required to avoid irreversible complications. This review documents the systematic approach to diagnosis and management of septic arthritis in children.

Diagnostic Approach to Limp in Children

"Limp" is a common complaint of children presenting to the emergency department or physician's office. For most patients presenting with limp, the diagnosis and management can be completed in the physician's office or emergency department by gathering a detailed history, performing a careful physical examination, and requesting a few laboratory and imaging studies. This article reviews common causes of atraumatic limp in children and discusses the evaluation and management of these conditions.

Septic Arthritis in Infants Younger Than 3 Months: A Retrospective Review

Septic arthritis in infants is rare and can be difficult to diagnose. This study reviewed a series of patients younger than 3 months to identify factors that may assist in early diagnosis and treatment. A query of records at a large Midwestern pediatric hospital (1994-2010) was performed to identify all patients younger than 3 months at the time of diagnosis. Analysis included birth history, joint involvement, physical examination findings, laboratory results, imaging results, method of treatment, and outcome. In 14 cases (11 boys, 3 girls; mean age at diagnosis, 42.2 days), complete records were available for review. Involved joints included the knee, hip, and shoulder. The most common findings on physical examination were decreased range of motion (100%), tenderness (100%), and swelling (71.4%). Mean temperature was 38.5°C. Mean white blood cell count was 18.5 K/µL, mean erythrocyte sedimentation rate was 48.9 mm/h, and mean C-reactive protein level was 6.1 mg/dL. More than half (57.1%) of joint aspirates grew positive cultures, and 41.7% of blood cultures had positive results. Causative organisms were group B streptococcus, methicillin-sensitive Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae, Salmonella enterica, and Candida albicans. The most common physical examination findings in infants younger than 3 months with septic arthritis include tenderness, decreased range of motion, and swelling. White blood cell count, C-reactive protein level, and erythrocyte sedimentation rate are likely to be elevated, but these findings should be used in combination with findings on physical examination and radiographic studies to aid in diagnosis.

Emergency department evaluation and treatment of pediatric orthopedic injuries

Orthopedic injuries in children are unique when compared to those of adults because of the physiologic differences, especially the growth plates, stronger periosteum, and dynamic state of growth. The approach to the orthopedically injured child requires a gentle yet thorough focus with consideration of the growth plates as a primary area of weakness and growth when the child sustains an injury. Understanding the developmental stages of bones is paramount to being able to manage any injuries. Finally, what appears to be a benign injury may portend more serious issues, because nonaccidental trauma must always be considered in the evaluation of the injured child.

The use of ultrasound in the management of septic arthritis of the hip

In the assessment of septic arthritis of the hip in a pediatric population, ultrasound is a safe and easily conducted method to confirm an effusion. The need for MRI to further evaluate the patient for adjacent infection before treatment is debatable. Once an effusion is confirmed on ultrasonography, we have found that septic arthritis of the hip does not need advanced imaging before arthrotomy and debridement. Patients who fail to clinically respond to an initial hip arthrotomy and appropriate antibiotics may benefit from an MRI for the identification of concomitant infections that may require surgical intervention.

Transient synovitis, septic hip, and Legg-Calvé-Perthes disease: an approach to the correct diagnosis

Transient synovitis, septic hip, and Legg-Calvé-Perthes disease are common conditions in children. Distinguishing between these disorders can be a diagnostic challenge. Similar presentations, in an age group difficult to examine, coupled with literature that is confusing creates difficulty. It is important to make the correct diagnosis of septic hip in a timely fashion to avoid serious and potentially crippling consequences. As there is no single test for discriminating between these conditions, knowledge of the nuances of clinical presentation, physical examination, laboratory investigations, and imaging is essential. Judicious use of clinical algorithms can complement clinical acumen.

Ultrasonographic findings in 38 horses with septic arthritis/tenosynovitis

Septic arthritis/tenosynovitis in the horse can have life-threatening consequences. The purpose of this cross-sectional retrospective study was to describe ultrasound characteristics of septic arthritis/tenosynovitis in a group of horses. Diagnosis of septic arthritis/tenosynovitis was based on historical and clinical findings as well as the results of the synovial fluid analysis and/or positive synovial culture. Ultrasonographic findings recorded were degree of joint/sheath effusion, degree of synovial membrane thickening, echogenicity of the synovial fluid, and presence of hyperechogenic spots and fibrinous loculations. Ultrasonographic findings were tested for dependence on the cause of sepsis, time between admission and beginning of clinical signs, and the white blood cell counts in the synovial fluid. Thirty-eight horses with confirmed septic arthritis/tenosynovitis of 43 joints/sheaths were included. Degree of effusion was marked in 81.4% of cases, mild in 16.3%, and absent in 2.3%. Synovial thickening was mild in 30.9% of cases and moderate/severe in 69.1%. Synovial fluid was anechogenic in 45.2% of cases and echogenic in 54.8%. Hyperechogenic spots were identified in 32.5% of structures and fibrinous loculations in 64.3%. Relationships between the degree of synovial effusion, degree of the synovial thickening, presence of fibrinous loculations, and the time between admission and beginning of clinical signs were identified, as well as between the presence of fibrinous loculations and the cause of sepsis (P ≤ 0.05). Findings indicated that ultrasonographic findings of septic arthritis/tenosynovitis may vary in horses, and may be influenced by time between admission and beginning of clinical signs.

