title: Nerve stretch injury induced pain pattern and changes in sensory ganglia in a clinically relevant model of limb-lengthening in rabbits.
abstract: We used a model of tibial lengthening in rabbits to study the postoperative pain pattern during limb-lengthening and morphological changes in the dorsal root ganglia (DRG), including alteration of substance P (SP) expression. Four groups of animals (naive; OG: osteotomized only group; SDG/FDG: slow/fast distraction groups, with 1 mm/3 mm lengthening a day, respectively) were used. Signs of increasing postoperative pain were detected until the 10(th) postoperative day in OG/SDG/FDG, then they decreased in OG but remained higher in SDG/FDG until the distraction finished, suggesting that the pain response is based mainly on surgical trauma until the 10(th) day, while the lengthening extended its duration and increased its intensity. The only morphological change observed in the DRGs was the presence of large vacuoles in some large neurons of OG/SDG/FDG. Cell size analysis of the S1 DRGs showed no cell loss in any of the three groups; a significant increase in the number of SP-positive large DRG cells in the OG; and a significant decrease in the number of SP-immunoreactive small DRG neurons in the SDG/FDG. Faster and larger distraction resulted in more severe signs of pain sensation, and further reduced the number of SP-positive small cells, compared to slow distraction.
authors.affiliation: Department of Traumatology, Semmelweis University & Department of Orthopedics and Traumatology, Uzsoki Hospital, Budapest, Hungary, Szentágothai János Laboratory, Department of Anatomy, Histology and Embryology, Semmelweis University, Budapest, Hungary. zpuskar@ana.sote.hu.
authors.forename: K
authors.initials: K
authors.lastname: Pap
authors.forename: Á
authors.initials: Á
authors.lastname: Berta
authors.forename: G
authors.initials: G
authors.lastname: Szőke
authors.forename: M
authors.initials: M
authors.lastname: Dunay
authors.forename: T
authors.initials: T
authors.lastname: Németh
authors.forename: K
authors.initials: K
authors.lastname: Hornok
authors.forename: L
authors.initials: L
authors.lastname: Marosfői
authors.forename: M
authors.initials: M
authors.lastname: Réthelyi
authors.forename: M
authors.initials: M
authors.lastname: Kozsurek
authors.forename: Z
authors.initials: Z
authors.lastname: Puskár
mesh_terms: D000818:Animals; D001852:Bone Lengthening / Q000009:adverse effects*; D004195:Disease Models, Animal; D005260:Female; D017950:Ganglia, Sensory / Q000503:physiopathology*; D008297:Male; D009437:Neuralgia / Q000209:etiology / Q000503:physiopathology*; D010146:Pain / Q000503:physiopathology*; D058748:Pain Perception; D059348:Peripheral Nerve Injuries / Q000209:etiology* / Q000503:physiopathology; D011817:Rabbits