The so called free and functional muscle transfer consists another therapeutic option in the field of plastic and reconstructive microsurgery in the case of complicated injuries of the brachial plexus. These free und functional muscle transfers are especially useful when referring to complete plexus lesions but also after incomplete regeneration of the network of nerves responsible for the innervation of the shoulders, arms and hands. During this procedure, a healthy donor-muscle ( for example the gracilis muscle from the thigh) will be harvested and transplanted on an injured extremity ( shoulder, upper of lower arm, hand). The muscle will be microsurgically transplanted on the receiver area together with its arterial as well as with its nerve supply (impulse generator). The muscle graft will be microsurgically connected to an artery and vein of the receiver area with the use of a microscope. In doing so, the muscle taken from the thigh will now survive receiving its perfusion from the arm. For the same reason, during the transplantation, the nerves of the graft have to connected as well with nerves of the receiver area so that electric impulses can be brought at a later time into the transplanted muscle. This could cause though sometimes strategical problems since there is not always an available functional nerve in the immediate receiver area of the injured muscle. In this case, as during the intra- or extra-plexus nervetransfers, a nerve, that can be extracted without causing functional deficits and muscle injuries, can be harvested from another site and used as a graft. When the distance between the site of muscle reconstruction and the donor-nerve (accessory nerve of the neck or pectoral nerve of the chest muscle) is too big, a long “cable-like” nerve-graft ( sural nerve or another nerve graft ) should be in advance transplanted. This long nerve graft ends initially blind because time ( according to length) is needed until functional impulses can be conducted thought its entire length. The reason for this is that the nerve fibers at the spinal cord level should gradually sprout and grow and reach the site of the affected muscle. Thus, the operation and reconstruction with a free and functional muscle should be planned and executed as a two step process. This two step process consists initially of a nerve transplantation and subsequently after about a year, of the harvest and transplantation of the muscle. During the transplantation, the muscle graft will be and fixated in a way that the joint will be overlapped. For example, during the reconstruction of the biceps muscle, the muscle graft will be anchored on the clavicle on the one end and fixated distally on the lower arm overriding the joint of the elbow on the other.
As a general rule, this type of operation is followed by an intensive and long-time physiotherapie. In Berlin, the these type of operations are being successfully performed only from a few surgeons. In our clinic for plastic and reconstructive microsurgery, these procedures represent a secure and tested therapeutic approach in order to restore and reinforce the essential functions of the brachial plexus.