Mechanical properties of heel pads reconstructed with flaps

We compared the mechanical properties of normal and reconstructed heel pads in seven patients. Four had latissimus dorsi flaps and one each an anterio r thigh flap, a local dorsalis pedis flap and a sural arterial flap. The thickness of the heel pad was measured under serial incremental loads o f 0.5 kg to a maximum of 3 kg and then relaxed sequentially. The load-displ acement curve of the heel pad during a loading-unloading cycle was plotted and from this the unloaded heel-pad thickness (UHPT), compressibility index (CI), elastic modulus (Ep), and energy dissipation ratio (EDR) were calcul ated. The EDR was significantly increased in the reconstructed heels (53.7 +/- 18 % v 23.4 +/- 6.5%, p = 0.003) indicating that in them more energy is dissip ated as heat, Insufficient functional capacity in the reconstructed heel pa d can lead to the development of shock-induced discomfort and ulceration.