Aims

The aim of this study was to determine the consensus best practice approach for the investigation and management of children (aged 0 to 15 years) in the UK with musculoskeletal infection (including septic arthritis, osteomyelitis, pyomyositis, tenosynovitis, fasciitis, and discitis). This consensus can then be used to ensure consistent, safe care for children in UK hospitals and those elsewhere with similar healthcare systems.

Acute bone and joint infections in children are serious, and misdiagnosis can threaten limb and life. Most young children who present acutely with pain, limping, and/or loss of function have transient synovitis, which will resolve spontaneously within a few days. A minority will have a bone or joint infection. Clinicians are faced with a diagnostic challenge: children with transient synovitis can safely be sent home, but children with bone and joint infection require urgent treatment to avoid complications. Clinicians often respond to this challenge by using a series of rudimentary decision support tools, based on clinical, haematological, and biochemical parameters, to differentiate childhood osteoarticular infection from other diagnoses. However, these tools were developed without methodological expertise in diagnostic accuracy and do not consider the importance of imaging (ultrasound scan and MRI). There is wide variation in clinical practice with regard to the indications, choice, sequence, and timing of imaging. This variation is most likely due to the lack of evidence concerning the role of imaging in acute bone and joint infection in children. We describe the first steps of a large UK multicentre study, funded by the National Institute for Health Research, which seeks to integrate definitively the role of imaging into a decision support tool, developed with the assistance of individuals with expertise in the development of clinical prediction tools. Cite this article: Bone Joint J 2023;105-B(3):227–229

Aims

The aim of this study was to determine the extent to which patient demographics, clinical presentation, and blood parameters vary in Kingella kingae septic arthritis when compared with those of other organisms, and whether this difference needs to be considered when assessing children in whom a diagnosis of septic arthritis is suspected.

Objectives

Legg–Calvé–Perthes’ disease (LCP) is an idiopathic osteonecrosis of the femoral head that is most common in children between four and eight years old. The factors that lead to the onset of LCP are still unclear; however, it is believed that interruption of the blood supply to the developing epiphysis is an important factor in the development of the condition.

Background. We herein report a case of isolated hip pain in a four year old boy. The unique aspect of this case study is the unusual history, presentation, ultrasonography, MRI and blood culture results, which lead to the diagnosis and treatment of adductor pyomyositis with a rare organism (Streptococcus Mitis) in a temperate country. The objectives of this case study is to discuss the key learning outcomes with respect to assessment and management of this case. Methods. The patient presented with a one day history of malaise, fever, left groin pain and inability to weight bear on the left leg. There was no history of any trauma, predisposing infections or recent travel. A working diagnosis of transient synovitis / septic arthritis of the hip was made on clinical examination. Results. Plain radiograph and ultrasound of the hip was normal with no effusion. Two consecutive blood cultures suggested Streptococcus Mitis bacteriaemia and MRI scan confirmed pyomyositis of the left hip adductors that was too small to drain. Streptococcus Mitis is a normal commensal organism of the oral cavity however it can lead to opportunistic infections particularly endocarditis. Echocardiogram revealed no cardiac complications, in particular no endocarditic vegetation. Patient was treated with intravenous benzylpenicillin for a week followed by oral phenoxymethylpenicillin for a week. Conclusion. Adductor pyomyositis must be considered as a differential diagnosis in a child with unusual presentation of hip pain. When an ultrasound is normal, MRI scan is warranted to confirm diagnosis. Septic screen should include blood cultures. The commonest causative organisms are the Staphylococcus family. However if Streptococcus Mitis is isolated, cardiac sources of infection resulting in septic emboli must be investigated. Repeated MRI scans are required particularly if the patient does not respond to medical management. Level of Evidence. IV

The aim of this study was determine if the detection of pathology in children with a limp can be optimised by screening with blood tests for raised inflammatory markers. The entry criteria for the study were children (0–15 years) presenting to our hospital Emergency Department from 2012–2015 with a non-traumatic limp or pseudoparalysis of a limb, and no sign of fracture or malignancy on plain radiographs. ESR and CRP blood tests were performed along with other standard investigations. Children with ESR or CRP over 10 underwent MRI scan of their area of pain or tendernesss, with those under 7 years old having general anaesthetic. MRI provided the diagnosis in cases of osteomyelitis, pyomyositis, fasciitis, cellulitis, discitis, as well as non-infective conditions such as malignancy and fracture not visible on plain radiographs. Where a joint effusion was present, the diagnosis of septic arthritis was made from organisms cultured following surgical drainage, or high white cell count in joint fluid if no organisms were cultured. The study was completed once data from 100 consecutive children was available. 64% of children 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 occult fracture). The remaining 25% had either a normal scan, or transient synovitis. ESR was a more sensitive marker than CRP, since ESR was raised in 97% of those with abnormal scans, but CRP in only 70%. There were no complications from any of the GA MRI scans. Conclusion: This shows that MRI imaging of all children with a limp and either raised ESR or CRP is a sensitive method to minimise the chance of missing important pathology in this group, and is not wasteful of MRI resources

