Results of a long-term study undertaken in Australia that analysed data from more than 240,000 patients with hip osteoarthritis who underwent total hip replacement surgery have just been published. The objective of the research was to glean a greater understanding of the relative durability of ‘cross-linked’ polyethylene bearings hip implants (ie the moving parts), compared with other materials.
Although total hip replacement surgery is recognised as a very effective resolution for patients who are experiencing long-term and significant osteoarthritis, it is not without its challenges. The current materials favoured for artificial joint bearings will eventually wear, which can damage bone and lead to the artificial joint working loose, meaning a proportion of patients will require revision surgery. Researchers were keen to explore the effectiveness of new bearing materials, and this study, one of the largest of its kind, afforded them the data and time to conduct a very in-depth piece of research.
What are cross-linked polyethylene implants?
To understand the implications of this research, it is important to understand more about what exactly was being analysed. This technique uses different materials than those conventionally used for hip replacement bearing surfaces. The driving force behind needing to find a more durable, hard wearing material was the prevalence of total hip replacements amongst younger patients, those who had led a more active lifestyle – and those who were hoping to continue to engage in more active pursuits once they had recovered from their hip replacement surgery.
The challenge for conventional hip replacement materials was that the greater wear and tear that patients were placing on the artificial joint was leading to more revision surgeries in the years following the initial operation.
Key statistics from the study design are as follows:
- The study was huge – over 240,000 patient records were assessed
- It was conducted over 17 years, taking place from 1999 to 2016
- These contained a mix of cross-linked polyethylene implants and conventional polyethylene (CPE) components: 199,000 of the cases analysed were cross-linked polyethylene bearings and 41,000 cases were CPE bearings
The results are extremely positive in favour of the longevity of cross-linked polyethylene bearings, with the study finding: “As early as six months after hip replacement, revision rates were substantially lower in patients with XLPE [cross-linked polyethylene] bearings. Over 16 years, the cumulative rate of revision surgery was 11.7 percent in the CPE [conventional polyethylene] group compared to 6.2 percent in the XPLE group”.
Implications of these results
What this essentially means is great news for patients in general, but particularly good news for younger patients who would be hoping that their new hip joint(s) would be able to stand the test of time. Owing to the length of the study (looking at data collected over 17 years), researchers were able to conclusively report that they had found that using cross-linked polyethylene bearings in total hip replacement joints provides “a significant reduction in the rate of revision at 16 years following THA for osteoarthritis.”
For patients at Mr Simon Bridle’s hip replacement clinic in London, the good news is that this is the material that he routinely uses in these procedures due to its safety and effectiveness for long-term results. For more information, call 020 8947 9524 to book a consultation.
