MRI for paediatric flatfoot: is it necessary?

OBJECTIVE: To determine the additional benefit of MRI for children with flatfoot deformity assessed with weight-bearing radiographs in a specialist paediatric orthopaedic unit. METHODS AND MATERIALS: Patient cohort was obtained by searching the Radiology Information System for children referred for investigation of flatfoot. All patients with flatfoot on weight-bearing radiographs who had undergone MRI were included. Radiographs were classified by a consultant musculoskeletal radiologist as showing no underlying abnormality, talo-calcaneal coalition, calcaneonavicular coalition, accessory navicular or other abnormality. MRI studies were classified similarly by a different consultant musculoskeletal radiologist blinded to the radiographic findings. RESULTS: 33 males and 24 females were included (mean age 12.5 years; range 3-18 years). 24 had bilateral abnormality, so 81 feet were assessed. Radiographs showed no specific abnormality (n = 51), talocalcaneal coalition (n = 6), calcaneonavicular coalition (n = 3), os naviculare (n = 12) or other abnormality (n = 9). MRI showed no specific abnormality (n = 40), talocalcaneal coalition (n = 10), calcaneonavicular coalition (n = 5), os naviculare (n = 12) or other abnormality (n = 14). Assuming MRI as the diagnostic gold-standard, additional relevant diagnostic information was identified in 19 (23.5%) cases, while in the 51 cases for which radiographs provided no specific diagnosis MRI confirmed no underlying abnormality in 31 (60.8%). CONCLUSION: MRI is a valuable adjunct to weight-bearing radiography for investigating paediatric flatfoot deformity. ADVANCES IN KNOWLEDGE: MRI is of value in the assessment of paediatric flatfoot, additional diagnostic information to radiography being identified in 23.5% cases, while in 60.8% of cases for which radiographs provided no specific diagnosis MRI confirmed no underlying abnormality.

Multimodality imaging of the paediatric flatfoot.

Flatfoot is commonly encountered in the paediatric population and describes a spectrum of clinical and radiological presentations which encompass both normally developing and pathological feet. Flatfoot can be categorised as flexible or rigid, a distinction which has important implications when considering the potential underlying aetiology and treatment options, and therefore imaging is an important component of the diagnostic workup. Weight-bearing plain radiographs are established initial investigations, although the significance of a number of the commonly derived quantitative parameters in children remains unclear. CT and MRI are important additional imaging modalities reserved for the investigation of symptomatic cases or those in which an underlying structural abnormality is suspected, rigid flatfoot commonly falling into one of these two categories. We review and illustrate the multimodality imaging of the paediatric flatfoot, with reference to both qualitative and quantitative radiographic assessment and cross-sectional imaging appearances.

The incidence and relevance of non-fatty components in trunk and extremity lipomatous soft tissue masses.

OBJECTIVES: To determine the incidence and diagnostic relevance of non-fatty 'solid appearing' components within lipomatous tumours of the trunk and extremity. METHODS AND MATERIALS: Retrospective review of patients referred to a specialist musculoskeletal oncology service over a 12-month period with a lipomatous trunk or extremity soft tissue tumour. The presence and morphology (solitary/multifocal; homogeneous/heterogeneous; well-defined/poorly defined) of non-fatty components was recorded based on MRI and compared with the final histological diagnosis. RESULTS: 213 patients with 217 lipomatous tumours were included, 119 (55.9%) males and 94 (44.1%) females with mean age of 54.6 years (range 7-93 years). Seventy-seven (35.5%) lesions arose superficial to the fascia and 139 (64.1%) deep, while a single case involved both compartments. Mean maximal tumour dimension was 94.9 mm (range 12-288 mm). Non-fatty 'solid appearing' components were identified in 28 (12.9%) cases, of which eight were solitary and 20 were multifocal, six had homogeneous SI and 22 had heterogeneous SI, and eight had well-defined margins, while 20 had poorly defined margins. Histological diagnosis was available in 20 of the tumours containing non-fatty components, 16 of which were benign, two intermediate grade and two malignant (a dedifferentiated liposarcoma and a myxoid liposarcoma). The commonest diagnosis was spindle cell lipoma, which accounted for 10 of 20 (50%) cases with confirmed histology. CONCLUSIONS: Non-fatty components are identified in ~13% of trunk and extremity lipomatous tumours. The majority of such lesions are benign lipoma variants, most commonly spindle cell lipoma. ADVANCES IN KNOWLEDGE: Solid non-fatty components are identified in approximately 13% of lipomatous tumours referred to a specialist sarcoma service. Despite the concern that these may represent dedifferentiated liposarcomas, high-grade tumours were seen in only two cases, the commonest diagnosis being a spindle cell lipoma.