Pyogenic sacroiliitis (PS) is one of the less frequent localizations among joint infections, near the 1,5%. A late diagnosis generally exists. So we decided to analyze its behaviour in our uniit. A retrospective study of 39 records was carried out, 32 with diagnosis of entrance of PS and 7 with another pathology's diagnosis that turned out to be a PS, among the years 1999 and 2014 in our unit. 27 only fulfilled the requirements to be classified as PS (Clinic features of infection and sacroiliac localization, laboratory exams and Tc-99 bone scintigraphy alterations). 20 males and 7 females (74% males), 52% right sacroiliac joint, only 7 had clinically predisposing conditions (trauma), aged between 3 and 14 years (average 9.6 years). The half time of clinical evolution foresaw to diagnosis was of 4,7 days (6,7 days between 1999–2005 and 3,5 between 2006–2014) (range between 1 and 10 days). The main symptom that motivates the consultation was fever (96%) accompanied by FABER test positive (70%) by buttock pain (52%) and by limping (48%). Laboratory exams: WBC count was normal in 11 cases and elevated in 16 cases too and only in 5 cases with left deviation (PMNs elevated); CRP higher than 55 mg/dl in 23 patients (100% over 20mg/dl), ERS with value average of 72 mmHg/hour (27–111). Blood cultures were positive in 70% and the Staphylococcus aureus was the main bacteria founded (89%). No radiological alterations were found initially. The TC-99 bone scintigraphy was positive in all cases after the third day. All patients had a 5 to 12 days course of intravenous antibiotics (oxacillin + amikacin in 96% of patients) and then completed 4 weeks with oral oxacillin. All patients recovered without sequel. Blood cultures may be obtained prior the antibiotics’ administration. The Staphylococcus aureus is by far the most frequent germ involved in this process, and it may guide the empiric antibiotic therapy. The precocious antibiotic treatment solves the case without sequels. The PS is an uncommon pathology in children that makes it often not recognized initially. Wrong diagnosis such as appendicitis, transient synovitis of the hip, discitis, etc. can be avoided if PS is sought in a systematic way

We herein report a case of isolated hip pain in a four year old boy. The importance of this project is the unusual history, presentation, ultrasound, MRI and blood culture results and treatment, which lead to the diagnosis of adductor pyomyositis with a rare organism (Streptococcus Mitis) in a temperate country. The patient presented with a one day history of malaise, fever, left groin pain and inability to weight bear on the left leg. There was no history of any predisposing infections or recent travel. A working diagnosis of transient synovitis / septic arthritis of the hip was made on clinical examination. Plain radiograph and ultrasound of the hip was normal with no effusion. Two consecutive blood cultures suggested Streptococcus Mitis bacteriaemia and MRI scan confirmed pyomyositis of the left hip adductors that was too small to drain. Streptococcus Mitis is a normal commensal organism of the oral cavity however it can lead to opportunistic infections particularly endocarditis. Echocardiogram revealed no cardiac complications, in particular no endocarditic vegetation. Patient was treated with intravenous benzylpenicillin for a week followed by oral phenoxymethylpenicillin for a week. As it was a soft tissue infection, a short course of antibiotics was sufficient and he made a complete recovery. Adductor pyomyositis must be considered as a differential diagnosis in a child with unusual presentation of hip pain. When an ultrasound is normal, MRI scan is warranted to confirm diagnosis. Septic screen should include blood cultures. The commonest organisms are the Staphylococcus family. However if Streptococcus Mitis is isolated, cardiac sources of infection resulting in septic emboli must be investigated. Repeated MRI scans are required particularly if the patient does not respond to medical management

