Anterior Column of the Acetabulum  

- See: Classification and Column Theory

- Discussion:
    - anterior column extends from symphysis pubis & obturator foramen thru
              acetabulum to ASIS and up through iliac crest;
    - anterior column is less frequently fractured than posterior column due to frequency
              of posteriorly directed forces;
    - frxs of the anterior column may comprimise any portion of the column;
    - fracture line may extends from the middle of the pubic ramus to any point above
              anterior segment of the iliac crest;
    - most commonly, anterior column fracture exits below anterior inferior iliac spine;
    - distal anterior column fractures:
          - from exam of CT scan, look for frxs of superior pubic ramus which may
                    enter inferior portion of acetabulum, violating joint;
    - frx of anterior column frequently occur in middle or articular segment;
          - in this region bone is relatively thin and overlies the joint;
          - there is often comminution into quadrilateral plate surface;
          - area is less accessible becuase of overlying iliopsoas muscle & obturator internus muscle;
    - associated injuries: anterior hip dislocation;


- Radiographs:
    - Internal (Obturator) Oblique View:
          - visualizes iliopubic / iliopectineal line of pelvis & posterior acetabular rim;
          - disruption of the iliopectineal line indicates anterior column frx;
          - technique:
                 - patient is supine w/ involved side of pelvis rotated anteriorly 45 deg;
                 - central beam directed vertically toward the affected hip;

- Indications for Operative and Non Operative Treatment:
    - CT scan can give an indication of the amount of involvement of the wt bearing dome;
    - in the study by Vrahas MS, et al (1999), a cadaveric biomechanical study was performed to determine the relative stability of
           anterior column, posterior column, and transverse fractures;
           - they noted that anterior column fractures with an anterior roof-arc angle (obturator oblique radiograph) of 25 degrees or less
                     were unstable and required ORIF;
           - fractures which fall outside of this zone can potentially be treated non operatively;
           - ref: The effects of simulated transverse, anterior column, and posterior column fractures of the acetabulum on the stability of the hip joint.  



- Non Operative Treatment:
    - fractures must fall outside of the danger zone (roof-arc angle on obturator oblique radiograph of 25 degrees) and hip reduction
                must be congruent;
    - in some cases, traction is necessary to maintain the reduction;
    - if once the patient is mobilized, new radiographs can be taken to ensure that the frx postion has not shifted;



- Surgical Treatment:  
    - surgical approach: ilioinguinal
           - frx of anterior column are exposed using ilioinguinal approach w/ supine positioning;
    - reduction and initial fixation:
          - initial fixation of anterior column may require interfragmentary screws & plates to stabilize frx
                    of iliac wing, depending on fracture type;
          - during reduction, reestablishment of pelvic brim allows reconstruction of entire anterior column (iliac fossa is more concave
                    than is often appreciated);
          - initial reduction reduction may be obtained w/ lateral traction applied by a half pin inserted in the femoral neck;
    - percutaneous fixation: (Internal (Obturator) Oblique View:)
          -
The Modified Iliac Oblique - Outlet View: A Novel Radiographic Technique for Antegrade Anterior Column Screw Placement.
          - Percutaneous Fixation of Anterior and Posterior Column Acetabular Fractures
          - Axial view of acetabular anterior column: a new X-ray projection of percutaneous screw placement

    - implants:
synthes implants
          - early application of precurved plates simplifies the reduction;
          - plate is slide underneath musculature of iliopsoas and femoral vessels;
          - plate attached to body of pubis w/ a screw & then plate is rotated along superior pubic ramus until it
                     sits congruently on iliopectineal line and pelvic brim; 
          - plate extends posteriorly along pelvic brim from posterior part of iliac fossa and anteriorly to
                     pubic symphysis;
          - screw purchase is best obtained far medially on superior pubic ramus and posteriorly, in iliac wing;
          - because frx of ischiopubic ramus are difficult to reach & do not appear to significantly influence end
                     results, no attempt is made to stabilize this component of the fracture;



    - Case Example:
          25 year old male involved in MVA, sustaining an iliac wing fracture and a low transverse acetabular frx;

                   


- Danger Zone: (from Benedetti et al. 1996)
    - diagram shows danger zone at 1, 2, and 3 cm above the inferior acetabulum rim;
    - in general the danger zone extends about 2.5 cm medially from the acetabular rim;

- Screw Placement into the Anterior Column:
    - applicable for T-type frx, transverse frx, and both column frx;
    - 1 cm above the inferior edge of the acetabulum:
          - at 0.5 mm lateral to the pelvic brim, screw are inserted at 25 deg of medial angulation
                   (screw length 20 mm);
          - at 1.0 cm lateral to the pelvic brim, screw are inserted at 35 deg of medial angulation (screw length
                   20-25 mm);
          - at 1.5 cm lateral to the pelvic brim, screw are inserted at 45 deg of medial angulation (screw length 25 mm);
    - 2 cm above the inferior edge of the acetabulum:
          - at 0.5 mm lateral to the pelvic brim, screw are inserted at 30 deg of medial angulation (screw length 20 mm);
          - at 1.0 cm lateral to the pelvic brim, screw are inserted at 40 deg of medial angulation (screw length 20-25 mm);
          - at 1.5 cm lateral to the pelvic brim, screw are inserted at 50 deg of medial angulation (screw length 25 mm);
    - 3 cm above the inferior edge of the acetabulum (level of ASIS):
          - at 0.5 mm lateral to the pelvic brim, screw are inserted at 20 deg of medial angulation (screw length of 45 mm);
          - at 1.0 cm lateral to the pelvic brim, screw are inserted at 30 deg of medial angulation (screw length of 45-50 mm);
          - at 1.5 cm lateral to the pelvic brim, screw are inserted at 40 deg of medial angulation (screw length of 50 mm)



- Percutaneous Screw Placement
   

Anterior column fractures of the acetabulum.

Anatomic Considerations of Plate-Screw Fixation of the Anterior Column of the Acetabulum.

Acetabular fracture fixation via a modified Stoppa limited intrapelvic approach. Description of operative technique and preliminary treatment results.

Percutaneous Fixation of the Columns of the Acetabulum. A New Technique.  

Percutaneous Screw Fixation of Acetabular Fractures: Applicability of Hip Arthroscopy 

The surgical treatment of anterior column and anterior wall acetabular fractures: short- to medium-term outcome.

The Pararectus approach for anterior intrapelvic management of acetabular fractures. An anatomical study and clinical evaluation

Cerclage wiring in displaced associated anterior column and posterior hemi-transverse acetabular fractures.




- PreOp Planning:




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

Last updated by Data Trace Staff on Thursday, July 28, 2016 7:05 am