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. Methods. A Delphi approach was used to determine consensus in three core aspects of care: 1) assessment, investigation, and diagnosis; 2) treatment; and 3) service, pathways, and networks. A steering group of paediatric orthopaedic surgeons created statements which were then evaluated through a two-round Delphi survey sent to all members of the British Society for Children’s Orthopaedic Surgery (BSCOS). Statements were only included (‘consensus in’) in the final agreed consensus if at least 75% of respondents scored the statement as critical for inclusion. Statements were discarded (‘consensus out’) if at least 75% of respondents scored them as not important for inclusion. Reporting these results followed the Appraisal Guidelines for Research and Evaluation. Results. A total of 133 children’s orthopaedic surgeons completed the first survey, and 109 the second. Out of 43 proposed statements included in the initial Delphi, 32 reached ‘consensus in’, 0 ‘consensus out’, and 11 ‘no consensus’. These 11 statements were then reworded, amalgamated, or deleted before the second Delphi round of eight statements. All eight were accepted as ‘consensus in’, resulting in a total of 40 approved statements. Conclusion. In the many aspects of medicine where relevant evidence is not available for clinicians to base their practice, a Delphi consensus can provide a strong body of opinion that acts as a benchmark for good quality clinical care. We would recommend clinicians managing children with musculoskeletal infection follow the guidance in the consensus statements in this article, to ensure care in all medical settings is consistent and safe. Cite this article: Bone Joint J 2023;105-B(7):815–820

Primary pyomyositis is increasing in incidence in the western world. Although a commonly encountered condition in the tropics it was not described in the USA until 1971 and the UK until 1998. The reason for the increasing incidence is not understood. Typically pyomyositis affects the muscles around the hip and may present in a variety of ways to orthopaedic or general surgeons – occasionally leading to unnecessary operative intervention. We sought to identify the experience gained, of this condition, within a UK paediatric tertiary referral unit. A retrospective review of cases of pyomyositis, from our institution, since 1998 was undertaken to identify demographics, presentation, diagnosis and management. Thirteen cases of pyomyositis were identified. Obturator internus was most commonly affected (n = 7). Trauma was implicated in three cases and group A staphylococcus was cultured in nine cases. Male:Female ratio ~ 3: 2. Initial working diagnosis at presentation was septic joint in eight cases, appendicitis in three cases and soft tissue abscess in two cases. Ten cases settled with antibiotics alone. One diagnostic retroperitoneal exploration was performed which may have been avoided with greater preoperative awareness of this condition. On reflection, all cases were identified by CT or MRI. To our knowledge, this is the first UK series of pyomyositis, reflecting its increasing incidence in the western world. Its presentation is similar to other common paediatric surgical emergencies, yet its management is very different – often not requiring surgery. A greater awareness of this emerging condition is therefore essential to both general and orthopaedic surgeons in order to prevent misdiagnosis and unnecessary surgical intervention

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

Tropical pyomyosistis is an uncommon condition in the United Kingdom. Early diagnosis and appropriate treatment are crucial for a good outcome. We had seen 13 cases in our previously published series from 1998 to 2009. This is an update showing a significantly increased incidence from 2010 to 2016. A retrospective review of all cases of pelvic pyomyositis in our centre from January 2010 to April 2016 was undertaken from case notes and radiology reports. All children with clinical and radiographic evidence of pyomyositis were included. Since our previous publication we had changed our practice to get an MRI scan in all children who presented with a limp, fever and raised inflammatory markers, and had no effusion in the hip ultrasound scan. We identified 24 children with a mean age of 7 years (range, 1 week to 14 years). MSSA (Methicillin-Sensitive Staphylococcus aureus) was the most common cultured organism (n=8). Median hospital stay was 9 days (3 to 12). Obturator internus was the most common muscle affected. All patients had appropriate antibiotics with 2 patients requiring surgical drainage of abscesses. The majority of children (n=22) showed a complete recovery with antibiotics only. Incidence of pyomyositis has increased dramatically in our population and early diagnosis can result in a good outcome. We recommend MRI scan in all patients who present with a clinical picture of septic arthritis of the hip but with no effusion

