[Thenar branch of the median nerve and innervation of the trapeziometacarpal joint].
BACKGROUND
Denervation has been proposed successfully for chronic wrist pain. This procedure is not commonly performed for degenerative osteoarthritis of the trapeziometacarpal joint. According to the classic anatomical descriptions of the wrist innervation, it seems that the thenar branch of the median nerve (TBMN) is the only nerve of the wrist for which no articular branches are clearly defined. The aim of this study is to complete the few anatomical descriptions of the trapeziometacarpal joint innervation with microdissections of the TBMN.


METHODS
Ten wrist and hand specimens from fresh cadavers were dissected by the same operator under magnification (3.5-12x). The TBMN was identified at its origin from the median nerve and followed in the thenar muscles. All the divisions of the TBMN were identified and followed to their terminal branches.


RESULTS
The TBMN divided in at least two main branches, one each to the opponens and to the abductor pollicis brevis. In all but one specimen, the branch to the opponens pollicis muscle passed over or into its medial aspect to spread on the palmar side of the trapezium. Each dissected articular branches were histologically confirmed.


CONCLUSIONS
Our results show a clear participation of the TBMN in the innervation of the trapeziometacarpal joint. The lack of knowledge of this anatomical feature may explain the inconstant results obtained with selective denervation of the trapeziometacarpal joint.
Loréa
P
P
Laboratoire de chirurgie plastique expérimentale, fondation médicale Reine Elisabeth, CHU Brugmann, place Van Gehuchten, 4, 1020 Bruxelles, Belgique. loreapatrick@yahoo.fr
Berthe
J V
JV
De Mey
A
A
Coessens
B C
BC
Rooze
M
M
Foucher
G
G
D002102:Cadaver; D003714:Denervation; D006801:Humans; D008475:Median Nerve / Q000033:anatomy & histology* / Q000601:surgery; D008663:Metacarpus / Q000033:anatomy & histology; D010003:Osteoarthritis / Q000628:therapy; D059408:Pain Management; D014953:Wrist / Q000294:innervation* / Q000473:pathology