Internal fixation of osteopenic acetabular fractures involving the quadrilateral plate

Older patients tend to have acetabular fractures with medial displacement patterns and associated comminution, particularly of the quadrilateral surface. Our goal was to investigate the appropriateness of open reduction and internal fixation using an infra-pectineal buttress plate for osteopenic acetabular fractures.

We conducted a retrospective review involving twenty one consecutive patients over the course of 4 years with an acetabular fracture in an academic level 1 trauma centre. We performed the modified Stoppa approach with buttress plating of the quadrilateral surface. Clinical examination radiographs was done using criteria described by Matta. Functional outcome was evaluated using surveys including SF-12, WOMAC, Harris Hip score and modified Postel Merle D'Aubigne.

Average follow-up was 4.2 years with a minimum of 2 years. Mean age for patients was 64.3 years. We obtained anatomic reduction in 52.4% (11/21) of cases, imperfect reduction in 38.1% (8/21) of cases and poor reduction in 9.5% (2/21) of cases. Significant loss of reduction was seen in 2 patients. A superior dome impaction (a Gull sign) was correlated to arthroplasty (p=0.02) and reduced quality of initial reduction (p=0.02). Two patients required re-intervention with a total hip arthroplasty. There was one traumatic injury to the obturator nerve and 2 patients were noted to have temporary weakness of the hip adductors postoperatively.

Internal fixation using the modified Stoppa approach to buttress the quadrilateral plate should be considered a viable alternative to total hip arthroplasty for the initial treatment of acetabular fractures in the elderly.