KERBOULL SUPPORT FOR SOFCOT STAGE III ACETABULAR LOOSENING: RETROSPECTIVE CONTINUOUS SERIES OF 54 CASES WITH MINIMUM FIVE YEARS FOLLOW-UP

Abstract

Purpose: Acetabular revision has become a challenging situation due to the importance of bone stock loss encountered in SOFCOT stage III acetabula. The number of failures due to loosening are explained by the strong mechanical stress on the bone grafts or inadequate restitution of the rotation centre of the hip. The purpose of this study was to evaluate mid-term results of the Kerboull support used to achieve anatomic recentring of the hip and progressive weight bearing on the bone grafts.

Material and methods: This retrospective series included 54 acetabular revisions performed for stage III loosening between 1989 and 1996. A Kerboull support was used in all cases. The patients were assessed with the Postel Merle d’Aubigné score and radiographically on plain pelvis films in order to search for recurrent loosening or arthroplasty failure. The log rank test was used to compare actuarial survival.

Results: The series included 62% women. Mean age was 62.3 years (33–87). This was the first revision for 78% and a second or more revision for 22%. The preoperative Postel Merle d’Aubligné score was 9.18 points. This score was 12.3 postoperatively, 15.6 at one year, 15.5 at five years and 14.8 at last follow-up. Dislocation was the most frequent complication, with 55% occurring on cups more than 46° oblique. Grafts were considered radiographically integrated in 58% of the cases. There were 5.5% failures due to migration, 13.8% due to fracture of the superior screw. The actuarial survival was 97.4% at three years, 94.7% at four years, 89.2% at five years and 73% at seven and ten years.

Conclusion: On the basis of these good short-, mid- and long-term clinical and radiographic results, we recommend Kerboull support for the treatment of stage III acetabular loosening.