Biosport Project

Is ACI still seen as an experimental therapy?

12th October 2015

Writing in the Aspetar Sports Medicine Journal in February 2014, Swedish Professor of Orthopaedics Mats Brittberg reminds us that the first human autologous cartilage implantation (ACI) was performed almost 30 years ago. Apparently, around 30,000 patients worldwide have undergone ACI surgery since then.

Brittberg’s article reviews the evidence base for ACI that has accumulated since the 1980s as well as giving details of his own operative technique. He concludes that although the ACI method could do with further improvement and refinement, it is a well-established method of cartilage repair. Despite this, he claims that ACI is still widely regarded as an experimental therapy:

“Few other orthopaedic techniques have been so carefully studied but in many occasions, people still talk about ACI as an experimental surgery”.

In the UK, NICE guidelines on ACI for the treatment of cartilage defects in the knee were first developed in 2000, and reviewed in 2005. This guidance, issued as TA89, states that: “ACI is not recommended for treating knee problems caused by damaged articular cartilage, unless it is used in studies that are designed to produce good-quality information about the results of the procedure”.

These guidelines are currently undergoing their third review, in which safety, efficacy and costs effectiveness of the technology will be reassessed, due to the acknowledgement that the evidence base for ACI has increased since the last time the technology was appraised.

So is Autologous Cartilage Implanation for cartilage repair still regarded as an experimental therapy? And to what extent is it being used in elite sport medicine?

The BIOSPORTproject team have now interviewed around 40 people affiliated with UK sports medicine community, including leading orthopaedic surgeons, sports physicians (working in elite football or cycling in the UK), sports scientists, medical insurers and producers/developers of ‘orthobiologics’. We asked them their opinions about the use of ACI in treating articular cartilage defects. Here is a summary of what they had to say:

Cartilage injuries are comparatively rare in elite football and cycling. However, ACI is generally seen as an acceptable and established clinical procedure.

Interviewer: Have you any experience of some of these newer technologies in relation to cartilage repair?

Sports medic, interview 6: Not a lot because it doesn’t happen a lot, if you know what I mean. It’s still quite extraordinary. But, [ACI] is something that I find acceptable […] when it comes to things like a damaged cartilage where you know it’s not going to heal, you have to do something to correct it. If you don’t correct it then it’s either going to stop them from playing because it’s actually catching or locking the knee or whatever, or it’s going to lead to early onset arthritis or whatever, then something obviously has to be done.

The evidence base is regarded as good, but the technology could still do with some improvement

Sports medic, interview 10: The evidence is good… Our group, we’ve done several randomised control studies on single and also chondral injuries of knees and we’re trying different versus placebo in those. And so, for me personally, I will look at the trials that there are and if they are similar and make sense then we will say this is something that now is okay. It does happen with cell transplantation, for example, only about 75% of patients do really get a result short term, five years, but it’s better than anything else we have for those particular patients. So, therefore, you can say it is okay to do that.

Treatment decisions are often driven by the surgeon and their preferences; Sports medics and physio’s working within professional sports teams tap into the knowledge of recognised experts in the field

Sports medic, interview 16: What I would do is we would tap into the knowledge of the likes of [leading orthopaedic surgeon]. The problem you’ve got, though, is the early stuff that was done on [ACI] was going to take too long […] If you take a player out of senior football for two years they’re almost finished, even if the good news is that his knee joint is better; the bad news is physically deconditioning, they don’t come back. So, it’s weighing up the costs.

However, recovery time is also a major factor when considering ACI surgery in professional athletes

Orthopaedic surgeon, interview 36: A lot of the guys treating sports people will just do a microfracture and a lot of that is driven by the clubs preference because of rehabilitation times. […] In terms of the actual elite, I think there is massive pressures obviously, to always get them back as soon as they can and so, it is a fine balance. So, if you are recommending a strategy which is going to take them twice as long [to recover from], they are getting paid £100,000 a week, then it’s obviously very difficult to go down that route. So, yeah, I think the field of cartilage within elite athletes is more restricted more by that, really, than anything else, I would have thought.

In addition, the technology is expensive, which is seen as a barrier it being used more widely

Sports scientist, interview 24: Autologous chondrocyte transplantation happens anyway. There are a number of companies doing it… the biggest problem with things like this is the expense of it, especially if it’s autologous; that means you have to take it from somebody, you have to grow it and re-inject it so it’s bloody expensive […]But, no real issue around that, I think that’s an expense thing.

Newer ACI technologies and techniques are being developed and refined to address some of these issues, which is an exciting prospect

Orthopaedic surgeon, interview 25: I got a license to do ACI many years ago, but I didn’t really ever take it up because two operations, NHS funding nigh impossible, too expensive, too slow, and lots of niggling problems with it. But [product name] have got the advantage in that you don’t actually take the cells out of the operating theatre. So you take them out, process them, 45 minutes later, you’ve got the material to put back in the knee. So I think they’ve probably dealt with one of the really major obstacles and in two fell swoops would’ve reduced the cost, half the number of surgery, and made my life much easier to use it. So I’m quite excited to potentially look at that as a process to use.

In sum, in an elite sports environment, it appears that ACI is regarded as an acceptable but exceptional therapeutic option to treat articular cartilage injuries. Barriers to its use include the length of time it takes to recover from the surgery and its cost, rather than gaps in the scientific evidence base. A small number of surgeons –regarded as experts in the field – have a large role in driving which therapies are used. There is interest in the development of newer versions of ACI but these are only likely to be adopted in an elite sporting environment if the aforementioned barriers can be overcome.

Perhaps the various ACI techniques are more suited to the weekend warrior than the elite sportperson?

You can find out more about the various ACI techniques and technologies by visiting our ‘Technologies’ page and our recent survey of ACI technologies on the market and/or in development.