The Hip: Preservation, Replacement and Revision Tracking Pixel
Duke Orthopaedics
presents
Wheeless' Textbook of Orthopaedics

Roof Arc Measurements for Acetabular Frx 

 - Discussion
    - roof arc concept (Matta, et al (1986)), and was based on analysis of 204 acetabular fractures with avg 3.7 year follow up;
    - helps determine the amount of intact acetabular dome;
    - is a useful method for determining need for surgery, however, it is less predictive for two column injuries & posterior wall frx;
    - radiographs need to be taken w/ the patient out of traction;

- Measurement:
    - these are made on AP, obturator and iliac oblique views;
    - vertical line is drawn to the geometric center of the acetabulum;
    - another line is drawn through point where frx line intersects acetabulum & again to geometric center of the acetabulum;
    - angle drawn in this way represents medial, anterior, or posterior roof arc as seen on AP, obturator oblique, or iliac views, respectively;
    - medial roof arc:
          - AP view;
          - verticle line is drawn from roof of acetabulum to geometric center of the femoral head;
          - second line is drawn from fracture to the geometric center;
          - angle subtended by these lines forms the medial roof arc;
          - this measurement applies to transverse acetabular fractures and if less than 45 deg, frx is unstable and requires ORIF;
    - anterior roof arc:
          - obturator oblique view
          - this measurement applies to anterior column fractures and if the roof arc is less than 25 deg, then the frx is unstable and requires fixation;
    - posterior roof arc:
          - iliac oblique view
          - this measurement applies to posterior column fractures and if less than 70 deg, then the frx is unstable and requires fixation



Fractures of the acetabulum. A retrospective analysis.     

The Effects of Simulated Transverse, Anterior Column, and Posterior Column Fractures of the Acetabulum on the Stability of the Hip Joint

Roof-arc angle and weight-bearing area of the acetabulum.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, September 13, 2012 3:31 pm