Hip replacement: the rise of cementless hips
Written by:
Orthopaedic surgeon
Published: 15/10/2019
Edited by: Laura Burgess
Hip replacement is a procedure where the hip joint is replaced by a prosthetic implant, and is a very common orthopaedic operation. Hip replacement surgery was first performed in the 1930s. Almost a million hip replacements are performed now, worldwide, each year and the designs and ways of fixing the implants to the skeleton have changed, particularly over the past 20 years.
Here, one of our top orthopaedic surgeons Mr Godfrey Charnley describes how the cementless options have become used more widely, and the advantages of this.
What is the history of hip replacement?
In November 1962 Sir John Charnley, a pioneer of hip replacement surgery in the UK but also worldwide, implanted his first cemented total hip replacement. He fixed both the hip socket, (acetabular component) and the femoral stem with acrylic cement. This mode of fixation became the standard practice in the UK for 40 years.
What many people do not realise is that before this in the late 1950s, he tried a press-fit, cementless acetabular ‘Teflon’ component but these did not survive and he moved to a different way of fixing hips.
A decade or so later, other surgeons, particularly French surgeons, found alternative ways to fix hip components within the skeleton by using rough surface finishes or coatings to attract bone to adhere or grow onto the components. This is to achieve a more ‘biological’ fixation.
What are the differences between cemented and cementless hip replacements?
The 2019 National Joint Registry figures report that of over 100,000 hip replacements performed, 67,000 acetabular components were fixed without cement and over the same period, almost 40,000 femoral components were also cementless.
These numbers reflect a trend in the UK away from cemented to cementless fixation. This is due to better surface finishes and better biological coatings. The work from France has demonstrated that a calcium-based coating on the femoral components, ‘hydroxyapatite’, is very successful and I prefer for my acetabular components, a ‘trabecular metal’ – Tantalum surface finish.
This metal, microscopically, has a honeycomb lattice-like structure which bone cells recognise as being similar to their structure, enabling them to grow into the surface finish, giving an excellent fixation.
What are the advantages of a cementless hip replacement?
The benefits of modern cementless fixation are that they avoid the debris and inflammation associated with fragmentation and loosening of the bone cement in time. They also enable larger diameter bearings to be used than with cemented acetabular components, giving patients greater hip stability.
In my clinic, I routinely use the CORAIL Total Hip System®, which is a popular brand and design of stem with a hydroxyapatite coating. This bone-conserving option is designed for easy surgical installation. It was originally pioneered near Lyon in France and has a 30-year track record. It is the most commonly used stem not only in France and Europe but now in the UK.
The results of trabecular metal developed in the early 2000s in the United States of America have shown a dramatic improvement in survival of acetabular components in both primary and especially revision hip surgery.
Are there any drawbacks to having a cementless hip replacement?
The costs of cementless hips are more than those of cemented components. It is essential that surgeons pre-operatively plan and intra-operatively assess the stability of cementless components. This is to minimise the risk of subsidence or premature loosening.
Book an appointment with Mr Charnley if you would like to discuss your hip replacement options.