Abstract
While total hip arthroplasty (THA) has been shown successful at relieving pain and improving function in patients with coxarthrosis, wear and instability remain leading causes for revision surgery. Highly crosslinked polyethylene (HXPE) has significantly reduced wear and osteolysis but volumetric wear associated with the use of larger diameter ball heads may be an issue in the long-term. Finally, concerns with femoral taper corrosion have increased the utilization of ceramic ball heads in recent years.
Ceramic on ceramic articulations are optimised for both minimizing implant wear and instability. It is biocompatible, wettable, and possesses the lowest in vitro and in vivo wear rates among all bearing couples. In fact, wear rates are lowest when the ceramic ball head size is maximised. Additionally, modern ceramic on ceramic THA designs have had an excellent clinical track record with low rates of loosening, failure, and no reports of osteolysis in even highly active, young patients.
Concerns with ceramics center around issues related to fracture risk, squeaking, and cost. While the phenomenon of squeaking remains poorly understood, the reliability of ceramic implants have steadily improved with better materials, design, and manufacturing. The fracture risk for modern pure alumina implants and the newer alumina matrix composite ceramics are 1 in 5000 and 1 in 100,000, respectively.
The advantages of ceramic on ceramic THAs will not be realised on every patient and therefore, should be selectively used. However, with expected increases in life expectancy and more young, active patients undergoing THA, ceramic on ceramic THA should be strongly considered in patients under age 60 years.
