In My Time Of Knee(d)
Last year I got into a tussle with the Edinburgh Marathon, and let us just say it won… 18 months down the line my left knee is still not the same. I have tried physiotherapy, acupuncture and even toga (toe yoga) but still cannot run more than a couple of miles without significant lateral pain.
After visiting my GP for the 4th time I finally got referred for an MRI. The prognosis is inflamed or partially detached cartilage. In the best case scenario this will result in arthroscopic surgery and a few weeks with my feet up, but it got me thinking — what if my knee needs replaced?
Total knee replacement (TKR) in younger patients (18–64 years old) is increasing. In the UK there are 90,000 TKR’s per year, from 1997 to 2009 the share of younger patients undergoing TKR rose 56 per cent. The well-documented obesity epidemic is believed to be a main cause, but (conversely) the UK’s growing enthusiasm for mass participation endurance events is also a factor. A record number of 247,069 people applied for a place in the 2016 London Marathon, more than 55 per cent of these applicants have never run a marathon.
It is common knowledge that pavement pounding causes joint damage, and as more people put themselves through the rigours of training for the 26.2 (or any other run-based endurance event) there will be a greater number of poor souls who, like me, come out of it with a gammy knee.
In 90 per cent of people who undergo TKR the new joint will last ~20 years. This length of time is generally considered fit for purpose and affords a quality of life that most senior citizens can deal with. However, as the average age of those requiring TKR falls it raises problems regarding implant longevity. Throw in the UK’s increasing life expectancy and it could become common place for patients to require a TKR implant for upwards of half a century.
The risks and complications associated with TKR grow with the number of operations required, meaning that simply replacing an implant each time one wears out is not a long-term solution. The spotlight is on the orthopaedics industry to step up and cater for the incoming generation who will need implants that can last for more than two decades.
The global knee implant market was valued at USD8.4bn in 2011 and is forecast to reach USD15bn by 2018. The leading players (DePuy Synthes, Zimmer Biomet, Smith & Nephew, Stryker and B Braun) account for almost 80% of the total market, with Zimmer Biomet leading the way with 30% market share. Whether such dominance provides the impetus or competition for product development is a whole other blog, but in short, while the current TKR offering of each company is well renowned it remains to be seen if they have the capacity to service future requirements (I will add that even if they do not, they will probably just bulldoze their way through using M&A…).
A potential mid-size challenger could be Corin — an orthopaedic medical device company specialising in knee and hip replacement. It has recognised the needs of an ‘increasingly active and demanding patient population’ and aims to utilise ‘the most advanced technologies available in the world to enhance implant longevity’. Outwith the corporate lingo, Corin appears focused on producing longer lasting implants and its newest product iteration, the Unity Knee system, is clinically proven to show a significant reduction in wear compared to other implants.
The rapid growth of the lower extremities (knees and ankles) market makes it attractive for academic funding bodies as well as corporations. Novel developments are arguably more common in an academic setting and one of the most promising to come from a UK university is the founding of Orthox. The Oxford University spin-off has developed small implants for the knee using silk proteins to produce a strong, curved rubber-like material. The technology was based on fibroin, the major component of silk, which can be manipulated (using the same conditions as spiders when they spin webs) to produce a resilient cartilage-like biomaterial called FibroFix.
Aside from the material/manufacturing innovation, what is particularly novel about FibroFix is its potential as an early stage preventative intervention. With this approach, the founders of Orthox have attempted to reduce the need for full scale TKR in the population, rather than solve the problem of implant durability. They predict FibroFix could be used in younger ages (as early as mid-twenties) when someone suffers a sporting injury, to prevent a condition worsening during later life. Clinical trials began this year and if successful FibroFix could be on the market by 2018.
My MRI is on Tuesday so I will find out soon how knackered my knee is. I suppose it is reassuring to know that whatever the outcome, the industry seems well positioned to provide options.
