Microfracture is a way to treat defects, lesions, or ‘holes’ that go all the way through the protective cartilage to the bone. In this procedure, tiny holes are drilled around the lesion through the bone to the bone marrow. Breaching the bone in this way releases stem cells from inside the bone to improve blood circulation to the area. The stem cells form fibrocartilage and fill in the hole.
Defects (holes) that measure less than one-half inch (15 millimeters) can be treated this way. In fact, size and location of the defect are two of the most important factors that predict results. Your activity level and body size (body mass index or BMI) are also important variables that help determine long-term outcomes.
The hope for this treatment is that the new fibrous cartilage will act as a shock absorber and protect the bone underneath. But no one really knows if the fibrocartilage that forms can hold up under constant load through the ankle — especially in athletes or active adults.
There have been a few studies that suggest the fibrocartilage starts to break down over time. Patients who once experienced pain relief and improved function suddenly find themselves back where they started from. Other injuries suffered at the same time (and treatment for those injuries) can also impact how well microfracture works.
Efforts have been made to study and report the long-term results for microfracture to treat osteochondral lesions (holes in the bone). Most of the studies include complete demographic information about the patients (e.g., age, sex, body size, duration of symptoms, type of injury). But clinical information (e.g., size of lesion, location of defect, presence of other injuries, rehabilitation protocol) is often limited. And imaging data (e.g., results from X-rays, MRIs, CT scans) has been very poorly reported.
Patient-reported outcomes (e.g., pain, function, activity, satisfaction) is an important part of any patient-centered study. A recent study showed that 87 per cent of the studies on microfracture for osteochondral lesions of the ankle included this information. But they all used different assessment tools to judge results. Without a consistent scoring system, these results cannot be compared.
We do know that injuries of this kind do not heal on their own. Treatment is usually necessary and often includes microfracture. When you see your surgeon for the next follow-up appointment, don’t hesitate to bring up your concerns and questions. Sometimes just reviewing why the surgeon thought you were a good candidate for this type of procedure can be very helpful to allay fears and worries.