Background. Establishing the diagnosis in a child presenting with an atraumatic limp can be difficult. Clinical prediction algorithms have been devised to distinguish septic arthritis (SA) from transient synovitis (TS). Within Europe measurement of the Erythrocyte Sedimentation Rate (ESR) has largely been replaced with assessment of C-Reactive Protein (CRP) as an acute phase protein. We produce a prediction algorithm to determine the significance of CRP in distinguishing between TS and SA. Method. All children with a presentation of ‘atraumatic limp’ and a proven effusion on hip ultrasound between 2004 and 2009 were included. Patient demographics, details of the clinical presentation and laboratory investigations were documented to identify a response to each of the four variables (Weight bearing status, WCC >12,000 cells/m3, CRP >20mg/L and Temperature >38.5°C). SA was defined based upon culture and microscopy of the operative findings. Results. 311 hips were included within the study. Of these 282 were considered to have transient synovitis. 29 patients met criteria to be classified as SA based upon laboratory assessment of the synovial fluid. The introduction of CRP eliminated the need for a four variable model as the use of two variables (CRP and weight bearing status) had similar efficacy. Treating individuals who were non-weight-bearing and a CRP >20mg/L as SA correctly classified 94.8% individuals, with a sensitivity of 75.9%, specificity of 96.8%, positive predictive value of 71.0%, and negative predictive value of 97.5%. CRP was a significant independent predictor of septic arthritis. Conclusions. CRP was a strong independent risk factor of septic arthritis, and its inclusion within a regression model simplifies the diagnostic algorithm. Nevertheless, this and other models are generally more reliable in excluding SA, than confirming SA, and therefore a clinician's acumen remains important in identifying SA in those individuals with a single abnormal variable

Background. Establishing the diagnosis in a child presenting with an atraumatic limp can be challenging. There is particular difficulty distinguishing septic arthritis (SA) from transient synovitis (TS) and consequently clinical prediction algorithms have been devised to differentiate the conditions using the presence of fever, raised erythrocyte sedimentation rate (ESR), raised white cell count (WCC) and inability to weight bear. Within Europe measurement of the ESR has largely been replaced with assessment of C-reactive protein (CRP) as an acute phase protein. We have evaluated the utility of including CRP in a clinical prediction algorithm to distinguish TS from SA. Method. All children with a presentation of ‘atraumatic limp’ and a proven effusion on hip ultrasound between 2004 and 2009 were included. Patient demographics, details of the clinical presentation and laboratory investigations were documented to identify a response to each of four variables (Weight bearing status, WCC >12,000 cells/m3, CRP >20mg/L and Temperature >38.5 degrees C. The definition of SA was based upon microscopy and culture of the joint fluid collected at arthrotomy. Results. 311 hips were included within the study. Of these 282 were considered to have transient synovitis. 29 patients met criteria to be classified as SA based upon laboratory assessment of the synovial fluid. The introduction of CRP eliminated the need for a four variable model as the use of two variables (CRP and weight bearing status) had similar efficacy. An algorithm that indicated a diagnosis of SA in individuals who could not weight-bear and who had a CRP >20mg/L correctly classified SA in 94.8% individuals, with a sensitivity of 75.9%, specificity of 96.8%, positive predictive value of 71.0%, and negative predictive value of 97.5%. CRP was a significant independent predictor of septic arthritis. Conclusions. CRP was a strong independent risk factor of septic arthritis, and its inclusion within a regression model simplifies the diagnostic algorithm, such that a two-variable model correctly classified 95% individuals with SA. Nevertheless, this and similar algorithms are generally more reliable in excluding SA, than confirming SA, and therefore a clinician's acumen remains important in identifying SA in those individuals with a single abnormal variable

Purpose. To evaluate the efficacy of Kocher's criteria to differentiate between transient synovitis and septic arthritis in children. Methods and results. All children with a presentation of ‘atraumatic limp’ and a proven effusion on hip ultrasound between 2004 and 2009 were included. Patient demographics, details of the clinical presentation and laboratory investigations were documented to identify a response to each of the four variables (Weight bearing status, WCC >12,000 cells/m3, CRP >20mg/L and Temperature >38.5°C). SA was defined based upon culture and microscopy of the operative findings. 311 hips were included within the study. Of these 282 were considered to have transient synovitis. 29 patients met criteria to be classified as SA based upon laboratory assessment of the synovial fluid. The introduction of CRP eliminated the need for a four variable model as the prediction for two variables (CRP and weight bearing status) was of similar efficacy. Treating individuals who were non-weight-bearing and a CRP >20mg/L as SA correctly classified 94.8% individuals, with a sensitivity of 75.9%, specificity of 96.8%, positive predictive value of 71.0%, and negative predictive value of 97.5%. CRP was a significant independent predictor of septic arthritis. Conclusion. Mathematical models using common variables used in clinical practice are a useful way of considering ‘risk’ in SA. However, whilst such models correctly classify the majority of individuals they are by no means failsafe. Such models are more reliable in excluding SA, than including SA, and therefore a clinician's acumen remains important in identifying SA in those individuals with a single abnormal variable

