Diabetes Care, Vol 23, Issue 5 634-638, Copyright © 2000 by American Diabetes Association
Efficacy of injected liquid silicone in the diabetic foot to reduce risk factors for ulceration: a randomized double-blind placebo-controlled trial
CH van Schie, A Whalley, L Vileikyte, T Wignall, S Hollis and AJ Boulton
Department of Medicine, Manchester Royal Infirmary, UK. carine@footclinic.demon.co.uk
OBJECTIVE: To investigate the effectiveness of injecting liquid silicone in
the diabetic foot to reduce risk factors for ulceration in a randomized
double-blind placebo-controlled trial. RESEARCH DESIGN AND METHODS: A total
of 28 diabetic neuropathic patients without peripheral vascular disease
were randomized to active treatment with 6 injections of 0.2 ml liquid
silicone in the plantar surface of the foot or to treatment with an equal
volume of saline (placebo). No significant differences were evident
regarding age or neuropathy status between the 2 groups. All injections
were under the metatarsal heads at sites of calluses or high pressures.
Barefoot plantar pressures (pedobarography) and plantar tissue thickness
under the metatarsal heads (Planscan ultrasound device) were measured at
baseline and at 3, 6, and 12 months after the first injection. Injection
sites were photographed at all stages, and callus formation was scored as a
change from baseline. Throughout the study, patients were treated by the
same podiatrist for all podiatry treatment. RESULTS: Patients who received
silicone treatment had significantly increased plantar tissue thickness at
injection sites compared with the placebo group (1.8 vs. 0.1 mm) (P <
0.0001) and correspondingly significantly decreased plantar pressures (-232
vs. -25 kPa) (P < 0.05) at 3 months, with similar results at 6 and 12
months. A trend was noted toward a reduction of callus formation in the
silicone-treated group compared with no change in the placebo group.
CONCLUSIONS: The results confirm the efficacy of plantar silicone
injections in reducing recognized risk factors associated with diabetic
foot ulceration.