A comparison of functional and prefabricated insoles used for the preventative management of neuropathic diabetic foot ulceration : a single blind randomised control trial

• Main Author: Paton, J. S.
• Published: University of Plymouth 2008
• Subjects: 616.4
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.504794

Background: Neuropathic diabetic foot ulceration may be prevented if the mechanical stress transmitted to the plantar tissues can be modified. Insole therapy is one practical method commonly used to reduce plantar loads and ulceration risk. The type of insole best suited for purpose is unknown. Aim: The study compared custom-made functional insoles with prefabricated insoles for the preventative management of neuropathic diabetic feet, assessing effects on peak pressure, forefoot pressure time integral, total contact area, forefoot rate of loading, duration of load as a percentage of stance, quality of life, perceived foot health and cost. Method: A single-blind randomised control trial recruited 119 neuropathic participants with diabetes from two Primary Care Trusts and randomly allocated them to either custom-made functional or prefabricated insoles. Data was collected at issue and 6-month follow-up using the F-scan in-shoe pressure measurement system. Patient perceptions were evaluated with the Bristol Foot Score and Audit of Diabetes Dependant Quality of Life. Further separate sub-group analyses assessed insole effect in participants with pronated feet and insole durability. Results: The results presented in this abstract are based on intention-to-treat analysis. The custom-made functional insole was more effective than the prefabricated insole in reducing forefoot pressure time integral both at issue (25% vs. 22%) and 6-month follow-up (27% vs. 23%). No other significant difference between insoles in kinetic measures or patient perceptions was evident either in full or sub-sample analyses. Both insoles showed a beneficial effect on peak pressure, peak pressure in pronated feet, total contact area, rate of forefoot loading and perceived foot health. The prefabricated insole was provided at less cost (£554 vs. £656). Conclusion: This study has shown that the custom-made functional insole is more effective in reducing forefoot pressure time integral than the less expensive prefabricated insole, amongst people with diabetes and neuropathy. There was no difference in other measures. A definitive recommendation regarding insole selection cannot be made at this time. However should further research establish pressure time integral as a better predictor of neuropathic foot ulceration than peak pressure, then the custom-made functional insole is likely to be the more cost-effective.