Fractures of a sandwich ceramic liner at ten year follow-up.

PURPOSE

The aim of this study was to understand the causes of sandwich liner fractures implanted at our institution by evaluating the long-term results of this device.

METHODS

We retrospectively assessed 143 patients (151 hips) consecutively operated upon in our department by the same senior surgeon between 1999 and 2001 and with a mean follow-up period of 9.9 years (range 8.5-11.5). The components used were Cerasul® sandwich ceramic liners within a cementless cup. Patient assessment was based on demographic factors (age, gender, body mass index), the clinical scores according to Devane (activity), the potential complications and a radiographic analysis from an anteroposterior pelvic radiograph (cup inclination). Revision cases and their cause were classified (implant fracture, loosening, dislocation, periprosthetic fracture).

RESULTS

Five cases of liner fracture (3.7%) were observed at a mean seven year (4.5-8.5) follow-up. The risk factor for implant failure was found to be patient activity: the mean preoperative Devane score was 3.5 in the fracture group vs 2.6 in the control group (p = 0.008). Mean cup inclination was 52°. The survivorship analysis at ten years was 85% with revision as the endpoint. Prosthetic complications accounted for 8.6% of all 151 hips (fractures included): one case of aseptic loosening (0.7%), two cases of sepsis (1.4%), four cases of isolated dislocation (2.8%) and one case of recurrent dislocation (0.7%).

CONCLUSIONS

Alumina sandwich liners remain a subject of concern since the increasing clinical follow-up period may predispose them to fatigue failure. This system has been abandoned in our department since 2005.