Comparison of open reduction and internal fixation and primary total hip replacement for osteoporotic acetabular fractures: a retrospective clinical study.

Purpose: Treating acetabular fractures with open reduction and internal fixation (ORIF) may lead to poorer outcomes in older patients. As data for osteoporotic acetabular fractures are limited, we compared primary total hip replacement (THR) with ORIF for treating osteoporotic acetabular fractures, including those with posterior column instability.

Methods: All patients with osteoporotic acetabular fractures, treated with ORIF or primary THR from 2005 to 2015, were assessed retrospectively for clinical and radiologic outcomes. Indication criteria for selecting primary THR were evaluated.

Results: Twenty-three patients were treated with ORIF and nine with primary THR (performed with an anti-protrusion cage). If the posterior column was unstable, THR was combined with posterior column bridge plating. Indications for THR were the presence of a comminuted fracture pattern, approach-related risk factors for ORIF, and mobilization issues. Biomechanical reconstruction was acceptable with THR. Acetabular component loosening was observed only once. Secondary THR was indicated in 45 % of the ORIF cases.

Discussion: ORIF for acetabular fracture in older patients is unsatisfactory and may be even worse for osteoporotic fractures. Immobilization for long-term restricted weight bearing after ORIF is hazardous. Primary THR may enable early post-operative full weight-bearing. Various techniques, affording fixation of the unstable acetabular columns, are described. In THR with an anti-protrusion cage, only dorsal column instability needs to be addressed.

Conclusion: The described technique achieved sufficient acetabular component stability. Primary THR with an anti-protrusion cage is an advantageous option to ORIF and should be strongly considered for osteoporotic acetabular fractures.