Outcome of unstable isolated fractures of the posterior acetabular wall associated with hip dislocation.

BACKGROUND: Traumatic hip dislocation with fracture of the posterior acetabular wall is associated with high rates of residual invalidity.
METHODS: The records of patients who underwent surgical treatment of traumatic dislocation of the hip associated with an isolated fracture of the posterior acetabular wall from 1999 to 2009 were reviewed. There were 30 men and 12 women, who at the time of the trauma had a mean age of 42 years (range 21-65). Mean follow-up duration was 5 years (range 2-10). Pre-operative fracture evaluation was based on the classification of Judet et al. which divided this fractures into three types: type 1 is characterized by a single fracture line separating a single bone fragment from the remaining part of the posterior wall; type 2 fracture involves several fragments of the posterior wall and in type 3, a type 1 or type 2 fracture is associated with a sunk cancellous area in the acetabular wall medial to the fracture line but not affected by it, due to the shear impact of the femoral head at the time of dislocation. Clinical evaluation of the outcome was according to the criteria of Merle D'Aubigné and Postel as modified by Matta. Outcomes were divided into excellent/good and fair/poor. Since treatment was standard, data were further analyzed to assess the relative importance of age, sex, follow-up duration, sciatic nerve lesion on admission and mechanism of injury, using the Chi-square test.
RESULTS: Full clinical recovery without sequelae or radiographic abnormalities was achieved by 10 patients, 8 with type 1 fracture and 2 with type 2 fracture. A good outcome was seen in 13 patients, 3 with type 1 fracture, 9 with type 2 fracture and 1 with type 3 fracture. Eight patients, 3 with type 2 fracture and 5 with type 3 fracture, had a fair outcome. Only follow-up ≥6 years influenced outcome significantly (p > 0.005).
CONCLUSION: Our conclusions in light of our experience are that in type 1 lesions, anatomical reduction and stabilization achieve excellent outcomes, both clinical and radiographic; type 2 fractures pose greater prognostic problems because their outcome is determined by the success of the reduction and fixation of a multi-fragment fracture; finally, different considerations apply to type 3 fractures, which present varying degrees of comminution and an impacted acetabular surface: their outcome depends on the quality of the anatomical and morphological restoration of acetabular congruence.