The unwell child with an acutely irritable hip poses a diagnostic dilemma. Recent studies indicate that pericapsular myositis may be at least as common as joint infection in the septic child. MRI might therefore be a critical first step to avoid unnecessary hip drainage surgery in the septic child with hip symptoms. We reviewed our own experience with MR imaging in this setting. We searched our PACS system to retrieve MRI scans performed for children with suspected hip sepsis from August 2008 to August 2014 using the following terms: hip, septic arthritis, osteomyelitis, mysositis, abscess, femur, acetabulum. 56 cases fulfilled inclusion criteria that included acute presentation with hip symptoms and 2 or more Kocher criteria for septic arthritis. Recent unsuccessful hip washout was not a contra-indication. 56 patients presented with acute infection around the hip. 47 (84%) had MRI scans before any surgical intervention and 9 (16%) had scans promptly following unsatisfactory hip washout with failure to improve. 20 (36%) were found to have pericapsular myositis. In this group, the infection commonly involved the iliopsoas (4), gluteal (4), piriformis (5) or obturator (7) muscles. 15 (27%) children had proximal femoral or acetabular osteomyelitis and 8 (14%) were diagnosed with septic arthritis. The 13 (23%) remaining scans did not show infection around the hip. This study confirms a high rate of extracapsular foci in septic children presenting with hip irritability. Less than 20% had actual septic arthritis in this series. While drainage of a septic joint should never be delayed in the face of a large joint effusion with debris on US, there is a clear role for MRI scanning in the acute setting when the diagnosis is less certain

In order to treat painful subluxation or dislocation secondary to cerebral palsy, 11 patients (12 hips) underwent combined femoral and Chiari pelvic osteotomies with additional soft-tissue releases at a mean age of 14.1 years (9.1 to 17.8). Relief of pain, improvement in movement of the hip, and in sitting posture, and ease of perineal care were recorded in all, and were maintained at a mean follow-up of 13.1 years (8 to 17.5). The improvement in general mobility was marginal, but those who were able to walk benefited the most.

The radiological measurements made before operation were modified afterwards to use the lateral margin of the neoacetabulum produced by the pelvic osteotomy. The radiological migration index improved from a mean of 80.6% (61% to 100%) to 13.7% (0% to 33%) (p < 0.0001). The mean changes in centre edge angle and Sharp’s angle were 72° (56° to 87°; p < 0.0001) and 12.3° (9° to 15.6°; p < 0.0001), respectively. Radiological evidence of progressive arthritic change was seen in one hip, in which only a partial reduction had been achieved, and there was early narrowing of the joint space in another. Painless heterotopic ossification was observed in one patient with athetoid quadriplegia. In seven hips the lateral Kawamura approach, elevating the greater trochanter, provided exposure for both osteotomies and allowed the construction of a dome-shaped iliac osteotomy, while protecting the sciatic nerve.