Volumetric Analysis in Autologous Fat Grafting to the Foot.

Background: Pedal fat grafting is a safe, minimally invasive approach to treat pedal fat pad atrophy. Prior randomized controlled trials demonstrate that the fat as measured directly under the metatarsal heads disappears between 2 and 6 months after fat grafting, despite patients having relief for 2 years. The authors aim to use magnetic resonance imaging to further assess three-dimensional volume of fat in the foot after autologous fat grafting to help explain the mechanism for improved pain.

Methods: A prospective study was performed using magnetic resonance imaging before and at 6 months after pedal fat grafting to assess changes in the three-dimensional morphology of the fat.

Results: Seventeen patients (six men and 11 women) underwent injections with a mean volume of 5.8 cc per foot. At 6 months, patients demonstrated increased tissue thickness (p = 0.008) and volume (p = 0.04). Improvements were seen in pain (p < 0.05) and activity (p < 0.05). Foot pressures and forces were significantly decreased and positively correlated with increased fat pad volume (p < 0.05).

Conclusions: Pedal fat grafting significantly increases metatarsal fat pad volume. The distribution of the fat may contribute to lasting clinical relief in these patients.

Clinical Question/level Of Evidence: Therapeutic, IV.