Reproducible simple fractures and osteotomies of the posterior wall of
the acetabulum were created in twenty paired hemipelves from fresh human
cadavera. Comminution was created with an additional fracture line that was
either parallel (concentric comminution) or perpendicular (transverse
comminution) to the posterior rim of the acetabulum. Under simulated
weight-bearing, the stiffness of fixation of the transversely comminuted
fractures that had been achieved with use of a reconstruction plate and
screws was significantly higher than that achieved with fixation with
screws alone (p < 0.05). The load to failure of the fixation of
transversely comminuted fractures treated with a reconstruction plate and
screws was also significantly higher than that of fixation of such
fractures with screws alone (p = 0.05). The load to failure of the fixation
of concentrically comminuted fractures was significantly higher when a
reconstruction plate and accessory spring plates had been used than when a
reconstruction plate alone had been employed (p < 0.05).