Clinical trial NCT02679651: Diagnostic Modeling for Pedal Fat Pad Atrophy
Official title: Diagnostic Modeling for Pedal Fat Pad Atrophy
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Fat Pad Atrophy
Pain
Lead sponsor: University of Pittsburgh
Sponsor class: OTHER
First posted: 2016-02-10
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: 30 healthy, age matched adults with normal foot fat pads to compare to 30 patients in the fat pad atrophy group from our other IRB approved clinical trials.

Brief summary: The investigators hypothesize that there is a difference in plantar tissue thickness, plantar pressure, and pain score in patients diagnosed with plantar fat pad atrophy compared to healthy, foot-type matched controls. Results will be measured objectively using ultrasound for tissue thickness, optical pedobarograph for plantar pressure, and Manchester foot pain and disability index (MFPDI) for pain score. Furthermore, investigators predict that these results will help establish criteria for fad pad atrophy diagnosis in the clinic as well as determine which patients would receive greatest benefit from fat grafting to the foot.

Detailed description: Human feet must bear the entire weight of the body. Feet have fat pads on their plantar surface that act as shock absorbers between the skin and bone. However, repetitive mechanical stress throughout a person's lifetime leads to gradual atrophy of these fat pads. In addition to this age-related degeneration, fat pad atrophy can be caused by other mechanisms such as abnormal foot mechanics, steroid use, and collagen vascular disease. Regardless of the cause, many patients with plantar fat pad atrophy experience considerable pain and loss of function.

Previous studies have negatively correlated plantar soft tissue thickness with plantar pressure, with the loss of plantar fat being a fundamental mechanism associated with pressure-related foot disorders. Increased pressure from fat pad atrophy is commonly managed with padded socks, insoles, and shoe modification. However, these extrinsic strategies are totally dependent on patient compliance, and devices must be replaced as soon as they begin to break down. Another treatment option includes silicone injections into the plantar aspect of the foot. In one study, patients receiving silicone treatment experienced increased plantar tissue thickness and decreased plantar pressure, but these cushioning properties decreased over time and the need for additional booster injections was ultimately suggested. Furthermore, silicone has been known to migrate away from the injection site and has been found in the inguinal lymph nodes of patients.

A different strategy that is gaining momentum is autologous fat grafting to the foot. Taking a patient's own tissue, often from the abdomen or thigh, and transplanting it to areas of plantar fat pad atrophy may reduce pressure in a more natural and permanent manner. Only one study to date has been published on autologous fat grafting to the foot, but the patients were receiving concurrent surgical procedures with their fat grafting and the results were reported subjectively by the patients.

In this study, the investigators hypothesize that there is a difference in plantar tissue thickness, plantar pressure, and pain score in patients diagnosed with plantar fat pad atrophy compared to healthy, foot-type matched controls. Results will be measured objectively using ultrasound for tissue thickness, optical pedobarograph for plantar pressure, and Manchester foot pain and disability index (MFPDI) for pain score. Furthermore, the investigators predict that these results will help establish criteria for fad pad atrophy diagnosis in the clinic as well as determine which patients would receive greatest benefit from fat grafting to the foot.

Eligibility criteria: Inclusion Criteria:

1. Aged 18 years or older
2. Patients without foot pain at the plantar surface of the foot near the head of the metatarsals
3. 6 months post any surgical intervention to the foot
4. Subjects must be determined by the PI or a Co-Investigator to not suffer from pedal pad atrophy

Exclusion Criteria:

1. Age less than 18 years
2. Inability to provide informed consent
3. Feet with open ulcerations or osteomyelitis
4. Diabetics: Type I and II
5. Active infection anywhere in the body
6. Diagnosed with cancer within the last 12 months and /or presently receiving chemotherapy or radiation treatment
7. Pregnancy
8. Tobacco use: Last use within 1 year per patient report

Primary outcomes:
measure: Plantar fat pad thickness
timeFrame: Screening
measure: Plantar foot pressure
timeFrame: Screening
measure: Pain score
timeFrame: Screening
Secondary outcomes:
Other outcomes:
Locations:
city: Pittsburgh
country: United States
facility: UPMC Department of Plastic Surgury
state: Pennsylvania
Study officials:
affiliation: University of Pittsburgh Department of Plastic Surgery
name: Jeffrey A Gusenoff, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Pittsburgh
name: Connor Davenport, BS
role: PRINCIPAL_INVESTIGATOR
References:
citation: Bowling FL, Metcalfe SA, Wu S, Boulton AJ, Armstrong DG. Liquid silicone to mitigate plantar pedal pressure: a literature review. J Diabetes Sci Technol. 2010 Jul 1;4(4):846-52. doi: 10.1177/193229681000400412.
citation: Abouaesha F, van Schie CH, Griffths GD, Young RJ, Boulton AJ. Plantar tissue thickness is related to peak plantar pressure in the high-risk diabetic foot. Diabetes Care. 2001 Jul;24(7):1270-4. doi: 10.2337/diacare.24.7.1270.
citation: Abouaesha F, van Schie CH, Armstrong DG, Boulton AJ. Plantar soft-tissue thickness predicts high peak plantar pressure in the diabetic foot. J Am Podiatr Med Assoc. 2004 Jan-Feb;94(1):39-42. doi: 10.7547/87507315-94-1-39.
citation: van Schie CH, Whalley A, Vileikyte L, Wignall T, Hollis S, Boulton AJ. Efficacy of injected liquid silicone in the diabetic foot to reduce risk factors for ulceration: a randomized double-blind placebo-controlled trial. Diabetes Care. 2000 May;23(5):634-8. doi: 10.2337/diacare.23.5.634.
citation: 5. Van Schie CHM, Whalley A, Vileikyte L, Boulton AJM (2002) Efficacy of injected liquid silicone is related to peak plantar foot pressures in the neuropathic diabetic foot. Wounds 14:26-30
citation: Chairman EL. Restoration of the plantar fat pad with autolipotransplantation. J Foot Ankle Surg. 1994 Jul-Aug;33(4):373-9.
citation: Menz HB, Tiedemann A, Kwan MM, Plumb K, Lord SR. Foot pain in community-dwelling older people: an evaluation of the Manchester Foot Pain and Disability Index. Rheumatology (Oxford). 2006 Jul;45(7):863-7. doi: 10.1093/rheumatology/kel002. Epub 2006 Jan 31.
citation: Waldecker U. Plantar fat pad atrophy: a cause of metatarsalgia? J Foot Ankle Surg. 2001 Jan-Feb;40(1):21-7. doi: 10.1016/s1067-2516(01)80037-5.