Abstract
Background
The optimal surgical treatment for osteonecrosis of the femoral head has yet to be elucidated. To evaluate the role of femoral fixation techniques in hip resurfacing, we present a comparison of the results for two consecutive groups: Group 1 (75 hips) received hybrid hip resurfacing implants with a cemented femoral component; Group 2 (103 hips) received uncemented femoral components. Both groups received uncemented acetabular components.
Methods
We retrospectively analyzed our clinical database to compare failures, reoperations, complications, clinical results, metal ion test results, and x-ray measurements. Using consecutive groups caused time interval bias, so we required all Group 2 patients be at least two years out from surgery; we compared results from two years and final follow-up.
Results
Patient groups matched similarly in age, BMI, and percent female. Despite similar demographics, the uncemented, Group 2 cases showed a lower raw failure rate (0% vs. 16% p<0.0001), a lower 2-year failure rate (0% vs. 7%, p=0.04), and a superior 8-year implant survivorship (100% vs. 91%, log-rank p=0.0028, Wilcoxon p=0.0026). In cases that did not fail, patient clinical (p=0.05), activity (p=0.02), and pain scores (p=0.03), as well as acetabular component position (p<0.0001), all improved in Group 2, suggesting advancements in surgical management. There were no cases of adverse wear related failure in either group.
Conclusions
This study demonstrates a superior outcome for cases of osteonecrosis with uncemented hip resurfacings compared to cases employing hybrid devices.
