Limits of Muscle-to-Nerve Ratio in Functional Muscle Transplantation

ABSTRACT

The aim of the present study was to investigate the functional limits of over-dimensioning a free functioning muscle transplant for neuromuscular reconstruction. A part of the rectus femoris muscle, two and three times bigger than a scutuloauricularis muscle, was used to functionally replace the latter after removal. The major finding of these experiments is that both double-sized and triple-sized portions of the rectus femoris muscle developed maximal tetanic tensions during isometric contractions, which were up to 175 percent of the control scutuloauricularis muscle of the unoperated, contralateral side, although the same branch of the facial nerve was used for reinnervation of the grafted muscle. This implies that the supplying branch of the facial nerve has the potency to innervate a muscle much larger than the originally supplied muscle with optimal efficiency. These results underline the usefulness of overdimensioning during functional muscle transplantation, and also in limited neural capacity situations.

KEYWORD

Functioning muscle transplantation - muscle reinnervation - experimental

REFERENCES

• 1 Harii K, Ohmori K, Torii S. Free gracilis muscle transplantation with microneurovascular anastomoses for treatment of facial paralysis.  Plast Reconstr Surg . 1976;  57 133-143
• 2 Frey M, Happak W, Girsch W, Bittner R E, Gruber H. Histomorphometric studies in patients with facial palsy treated by functional muscle transplantation: new aspects for the surgical concept.  Ann Plast Surg . 1991;  26 370-379
• 3 Tamai S, Komatsu S, Sakamoto H. Free muscle transplants in dog, with microsurgical neurovascular anastomoses.  Plast Reconstr Surg . 1970;  57 219-225
• 4 Ikuta Y, Takashi K, Tsuge K. Free muscle transplantation by microsurgical technique to treat severe Volkmanńs contracture.  Plast Reconstr Surg . 1976;  58 407-411
• 5 Manktelow R T, McKee N H. Free muscle transplantation to provide active finger flexion.  J Hand Surg . 1978;  3A 416-26
• 6 Terzis J K, Sweet R C, Dykes R W, Williams H B. Recovery of function in free muscle transplants using microneurovascular anastomoses.  J Hand Surg . 1978;  3 37-59
• 7 Frey M, Giovanoli P, Meuli-Simmen C. The qualification of different free muscle transplants to reconstruct mimic function: an experimental study in rabbits.  Plast Reconstr Surg . 1998;  101 1774-1783
• 8 Frey M, Giovanoli P, Deutinger M, Meuli-Simmen C. Scutuloauricularis muscle of the rabbit: a new model for free functional muscle transplantation in the mimic system.  Microsurgery . 1996;  17 254-258
• 9 Rafuse V F, Gordon T. Incomplete rematching of nerve and muscle properties in motor units after extensive nerve injuries in cat hindlimb muscle.  J Physiol . 1998;  509 909-926
• 10 Cederna P S, Eguchi T, van der Meulen H J, Urbanchek M G, Kuzon Jr M W. Force deficits in neurovascular muscle transfer.  Surg Forum . 1998;  49 627
• 11 Gordon T, Stein R B. Reorganization of motor unit properties in reinnervated muscles in the cat.  J Neurophysiol . 1982;  48 1175-1190
• 12 Gordon T, Yang J F, Ayer K, Stein R B, Tyrema N. Recovery potential of muscle after partial denervation: a comparision between rats and humans.  Brain Res Bull . 1993;  30 477-482
• 13 Cope T C, Webb C B, Botterman B R. Control of motor unit tension by rat modulation during sustained contractions in reinnervated cat muscle.  J Neurophysiol . 1991;  65 648-656
• 14 Käser L, Müntener M. Delayed muscle fiber transformation after foreign-reinnervation of excessive muscle tissue.  Anat Rec . 1989;  223 347-355
• 15 Yoshimura K, Asato H, Cederna P S, Urbanchek M G, Kuzon Jr M W. The effect of reinnervation on force production and power output in skeletal muscle.  J Surg Res . 1999;  81 201-208
• 16 Cederna P S, Youssef M K, Asato H, Urbanchek M G, Kuzon Jr M W. Skeletal muscle reinnervation by reduced axonal numbers result in whole muscle force deficit.  Plast Reconstr Surg . 2000;  105 2003-2009
• 17 Koller R, Rab M, Todoroff B P. The influence of the graft length on the functional and morphological result after nerve grafting: an experimental study in rabbits.  Br J Plast Surg . 1997;  50 609-614
• 18 Frey M, Gruber H, Havel M, Steiner E, Freilinger G. Experimental free muscle transplantation with microneurovascular anastomoses.  Plast Reconstr Surg . 1983;  71 689-701
• 19 Frey M, Gruber H, Stransky G, Havel M. Time course of alterations in muscle transfers with microneurovascular anastomoses.  J Reconstr Microsurg . 1985;  112 33-43