Objective: The aim of this study was to evaluate the primary and secondary stability, where 100% or virtually 100% of the uncemented acetabular component contacted with impacted cancellous allografts, focusing especially on the amount of graft used and rim contact.
Methods: Fifteen cases of acetabular reconstruction using impacted cancellous allografts and cementless porous-coated component in which 100% or virtually 100% of the component contacted only with the allograft were reviewed. Mean follow-up was 97.5 (range: 58 to 130) months after revision. The Harris hip score was used to evaluate clinical results. Radiographic evaluations were done using standard anteroposterior views obtained at the final follow-up.
Results: Two patients underwent re-revision. The mean Harris hip score of the remaining 13 patients was 88.3±11.9 (range: 68 to 100) at the final follow-up. Early postoperative radiographs showed mean angle of inclination of 45° (range: 30° to 55°). There was a mean migration of 6.2±7.8 (range: 0 to 29) mm and the migration amount did not differ according to rim contact (p=0.054). There was no correlation between migration and amount of graft used (p>0.05). There was a significant correlation between migration and follow-up time (p<0.01).
Conclusion: Our results imply that 50% host bone contact is not absolutely necessary to form a stable construct while restoring the centre of hip rotation.