Transient synovitis as a cause of painful limps 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.

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.

Acute Arthritis in Children: How to Discern between Septic and Non-Septic Arthritis?

The term septic arthritis refers to an infection of the synovial space. This is an infrequent condition in healthy children, but it should be considered a medical emergency potentially leading to irreversible articular damage. Therefore, prompt diagnosis and antimicrobial treatment play a crucial role in improving the prognosis. Although septic arthritis is the most common cause of acute arthritis, many other diseases may mimic a similar clinical picture, constituting a diagnostic challenge for the clinician who first approaches the patient. Herein we analyze the main features of septic arthritis, offering an overview of the main conditions involved in the differential diagnosis and suggesting a diagnostic workup plan.

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.

Epidemiology of Irritable Hip in Western Scotland: A Follow-Up Study

Background

A ‘limping child’ commonly presents to the emergency department (ED). In the absence of trauma, many are diagnosed with irritable hip (IH). The aetiology of IH is not well understood and there may be geographical and seasonal variations. We previously established one year (2016) epidemiological data of IH presenting to the Royal Hospital for Children (RHCG) ED in Glasgow, Scotland. The sentinel findings in that year were (i) an age distribution shift to younger (peak at two years of age), (ii) no marked association with social class, and (iii) a spring preponderance. We sought to strengthen or refute these findings by repeating our study to obtain comparative data for 2017.

Methods

We performed a retrospective analysis of all children discharged from the RHCG ED from January to December 2017. Relevant discharge codes were determined, and patient records screened. Patients without a discharge code had their presenting complaint and medical record screened. These data were compared to that of the previously published study from the same ED (2016).

Results

Several findings were consistent with the conclusions of the 2016 study. The incidence was similar with 362 and 354 cases diagnosed in 2017 and 2016 respectively. The boy-girl ratio was consistent across both data-sets, 2:1 and 1.9:1 respectively. The mean age of presentation was similar (3.3 vs 3.5 years) across both years, with the same medians (three years) and peaks (two years). There was no overt difference in incidence or correlation to social deprivation. However, in 2016, a spring preponderance was seen whereas there was an autumn preponderance in 2017. Pooling data from the two cohorts, 93% (n=668) of patients were managed exclusively by ED physicians, with 70% (n=504) not requiring any further follow-up. The majority of patients who required follow-up were seen in ED clinics (169/212, 79.7%). No patient initially diagnosed as IH was found to have septic arthritis (SA).

Conclusion

In this follow-up study, we again found (i) a younger age profile than other studies, and (ii) no overt association with social deprivation. The major difference between the previous (2016) and current (2017) study was the apparent seasonal peaks: spring (2016), and autumn (2017). This difference does not negate the 'antecedent infection' hypothesis, but any aetiological proposal should be capable of accounting for this discrepancy. Additionally, our studies highlight that the majority of these patients can be managed in the ED alone.

Multiple bilateral trigger fingers in a child with neurofibromatosis type I following an acute viral infection: A case report

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We report on a case of multiple bilateral trigger fingers in a child with NF I.

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Triggering developed while the child was on chemotherapy following an acute viral infection.

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The pathogenesis is discussed.

Introduction

Triggering of the fingers in children is an uncommon entity. A review of the literature on the topic did not reveal any reports of multiple triggering in patients with neurofibromatosis.

Case report

Our patient is a known case of neurofibromatosis type I (NF 1). At the age of 4 years, the child required chemotherapy to treat symptomatic bilateral optic glioma. Chemotherapy was complicated by severe viral upper respiratory tract infection with concurrent multi-joint synovitis and mild triggering of the fingers. A second course of chemotherapy was required 2 years later. This was also complicated by a viral infection, joint synovitis, and worsening of the triggering. Surgical release of the A1 and part of the A2 pulleys was curative.

Discussion

Two factors contributed to the development of multiple triggering in our pediatric patient. The NF 1 itself predisposes to fibrosis. The second factor is the synovitis that accompanied the acute viral infection.

Conclusion

We report on a case of multiple bilateral trigger fingers in a child with NF 1 following an acute viral infection and discuss the pathogenesis.

Trochanteric Fractures in Young Children

BACKGROUND

Isolated avulsion fractures of the greater and lesser trochanter are usually seen in adolescents prior to the fusion of the apophysis. Greater trochanter fractures in adults have a high incidence of intertrochanteric extension and lesser trochanter fractures are regarded as a pathognomonic sign of metastatic disease. These fractures are very rare among children.

