J Reconstr Microsurg 2020; 36(05): 311-315
DOI: 10.1055/s-0039-1701036
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Cadaveric Evaluation of Myelinated Nerve Fiber Count in the Nerve to the Gracilis Muscle in Relation to Use as a Free Functional Muscle Transfer for Elbow Flexion

1   Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York
,
Danielle C. Marshall
2   Department of Orthopaedic Surgery, University of Miami Hospital, Miami, Florida
,
Scott W. Wolfe
1   Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York
,
Steve K. Lee
1   Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York
,
Duretti T. Fufa
1   Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York
› Author Affiliations
Funding None.
Further Information

Publication History

17 July 2019

02 December 2019

Publication Date:
27 January 2020 (online)

Abstract

Background Optimizing axon count is essential for successful nerve transfer surgery, and a donor-to-recipient axon count ratio greater than 0.7:1 has been associated with improved outcomes. A gracilis free functioning muscle transfer (FFMT) is an option to restore elbow flexion, but its axon count has not been evaluated. Our aim was to quantify the axon count of the nerve to the gracilis muscle.

Methods The nerve to the gracilis was dissected in 10 fresh frozen adult cadaveric hindquarter specimens (four females and six males). The length of the nerve to the gracilis was measured and a biopsy taken. A validated histologic preparation technique was utilized, and axons were counted. The mean length and axon counts were calculated.

Results The average axon count in the nerve to the gracilis was 818 (range = 684–1,000, standard deviation [SD] = 116). The average length was 98 mm (range = 81–115 mm, SD = 13 mm).

Conclusion Our study found the average axon count in the nerve to the gracilis was 818. Prior literature suggests axon count ratio greater than 0.7:1 is associated with better clinical outcomes. Using data from prior studies, the spinal accessory, three intercostal, and two intercostal nerves are all sufficient for the transfer to the nerve to the gracilis with donor to recipient ratios of 1.7:1, 1.3:1, and 0.9:1, respectively.

Note

This study was presented at American Society for Surgery of the Hand Annual Meeting (ASSH) 2018 in Boston, Massachusetts and New York Society for Surgery of the Hand Annual Conference (NYSSH) 2018 in New York, New York.


 
  • References

  • 1 Shin AY, Spinner RJ, Steinmann SP, Bishop AT. Adult traumatic brachial plexus injuries. J Am Acad Orthop Surg 2005; 13 (06) 382-396
  • 2 Maldonado AA, Kircher MF, Spinner RJ, Bishop AT, Shin AY. Free functioning gracilis muscle transfer versus intercostal nerve transfer to musculocutaneous nerve for restoration of elbow flexion after traumatic adult brachial pan-plexus injury. Plast Reconstr Surg 2016; 138 (03) 483e-488e
  • 3 Giuffre JL, Kakar S, Bishop AT, Spinner RJ, Shin AY. Current concepts of the treatment of adult brachial plexus injuries. J Hand Surg Am 2010; 35 (04) 678-688 , quiz 688
  • 4 Akasaka Y, Hara T, Takahashi M. Restoration of elbow flexion and wrist extension in brachial plexus paralyses by means of free muscle transplantation innervated by intercostal nerve. Ann Chir Main Memb Super 1990; 9 (05) 341-350
  • 5 Maldonado AA, Kircher MF, Spinner RJ, Bishop AT, Shin AY. Free functioning gracilis muscle transfer with and without simultaneous intercostal nerve transfer to musculocutaneous nerve for restoration of elbow flexion after traumatic adult brachial pan-plexus injury. J Hand Surg Am 2017; 42 (04) 293.e1-293.e7
  • 6 Bishop AT. Functioning free-muscle transfer for brachial plexus injury. Hand Clin 2005; 21 (01) 91-102
  • 7 Mackinnon SE, Novak CB. Nerve transfers. New options for reconstruction following nerve injury. Hand Clin 1999; 15 (04) 643-666 , ixix.
  • 8 Schreiber JJ, Byun DJ, Khair MM, Rosenblatt L, Lee SK, Wolfe SW. Optimal axon counts for brachial plexus nerve transfers to restore elbow flexion. Plast Reconstr Surg 2015; 135 (01) 135e-141e
  • 9 Snyder-Warwick AK, Fattah AY, Zive L, Halliday W, Borschel GH, Zuker RM. The degree of facial movement following microvascular muscle transfer in pediatric facial reanimation depends on donor motor nerve axonal density. Plast Reconstr Surg 2015; 135 (02) 370e-381e
  • 10 Norkus T, Norkus M, Ramanauskas T. Donor, recipient and nerve grafts in brachial plexus reconstruction: anatomical and technical features for facilitating the exposure. Surg Radiol Anat 2005; 27 (06) 524-530
  • 11 Samardzic M, Antunovic V, Joksimovic M, Bacetic D. Donor nerves in the reinnervation of brachial plexus. Neurol Res 1986; 8 (02) 117-122
  • 12 Brandt KE, Mackinnon SE. A technique for maximizing biceps recovery in brachial plexus reconstruction. J Hand Surg Am 1993; 18 (04) 726-733
  • 13 Pruksakorn D, Sananpanich K, Khunamornpong S, Phudhichareonrat S, Chalidapong P. Posterior approach technique for accessory-suprascapular nerve transfer: a cadaveric study of the anatomical landmarks and number of myelinated axons. Clin Anat 2007; 20 (02) 140-143
  • 14 Vathana T, Larsen M, de Ruiter GC, Bishop AT, Spinner RJ, Shin AY. An anatomic study of the spinal accessory nerve: extended harvest permits direct nerve transfer to distal plexus targets. Clin Anat 2007; 20 (08) 899-904
  • 15 Placheta E, Tinhofer I, Schmid M. , et al. The spinal accessory nerve for functional muscle innervation in facial reanimation surgery: an anatomical and histomorphometric study. Ann Plast Surg 2016; 77 (06) 640-644
  • 16 Rodríguez Lorenzo A, Morley S, Payne AP, Tollan CJ, Soutar DS. Anatomy of the motor nerve to the gracilis muscle and its implications in a one-stage microneurovascular gracilis transfer for facial reanimation. J Plast Reconstr Aesthet Surg 2010; 63 (01) 54-58
  • 17 Bohac M, Palkovic M, Fedeles J, Hodosy J. Body proportions as possible predictors for free gracilis one-stage facial reanimation. Bratisl Lek Listy 2016; 117 (09) 547-550
  • 18 Chung DC, Carver N, Wei FC. Results of functioning free muscle transplantation for elbow flexion. J Hand Surg Am 1996; 21 (06) 1071-1077
  • 19 Merrell GA, Barrie KA, Katz DL, Wolfe SW. Results of nerve transfer techniques for restoration of shoulder and elbow function in the context of a meta-analysis of the English literature. J Hand Surg Am 2001; 26 (02) 303-314
  • 20 An X, Dong P, Qu X, Li S. Demonstration of intramuscular artery and nerve distribution in the same whole mount gracilis muscle by different colors. Int J Morphol 2016; 34 (03) 1034-1038