Meeting News

History, evaluation of taper corrosion discussed at AAHKS Annual Meeting

Brett Levine AAHKS headshot 
Brett R. Levine
Joshua Jacobs AAHKS headshot 
Joshua J. Jacobs

DALLAS — In a symposium at the American Association of Hip and Knee Surgeons Annual Meeting, several orthopedic surgeons discussed the history and prevalence of taper corrosion in total hip arthroplasty, reviewed why taper corrosion is an issue now and how to evaluate for taper corrosion in metal-on-polyethylene THAs.

“We want to catch these people early, if we can, before massive damage happens, and I think ... it is important to realize [taper corrosion] is a real problem and we do want to make sure we make the diagnosis,” Brett R. Levine, MD, said in his presentation.

Factors of taper corrosion

Joshua J. Jacobs, MD, noted changes in implants, patients, the operation and surgeon awareness are all factors related to increased awareness of taper corrosion. When looking specifically at implant factors, he said surface finish, flexural rigidity and metallurgy are all areas that may “explain why this issue has resurfaced.”

“When [taper corrosion] first started happening, we were attributing the problem to changing the surface finish on trunion to allow the use of ceramic and metal balls on the same trunion,” Jacobs said. “It is simply not that easy.”

Previously published research by Jacobs and colleagues has shown a complex relationship between surface finish and time in situ, with Jacobs noting an association between a smoother surface finish with less corrosion damage. In their research, Jacobs and colleagues also found flexural rigidity of the neck was inversely proportional to the damage of the trunion.

“There is this significant temporal trend toward shorter and more flexible trunions in our group of revised implants, and so this may be a factor of why we have been seeing this more recently,” Jacobs said.

Finally, Jacobs noted variability in the metallurgy among hips with taper corrosion, with the prevalence varied by year and manufacturer.

“This strongly suggests a manufacturing processing issue, a material issue, as opposed to some of the other issues,” Jacobs said.

How to diagnose

Although taper corrosion should not be the first differential diagnosis on an orthopedic surgeon’s list, Levine said surgeons should be aware of and thinking about it. When a patient presents with unexplained hip pain several years after a THA, he noted surgeons should start with a history report and physical examination.

“Then, we will look at the imaging studies,” Levine said. “These are often not that helpful except to tell you what implants are there and if there is any significant osteolysis around the implants.”

Next, surgeons should collect ESR and C-reactive protein, according to Levine. If both levels are normal, he noted the next step is to collect metal levels. If there is still suspicion for infection, Levine noted he will aspirate the joint, which may involve getting a manual cell count. He added it is important to use multiple tests together for a trunion diagnosis.

“Esterase and alpha defensin are good in ruling out infection alone, but in the setting of an adverse local tissue reaction, they become a little less sensitive and a little more specific,” Levine said.

Finally, patients should undergo advanced imaging, such as ultrasound, CT scan or a metal artifact reduction sequence MRI, to confirm taper corrosion once infection is ruled out. Levine noted patients with elevated metal levels and fluid collection should consider an operation, while patients who are asymptomatic should be followed for 3 to 6 months.

“When we revise patients, there is not a consensus, but I think right now most people will use the ceramic head with the titanium sleeve, but you do want to make sure you are prepared,” Levine said. – by Casey Tingle

 

References:

Jacobs JJ. Symposium VIII: What surgeons need to know about taper corrosion in THA. Presented at: American Association of Hip and Knee Surgeons Annual Meeting; Nov. 1-4, 2018; Dallas.

 

Levine BR. Symposium VIII: How to evaluate for taper corrosion in MoP THA? Presented at: American Association of Hip and Knee Surgeons Annual Meeting; Nov. 1-4, 2018; Dallas.

 

Disclosures: Jacobs reports he has stock or stock options in Implant Protection and receives research support from Medtronic Sofamor Danek, NuVasive and Zimmer. Levine reports no relevant financial disclosures.

Brett Levine AAHKS headshot 
Brett R. Levine
Joshua Jacobs AAHKS headshot 
Joshua J. Jacobs

DALLAS — In a symposium at the American Association of Hip and Knee Surgeons Annual Meeting, several orthopedic surgeons discussed the history and prevalence of taper corrosion in total hip arthroplasty, reviewed why taper corrosion is an issue now and how to evaluate for taper corrosion in metal-on-polyethylene THAs.

“We want to catch these people early, if we can, before massive damage happens, and I think ... it is important to realize [taper corrosion] is a real problem and we do want to make sure we make the diagnosis,” Brett R. Levine, MD, said in his presentation.

Factors of taper corrosion

Joshua J. Jacobs, MD, noted changes in implants, patients, the operation and surgeon awareness are all factors related to increased awareness of taper corrosion. When looking specifically at implant factors, he said surface finish, flexural rigidity and metallurgy are all areas that may “explain why this issue has resurfaced.”

“When [taper corrosion] first started happening, we were attributing the problem to changing the surface finish on trunion to allow the use of ceramic and metal balls on the same trunion,” Jacobs said. “It is simply not that easy.”

Previously published research by Jacobs and colleagues has shown a complex relationship between surface finish and time in situ, with Jacobs noting an association between a smoother surface finish with less corrosion damage. In their research, Jacobs and colleagues also found flexural rigidity of the neck was inversely proportional to the damage of the trunion.

“There is this significant temporal trend toward shorter and more flexible trunions in our group of revised implants, and so this may be a factor of why we have been seeing this more recently,” Jacobs said.

Finally, Jacobs noted variability in the metallurgy among hips with taper corrosion, with the prevalence varied by year and manufacturer.

“This strongly suggests a manufacturing processing issue, a material issue, as opposed to some of the other issues,” Jacobs said.

How to diagnose

Although taper corrosion should not be the first differential diagnosis on an orthopedic surgeon’s list, Levine said surgeons should be aware of and thinking about it. When a patient presents with unexplained hip pain several years after a THA, he noted surgeons should start with a history report and physical examination.

“Then, we will look at the imaging studies,” Levine said. “These are often not that helpful except to tell you what implants are there and if there is any significant osteolysis around the implants.”

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Next, surgeons should collect ESR and C-reactive protein, according to Levine. If both levels are normal, he noted the next step is to collect metal levels. If there is still suspicion for infection, Levine noted he will aspirate the joint, which may involve getting a manual cell count. He added it is important to use multiple tests together for a trunion diagnosis.

“Esterase and alpha defensin are good in ruling out infection alone, but in the setting of an adverse local tissue reaction, they become a little less sensitive and a little more specific,” Levine said.

Finally, patients should undergo advanced imaging, such as ultrasound, CT scan or a metal artifact reduction sequence MRI, to confirm taper corrosion once infection is ruled out. Levine noted patients with elevated metal levels and fluid collection should consider an operation, while patients who are asymptomatic should be followed for 3 to 6 months.

“When we revise patients, there is not a consensus, but I think right now most people will use the ceramic head with the titanium sleeve, but you do want to make sure you are prepared,” Levine said. – by Casey Tingle

 

References:

Jacobs JJ. Symposium VIII: What surgeons need to know about taper corrosion in THA. Presented at: American Association of Hip and Knee Surgeons Annual Meeting; Nov. 1-4, 2018; Dallas.

 

Levine BR. Symposium VIII: How to evaluate for taper corrosion in MoP THA? Presented at: American Association of Hip and Knee Surgeons Annual Meeting; Nov. 1-4, 2018; Dallas.

 

Disclosures: Jacobs reports he has stock or stock options in Implant Protection and receives research support from Medtronic Sofamor Danek, NuVasive and Zimmer. Levine reports no relevant financial disclosures.

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