METHODS

We report five cases of trochanteric fractures in children of less than two years of age three of which were unrecognized initially in the accident and emergency department.

RESULTS

Early and complete recovery ensued following immobilization and symptomatic treatment. Surgical intervention was not required.

CONCLUSIONS

There needs to be a high index of suspicion to diagnose these fractures in children and plain radiographs need to be carefully examined when assessing a limping child. Our experience shows when correctly diagnosed these injuries can be treated successfully with supportive treatment and no need for surgical intervention.

LEVEL OF EVIDENCE

IV Case series.

A prospective study of screening for musculoskeletal pathology in the child with a limp or pseudoparalysis using erythrocyte sedimentation rate, C-reactive protein and MRI

PURPOSE

To determine if the detection of musculoskeletal pathology in children with a limp or acute limb disuse can be optimized by screening with blood tests for raised inflammatory markers, followed by MRI.

METHODS

This was a prospective observational study. Entry criteria were children (0 to 16 years of age) presenting to our emergency department with a non-traumatic limp or pseudoparalysis of a limb, and no abnormality on plain radiographs. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) blood tests were performed. Children with ESR > 10 mm/hr or CRP > 10 mg/L underwent a MRI scan. When the location of the pathology causing the limp was clinically unclear, screening images (Cor t1 and Short Tau Inversion Recovery) of both lower limbs from pelvis to ankles ('legogram') was undertaken. Data was gathered prospectively from 100 consecutive children meeting the study criteria.

RESULTS

In all, 75% of children had a positive finding on their MRI. A total of 64% of cases had an infective cause for their symptoms (osteomyelitis, septic arthritis, pyomyositis, fasciitis, cellulitis or discitis). A further 11% had positive findings on MRI from non-infective causes (juvenile idiopathic arthritis, cancer or undisplaced fracture). The remaining 25% had either a normal scan or effusion due to transient synovitis. ESR was a more sensitive marker than CRP in infection, since ESR was raised in 97%, but CRP in only 70%.

CONCLUSION

In our opinion MRI imaging of all children with a limp and either raised ESR or CRP is a sensitive method to minimize the chance of missing important pathology in this group, and is an effective use of MRI resources. We advocate the use of both blood tests in conjunction.

LEVEL OF EVIDENCE

Level II.

Management of pediatric patients with synovial fluid white blood-cell counts of 25,000 to 75,000 cells/mm³ after aspiration of the hip

BACKGROUND

In this study, we sought to elucidate the presentation, clinical course, treatments pursued, final diagnosis, and risk factors for septic arthritis in a series of children with hip pain and intermediate synovial fluid values (white blood-cell [WBC] counts of 25,000 to 75,000 cells/mm(3) [25 to 75 × 10(9) cells/L]).

METHODS

We reviewed the records of pediatric patients who underwent hip aspiration between 2005 and 2012 at a tertiary-care pediatric hospital. Demographic data, laboratory values, final diagnosis, and treatment details were recorded for the subpopulation of patients with an aspirate WBC count of 25,000 to 75,000 cells/mm(3) (25 to 75 × 10(9) cells/L). Univariate and multivariable logistic regression analysis was used to assess risk factors for septic arthritis of the hip across final diagnostic groups and subgroups with WBC values of <50,000 and ≥50,000 cells/mm(3) (<50 and ≥50 × 10(9) cells/L).

RESULTS

Forty-six children (twenty-seven males and nineteen females) with a mean age of 7.6 years met the inclusion criteria. The final diagnoses were septic arthritis of the hip (n = 15; 33%), Lyme arthritis (n = 13; 28%), transient synovitis (n = 8; 17%), and other findings (n = 10; 22%). Subjects with a synovial fluid WBC count of ≥50,000 cells/mm(3) (≥50 × 10(9) cells/L) were more likely to be diagnosed with septic arthritis of the hip (odds ratio, 4.4; 95% confidence interval, 1.1 to 16.9; p = 0.03). While septic arthritis of the hip was the most common diagnosis (48%) in patients with WBC values of ≥50,000 cells/mm(3) (≥50 × 10(9) cells/L), it also represented 17% of cases with WBC values of <50,000 cells/mm(3) (<50 × 10(9) cells/L).

