[Percutaneous fixation of anterior column acetabular fractures--first experience]

Abstract

Purpose of the study: Percutaneous fluoroscopy-assisted fixation of acetabular fractures is not a widely used technique. Its advantage lies particularly in percutaneous placement of screws in the anterior column of the acetabulum. The operative procedure is described and the first experience of the authors with this minimally invasive technique at their department is reported.

Material: Between December 2007 and April 2009, 10 fractures of the anterior column of the acetabulum were treated by percutaneous stabilisation in 10 patients. There were six men and four women aged 25 to 76 (average, 46) years. Retrograde screw fixation was used in three, anterograde screw fixation in two and anterograde screw placement following retrograde guide wire insertion in five patients.

Methods: The minimally invasive method of acetabular stabilization using 6.5-mm or 7.3-mm cannulated screws was facilitated by the use of intra-operative fluoroscopic imaging. Following fracture reduction, a percutaneous guide wire, aided by a C-arm, was placed in the upper pubic ramus and the anterior column of the acetabulum in either an anterograde or a retrograde mode. Subsequently, a traction cannulated screw was inserted. When anterograde guide wire placement was difficult to do, the retrograde guide wire placement was used for anterograde screw insertion. The quality of fracture reduction and the placement of screw were evaluated by a post-operative CT examination.

Results: The average follow-up was 11 (range, 2-19) months. The average operative time necessary for percutaneous screw insertion in the anterior column of the acetabulum was 26.4 (range, 15-45) min, and the average X-ray exposure time for the screw placement was 3 min and 13 sec (range, 40-448 sec). The average time needed for screw insertion following the retrograde guide wire was 2 min and 30 sec (range, 40-242 sec). The average post-operative fragment dislocation leading to incongruency was 1.3 mm (range, 0-4 mm). The results of reduction assessed as excellent (<2 mm) and poor (>or=2 mm) were achieved in six and four patients, respectively. No screw malplacement was recorded. Post-operative infectious complications occurred in one (10 %) patient.

Discussion: Important factors for avoidance of intra-operative complications included a thorough pre-operative planning on the basis of CT diagnostic examination, meeting the indication criteria and using a safe stabilisation technique. However, the percu- taneous fluoroscopy-assisted method requires a longer exposure to X-ray than do the techniques utilising computerised navigation. The occurrence of infectious complications was not lower than with the use of open reduction and internal fixation methods.

Conclusions: After the operative technique has been mastered, the minimally invasive method of osteosynthesis is likely to become a method of choice for certain kinds of acetabular fractures. The current, most frequent indications are minimally displaced transverse fractures, T-shaped fractures and anterior column acetabular fractures. A limiting factor of this technique is reduction. It is certain that further evolution of this technique and its more frequent use will be associated with computerised navigation.