The rare primary bone sarcomas: imaging-pathological correlation.

Rare primary bone sarcomas are challenging entities both radiologically and pathologically. These include the diagnoses of spindle cell sarcoma (leiomyosarcoma, fibrosarcoma, synovial sarcoma, and malignant peripheral nerve sheath tumor), pleomorphic liposarcoma, and undifferentiated pleomorphic sarcoma. The radiographic and cross-sectional imaging features of each of these tumors are presented, along with current key pathological concepts. Frequently non-specific, the radiological appearances must be correlated with all clinical and pathological information available to enable an accurate diagnosis.

Initial seronegative immune-mediated necrotising myopathy with subsequent anti-HMGCR antibody development and response to rituximab: case report.

BACKGROUND: Immune-mediated necrotising myopathy (IMNM) is characterised by severe muscle weakness and necrosis with a paucity of inflammation on muscle biopsy. Around 60% of cases are associated with antibodies to the signal recognition particle (SRP) or 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR); the remainder are seronegative. IMNM is more treatment resistant than inflammatory myopathies. CASE PRESENTATION: A 69-year-old woman with previous statin exposure presented aged 63 with muscle weakness and raised creatinine kinase (CK). Anti-SRP and anti-HMGCR antibodies were not detected, but muscle biopsy revealed changes consistent with necrotising myopathy. Statins were discontinued, and she was treated with prednisolone and methotrexate achieving disease remission. Clinical and biochemical parameters were largely stable until 6 years after diagnosis she experienced a rapid deterioration. This was found to be associated with new development of anti-HMGCR antibody. Rituximab was commenced, resulting rapidly in remission. She has remained in remission since, following 2 cycles of rituximab. CONCLUSIONS: To our knowledge, this is the first reported case of serologically negative IMNM whose subsequent rapid deterioration was associated with development of anti-HMGCR antibody. The response to rituximab and subsequent sustained remission suggests a role for early use of rituximab in aggressive cases of anti-HMGCR myopathy.

Vascular anomalies of the head and neck in children.

Sixty percent of vascular anomalies in children are found in the head and neck. These lesions can present throughout antenatal, perinatal and childhood development. They broadly fall into two categories: vascular tumours and vascular malformations. Their clinical and, often, psychological impact is determined by both pathological type and location: many lesions follow an uncomplicated natural course and other more complex, extensive or progressive lesions can present a threat to life from mass effect, haemorrhage or large volume arteriovenous shunting. Vascular tumours include infantile haemangioma (IH), congenital haemangioma (CH) and kaposiform hemangioendothelioma (KH); of which IH is the most common. Management options for vascular tumours include conservative approaches, oral medications and surgical intervention as determined by tumour type, location and associated complications. Vascular malformations can be categorised into low flow and high flow lesions. Low flow lesions include capillary, venous and lymphatic malformations (LMs). High flow lesions describe the arteriovenous malformations (AVMs), a highly heterogeneous group of lesions which can present in a variety of ways-the mainstay of treatment for these dynamic lesions is endovascular or surgical obliteration. We provide a practical framework for clinical classification of vascular anomalies of the head and neck in children. We also explore principles of their clinical and radiological assessment along with management, highlighting the importance of a multi-disciplinary approach.