Corrosion at the interface. A possible solution to cobalt-chrome heads on titanium alloy stems

Area of Science:

• Biomaterials Science
• Orthopaedic Surgery
• Materials Engineering

Background:

• Cobalt-chrome femoral heads and titanium alloy stems are widely used in total hip arthroplasty due to their favorable properties.
• However, the combination of these dissimilar metals can lead to crevice corrosion and metallosis in the joint environment.
• This necessitates exploring alternative head-neck junction designs to mitigate adverse reactions.

Purpose of the Study:

• To investigate the corrosion resistance of a novel head-neck junction design.
• To evaluate the efficacy of premating cobalt-chrome femoral heads with titanium alloy sleeves.
• To assess the potential of this alternative to reduce corrosion and metallosis in total hip arthroplasty.

Main Methods:

• Five cobalt-chrome femoral heads premated with titanium alloy sleeves were examined.
• Methods included gross examination, dissecting microscopy, and scanning electron microscopy.
• Corrosion was assessed at the head-neck junction.

Main Results:

• Gross examination and dissecting microscopy revealed no signs of corrosion in any of the tested samples.
• Scanning electron microscopy identified slight crevice corrosion in only one sample with a +15-mm neck length.
• The premating design generally demonstrated excellent resistance to corrosion.

Conclusions:

• Premating cobalt-chrome femoral heads with titanium alloy sleeves appears to be an effective strategy for preventing corrosion.
• This approach shows potential for reducing the incidence of metallosis and improving the longevity of total hip arthroplasty implants.
• Further investigation into longer neck lengths and different articulating surfaces is warranted.