title: Pre-degenerated nerve shows enhanced regeneration after incremental elongation in rats.
abstract: Following nerve degeneration, we investigated effects of linear elongation on subsequent nerve regeneration in a total of 92 Wistar rats (weight 380-430 g). The nerve was ligated at the midthigh and then elongated incrementally by a total of 15 mm by leg lengthening at a rate of 3 or 5 mm/day. Seven days after initiation of nerve elongation, the external fixator was removed and normal leg length was restored with internal fixation. Then a 10 mm nerve segment at the ligature site was excised, and the nerve was repaired with sutures (group D). At 2, 4, 6, and 8 weeks after nerve suturing, we examined transverse semi-thin nerve sections compared with group I (severed and repaired after leg lengthening without a nerve ligature) and control group (severed and repaired without leg lengthening). After lengthening at 3 mm/day, nerve regeneration in group D was enhanced at 4 weeks. After lengthening at 5 mm/day, nerve regeneration in group D also was enhanced at 6 and 8 weeks. Pre-degenerated nerve showed better regeneration after suturing than intact nerve. Elongation holds promise as an alternative to nerve grafting in treatment of nerve injury.
authors.affiliation: Department of Orthopaedic Surgery, University of Tsukuba, 1-1-1, Tennoudai, Tsukuba-shi, Ibaraki 305-8575, Japan. yukihara@mail1.accsnet.ne.jp
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hara
authors.forename: Akihito
authors.initials: A
authors.lastname: Tsujino
authors.forename: Ichiro
authors.initials: I
authors.lastname: Abe
authors.forename: Harumitsu
authors.initials: H
authors.lastname: Ichimura
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Ochiai
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D008026:Ligation; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D009416:Nerve Regeneration / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000166:cytology / Q000293:injuries / Q000502:physiology*; D014855:Wallerian Degeneration / Q000473:pathology / Q000503:physiopathology*