No increased migration in cups with ceramic-on-ceramic bearing: an RSA study
Zong-Ke Zhou1, Ming G Li, Niclas Börlin
1Perth Orthopaedic Institute, the University of Western Australia.
Clinical Orthopaedics and Related Research
|July 11, 2006
Summary
Ceramic-on-ceramic hip replacements show similar cup migration to metal-on-polyethylene implants. Both implant types appear equally safe, though cross-linked polyethylene offers lower wear and cost.
Area of Science:
- Orthopedic Surgery
- Biomaterials Science
- Medical Device Engineering
Background:
- Ceramic-on-ceramic (Ce/Ce) hip implants may increase stress at the bone interface compared to metal-polyethylene (PE) implants due to material properties.
- Potential for increased stress raises concerns about greater cup migration in Ce/Ce implants.
Purpose of the Study:
- To compare cup migration between Ce/Ce and PE total hip arthroplasty (THA) implants.
- To evaluate the safety and efficacy of Ce/Ce versus PE bearings in uncemented THA.
Main Methods:
- Randomized controlled trial comparing 61 patients undergoing THA for osteoarthritis.
- Patients received either Ce/Ce or cobalt-chromium on cross-linked PE bearings in identical uncemented cups.
- Cup migration was assessed using radiography (RSA) over a 2-year period.
Main Results:
- Similar mean cup translations and rotations were observed between Ce/Ce and PE groups at 2 years.
- No significant differences in WOMAC and SF-36 scores, radiolucent lines, or osteolysis were found between groups.
- Mean polyethylene liner wear was 0.016 mm between 2 and 24 months.
Conclusions:
- Ce/Ce hip implants do not demonstrate increased cup migration compared to PE implants.
- Both implant types appear to be equally safe choices for THA.
- Low wear and cost-effectiveness of cross-linked polyethylene make it a competitive option.