The acetabular T-type fracture. A biomechanical evaluation of internal fixation.

The purpose of this study was to evaluate the stability of different types of internal fixation requiring anterior, posterior, or combined surgical approaches for the T-type acetabular fracture. Eight specimens were loaded 25 times in a cyclic manner to 150 N for each type of fixation construct evaluated. The model attempted to range the hip through an arc of motion anticipated in the limited activities expected after surgery. Strain gauges were placed on the 3 fracture planes of the T-type fracture. These gauges measured displacements. Internal fixation consisted of a single anterior column plate, compared with a single posterior column plate, compared with simultaneous placement of both anterior column and posterior column plates. The differences in displacements measured between the 3 types of fixation at each of the 3 fracture sites were not statistically significant. In evaluating motion at the anterior fracture line, the anterior plate made the largest contribution to stability, although this result was not statistically significant. The posterior plate similarly contributed most to posterior fracture stability, although again not statistically significant. Each of the 3 fixations controlled the inferior fracture line motions in a comparable manner.