Knee microfracture surgery is meant to help individuals in pain resulting from a cartilage defect(s) in the knee. There are not great options for restoring one’s native cartilage, so the procedure has produced reasonably satisfactory results.
A new study regarding knee microfracture surgery was recently presented at an international cartilage society meeting. The results of the study showed that knee microfracture is an effective way to treat smaller cartilage defects in athletically active patients, but the results tend to deteriorate over time.
The researchers looked at over 150 athletes who had undergone a microfracture surgery in a painful knee. Follow up on each patient was between 10 and 15 years, and athletes filled out numerous questionnaires during that timeframe with regards to activity and pain levels. The typical experience outside of this study has been that pain relief with small to moderate sized cartilage defects is pretty good, and lasts for a few years.
The results in this study showed that athletes who underwent microfracture surgery for a full thickness cartilage defect that was larger than 3 cm in diameter tended to fail within one year after the procedure. These athletes typically required another surgery with a large defect who received a microfracture procedure. This is very disappointing since the whole concept is to avoid a knee replacement, and such early failures are not delaying effectively.
For those who underwent microfracture surgery for a cartilage defect less than 2.5 cm, which is approximately 1 inch in diameter, they had much better results. By and large, those athletes had significant functional improvement and decreased pain for five postoperative years. After that time point, the results began to gradually decline in the athletes were able to do less activities at that point. This is much more encouraging as five years of pain relief is substantial for a big problem.
In that group the microfracture procedure was functionally successful with less pain and increased function. It is been known for a long time that a microfracture procedure is not meant to be a definitive surgery giving pain relief forever. It’s been shown in numerous research studies that it’s only meant to give a few years of significant pain relief and functional cartilage.
When a microfracture procedure is performed, a surgeon does some slight drilling into the areas where cartilage is deficient. This sparks up some bleeding and some new cartilage formation. The cartilage that is formed is not identical to ones made of cartilage. It is called fibrocartilage and is structurally defective compared to what humans are born with. So it works well for two years, and then deteriorates.
What remains to be seen is how well microfracture surgery can work for older individuals. If a person is trying to avoid a knee replacement surgery, microfracture procedure may work well the delay that surgery for years by allowing some sort of cartilage to regrow along with pain relief and increase in function.