The role of osseointegration in bionic prostheses of the upper limb

Osseointegration and osseoperception improve prosthetic control, prostheses perception and adaptation supporting the creation of a new reinforced image of themselves in which the external device became part of their body. Bodily incorporation of the prosthesis has significant repercussions on the social and psychosocial adjustments of the patients themselves, giving functional improvements and reserving existential implications in the concept of quality of life. The patient is a male of 35 years old and underwent to amputation of his right upperlimb for a traffic accident in 2007. The patient is been underwent a one stage osseointegration surgical technique with a target muscle and sensitive reinnervation. To explore the role of osseointegration surgical technique in the embodiment process we have performed the following behavioral studies: Temporal order Judgment and Top- bottom hand reaction time. The results of the first test highlighted as the visual stimuli seems to play an important role, but only the application of weight restored the crossing effect. Moreover, the visual stimuli alone seems to be highly misleading denoted by a shift of the curve with a Point of subjective simultaneity that become positive. The results of top-bottom hand reaction time instead showed statistical differences within the different sessions regarding the finger, the hand position and the interaction between the stimulated finger space and the hand position. In the healthy patient, there is an interaction between the space of stimulated finger and the position of the finger. This leads us to hypothesize that the body pattern varies, reorganizes itself after the amputation, and changes the frame of reference that moves from the finger to the whole limb. The results of these tests suggest a sensitive feedback by the application of weight derived from the direct connection to the bone of prosthesis that seems to improve the embodiment process of this one.