Native hip dislocation at acetabular fracture predicts poor long-term outcome

The aim of this study was to evaluate the long-term clinical outcomes and complications following an acetabular fracture associated with a posterior hip dislocation compared to those without dislocation.

A retrospective cohort study of 113 patients (mean age 42 (14-95), 77% male) with acetabular fracture dislocations compared to 367 patients with acetabular fractures without dislocation (mean age 54 (16-100), 66% male) treated from 1988 to 2010. Patient characteristics, complications, reoperations, and conversion to total hip arthroplasty (THA) were recorded. Long term patient reported outcomes (Oxford Hip Score and SF-12) were measured at mean follow up 9.7 years (5-26).

At long-term follow up 12/113 (11%) patients had died and 22/113 (19%) were lost. Isolated posterior wall fracture was the most common fracture associated with dislocation. Patients with dislocation were more likely to be younger and male with higher Injury Severity Scores (ISS). There was no significant difference in radiographic post-traumatic osteoarthritis development between fractures with and without dislocation (p = 0.246). Sciatic nerve palsy (12% Vs 1%, p < 0.001) and avascular necrosis (AVN) (11% Vs 1%, p < 0.001) were more common when dislocation was present. AVN was associated with increasing age and hypotension on arrival to the emergency department. Ten-year native hip survival was worse following fracture dislocations compared to fractures without dislocation: 75.1% (65.7-84.5 95% CI) Vs 90.7% (87.0-94.4), p < 0.001. Significant predictors of THA requirement were older age, particularly age >55 years at fracture, and increased ISS. Long-term OHS was worse in fractures with dislocations (33.6 ± 13.1 Vs 37.0 ± 14.0, p = 0.016).

Acetabular fractures with an associated dislocation have worse long-term functional outcomes with higher rates of complications and conversion to late THA compared to acetabular fractures without a dislocation.