Impaction bone grafting combined with lateral trabecular augments in acetabular revision surgery: a case-control study.

Background: Impaction bone grafting (IBG) has been shown to be effective and reliable for contained or medial large acetabular defects, but large segmental rim defects may need alternative options for reconstruction. We hypothesised that IBG combined with lateral trabecular augments in large segmental acetabular bone defects can provide comparable results to IBG combined with conventional metallic meshes.

Methods: In a series of 382 acetabular revisions using IBG 30 hips with a lateral trabecular augment (case group) were matched for age, gender and bone defect with 54 controls (with a lateral mesh). The mean follow-up was 5 years. All hips had a Paprosky 3A or 3B bone defect. Clinical outcome, radiological results and re-revisions rate were analysed in each over time. A Kaplan-Meier analysis was used to determine the survival of the cup, with radiological failure and re-revision as the endpoints.

Results: 5 (16.7%) hips in the case group and 9 (16.7%) in the control group were re-revised. The 10-year survival for reoperation for any reason was 80.8% (95% CI, 69.7-92.0) and 93.3% (95% CI, 84.0-100) respectively. At latest follow-up the mean Harris Hip Score was 85.3 in the case group and 82.9 in the control group (p = 0.4). In the case group, 7 (23%) hips showed acetabular radiological migration, 3 requiring further revision surgery. In the control group, 12 (22%) hips showed acetabular radiological migration, with 6 needing re-revision. Acetabular radiological migration was more frequent in hips with a greater radiological horizontal distance (p = 0.01).

Conclusions: IBG combined with lateral trabecular augments in large segmental acetabular bone defects was comparable to IBG combined with a lateral mesh. Improvements in surgical reconstruction could decrease the radiological migration rates of the acetabular component.