CONCLUSIONS

Septic arthritis of the hip is the most common ultimate diagnosis in children with synovial fluid WBC values of 25,000 to 75,000 cells/mm(3) (25 to 75 × 10(9) cells/L) following hip aspiration, and it should be high on the differential diagnosis, even in cases with synovial fluid WBC values of <50,000 cells/mm(3) (<50 × 10(9) cells/L).

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.

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.

What is the clinical course of transient synovitis in children: a systematic review of the literature

Background

Transient synovitis of the hip (TS) is considered to be a self-limiting disease in childhood. However, because the etiology is unclear and some cases precede Legg-Perthes’ disease, data on follow-up are important. Our aim was to summarize the knowledge on the clinical course of TS in children.

Methods

The study design was a systematic review and a literature search was conducted in Medline and Embase. Studies describing short and/or long-term follow-up of TS in children were included. Case reports, reviews and studies describing traumatic hip pain were excluded. Study quality was scored and data extraction was performed. The main outcome measures were short-term and long-term clinical course, and recurrence of symptoms.

Results

A total of 25 studies were included of which 14 were of high quality. At two-week follow-up, almost all children with TS were symptom free. Those with symptoms persisting for over one month were more prone to develop other hip pathology, such as Legg-Perthes’ disease. The recurrence rate of TS ranged from 0–26.3%. At long-term follow-up, 0-10% of the children diagnosed with TS developed Legg-Perthes’ disease. Hip pain after intensive physical effort and limited range of motion of the hip at long-term follow-up was reported in 12-28% and in 0-18% of the children, respectively.

Conclusions

The majority of the studies indicate that children with TS recover within two weeks; recurrence was seen in 0-26% of the cases. Children with TS should be followed at least six months to increase the likelihood of not missing Legg-Perthes’ disease.

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.

The value of hip aspiration in pediatric transient synovitis

INTRODUCTION

Hip transient synovitis (TS) is a common pediatric orthopaedic problem. Although a self-limiting illness, it often makes the patient temporarily disabled and poses a diagnostic difficulty because of its similarity to septic arthritis in clinical manifestations. The aim of this study was to evaluate the use of a single ultrasound-guided hip aspiration as a treatment modality for TS.

METHODS

Between the years 1984 and 1989, 112 children with TS were treated through bed rest and using nonsteroidal anti-inflammatory drugs (group 1). Between the years 1990 and 1999, 119 children diagnosed with TS were treated using hip aspiration, bed rest, and nonsteroidal anti-inflammatory drugs (group 2). Recovery parameters were compared between these patient groups.

RESULTS

Twenty-four hours after admission, limping was noted in 92% and 10% of the patients in groups 1 and 2, respectively, (P < 0.001). Refusal to bear weight was observed in 14% and 1% in groups 1 and 2, respectively, (P < 0.001), and hip joint pain was reported in 81% and 6% in groups 1 and 2, respectively, (P < 0.001). Larger joint effusions were found to be the reason behind the inability to bear weight.

CONCLUSIONS

Pain due to TS may be because of capsule stretching owing to the accumulation of joint effusion. Ultrasound-guided hip aspiration relieves pain and limitation in movement and provides rapid differential diagnosis from septic arthritis of the hip joint.

Usefulness of dynamic contrast-enhanced MRI in differentiating between septic arthritis and transient synovitis in the hip joint

OBJECTIVE

The purpose of this study was to show the usefulness of dynamic contrast-enhanced MRI (DCE-MRI) and to determine the optimal time window in MRI for differentiating between septic arthritis and transient synovitis in painful hip joints.

MATERIALS AND METHODS

Eighteen patients who underwent DCE-MRI were enrolled, and the final diagnoses were septic arthritis (n = 7) and transient synovitis (n = 11). The enhancement patterns of DCE-MRI were dichotomized according to the shape of the time-signal intensity curves. The time at the maximal difference in the signal intensity between two time-signal intensity curves of both femoral heads was recorded. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Receiver operating characteristic curves were calculated.

RESULTS

Six of seven patients with septic arthritis in the hip joint had decreased enhancement during the early phase of DCE-MRI. The enhancement difference between the two patient groups was statistically significant (p = 0.0498). The time at the maximal difference in the signal intensity between two time-signal intensity curves of both femoral heads was approximately 3.5 minutes. The area under the receiver operating characteristic curve for predicting septic arthritis was 0.792.

