Aims: In many cases of acetabular revisions the socket has a prevalent superior migration and its longitudinal diameter is greater than its transverse diameter. The purpose of this paper was to evaluate the two to þve years results associated with the use of an oval revision cup.

Materials and methods: 31 acetabular revisions with a Longitudinal Oval Revision (LOR) were reviewed with a minimum of two years follow-up and an average follow-up of 3.3 years (range: 2 to 5 years). According to Paprosky acetabular defects classiþcation in 5 cases (16.1%) it was a type 1, in 7 cases (22.6%) a type 2a, in 12 cases (38.7%) a type 2b, in 2 cases (6.5%) a type 2c and in 5 cases (16.1%) a type 3a.

Results: One implant migrated more than two mm in the þrst year, then stabilized; The Harris hip score improved from was 34 preoperatively to 79. Results were rated as excellent in 9(29.0%) hips, good in 16 (51.6%), fair in 4(12.9%) and poor in 2 cases (6.4%). All the acetabular components were stable. Radiolucent lines were present in 7 sockets in 1 or more than 1 zone, but they were non progressive and less than 2 mm in width.

Conclusions: The ideal indication for the use of this cup were acetabular revisions with bone defects of type 2a, 2b, and 3a. In these cases we could achieve a good primary stability, even if screws supplementary þxation is mandatory for the stability of the implant and allograft incorporation. The geometry of the cup and the option of two PE liner allowed us to restore the physiological center of rotation in most of the cases. In conclusion our two to þve results are encouraging, we had no aseptic loosening, and no late migration of the cup.