The fat pad cushions the impact of the weight-bearing pressure points of the foot, allowing you to perform various activities and wear different types of footwear. Some health conditions and surgery complications can cause atrophy of the fat pad leading to painful effects. Fortunately, the latest fat pad augmentation procedures alleviate this dilemma with the restoration of a functional foot.
The fat pad in the foot is a thick layer of fat that lies on the plantar surface and cushions the forefoot and heel on contact with hard surfaces. This prevents the formation of calluses and damage to the forefoot and heel area where most of the body weight lies. The thickness of the fat pad ranges from 1-2 cm in normal individuals. The fibro-elastic tissue divides the pedal fat pad into many micro-chambers which stretches, absorbs, and dissipates pressure changes that are encountered during daily activity.
The partial or total loss of fat pad thickness is termed as atrophy. Age-related loss of fat tissue, medications, and surgical procedures predispose an individual to such risks. As the fat pad is lost, the body weight is transmitted directly from the heel and metatarsal heads onto the skin and fascia. For example, the pressure during heel strike when we step forward is 2.5 times the body weight and the absence of cushioning can lead to inflammation and injury.
The pedal fat pad is there to protect the underlying neurovascular tissues, sensitive periosteum, ligaments and tendons and a person with fat pad atrophy will develop very painful feet, a burning sensation, and tenderness in the area of atrophy. Walking barefoot will progressively become very difficult. The metatarsal heads of receptive feet appear prominent due to the loss or shift of the fat pad. Once inflammation sets in and the chances of Keratoma (benign tumor of keratin cells) formation are also increased. Bilateral centralized heel pain often occurs after prolonged periods of standing.
The treatment can either be conventional or augmentation surgery depending on the severity of symptoms and patient profile.
Significant potential for the treatment of fat pad atrophy lies in regenerative medicine by the use of Platelet Rich Plasma (PRP) Injections and Stem Cell Therapy.
The surgical treatment for footpad atrophy will focus on offloading the involved area via padding, inserts, corrective osteotomies and resections. The augmentation of the fat pad can be done in either of three ways, using:
Dermal fillers are made of various kinds of natural, man-made or synthetic materials that are injected into the skin to increase the volume of that area. They have been used for many years for the treatment of forefoot Metatarsalgia and foot pad atrophy. They’re preferred to orthotic pads and therapeutic footwear due to their “forced adherence”. The injection of a tissue volumizing agent beneath the plantar creates an internal accommodative effect. This acts to mitigate pressure 24 hours a day, wherever the patient goes without the need to carry therapeutic shoes.
During this minimally invasive procedure, the filler is injected into the fat atrophied area. Your doctor will carefully examine the feet to analyze the amount of filler needed in each area before sticking the needle into the sole of your foot. More than one filler injection might be needed depending upon the site and degree of fat pad atrophy.
The injection usually contains a local anesthetic (lidocaine) but some discomfort will still be had. In some cases, regional anesthesia might be used if the patient is already in pain. Regional anesthesia (ankle block in this case) involves the numbing of the tibial nerve and/or sural nerve with very little discomfort. The whole foot gets numbed and the procedure is then pain-free.
After the filler has been injected, the doctor will cover the area with a couple of bandages and offload pads. The infection rate with this minimally invasive procedure is very low, but care is still taken to avoid unnecessary complications.
In most patients, the weight-bearing is immediate, and pain is relieved. There is little to no recovery time for this procedure as compared to other treatment options. Depending upon the filler used and the patient profile, a filler might last anywhere from eight to twenty-four months.
Short-term complications of the procedure include: tenderness on pressure, bruising, and localized inflammation. You’ll be advised to do low impact activities, avoid weight-bearing, do foot exercises, wear supportive sneakers, and take analgesics.
This reconstructive procedure involves taking fat tissue from one site of the body and using it to fill another (also known as autologous fat transplantation). The fat tissue is taken from areas with a considerable amount of fat, such as the abdomen or upper thighs, and transferred to the graft site i.e. the plantar surface of the foot. The fat is sucked from the host site using a liposuction tube and is then sterilely centrifuged and allowed to decant. It is then filled into a syringe to be precisely injected into the plantar fat pad using specialized injection cannulas. Only a few cubic centimeters of fat are needed for this procedure.
Local anesthesia will be given near the posterior tibial nerve using a combination of lidocaine and epinephrine. The same anesthesia will be used at the harvest site (i.e. abdomen or thigh). This will allow a small incision to be made so that the solution can be injected into the area of fat graft harvest. This limits pain and bruising during the procedure.
The fat grafting can be performed as an outpatient procedure meaning you will be in and out on the same day.
The foot will be bandaged for twenty-four hours post operatively and you will be advised to avoid mobilization until absolutely necessary. Over the span of the next three weeks, you will be instructed to wear supportive shoes and participate in only in normal day-to-day activities with no excessive aerobic activity.
The success rate of pedal fat grafting is estimated to be around 98%. As you move about after having fat grafts, the fat may redistribute pressure to offload the bone, promoting the healing process and resulting in long-term pain relief. It is still recommended to wear sensible, supportive and cushioned shoes after the procedure but not as strictly. You can wear high heels and less supportive shoes in moderation.
Augmentation with an allograft (tissue obtained from another person) is human acellular dermal filler which can be used for fat pad atrophy. The recovery time for this procedure is around six to eight weeks. The only possible complication is an infection. Since the processing of graft material removes all the living cells, the chances of graft rejection are eliminated. After the incorporation of the graft in pedal fat tissue, patients notice a significant improvement of their discomfort and pain, with on average five years of relief of symptoms. The acellular dermal graft appears to be a remarkable solution for the correction of soft tissue deficits and soft tissue augmentation.
Plantar fat pad atrophy is a significant cause of pain and limitation of function, particularly after neuroma surgery and in the elderly. In the patient with diabetic neuropathy, it can have catastrophic consequences. While the diagnosis is usually straightforward, treatment can be difficult. Several therapeutic modalities have demonstrated varying degrees of efficacy. Other potential treatments are in clinical trials and will hopefully add to our therapeutic options.