STAR® total ankle replacements with BONIT® coating: A prospective 2-17 year follow-up study of 474 ankles from a single center.

BACKGROUND

Different coatings of the metal implants of STAR prostheses have been used since 1999. In Europe metal implants with a double calcium-phosphate coating (BONIT) on a titanium sprayed surface have been available since 1999.

METHODS

We present a 2-17 year follow-up of a consecutive series from a single center with 474 STAR ankle replacements where the BONIT type of coating has been used.

RESULTS

55 prostheses (12%) have been revised, the majority of them due to fracture of the mobile bearing. 22 prostheses (5%) have been converted to an arthrodesis. Analysis of survival of the specific components showed an estimated 10-year survival rate of the tibia component, talus component and polyethylene mobile bearing of 99%, 98% and 84%, respectively. The corresponding estimated 15-year survival was 98%, 98% and 74%, respectively.

CONCLUSION

This study showed an extraordinary high survival rate of the metal implants.

LEVEL OF EVIDENCE: Level III, prospective cohort series.