A biomechanical study in cadavers of cast boots used in the early postoperative period after first metatarsophalangeal joint arthrodesis.

OBJECTIVES

To compare the effectiveness of 3 common models of walking boots (Walkabout, Samson Walker and Equalizer Premium Walker) to that of a fibreglass cast in protecting an arthrodesis of the first metatarsophalangeal (MTP) joint in the early postoperative period, we carried out a biomechanical study in cadavers in the bioengineering laboratory at Memorial University of Newfoundland.

METHODS

Two cadaver models of a first MTP joint arthrodesis were prepared by placing a strain gauge at the joint. This provided a measure of the bending moment across the fusion site. Walking was simulated by applying a force to the sole of the cadaver foot at multiple positions from heel to toe, representing the stages of gait from heel strike to toe off.

RESULTS

For both cadaver specimens, the Walkabout boot had the lowest mean moment. The Walkabout and Sampson Walker boots were better than the Equalizer Premium Walker boot and the fibreglass cast (p < 0.05), but the Walkabout boot was the best (p < 0.05). Also, for both specimens, the Walkabout boot had the smallest absolute maximum moment (p < 0.05).

CONCLUSION

On a first MTP joint arthrodesis site, removable cast boots provide the same, if not more, reduction of force as a traditional cast.