The April 2012 Children’s orthopaedics Roundup³⁶⁰ looks at osteonecrosis of the femoral head and surgery for dysplasia, femoral head blood flow during surgery, femoroacetabular impingement and sport in adolescence, the Drehmann sign, a predictive algorithm for septic arthritis, ACL reconstruction and arthrofibrosis in children, spinal cord monitoring for those less than four years old, arthroereisis for the flexible flat foot, fixing the displaced lateral humeral fracture, and mobile phones and inclinometer applications

Aim. This study aims to determine the value of MRI in children with hip pain which remained unexplained following routine investigations including ultrasound examination. Materials and methods. Retrospective review of clinical notes and MRI findings in all children who received and MRI scan for undiagnosed hip pain over three years. Results. Fifty five children underwent an MRI scan of their hips for unexplained hip pain. 29 were male and 26 were female. The mean age was 10.9 years. The MR study provided a diagnosis in 22 children (40%), and was normal in 33 children (60%). Five cases were considered to be due to transient synovitis. Three children were diagnosed as osteoid osteoma. Two children were were found to have trochanteric bursitis. Two children were shown to have muscle trauma (one child with adductor trauma and one child with piriformis trauma). Two children were diagnosed with non-specific bone oedema. The remaining eight children were diagnosed with Perthes' disease, haemarthrosis, sacro-iliac infection, synovitis secondary to juvenile idiopathic arthritis, ischio-pubic osteochondrosis, acetabular dysplasia, Klippel-Trenaunay syndrome and resolution of an eosinophilic granuloma. None of the children discharged following a normal scan has subsequently presented with hip disease. Conclusions. It is concluded that MRI is useful in the diagnosis of hip pain in children in whom routine investigation has not yielded an answer

Clinical prediction algorithms are used to differentiate transient synovitis from septic arthritis. These algorithms typically include the erythrocyte sedimentation rate (ESR), although in clinical practice measurement of the C-reactive protein (CRP) has largely replaced the ESR. We evaluated the use of CRP in a predictive algorithm. The records of 311 children with an effusion of the hip, which was confirmed on ultrasound, were reviewed (mean age 5.3 years (0.2 to 15.1)). Of these, 269 resolved without intervention and without long-term sequelae and were considered to have had transient synovitis. The remaining 42 underwent arthrotomy because of suspicion of septic arthritis. Infection was confirmed in 29 (18 had micro-organisms isolated and 11 had a high synovial fluid white cell count). In the remaining 13 no evidence of infection was found and they were also considered to have had transient synovitis. In total 29 hips were categorised as septic arthritis and 282 as transient synovitis. The temperature, weight-bearing status, peripheral white blood cell count and CRP was reviewed in each patient. A CRP > 20 mg/l was the strongest independent risk factor for septic arthritis (odds ratio 81.9, p < 0.001). A multivariable prediction model revealed that only two determinants (weight-bearing status and CRP > 20 mg/l) were independent in differentiating septic arthritis from transient synovitis. Individuals with neither predictor had a < 1% probability of septic arthritis, but those with both had a 74% probability of septic arthritis. A two-variable algorithm can therefore quantify the risk of septic arthritis, and is an excellent negative predictor.

