ABSTRACT
This study examined the use of freeze-thawed muscle as a nerve graft material in Sprague-Dawley
rats. In Group 1 (n = 4), the sciatic nerve was isolated and the incision immediately
closed. In Group 2 (n = 4), a 5-mm segment of the nerve was removed and immediately
replaced. In Group 3 (n = 50), a 5-mm segment of nerve was removed and muscle (2×2×5
mm, harvested from the gluteus, frozen in liquid nitrogen, and thawed in sterile water)
was sutured in place. The short 5-mm segment of muscle provided an ideal situation
for regeneration of myelinated nerve. Sciatic functional indices were comparable in
all groups after 8 weeks and at 1 year. Histologic analysis showed comparable nerve
regeneration in Groups 2 and 3 at 4 months. Group 3 grafts exhibited new axonal growth
distal to the repaired gap at 4 weeks; myelinated fibers were present at 10 weeks.
At 1 year, Group 3 nerves had almost the same axon count as contralateral nerves.
However, myelin-sheath regeneration in the 5-mm muscle graft was incomplete, at 81
percent of normal, at 1 year.
