Radiographic appearance of changes produced in the pelvis by hip stabilization procedures.

Abstract

The intent of this report is to present the rather striking appearance of the pelvis after subjection to the Sharrard or Mustard operations for hip stabilization. This appearance may be quite misleading to radiologists who are not aware of these procedures. The Sharrard operation as performed by Dr. John Sharrard of the Children's Hospital, Sheffield, England, has been described in detail by Dr. J. H. Allan (1). It is being performed at several centers in the United States, and radiologists may expect to be confronted with this iatrogenic change. The Mustard operation is, however, more widely recognized (2). The operation consists of an iliopsoas transfer used to provide hip stability for patients with hip abductor weakness and is most commonly performed in myelomeningocele. Following an adductor tenotomy, the iliopsoas muscle is transplanted from the lesser trochanter of the femur, posteriorly, through a hole in the wing of the ilium, and attached to the greater trochanter of the femur. The Mustard operation is a similar procedure, except that the iliopsoas muscle is transferred posteriorly through a notch cut in the iliac wing, rather than through a hole. Comments Radiographically, the Sharrard operation results in a window in the mid ilium, and the Mustard operation in a fossa in the lateral aspect of the ilium (Fig.1). As observed over a period of years, these defects become smoothly outlined and in children appear to grow in proportion to the size of the bone (Fig.2). The appearance may be misleading in that evidences of surgery are lost, and we may be given the impression of a developmental or original bone lesion. Summary The Sharrard and Mustard operations for iliopsoas transplantation produce defects in the ilium which result in a striking radiographic appearance. These defects may be mistaken for developmental or original lesions if not recognized as postsurgical changes.