Treating Fat Pad Atrophy

Atrophy of the fat cushion on the plantar aspect of the foot, whether the heel or the forefoot, is an area of interest for many foot and ankle surgeons. Treatment modalities for fat pad atrophy are gaining momentum and, I believe, are here to stay. Most practitioners believe “cushioning,” “filler” or “restoration” treatments are aesthetic treatments as physicians often tout them as procedures to ensure comfortable high heel use. Moreover, these services are not currently covered by insurance.

During gait, there is a pressure equal to 2.5 times body weight on the heel during heel strike. This can lead to heel pain with an increase in pressure strike and load forces. This can subsequently lead to stress fractures of the calcaneus.

In the heel, there is an atrophy of the thickness of the fat cushion and we often mistake this for plantar fasciitis when there is actually a loss of shock absorbency of the heel on impact. Distally, on the plantar aspect of the ball of the foot, there is fat pad atrophy, which is common as we age and is also present in various disease processes such as autoimmune conditions. There is anterior displacement as one would see in the cavus foot type with some of the fat pad shifting under the digital sulcus. 

We can measure pressure as the force per unit area over time. In the gait cycle from heel strike to toe off, various foot types will accumulate a peak pressure differently. In those peak locations, there is atrophy of our natural fat pad cushioning. This often leads to pain, burning sensations, increases in keratinization with calluses and intractable plantar keratoma formation. All of these make it difficult to perform activities we like to perform and wear shoes we like to wear.

Padding is annoying, orthotics can't be worn in most sandals, and people like to walk barefoot. Some foot specialists feel that augmentation of this plantar fat pad is cosmetic. Just because treatments are not covered by insurance does not mean they are purely cosmetic. Our job is to find the best solution for the patient’s condition. If patients are not candidates for surgery and these treatments can help them remain active and pain-free, I will offer the treatment for their feet. 

Augmentation of the plantar fat pad breaks down into three categories. The first category is injectables. The second is autolipotransplantation. The third is use of an allograft.

Injectable fillers have been in use for over 20 years. Breakdown of the specifics of injectable filler is beyond the scope of this DPM Blog. However, the use of fillers is considered off-label for the foot. On the contrary, fillers offer a quick and easy, intermediate-term solution with little risk of side effects and minimal downtime. You can pre-order the injectable kits, stock them on your shelf and pull them quickly after an in-office consultation. I have found the effects last anywhere from eight months to two years depending on the filler, the amount of atrophy and patient activity. Side effects are minimal with the worst being inflammatory response and granulomas, which do not affect the overall benefit. Weightbearing is immediate with initial offloading pads and the use of supportive sneakers. 

Autolipotransplantation is another augmentation technique. Using the patient's own fat cells, one places the fatty layer into the foot. Physicians can perform this procedure in the office with the use of a tumescent anesthetic or in an outpatient surgical suite. There is a slightly longer recovery time with the procedure due to the harvest site and the implant site. However, weightbearing in a surgical shoe can occur immediately.

Finally, augmentation with an allograft is another option. I have found the injectable allografts to be less effective than the graft matrix sheets although there is a longer recovery with the graft. Implantation must occur in a surgical setting. I have found the recovery for the allograft procedure to be the longest of the options for fat pad atrophy, ranging from six weeks to eight weeks. Patients relate that they can feel the graft and a notable step off. Once the graft has incorporated with one’s own tissue, patients notice a significant improvement of their discomfort with on average five years of relief of symptoms. I have utilized this procedure in the heel as well as the ball of the foot and use it adjunctively when addressing other foot conditions requiring surgical reconstruction.

These techniques offer patients a relief of pain and allow them improvement of comfort in shoes as well as activity. I do believe this is just the beginning of fat augmentation restoration in the foot with more research and product development on the horizon.

For more info, visit www.bocaratonfootcare.com .