ABSTRACT
Wrist problems are not uncommon in sports requiring prolonged grip function – e.g. tennis, cycling, motor sport, baseball, golf – and are often associated with entrapment syndromes and related phenomena, emanating from an intrinsic (e.g. ganglia) or an extrinsic (e.g. nerve irritation caused by repetitive loading, repetitive traumata) aetiolology (Murata et al., 2003). To understand these syndromes and their related phenomena, it is necessary to clarify the existence of three different tunnels at the wrist. In clinical practice there seems to be a colloquial conviction that the wrist area contains two nervous and vascular passages only that can create entrapment symptoms, e.g. the carpal tunnel and the ulnar canal. Guyon’s canal or the canalis ulnaris, according to the nomina anatomica (Berkovitz et al. 1998) was first described in 1861 by the French urologic surgeon Jean Casimir Felix Guyon and is only occasionally mentioned in basic anatomy atlases. If the canal is mentioned, the information that is presented in a lot of books and reports is very often vague or confusing, in spite of the many publications dedicated to this subject under clinical circumstances. Seldom does one observe so many contradictory descriptions of a particular anatomical region covering a restricted area of the wrist. Most of the anatomical books and ad hoc internet sites, describe extensively and precisely the carpal tunnel but, if in addition a second passage is described, one of the different “versions” of the canalis ulnaris is presented. A clear description of the carpus with its three different tunnels is never found. One thing is clear, Guyon’s canal is considered to be the major cause of ulnar tunnel syndrome (Salgeback, 1977; Turner and Caird, 1977; Luethke and Dellon, 1992; Netscher and Cohen, 1997; Bozkurt et al., 2005; Sturzenegger, 2005; Wang et al., 2005). In an attempt to end the confusion, both for educational and for clinical purposes, the present study was undertaken in order to clarify the vagueness concerning the description of Guyon’s canal by pointing out the existence of the three “tunnels” that can be distinguished in the palmar carpus.
