Predictors of clinical outcomes after surgical treatment of displaced acetabular fractures in the elderly.

Outcomes following the open reduction and internal fixation (ORIF) of displaced acetabular fractures in the elderly have been inconsistent. Several factors associated with significant poor clinical outcomes have been reported; however, the factor that contributes independently to the outcomes remains unknown. This study aims to identify independent prognostic factors for the outcomes of surgically treated displaced acetabular fractures in the elderly. A total of 86 elderly patients with displaced acetabular fractures were treated by ORIF between May 1990 and June 2010. Matta's criteria and modified Merle d'Aubigne-Postel score were used as reduction grades and clinical outcome measures, respectively. Reduction grades and six radiographic features were identified as prognostic factors. The six radiographic features include quadrilateral plate fracture, Gull sign, posterior dislocation of hip, femoral head injury (FHI), comminuted posterior wall fracture (CPWF), and posterior wall marginal impaction. The average clinical score of the patients associated with the six radiographic features was 14.4 ± 3.1, whereas the average clinical score for those without was 17.2 ± 1.6 points. The average clinical score of the patients with anatomical, imperfect, and poor reduction were 16.8 ± 2.4, 14.5 ± 2.3, and 11.3 ± 1.4 points, respectively. Multivariate analysis identified three independent predictors of clinical outcomes: reduction grades (t = -10.45, p = 0.000), CPWF (t = -2.74, p = 0.008), and FHI (t = -3.51, p = 0.000). Both CPWF and FHI are important risk factors for clinical outcome. The postoperative quality of reduction independently predicted patient prognosis, and anatomical reduction is predictive of a good prognosis.