CONCLUSION

DCE-MRI is useful in differentiating between septic hip arthritis and transient synovitis. If static contrast-enhanced coronal MRI is used, the optimal time for the acquisition of contrast-enhanced coronal MRI is approximately 3.5 minutes.

Approach to the child with joint inflammation

Arthritis is manifested as a swollen joint having at least 2 of the following conditions: limited range of motion, pain on movement, or warmth overlying the joint. This article discusses an approach to the evaluation of a child with arthritis of one (mono) or several (poly) joints.

Tibial torus and toddler's fractures misdiagnosed as transient synovitis: a case series

Introduction

The high incidence of transient synovitis in early childhood makes it the first suspected pathology in a limping child. Trauma, which has long been regarded as a causative factor for transient synovitis, may be underestimated in a non-cooperative toddler.

After excluding most serious conditions, such as septic arthritis, a speculative diagnosis of transient synovitis can be made, and this can easily mask a subtle musculoskeletal injury.

Case presentations

We report the cases of three Caucasian patients (two boys, aged 20-months- and three-years-old, and one girl, aged two-years-old), with tibial torus and toddler's fractures which were late-diagnosed due to an initial misdiagnosis of transient synovitis of the hip.

Conclusion

In a non-cooperative child musculoskeletal trauma can be mistaken as a simple causative factor for transient synovitis of the hip and this can easily prevent further investigation for a possible subtle musculoskeletal injury of the lower extremities.

Our experience with the presented cases suggests the need to be more vigilant in the differential diagnosis of transient synovitis in young children.

Transient synovitis of the hip: Ultrasound appearance. Mini-pictorial essay

We describe the ultrasound (US) appearance of transient synovitis. Transient synovitis of the hip typically occurs in 3 to 8-year-old children. The onset is clinically characterized by acute hip pain and limp with limited joint mobility, and the leg is usually held in a position of flexion and external rotation to avoid pain. US image is characterized by joint effusion in the hip joint anterior recess, as described in the literature. Our experience confirms the importance of the technique with which the US examination is performed. In order to obtain the best diagnostic information the hip must be examined with the patient in the supine position and the hip joint in a neutral position (abduction of the hip with extension and slight external rotation) by means of an anterior approach along the long axis of the femoral neck in the parasagittal plane.

Bilateral trigger finger in a 7-year-old after a viral infection: case report

Triggering in young children is rare. In this report, we describe spontaneous bilateral ring finger triggering in a 7-year-old boy after a viral infection. The pathology completely resolved without intervention. We propose that the triggering resulted from a viral synovitis. Such a case highlights the importance of eliciting evidence of recent infections in children presenting to hand clinics with finger triggering. It also implies that the transient synovitis often described in children may actually occur symptomatically in tenosynovium as well as articular synovium.

Arthroscopic view of transient synovitis of the hip joint: a case report

We present a case of a 13-year-old male patient with hip pain and limp. Inconclusive investigations and persistent symptoms resulted in the patient undergoing hip arthroscopy. At arthroscopy, a large focal cartilaginous defect of the femoral head with synovitis was seen and synovial biopsy confirmed the diagnosis. Arthroscopic debridement of the lesion, synovectomy and non-weight bearing for 6 weeks resulted in relief of symptoms. Transient synovitis is a common diagnosis in young children, but the extent of damage to the femoral head has not been previously described. Transient synovitis may not always respond to symptomatic treatment and hip arthroscopy may be useful in detecting the actual lesion and plan the treatment.

Hip radiography for the investigation of nontraumatic, short duration hip pain presenting to a children's emergency department

OBJECTIVE

To assess the diagnostic accuracy of routine hip x-ray in 2- to 11-year-old children presenting to the emergency department with recent onset, nontraumatic hip pain and to assess the predictive value of other clinical presenting variables.

METHODS

Retrospective chart review of children with hip pain of less than 2 weeks duration, presenting to a metropolitan children's emergency department in New Zealand. Data were extracted on radiography results, diagnosis on final discharge from hospital, and other clinical details. Diagnostic categories were divided into urgent pathology (those requiring immediate treatment) and nonurgent pathology (those requiring follow up and those requiring no treatment or follow up). Contingency analysis and logistic regression were performed on variables to assess ability to predict urgent pathology.

