Background:
The purpose of this study was to determine the clinical outcome
in patients in whom a displaced fracture of the posterior wall of
the acetabulum had been treated by open reduction and internal fixation.
Methods:
One hundred patients who had had open reduction and internal fixation
of an unstable unilateral fracture of the posterior wall of the
acetabulum were studied. Ninety-four patients were assessed at a
mean of five years (range, two to fourteen years) after the injury.
Six patients with a poor result were followed for less than two
years. The functional outcome was evaluated with use of the clinical
grading system adopted by Letournel and Judet with incorporation
of modifications by Matta. Patient, fracture, and radiographic variables
were analyzed to identify possible associations with functional
outcome.
Results:
The reduction of the fracture, as determined with plain radiography,
was graded as anatomic in ninety-seven patients and as imperfect
in three. The clinical outcome at the time of final follow-up was
graded as excellent in fifty-five patients, very good in twenty-five,
good in nine, fair in one, and poor in ten. The radiographic result
was excellent in eighty-one patients, good in five, fair in four,
and poor in ten. There was a strong association between the clinical
outcome and the final radiographic grade. Variables identified as
risk factors for an unsatisfactory clinical result included a delay
of greater than twelve hours before reduction of an associated hip
dislocation, an age of fifty-five years or older at the time of
injury, intra-articular comminution, and osteonecrosis.
Conclusions:
The uncomplicated radiographic appearance and relatively simple
operative approach for fractures of the posterior acetabular wall
belie the risk of poor results. Prompt reduction of an associated
hip dislocation is imperative. Fractures in elderly patients and
those with extensive comminution are more likely to have a poor
clinical result. However, a high likelihood of a long-term good-to-excellent
result can be expected following anatomic reduction and internal
fixation of these fractures.