Transient synovitis of the hip: a comprehensive review

Transient synovitis is a benign, self-limiting condition that is diagnosed after the exclusion of more serious causes of acute hip pain in children. Although its etiology remains unclear, it is largely believed to be viral in nature. Transient synovitis typically presents as an acute onset of thigh pain with a limp or an unwillingness to bear weight. It can be distinguished from similar conditions by the absence of fever, as well as unremarkable bloodwork (WBC, CRP, ESR), radiographs, and hip aspiration. Conservative treatment and observation are the mainstay of management. Resolution of symptoms generally occurs by 1 week and may be accelerated by NSAIDs. Although numerous papers have emerged over the years with an effort to advance our understanding, many questions remain about its pathomechanics, etiology, and how to exclude other more serious conditions that present similarly.

Septic arthritis of the neonatal hip: acute management and late reconstruction

Septic arthritis of the hip in neonates is rare but can have devastating consequences. Presenting signs and symptoms may differ from those encountered in older children, which may result in diagnostic challenge or delay. Many risk factors predispose neonates to septic arthritis, including the presence of transphyseal vessels and invasive procedures. Bacterial infection of the joint occurs via hematogenous invasion, extension from an adjacent site, or direct inoculation. A strong correlation exists between younger age at presentation and severity of residual hip deformity. Diagnosis is based on clinical examination, laboratory markers, and ultrasound evaluation. Early management includes parenteral antibiotics and surgical drainage. Late-stage management options include femoral and pelvic osteotomies, trochanteric arthroplasty, arthrodesis, pelvic support procedures, and nonsurgical measures. Early diagnosis and management continues to be the most important prognostic factor for a favorable outcome in the neonate with septic arthritis.

Neonatal hip septic arthritis: ultrasound should not influence decision to aspirate

An 18-week-old boy presented to the emergency department with 24-h history of fever and irritability with a painful left hip held in flexion. Blood tests showed an elevated ESR of 65 mm/h, but white cell count and C-reactive protein were in the reference range. Admission hip ultrasound identified a small effusion (<2 mm at the recess), not large enough to determine turbidity. Joint aspiration under general anaesthesia yielded frank pus and mandated open arthrotomy. Physicians must maintain a high index of suspicion of hip septic arthritis irrespective of ultrasound findings and have a low threshold for joint aspiration. Aspiration ‘to dryness’ would have left substantial pus within the joint and is consistent with advocating arthrotomy and washout in this age group, when the diagnosis of septic arthritis has been made.

Hip pain in the paediatric age group - transient synovitis versus septic arthritis

Hip pain, in the paediatric population, is a common complaint and a cause for admission. There are several diagnoses one has to keep in mind, when making the differential diagnosis, as the treatment for each can be quite different. Often, the radiographs obtained for these patients turn up normal. Hence one has to rely on clinical findings, laboratory parameters, and possibly an ultrasound investigation in order to clinch the diagnosis and initiate the appropriate treatment.

KEY WORDS

Paediatric, hip, pain, normal radiographs.

Musculoskeletal ultrasonography of the lower extremities in infants and children

Ultrasonography is a powerful diagnostic imaging tool for evaluating lower extremity anatomy and pathology in children. Indications for pediatric musculoskeletal lower extremity sonography include developmental dysplasia of the hip, hip joint sonography for the child with a painful hip, evaluation and characterization of superficial soft-tissue masses, evaluation for deep venous thrombosis, and foreign body localization, characterization and removal. This review highlights these established indications, but primarily focuses on additional US applications for evaluation of the lower extremities, including diagnosis and characterization of arthritis and monitoring of therapy, evaluation of tendon tears and muscle strain injuries, characterization of soft-tissue masses and evaluation of certain congenital abnormalities of the lower extremities. Techniques for optimal utilization of musculoskeletal US in children are also discussed.

Ultrasound-guided hip arthrocentesis in a child with hip pain and Fever

Children presenting to the emergency department with hip pain and fever are at risk for significant morbidity due to septic arthritis. Distinguishing between septic arthritis and other causes of hip pain may be challenging. Sonographic visualization of the hip with real-time ultrasound-guided arthrocentesis may allow faster differentiation between etiologies, hastening definitive therapy and improving analgesia. This report describes the use of hip sonography in a case of Lyme arthritis. The authors review the medical literature in support of bedside hip sonography and discuss how to perform ultrasound-guided hip arthrocentesis. Clinical findings in septic and Lyme arthritis are also described.