Can the use of a terminal device augment plantar pressure reduction with a total contact cast?

HYPOTHESES/PURPOSE: Total contact casting (TCC) has been shown to promote the healing of plantar neurotrophic ulcers by reducing plantar pressures and has become the established treatment standard by which all others are measured. The purpose of this study was to determine if terminal cast devices (cast shoes and heels) significantly affect the amount of plantar pressure reduction when used with a total contact cast.

METHODS/RESULTS: Plantar pressures were measured in the right feet of 28 healthy adult volunteers using the Novel EMED PEDAR system (Novel GmbH, Munich, Germany) for six conditions: athletic shoe (i.e., control), TCC alone, TCC with a conventional cast shoe (EBI, Parsipanny, NJ), TCC with a custom rigid rocker cast shoe (NPS, St. Louis, MO), TCC with a rubber rocker heel (Cast Walker, DM Systems Inc., Evanston, IL), and TCC with a traditional flat rubber heel (Zimmer, Warsaw, IN). Peak plantar pressures were recorded from the forefoot, midfoot, and hindfoot. Analysis of variance (ANOVA) was used to determine statistical significance. The greatest reductions in forefoot plantar pressures compared to the athletic shoe control were seen in the TCC with the conventional cast shoe and the TCC with the rigid rocker shoe; a mean plantar pressure reduction of 30% was observed for both conditions (p < .001). Significant midfoot plantar pressure reductions (p < .001) were achieved with the TCC alone, TCC with the conventional cast shoe, TCC with the rigid rocker heel, TCC with the flat rubber heel, and TCC with the rubber rocker heel. Mean reductions were 42%, 51%, 47%, 40%, and 46%, respectively. While athletic shoe peak hindfoot pressures were only reduced by 15% by TCC alone, the addition of the rubber rocker heel to TCC reduced athletic shoe pressures by 32% and the addition of the flat rubber heel to TCC reduced athletic shoe pressures by 29%. The reductions with TCC and the heels were both significant when using the athletic shoe as the control (p < .001) and the TCC alone as the control (p < .05).

CONCLUSION

Plantar pressure reduction with TCC can be augmented with the addition of a terminal cast device and the effects shown in this study are significantly different than previously reported. These results suggest that terminal cast devices should be chosen according to location of the neuropathic ulcer. In this study, forefoot pressures were reduced the most with TCC and either the conventional cast shoe or the rigid rocker shoe. The authors therefore recommend these combinations for forefoot ulcers. TCC alone or combined with any of the terminal devices proved equally effective for midfoot plantar pressure reduction. Hindfoot ulcers should be treated with TCC and the rubber rocker heel or the flat rubber heel as these provided the best hindfoot pressure reductions.