Next let’s look at the cost.
At my institution, using cobalt chrome-on-highly crosslinked polyethylene as the base price, to add a Delta ceramic head adds 60% to the cost of that construct. Adding a Delta liner, makes that 120% plus your base so, a substantial cost premium.
Additionally, we have unique complications with ceramic-on-ceramic of squeaking and fractures. Robert Barrack led a five-center study of young patients, ceramic-on-ceramic (Nam et al., Clin Orthop Relat Res2016). He reported increased grinding, popping, clicking, with an odds ratio of 5 and a half times. Noise generation was associated with pain and stiffness. Another study, (Salo et al.,Bone Joint J2017), reported on 336 ceramic-on-ceramic total hip arthroplasties with a 17% incidence of noise, half of which was frequent, lower mean hip scores, and decreased physical function.
This isn’t just an annoyance; these patients are not doing as well.
In 2017, with our current implants, we have an incidence of squeaking of about 10-30%. They’re not being revised for the most part so that’s not captured in registries, but it is significantly affecting the patient outcomes.
What about ceramic fractures? It seems like the Delta ceramic head has pretty much solved that so the rate of fracture in the ceramic head in the Australian registry is 1 in 70,000 so pretty uncommon, however, that’s not the liner.
A great paper recently published (Howard et al., Bone Joint J2017) looked at 111,000 ceramic-on-ceramic total hip arthroplasties. Fracture rate for the Delta head in 2017, 1 in 11,000, this is the UK registry. The Delta liner, 1 in 893, that’s a significant difference.
The researchers concluded that previous studies have underestimated the risk of fracture. That’s not taking into consideration what happens in the OR when you get a little chip or mal-seating, which happens.
And then there are adverse soft tissue reactions. The National Registry for England and Wales published this year put the relative risk of adverse soft tissue reactions at 2.5 times higher in ceramic-on-ceramic bearings compared with hard-on-soft.
So, my friend you got it half right. Ceramic-on-crosslinked polyethylene is the bearing of choice in my opinion for young patients. Adding the ceramic liner increases your failures, increases your cost, increases noise, increases complications, with decreased satisfaction outcomes, and in my opinion is not the bearing of choice in 2017.
Moderator Thornhill: Bill, your thoughts.
Dr. Walter:Well Steve is a bit mischievous there because he showed the Australian registry data for all ages and then represented that as correlating with young patients, but there is actually registry data for young patients which shows that the ceramic-on-ceramic bearings are performing better than they were compared to the crosslinked polyethylene.
Dr. MacDonald: We have not solved the young patient regardless, we can both agree. Whether it’s crosslinked … it’s like knees, they have a higher failure rate.
Dr. Walter: So, mid 60s or 60s even for crosslinked polyethylene and then below that will be ceramic-on-ceramic. Wear rates being so low with the ceramic-on-ceramic I’m more confident that at 40 years the ceramics will be functioning better than the crosslinked polyethylene.
My friend who is 54 just had a hip replacement via a robot. He was so happy, he had another one done in 6 months. He can not recommend enough of ceramic hip replacement surgery.
Teri Green
Atlas Biomechanics