SLR - October 2016 - Daniel Halayko

Autologous Fat Grafting for Pedal Fat Pad Atrophy: A Prospective Randomized Clinical Trial

Reference: Gusenoff JA, Mitchell RT, Jeong K, Wukich DK, Gusenoff, BR. Autologous Fat Grafting for Pedal Fat Pad Atrophy: A Prospective Randomized Clinical Trial. Plast Reconstr Surg. 2016 Jul 5.

Scientific Literature Review
 
Reviewed By: Daniel Halayko, DPM
Residency Program: Medstar Washington Hospital Center

Podiatric Relevance: Atrophy and displacement of the plantar fat pad of the foot have long been difficult for podiatric physicians to evaluate and treat. The causes can vary greatly from age and obesity to abnormal foot mechanics, use of high-heeled shoes or iatrogenic surgical consequences. Various external devices, such as orthotics and pads, have been shown to decrease plantar foot pressure and clinically improve pain and healing of skin lesions. However, these devices are prone to breakdown, have patient compliance issues and their evidence is mainly anecdotal. To counter said issues with external devices, an in-situ solution was considered. This first-of-its-kind study hypothesized that pedal fat grafting can reduce pain, increase tissue thickness and decrease pedal pressures. Its aim is to decrease sequale of fat pad atrophy.

Methods: The authors performed a prospective, randomized study to assess tissue thickness, pain and foot pressures. Patients were included in the study if they had foot pain under the head of the metatarsals, were diagnosed with fat pad atrophy and were six months post any surgical intervention. Exclusion criteria included patients with open ulcerations or osteomyelitis, diabetes, active infection and other precluding systemic diseases. Grafting was done using a blunt-tip hollow cannula to aspirate approximately 50 to 100cc of fat tissue. The most common sites utilized were the abdomen and flanks. Fat was processed utilizing centrifugation at 3,000 rpm for three minutes. A 0.9 MM blunt cannula was used to inject 1cc syringes of fat into the foot in a cross-hatched pattern. Filling was performed until a “soft cushion” was created, utilizing on average 4 to 6ccs. Group 1 underwent fat grafting with one-year follow-up, while Group 2 underwent conservative management for one year. Foot tissue thickness was measured using a pedobarograph. Tissue thickness was evaluated using ultrasound and foot pain and disability were measured with the Manchester foot and disability index

Results: Thirteen patients (two male, 11 female) comprised Group 1, and 12 patients (four male, eight female) comprised Group 2. Ten patients in Group 1 underwent bilateral injections with a mean volume of 4.8cc per foot. Mean follow-up time was 11.1±5.4 months for Group 1 and 13.8±4.2 months for Group 2. At one year, Group 1 demonstrated improved foot function, pain and work/leisure activities. Group 1 had no change in tissue thickness, whereas in Group 2, the right third metatarsal tissue thickness decreased significantly. Foot pressures in Group 1 did not improve; however, Group 2 had a significant increase in left foot pressure. When comparing the groups at 1 year, Group 2 had significantly higher foot pressures and forces than Group 1.

Conclusions: The authors concluded that pedal fat grafting significantly improves pain and disability outcomes and prevents against worsening foot pressures. It was surmised that this may be due to the cushioning effect of the fat on the bone and due to internal offloading with subsequent healing of bone contusions and/or edema. However, the authors findings were not as hypothesized. The finding that at six months and 12 months fat resorbed under the metatarsal heads was not anticipated. In addition, the finding that plantar foot pressures started to normalize around two years was also something not predicted. This led the authors to the suggestion that retreatment might be necessary to see continued benefits of this therapy.

Even taking into account small sample size, this method seems to be a viable alternative to external devices. Nevertheless, due to small numbers, this study by itself does not yet convince that this therapy will be successful on one's own patients. A further investigation into techniques, use in the diabetic foot population, cost and retreatment effectiveness of this therapy should be further investigated.

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