Introduction: Evaluation of acute hip pain in children can be challenging, because there are several diagnoses to consider. Most patients have a transient synovitis of the hip, which is a benign and self-limited condition. However, its similarities with other more serious disease make the diagnosis one of exclusion. In the Children’s Hospital of Geneva, children presenting with an acute hip pain are treated according to a specific screening protocol including blood sample with rheumatoid panel, hip ultrasound, and conventional X-rays. The objective of our study were to assess the efficacy of the screening protocol on the final diagnosis. We also provided a better characterization of transient synovitis of the hip. Methods: We retrospectively reviewed the medical records of children who had the investigation’s protocol between 1999 and 2003. Results: 269 medical records were reviewed comprising 66.2% of boys and 33.8% of girls, with a mean age of 5.5 years. Prior to presentation, 68.4% of children reported pain of < 24 hours in duration. Limp or refusal to bear weight was observed in all cases. According to the Kocher’s predictors of septic arthritis of the hip (fever, non weight-bearing, ESR > 40 mm/h, serum WBC count of > 12000 cells/mm3), 62% had zero predictor, 22% had one, 15% two, 1% three, and none four. A positive rheumatoid factor test was found in 18% of children, whereas 16% of patients had a positive antinuclear antibody test. During hospitalisation one child was diagnosed as having septic arthritis. The remaining patients were diagnosed by exclusion as having a transient synovitis of the hip since clinical follow-up was normal at 6 weeks. Conclusion: Transient synovitis of the hip is a diagnosis of exclusion, and septic arthritis is the main condition to rule out. Using Kocher’s predictors of septic arthritis is useful for distinction between both conditions early at presentation. In our collective, only 3 patients with transient synovitis had a three of four predictors. Our study also showed that screening for a rheumatologic disease should not be done routinely at the first episode of hip pain. Indeed, positive tests were never confirmed with a clinical situation evocative of rheumatologic disease. More selective criteria should be used before doing a rheumatologic panel. Furthermore our work emphasizes the economical impact of a management of this frequent condition with less blood investigations

Background: Distinguishing septic arthritis from transient synovitis of the hip in children can be both crucial and challenging. In 1999, Kocher et al suggested four clinical predictors, fever > 38.5°C, inability to weight bear, WBC count > 12.0x109/L, and ESR> 40mm/hr; that, when combined were highly predictive of septic arthritis in children (99.6%). This figure was challenged by Luhmann et al, stating that the clinical prediction did not exceed 59%. In 2006, Caird et al recommended adding CRP of > 20mg/L as a fifth predictor. Aims: To assess the value and accuracy of clinical prediction algorithms in distinguishing septic arthritis from transient synovitis of the hip in children in our hospital. Methods: A retrospective review of all children admitted to our institution with painful hips was carried out over a period of four years (Feb 2003 to Mar 2007). One-hundred and twenty-two admissions (115 patients, 7 re-admissions) were reviewed. Results: 79 patients (64.8%) were males. The mean age was 6 years (9 months to 15 years). 86 patients (70.5%) were diagnosed with transient synovitis. All the 7 re-admissions were from this group. Only one of the re-admissions was diagnosed with confirmed septic arthritis. 4 patients (3.3%) were diagnosed with definite septic arthritis with positive cultures from the hip, and 1 (0.8%) with probable septic arthritis (negative culture). The presence of the clinical predictors was compared between the transient synovitis and septic arthritis groups, using Fisher’s exact test. Only the raised temperature and CRP were found to be significantly different (p< 0.05). Only two children (40%) with confirmed septic arthritis had four or more predictors (one had all five, and the other was able to partially weight bear). The third child had a raised temperature and CRP, and the fourth had a raised temperature only. The fifth patient (20%) was diagnosed with probable septic arthritis. His cultures were negative, but he was already on intravenous antibiotics. This patient did not have any of the predictors on admission (temperature was 38.3°C, CRP 10.7). However, he spiked a temperature of 40°C 24 hours post admission despite being on antibiotics, and his CRP increased to 34.5mg/L. In the transient synovitis group, two patients (2.2%) had positive five predictors, but were proven to have transient synovitis secondary to a urinary tract infection and gastroenteritis. 47 patients (51.6%) did not have any of the predictors, and 6 patients (6.6%) had three or more positive predictors. Conclusion: Although clinical predictors are helpful in distinguishing septic arthritis from transient synovitis, there were false negative and false positive findings in the study. The predictors cannot be considered alone, and ultimately clinical judgement must be exercised to ensure that cases of septic arthritis are not missed

The crucial differentiation between septic arthritis and transient synovitis of the hip in children can be difficult. In 1999, Kocher et al introduced four clinical predictors which were highly predictive (99.6%) of septic arthritis. These included fever (temperature ≥ 38.5°C), inability to bear weight, white blood-cell count > 12.0 × 10. 9. cells/L and ESR ≥ 40 mm/hr; CRP ≥ 20 mg/L was later added as a fifth predictor. We retrospectively evaluated these predictors to differentiate septic arthritis from transient synovitis of the hip in children over a four-year period in a primary referral general hospital. When all five were positive, the predicted probability of septic arthritis in this study was only 59.9%, with fever being the best predictor. When applied to low-prevalence diseases, even highly specific tests yield a high number of false positives and the predictive value is thereby diminished. Clinical predictors should be applied with caution when assessing a child with an irritable hip, and a high index of suspicion, and close observation of patients at risk should be maintained