[Clinical anatomy of the fat body in the forearm and in the palm].

In the hand the space between the deep flexor tendons and the interosseous fascia is named the midpalmar space, spatium palmare medianum. A fat body, Corpus adiposum palmare profundum, can be found there regularly. Despite the anatomical narrowness in this region, it reaches up into the carpal canal. Also in the deep forearm space there is always a fat body, Corpus adiposum profundum antebrachii, located dorsally to the deep flexor tendons, lying on the palmar fascia of the pronator quadratus muscle. Usually it is not connected to the Corpus adiposum palmare profundum. The regular occurrence of both fat bodies indicates their functional importance. It is to be supposed that they serve as a gliding layer for the deep flexor tendons. Especially the Corpus adiposum palmare profundum may provide an essential protecting function to the dorsally located deep branch of the ulnar nerve and deep palmar arch. In contrast there is a higher risk of mechanical irritation and compression of the deep branches of the ulnar nerve and artery during their more proximal course through the opponens muscle of the little finger ("opponens-canal") and the ulnar marginal septum. Characteristic features of dimensions and location of the Corpus adiposum profundum antebrachii and the Corpus adiposum palmare profundum and of the deep branches of the ulnar nerve and artery are described. The clinical relevance is discussed.