Microfracture for the Ankle: Taking a Step Back to Look at Results

Many people who sprain (or even break) their ankle end up with an additional injury known as an osteochondral lesion of the talus (OLT). Osteochondral refers to the layer of cartilage over the bone. The talus is one of the ankle bones between the heel and the lower leg bone. This type of defect in the bone can result in deep ankle pain, a clicking or locking sensation of the joint, and loss of motion and function.

Treatment is often with a technique known as microfracture. 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.

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.

In fact, 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. This study was done to help compile long-term data and see if studies on this topic are consistent enough to pool the information together. Such a review is referred to as a systematic review and helps give a better picture of what happens down the road.

The authors searched all the studies on osteochondral talus lesions (OTL) where microfracture was used as the main treatment. Over a period of 45 years (from 1966 to 2011), they found a total of 24 studies that could be included. But the data collected in these studies was NOT consistent enough to combine together for a big picture analysis.

Most of the studies included 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) was limited. And imaging data (e.g., results from X-rays, MRIs, CT scans) was very poorly reported (only present in about one-third of the studies).

Patient-reported outcomes (e.g., pain, function, activity, satisfaction) is an important part of any patient-centered study. And although 87 per cent of the studies included this information, they all used different assessment tools to judge results. Without a consistent scoring system, these results cannot be compared.

When studies are small and don’t routinely report the same information, it can be difficult to combine them together to create a systematic review. The authors suggest a set of guidelines is needed to aid researchers in collecting and then reporting information from their studies. In this way, data collected is standardized and can be organized and used to assess short- medium- and long-term results. Patients benefit by receiving the best treatment based on evidence that it works and has long-lasting effects.