A new internal fixation technique for acetabular fractures involving the quadrilateral plate

Background: The treatment of acetabular fracture involving the quadrilateral plate is a technical challenge, and the optimal management of the fracture remains controversial. We have designed a new implant (named acetabular fracture reduction internal fixator, AFRIF) for acetabular fractures involving the quadrilateral plate. This use of this new device was not investigated therefore we conducted a retrospective study aiming to determine whether the AFRIF can achieve satisfactory clinical and radiological outcomes for quadrilateral plate fracture.

Hypothesis: The AFRIF for quadrilateral plate fracture is an acceptable option to treat acetabular fracture involving the quadrilateral plate.

Materials and methods: We performed a retrospective analysis of prospectively collected data on 24 patients (15 males and 9 females) with acute displaced quadrilateral plate fractures of the acetabulum who were treated by the AFRIF between August 2011 and May 2015. The mean age of the patients was 61.5±9.2 years (range, 31-82 years). All hips had protrusion of the femoral head, of these 5 hips with associated articular impaction of the medial roof. The type of fractures included anterior column in 4, anterior column+posterior hemitransverse in 3, associated both column in 11, T-shaped in 6 patients. The approaches included Limited Ilioinguinal (5 patients) and Limited Standard-Ilioinguinal combined with Kocher-Langenbeck (19 patients). Quality of reduction was evaluated and graded as anatomical (0mm to 1mm of displacement), imperfect (2mm to 3mm displacement) or poor (more than 3mm displacement) according to the residual displacement as defined by Matta. The final follow-up clinical outcome was classified as excellent (18 points), good (15-17 points), fair (13-14 points) or poor (<13 points) in terms to the modified Merle d'Aubigné-Postel score, and radiological outcomes evaluation were as excellent, good, fair, or poor based on Matta score.

Results: The mean duration of follow-up was 45.7±13.0 months (range, 24-60 months). Average operative time and bleeding amount was 110.3±30.8min (range, 105-210min) and 950.6±348.6ml (range, 300-1500ml), respectively. There was anatomical reduction in 17 patients (17/24, 70.8%), imperfect in 5 patients (5/24, 20.8%), and poor in 2 patients (2/24, 8.3%). All of the quadrilateral plate fractures achieved anatomical except one imperfect reduction. No re-protrusion of the femoral head was observed at the final follow-up. The mean modified Merle d'Aubigné-Postel score was 16.9±2.0 points (range, 10-18 points), and 83.3% (20 of 24) have good or excellent radiological outcomes.

Discussion: The findings suggest that the AFRIF for quadrilateral plate fractures may prevent protrusion of the femoral head and achieve good to excellent clinical and radiological outcomes.

Level of evidence: IV, retrospective study.