Musculo-tendinous transfers of the hand and forearm.

The concept of providing a more equitable distribution of forces acting upon a disabled limb is the basis of tendon transfers. The musculo-tendinous transfer is usually performed by moving the insertion, thereby altering the direction of the unit in an attempt to replace a lost function. In order to obtain a successful result basic principles have to be followed. The transferred muscle must have enough strength, should have approximately the same amplitude as the muscle whose function it is replacing and should have a straight line of pull from the origin to the new insertion or distally from the newly created pulley. Furthermore, the nerve and blood supply should remain intact during the actual transfer. In the event of scarred tissue or poorly mobilized joints treatment should first deal with these problems before tendon transfer is carried out. After careful assessment of the patient's disability a plan of operation can be conceived on the basis of the extent of functional loss balanced against the muscle force available for transfer. Essential for forearm and hand function are wrist extension and finger flexion as well as thumb and intrinsic function. The loss of these functions may be compensated for by a variety of motors. The choice is made on the basis of the available possibilities and the demands of the patient. To obtain optimal postoperative results physiotherapy of the hand and a well motivated patient are necessary.