Five year results of the first US FDA-approved hip resurfacing device.

A prospective, multi-center postmarket approval study has been ongoing since May 2006 to assess safety and efficacy of the first US FDA approved hip resurfacing implant. 265 patients have been enrolled at five study sites. The average age of the patients is 51.3 years. There have been 7 revisions (2.4%) in the cohort to date. K-M survival curves for the cohort are 97.6% at 5 years. There is a trend toward a gender difference in implant survivorship, with 98.6% of men and 94.7% of women free from revision. Metal ion analysis revealed median cobalt and chromium levels of 1.5 ppb and 1.7 ppb at 1 year. In this prospective US study, the Birmingham Hip Resurfacing implant is demonstrating results comparable to those in the literature.