Roof Arc Measurements For Acetabular Fx

In acetabular fracture a medial roof arc angle less than 46 an anterior roof arc angle less than 52 or posterior roof arc angle less than 61 is considered to be involved in a weight bearing area.

Roof arc measurements for acetabular fx.

For patients with acetabular fractures the extent to which a fracture involves the weight bearing dome has been estimated with the roof arc measurement obtained on radiographs and computed tomographic ct studies. In acetabular fracture a medial roof arc angle less than 46 degrees an anterior roof arc angle less than 52 degrees or posterior roof arc angle less than 61 degrees is considered to be involved in a weight bearing area. The criteria to treat acetabular fractures operatively versus nonoperatively continue to evolve. The technique of roof arc measurements was developed to identify the extent of superior acetabulum left intact after fracture.

Computerized tomography ct of the superior 10 mm of the acetabular articular surface evaluates the area equivalent to roof arc measurements of 45. Roof arc measurements roof arc measurements are defined as the angle formed by a line parallel to the patient passing through the center of the acetabulum and a line from the center of the acetabulum to the fractured area of the dome. Less than 39 42 and 55 of medial anterior and posterior acetabular roof arc angles involve absawba of the femoral head.