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A study explores a possible new treatment for a common cause of foot pain. Bangmaha Art/EyeEm/Getty Images
  • Plantar fasciitis is one of the most common causes of foot pain.
  • Current treatments for persistent plantar fasciitis include steroid injections or surgery, which may have side effects.
  • A small study has found that injections of fat into the sole of the foot decrease pain and improve function.
  • Plans are in place for large-scale studies to verify these promising findings.

Many people experience foot and heel pain during their lifetime. And for about 80% of them, plantar fasciitis is the cause.

Plantar fasciitis is caused by inflammation or damage to the connective tissue — the plantar fascia — that runs along the sole of the foot. Females, older individuals, and people with obesity or overweight are most likely to suffer from the condition. However, it can also affect people who do regular, high-impact exercise, such as running.

“Plantar fasciitis is probably the most common foot condition that adults present with in the United States. While there are a number of potential therapies that have been successful, none are universally so.”

Dr. David G. Armstrong, Ph.D., a podiatric surgeon, speaking to Medical News Today.

For most people, exercises, orthotics, and night splints will resolve the problem within a year. However, for some, it can become a chronic condition, known as plantar fasciosis. The plantar fascia thickens, and collagen deteriorates.

People can have surgery to release the tension in the plantar fascia or steroid injections. Both treatments relieve pain but may have side effects, as body performance and injury expert, Dr. Rami Hashish, Ph.D., told MNT:

“Steroid injections tend to provide only temporary relief and also come with the potential side effect of weakening the plantar fascia, exposing it to a higher likelihood of rupture. And needless to say, there is a multitude of side effects with surgery, as well. Thus, the proposition of a safe alternative is quite exciting.”

Now, a team from the University of Pittsburgh, PA, has developed such a treatment for chronic plantar fasciitis. The study, which appears in the Journal of the American Society of Plastic Surgeons, suggests that fat injections in the sole of the foot can relieve pain and improve function.

In this small study, the researchers injected fat, under local anesthesia, into the sole of the participant’s foot. They took the fat from the person’s belly or elsewhere in their body.

They used a blunt needle to perforate the fascia in several places, injecting 0.1 milliliters (ml) of the person’s fat as the needle was withdrawn. Most participants were injected with a total of just over 3 ml of fat.

The researchers divided the 14 participants into two groups for the 12-month study. One group had the fat injections at the start of the study, and the other used night splints and arch supports for 6 months before receiving the fat injections.

Following the injections, the researchers told participants to limit weight-bearing exercise to 10 minutes per hour, use night splints for at least 1 hour each day, and wear supportive shoes without any accessory devices or arch

Both groups reported less pain following the treatment. The group given treatment at the start of the study had greater pain reduction than those treated at the 6-month point.

The researchers measured the thickness of the plantar fascia after treatment. They found a decrease in thickness at 6 months, and this improvement continued up to the 12-month stage.

Several aspects of the treatment may contribute to the positive effect. By using a blunt needle, the researchers caused a small injury which stimulates wound healing. Fat contains stem cells and growth factors that help bring in blood supply to promote healing.

“We developed this procedure to harness the regenerative properties of fat,” says lead researcher Dr. Jeffrey Gusenoff, professor of plastic surgery at the University of Pittsburgh School of Medicine. “In this proof-of-concept study, we showed that fat injections into the foot reduced heel pain, helped patients get back to doing sports and activities, and boosted quality of life.”

The study had several limitations. The sample size was small, and 13 of the 14 participants were women. Participants did not all have the same number of injections in the sole of the foot. And the researchers were unable to quantify participants’ compliance with the recovery instructions.

While acknowledging the limitations of the study, Dr. Hashish welcomed the findings: “[W]e should be reluctant to crown fat injections as a primary approach until further, large sample studies are conducted. Nonetheless, the findings are encouraging, so much so that I wouldn’t be surprised if fat injections become a primary approach to treating plantar fasciitis within the next few years.”

And Dr. Armstrong agreed: “The results of this study suggest that fat pad injections may hold promise to help to improve outcomes in this common and costly condition. I, for one, am cautiously optimistic.”

Dr. Gusenoff and his team plan a large-scale clinical study to validate their findings.