The Comparison Of Morphological Characteristics Of The Posterior Wall Fragments Between Acetabular Both Column Fracture And Posterior Wall Fracture

Objectives:Acetabular both column fractures were sometimes associated with posterior wall fractures.Traditional views was suggested that such posterior wall fracture required additional internal fixation at the same time of reduction and fixation of both column fracture.The mechanisms of injury between the posterior wall associated with both column fractures(Associated PW)and isolated acetabular posterior wall fracture(Isolated PW)were completely different,leading to the morphological discrepancy of the posterior wall fragments.In this study,two different types of acetabular fractures were compared and measured in morphology,analyzing the difference of the stability of the posterior wall fracture caused by two mechanisms,to find the theoretical support for the treatment protocol of acetabular both-column fractures with posterior wall involvement.Methods:The study randomly selected patients from the Trauma Emergency Center of the Third Hospital of Hebei Medical University between February 2015 and April 2018.Twenty patients with acetabular both column fractures with posterior wall involvement were selected into group A(BC Associated PW)and 20 patients with acetabular posterior wall fractures were selected into group B(Isolated PW).The preoperative CT scans of two groups were analyzed in morphology and select the appropriate sections.A series of indicators were measured and compared by computer software,which included direction angle,displacement,internal-posterior length ratio and articular surface area of fracture segment.The Interclass correlation coefficient(ICC)was used to evaluate the reliability of the measurement results.Results:The demographic details of the two groups were no statistically significant differences(P>0.05).The direction angle,displacement,internal-posterior length ratio and articular surface area of group A(BC Associated PW)are respectively 113.13°±7.98°,6.70(3.13)mm,0.91±0.13 and784.53±246.53 mm~2.The results of group B(Isolated PW)are respectively58.35°±8.52°,30.90(22.37)mm,0.56±0.08 and 529.91±256.05 mm~2.The differences were statistically significant between two groups(P≤0.05).The intraclass correlation coefficient(ICC)of the measurements including intraobserver and intraobserver were more than 0.8,which were considered as strong reliability.Conclusions:The mechanism,morphology,and the displacement direction of the posterior wall associated with both-column fractures is significantly different from that of an acetabular isolated posterior wall fracture.Treatment of the posterior wall fragment involved in both-column fractures of the acetabulum should be different from that for isolated acetabular posterior wall fracture.