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.

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. We present the method for measuring the roof arc on radiographs and estimating this arc on ct scans. 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.

Average medial anterior and posterior acetabular roof arc angles of the absawba of 94 normal acetabulum were 39 09 7 41 42 49 8 15 and 55 26 10 08 degrees respectively. Less than 39 42 and 55 of medial anterior and posterior acetabular roof arc angles involve absawba of the femoral head. These roof arc angle values may be used as a surgical guideline for an acetabular fracture around the weight bearing area.