Abstract
Low energy hip dislocation in children is an uncommon injury (0.335% of injuries ) which represents a true orthopaedic emergency.
Case 1 ; A 6 year old girl attended hospital non-weightbearing with right thigh pain after slipping whilst attempting to kick a football. The leg was shortened and internally rotated with no neurovascular deficit. Radiographs revealed a posterior dislocation of the right hip. A closed reduction was undertaken in theatre within four hours. She was immobilised in a hip spica for 6 weeks. At six month review she was pain free and back to full activities. Radiographs showed no abnormality.
Case 2 ; A 5 year old boy attended A+E non-weight-bearing with right lower leg and knee pain having done the splits playing football. Examination of knee and lower leg showed pain but nil else. Radiographs of the knee were normal. He was discharged with a diagnosis of possible ACL rupture. He re-attended 2 days later with immobility and increasing pain. Examination showed a 2cm leg length discrepancy. Radiographs revealed a posterior hip dislocation. He underwent a closed reduction in theatre. He progressed well under regular review until 5 months post-injury. He had increasing pain and decreasing range of movement. Radiographs showed trans-epiphyseal avascular necrosis. He therefore underwent a varus de-rotation osteotomy. One year on he has returned to full activities. He has a mild decreased range of movement. Radiographs show a flattened epiphysis and a united osteotomy.
Hip dislocation requires less trauma in children due to ligamentous laxity and a soft pliable acetabulum. Overall 64% are low energy and 80% are posterior dislocations. Complications include AVN, arthritis, nerve palsy and recurrent dislocation. AVN is 20 times more common if reduction is after 6 hours.
This report highlights the importance of thorough examination, accurate diagnosis and early treatment of paediatric hip dislocation.
Theses abstracts were prepared by Mr Peter Kay. Correspondence should be address to him at The Hip Centre, Wrightington Hospital, Appley Bridge, Wigan, Lancashire WN6 9EP.
