Advantages Over Tendon Transfers

Nerve transfers have many advantages over tendon transfers.

  1. Tendon transfers require significantly more dissection and extended post-operative limb immobilization while the tendon heals (Brown 2012). Less surgical scarring in common areas of the hand where tendons overlap anatomically, thus fewer chances of restricted motion (Keith & Peljovich 2012)
  2. Reconstruction of finger flexion and extension must be done in separate phases, owing to conflicting positions for postoperative immobilizations (Revol et al. 2002) which maybe problematic for some who are highly dependent on others for care to be incapable of performing most basic ADL for quite some time (Bertelli et al. 2011; Brown 2012; Hentz 2002)
  3. Tenotomy may cause detrimental effects on muscle function owing to the fact that reduced specific force is developed (Guelinekx et al. 1998)
  4. Nerve transfers take a shorter period of less restrictive immobilization probably with less pain, minimal loss of donor muscle function (Brown 2012)
  5. Reconstruction of finger flexion and extension can be done at the same time- tension-insertion balance of the muscle tendon unit is preserved because there is no disruption to the insertion or attachment of the muscle in question-maintaining line of pull and excursion and avoiding scar induced restrictions of movement (Brown 2012)
  6. Nerve transfers offer a greater functional gain for a given transfer (Brown 2011; Brown 2012; Brown et al. 2012), the transferred axon, which originally provided re-innervation to a single muscle can re-innervate multiple motor fibers, later on with motor re-education and central plasticity, it is possible to activate multiple functions independently by the same nerve that initially controls only a single function (Brown 2011; Brown 2012; Midha 2004).
  7. Nerve transfers can be accomplished without appreciable loss of function from the donor muscle group because nerve transfer can be performed with only a portion of the donor nerve, not entirely denervating the muscle associated with the donor nerve (Brown 2011; Brown 2012).

Although the partial denervation results in a reduced number of axons to the original muscle, the residual motor axons sprout within the muscle and innervate orphaned muscle fibers to enlarge the motor unit. Each motor axon can increase innervation 5x the number of muscle fibers that it originally served (Gordon et al. 1993). This phenomenon is called adoption (Brunelli & Brunelli 1983) and in time, the donor muscle may regain its original strength.