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

Pyomyositis is a primary pyogenic infection in skeletal muscle, often progressing to abscess formation. It is rare in temperate climates and generally deep-seated within the pelvis with non-specific clinical features, making diagnosis difficult. Magnetic Resonance Imaging (MRI) is highly sensitive for muscle inflammation and fluid collection and with its increasing availability is now the investigation of choice. Treatment of pyomyositis abscess has traditionally been with incision and drainage or guided aspiration followed by a prolonged course of antibiotics, although there are sporadic reports of cases treated successfully with antibiotics alone. From our 20 year database of over 16000 paediatric orthopaedic admissions we identified only 3 cases with MRI-confirmed pyomyositis abscess. These were all in boys (aged 2-12) and affected the gluteal, piriformis and adductor muscles. Despite the organisms not being identified, each patient was treated successfully with a short (4-7 day) course of intravenous antibiotics followed by 2-6 weeks of oral therapy. There were no recurrences or complications and all made a full recovery. We propose that uncomplicated pyomyositis abscess in children may usually be managed conservatively without the need for open or percutaneous drainage

Pyomyositis in a temperate climate is a rare condition in children according the number of reports. Most authors postulate trauma with simultaneous bacteriemia is the most likely mechanism. We reviewed 8 cases, 4 boys and 4 girls. Their mean age was 9,2 y. ( 5 to 16 y.). Pain, tenderness, limp and fever were the most common signs. Duration of symptoms before initial evaluation was 8,1 d. (5 to 15 d.). 6 patients had fever (> 38,5°C), all had leukocytosis and a shift to the left in the WBC, and a elevated ESR 69,3 mm/h(32 to110), as well as an increased C-protein reactive (mean=10). All cases had radiographs, US in 6, CT scan in 6 and MRI in 5. These studies demonstrated involvement of psoas muscle in 4, obturator internus and externus in 3, and gluteal and quadratus femoris in 1. We found simultaneous involvement of ischiopubic ramus in 3, one iliac osteomyelitis, one piogenic sacro-ileitis, one supurative lymphadenitis and one resection for Crohn’s disease. Incision and drainage of muscular abcess (5 cases)plus IV antibiotics(8 cases) provided uneventfully resolution. 4 cultures were positive to Staf Aureus, 1 to E. Coli and 3 negatives. In this series we found 87% of pelvic pyomyositis with simultaneous septic factors. We consider them more causative factors than predisponing, and pyomyositis as a secondary entity. Previous reports propose pyomyo-sitis as a primary condition after a speculative bacter-aemia with a muscle strain, as the likeliest cause. MRI could be helpful to determine bone involvement or other regional problems in pelvic pyomyositis

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

Introduction: In temperate places pyomyositis is very uncommon in children and adolescents. West European and North American Literature about is relatively poor (104 articles from 1998 to nowadays and most of these papers are case-rep orts). S. Aureus is the etiologic agent in 90% of cases. Muscle of the thighs and hips are the most frequent localisation and severe complications are observed in 10% of cases. Material and Methods: We reviewed all patients affected by primary pyomyositis and admitted in our Department from 1995 to nowadays. Age, sex, history and clinical findings, general and local risk factors were reported. X-rays, Ultrasonography, MRI, Scintigraphy, Haematological investigation and culture were considered in order to state the imaging and laboratory findings of the disease. Result: Pyomyositis was diagnosed in three males, aged 11, 13 and 16. There was no evidence of medical or familiar risk factors. Soleus, Otturatorius and Psoas muscles were respectively involved. In all cases fever, local signs of inflammation and pain, neutrophylic leukocytosis, increased ESR and CRP levels were present. Blood culture was positive in one case. Standard X-Rays were normal in all cases. Ultrasound scan, RMI and Scintigraphy were positive but non-specific in all cases. 2 cases underwent to surgical drainage and a 3 weeks antibiotic therapy; 1 case resolved performing only medical treatment (5 weeks of antibiotic). All patients showed complete clinical, haematological, and RMI recovered without reliquates. Conclusions: Pyomyositis is uncommon in temperate climate and it may be easy misdiagnosed at the onset. In our patients the mean time from onset of symptoms to diagnosis was 10 days. History and clinical examination might be evocative, but there are no pathognomonic haematological or radiological findings so that diagnosis is often the result of extensive and wide considerations. Pyomyositis should be suspected in any unclear septic condition of the musculoskeletal apparatus. High index of suspicion, prompt diagnosis, and early treatment can prevent complications and allow the recovery of this potentially life-threatening disease