Reconstruction of segmental defects during revision procedures of the acetabulum with the Burch-Schneider anti-protrusio cage.

Sixty-three Burch-Schneider rings in 62 patients with segmental or combined defects were followed up after a mean of 5.45 years. The mean Harris hip score was 74.9 points. Aseptic loosening occurred in 3 cases, and septic loosening occurred in 2 cases. All cases of aseptic loosening had Paprosky stage IIIb defects and defects of the posterior column. Radiologic migration analysis showed increased migration with increase in the Paprosky defect stage, defects of the posterior column, and cranial defects. The cage has the lowest migration and loosening rate in cases with medial defects or anterior column defects. Surgical treatment of defects of the posterior column is associated with an increased rate of aseptic loosening, whereas implantation with cranial defects shows a higher migration rate with no significant increase in loosening.