Saturday, October 22, 2016

ACI vs. Microfracture, Revisited

I originally wrote this post, which garnered a good deal of attention, about these two procedures.

I said that if forced to choose between the two, I’d rather have the less-invasive (and less-expensive) microfracture, which may even be more effective. In the comments section, several people disagreed. One commenter said that, over the long-term, ACI (or autologous chondrocyte implantation) leads to a better result.

Uh, maybe not.

This study (published in August in the reputable Journal of Bone and Joint Surgery) looked at large lesions treated with either ACI or microfracture. The 80 subjects were evaluated after 15 years (a suitably long timeframe, I think all would agree).

Check out the highlights:

* There were 17 failures in the ACI group compared with 13 for those who had microfractures.

* Total knee replacements: six in the ACI group, three in the microfracture.

* X-ray evidence of early osteoarthritis: 57 percent in the ACI group vs. 48 percent in the microfracture.

Luckily I don’t have to choose between either. But if I did, I think I’d stick with my original answer.


  1. Hi Richard and all,
    I wondered what you thought about this BBC article, which talks at length about the discredited surgeon Macchiarini and the key role a journalist plaid in the process. Macchiarini used a synthetic scaffold and stem cells to replace the windpipe, the organ in question is different but there are similarities with scaffolds that have been attempted to replace missing meniscus. I myself had a scaffold fitted for my lateral meniscus and ended up with a very bad infection which had become chronic due to the CMI scaffold becoming loose and not "growing" within the knee tissue. This is the article, any comments welcome:

    1. I skimmed the article, thanks. Partly it appears to be a story of reckless ambition and the tendency for people to believe in impressive-sounding technology, even before it's been studied that closely. But I think what happened also underscores the difficulty of creating spare body parts in a lab and swapping them in. Maybe someday this will work well, but it's certainly many orders more complex than changing a car tire. For knee cartilage that's grown outside the body, you have a high incidence of scar tissue formation when it's implanted, for example. And scar tissue comes with its own issues.

  2. Was the population of each group equivalent? 40 people in each group?

  3. Richard do you have any information on this? I hope it's the saving grace for my full thickness patellar chondral defect.

    1. This is the first I've heard of CartiHeal. Readers? I would approach with skepticism; much of the material about it circulating on the internet feels like marketing, but maybe someone out there is in the process of doing a good double-blind study.