RESULTS

Hip x-rays were performed in 99% of 310 eligible patients. Of these, 3% had some degree of significant abnormality reported on hip x-ray. Final diagnoses were transient synovitis in 86% of patients, osteomyelitis or other significant musculoskeletal sepsis in 8%, slipped upper femoral epiphysis in 1%, and other musculoskeletal disorder in 4%, with no cases of septic arthritis. In children 9 years or older, the likelihood ratio with a positive x-ray was 17, compared with 6 in children younger than 9 years. Fever, weight-bearing status, and age were the most important predictors of urgent pathology.

CONCLUSIONS

In children younger than 9 years presenting with recent onset, nontraumatic hip pain, hip x-ray is of limited value. In children 9 years or older, hip x-ray may be useful to exclude slipped upper femoral epiphysis. Fever, weight bearing status, and age may better predict urgent pathology.

Lyme arthritis presenting as transient synovitis of the hip

Transient synovitis of the hip is a common cause of hip pain in children. The etiology of transient synovitis of the hip is unknown. Lyme arthritis is characterized by brief, often recurrent episodes of oligoarthritis. Lyme arthritis most often affects a single knee, but hip involvement is uncommon. This report describes 2 children with Lyme arthritis who presented with features of transient synovitis of the hip. Lyme arthritis should be considered in the differential diagnosis of transient synovitis of the hip in children.

Septic Arthritis Versus Transient Synovitis of the Hip: Gadolinium-Enhanced MRI Finding of Decreased Perfusion at the Femoral Epiphysis

OBJECTIVE

The purpose of this study was to identify differences in the MRI findings of septic arthritis and transient synovitis in patients with nontraumatic acute hip pain and hip effusion.

MATERIALS AND METHODS

The MRI findings in nine patients with septic arthritis and 11 with transient synovitis were reviewed retrospectively. This study was approved by our institutional review board. The diagnoses were based on findings at physical examination, laboratory studies, and joint aspiration and bacteriologic study. The MRI findings were analyzed with emphasis on the grade of joint effusion, alterations in signal intensity in the soft tissues and bone marrow, and the presence of decreased perfusion at the femoral head.

RESULTS

Low signal intensity on fat-suppressed gadolinium-enhanced T1-weighted coronal MRI suggesting decreased perfusion at the femoral head of the affected hip joint was seen in eight of nine patients with septic arthritis and in two of 11 patients with transient synovitis. Statistically reliable differences (p = 0.005) were found between the two groups. Alterations in signal intensity in the bone marrow were seen in three patients with septic arthritis but in none of the patients with transient synovitis. Decreased perfusion on fat-suppressed gadolinium-enhanced coronal T1-weighted MRI was seen in the six patients with septic arthritis who did not have alterations in signal intensity involving the bone marrow.

CONCLUSION

Decreased perfusion at the femoral epiphysis on fat-suppressed gadolinium-enhanced coronal T1-weighted MRI is useful for differentiating septic arthritis from transient synovitis.

[Benefit of hip ultrasound in management of the limping child]

OBJECTIVE

To evaluate the contribution of sonography of the hip in the management of nontraumatic limping in children.

PATIENTS AND METHODS

Prospective study including children consulting for nontraumatic limping (n=93). These children had a clinical examination, a biological and imaging workup (pelvis x-rays (n=88), initial sonograph of the hip (n=93), and follow-up sonograph of the hip (n=29)).

RESULTS

Ninety-three children (69 boys, 24 girls) aged from 10 months to 13 years (median, 4 years) were included and divided into two groups: The sensitivity and specificity of sonography in establishing a serious diagnosis was 57% and 59%, respectively.

CONCLUSION

The advantage of systematic hip sonography is challenged in this study because of low sensitivity and specificity. Its main advantage seems to be in its negative results, which prompt other investigations.

Pediatric Hip Pain

Although there are many causes of an irritable hip in children, transient synovitis and septic arthritis are the two most common etiologies. Both present with inability or difficulty to bear weight on the affected leg, pain, stiffness, limp, and fluid within the synovium. Because of potential serious complications associated with septic arthritis, accurate and early differentiation between the two processes is important. The workup for pediatric hip pain includes a thorough history and physical examination, appropriate laboratory studies, pelvis/hip radiography, hip sonography, and possible arthrocentesis.

