Risk factors for conversion to total hip arthroplasty after acetabular fractures.

OBJECTIVES

To identify acetabular fracture patterns classified according to Letournel that are at risk of conversion to total hip arthroplasty (THA).

DESIGN

A retrospective cohort study.

SETTING

A Level-I trauma center.

PATIENTS/ PARTICIPANTS: Patients with an acetabular fracture, classified according to Letournel who were treated with ORIF (n = 280).

INTERVENTIONS

Various surgical treatments for acetabular fractures.

MAIN OUTCOME MEASURE

The primary outcome was the rate of conversion to total hip arthroplasty.

RESULTS

In this study, an overall conversion rate to THA of 13.9% within 2.2 years after initial surgery was found. Multivariate analysis revealed that several factors, namely, T-shaped fracture patterns (OR: 7.5, 95% CI 1.9-28.8, p = 0.003) and residual displacement (> 2 mm) (OR: 3.7, 95% CI 1.6-8.5, p = 0.002) are associated with an increased risk of conversion to THA. Furthermore, the risk of conversion to THA increases with 4.7% per gained year of age (OR: 1.047, 95% CI 1.0-1.1, p = 0,001). Other fracture patterns classified according to Letournel were not found to be independent risk factors.

CONCLUSION

The presence of T-shaped fracture patterns is found to be an independent risk factor for conversion to THA. Furthermore, age and degree of reduction are found to be independent risk factors, which is in line with existing literature. These finding should be taken into account when treating patients with T-shaped acetabular fractures.

LEVEL OF EVIDENCE

Prognostic study level III. See Instructions for Authors for a complete description of levels of evidence.