Properties of mechanoreceptive fibres serving skin grafts transferred to the hands of adult baboons (Papio anubis).

In nine adult baboons, full‐thickness skin grafts were reciprocally exchanged between three glabrous skin sites on one hand and glabrous skin sites on the contralateral hand or foot, and a hairy skin site on the dorsum of the ipsilateral hand. The grafts acquired some of the physical characteristics of the recipient site; glabrous skin became thinner and more pliable on the dorsum of the hand and hairy skin became thicker and displayed a more irregular surface contour when transferred to the palm. The electrophysiological properties of cutaneous mechanoreceptors serving these grafts were examined about 5 months after surgery and again after 1 year. Measurements of conduction velocity, receptive field size and shape, and responses to mechanical stimuli suggested that axons serving mechanoreceptors in glabrous grafts functioned at nearly normal levels by 5 months, while axons innervating hairy skin grafts, whether transferred to a glabrous skin site or to a hairy skin site, performed less well even after 1 year. These observations suggest that factors intrinsic to the graft are a major determinant of the quality of sensory function achieved following a skin graft procedure. These factors affect the relative proportions of rapidly and slowly adapting fibres, conduction velocities, thresholds and receptive field configurations. As a result, hairy skin is not the tissue choice for plastic surgical procedures requiring optimum sensory return.