Magnetic resonance tomography in therapy follow-up after repositioning treatment of congenital hip dislocation

Abstract

After treatment of infantile hip dislocation in terms of reduction and retention in plaster casts or splints a problem of therapy controlling exists. To assess if the femoral head is in correct position centered in the socket ultrasound is not possible, because one cannot achieve the necessary standard position. Computertomograms are associated with a hereditary taint of radiation and plain roentgenograms lack of presentation of the important cartilaginous structures. To control infantile hips after open or closed reduction from 1990 until 1996, 43 examinations by MR imaging were performed in 34 children. In our series MRI was able to provide exact information about the position of the femoral head independently of its state of ossification. Also, a clearly visualisation of the different structures of the acetabular fossa, particular acetabulum, pulvinar, bony and cartilaginous acetabular rim and limbus was possible. Furthermore the MR images showed interpositioned soft tissue, intraarticular effusion and displayed cartilaginous parts of the acetabular rim. MRI is an exact method to assess the anatomical and pathological conditions of the childlike hip joint. Because of the disadvantages of CT and X-ray, MRI is superior in terms of controlling the results after treatment of infantile hip dislocation.