Differentiation between septic arthritis and transient synovitis of the hip in children with clinical prediction algorithms

BACKGROUND

Differentiation between septic arthritis and transient synovitis of the hip in children can be difficult. Kocher et al. recently developed a clinical prediction algorithm for septic arthritis based on four clinical variables: history of fever, non-weight-bearing, an erythrocyte sedimentation rate of >or=40 mm/hr, and a serum white blood-cell count of >12000/mm(3) (>12.0 x 10(9)/L). The purpose of this study was to apply this clinical algorithm retrospectively to determine its predictive value in our patient population.

METHODS

A retrospective review was performed to identify all children who had undergone a hip arthrocentesis for the evaluation of an irritable hip at our institution between 1992 and 2000. One hundred and sixty-three patients with 165 involved hips satisfied the criteria for inclusion in the study and were classified as having true septic arthritis (twenty hips), presumed septic arthritis (twenty-seven hips), or transient synovitis (118 hips).

RESULTS

Patients with septic arthritis (true and presumed; forty-seven hips) differed significantly (p < 0.05) from patients with transient synovitis (118 hips) with regard to the erythrocyte sedimentation rate, differential of serum white blood-cell count, total white blood-cell count and differential in the synovial fluid, gender, previous health-care visits, and history of fever. If the four independent multivariate predictors of septic arthritis proposed by Kocher et al. were present, the predicted probability of the patient having septic arthritis was 59% in our study, in contrast to the 99.6% predicted probability in the patient population described by Kocher et al. Statistical analyses demonstrated that the best model to describe our patient population was based on three variables: a history of fever, a serum total white blood-cell count of >12000/mm(3) (>12.0 x 10(9)/L), and a previous health-care visit. When all three variables were present, the predicted probability of the patient having septic arthritis was 71%.

CONCLUSIONS

Although the use of a clinical prediction algorithm to differentiate between septic arthritis and transient synovitis may have improved the utility of existing technology and medical care to facilitate the diagnosis at the institution at which the algorithm originated, application of the algorithm proposed by Kocher et al. or of our three-variable model does not appear to be valid at other institutions.

The young adult with hip pain: diagnosis and medical treatment, circa 2004

Hip pain in young adults (18-35 years old) often is characterized by nonspecific symptoms, normal imaging studies, and vague findings from the history and physical examination. In younger patients, pain is more likely to be caused by congenital hip dysplasia, athletic injuries, trauma, spondyloarthropathy, and by conditions that first appear during this stage of life, such as rheumatoid arthritis, osteoarthritis, intravenous drug use, alcoholism, or corticosteroid use. The history and physical examination may narrow the diagnosis to intraarticular, extraarticular, or referred sources of pain. Plain radiography and magnetic resonance imaging are the preferred initial imaging procedures. Analyses of the blood, urine, and synovial fluid can be helpful in diagnosing inflammation, infection, and systematic rheumatic disease. Fractures, infection, and ischemic necrosis should be ruled out early because they require immediate treatment to prevent damage to the joint. Hip trauma at a young age increases the risk of osteoarthritis with advancing age, and, unlike most older adults, young adults receiving total hip replacement can expect revision surgery. Medical treatment often involves patient education, physical therapy, and pharmacotherapy. Acetaminophen, nonsteroidal anti-inflammatory drugs, and opioids for pain and antibiotics for infection are the most often prescribed drugs for this population.

Imaging of articular disorders in children

This article reviews aspects of arthritis imaging that are specific to children. The pediatric skeleton is unique and responds in characteristic ways to articular inflammation. Epiphyseal and physeal cartilage are affected by joint diseases, and disturbances of growth and maturation are sometimes the cardinal manifestations of arthritis. The target joints of pediatric articular diseases differ considerably from those of diseases in adults. Imaging techniques should be tailored to the children being studied.

Use of imaging in the differential diagnosis of rheumatic diseases in children

Imaging studies are important adjuncts in the evaluation of children with suspected rheumatic diseases. They are best used as follow-up investigations to exclude specific differential diagnoses, based upon a careful history and physical examination. Often, repeated examination over a period of time, sometimes months, is necessary before a diagnosis can be made. The addition of selected imaging studies can be important in the common circumstance where no diagnosis is made, but the physician must assure the child and family that all appropriate efforts have been made to exclude important illnesses.