title: BIOMECHANICS AND HISTOLOGICAL ANALYSIS IN RABBIT FLEXOR TENDONS REPAIRED USING THREE SUTURE TECHNIQUES (FOUR AND SIX STRANDS) WITH EARLY ACTIVE MOBILIZATION.
abstract: OBJECTIVE
  Analyzing suture time, biomechanics (deformity between the stumps) and the histology of three groups of tendinous surgical repair: Brazil-2 (4-strands) which the end knot (core) is located outside the tendon, Indiana (4-strands) and Tsai (6-strands) with sutures technique which the end knot (core) is inner of the tendon, associated with early active mobilization.
  
  
  METHODS
  The right calcaneal tendons (plantar flexor of the hind paw) of 36 rabbits of the New Zealand breed (Oryctolagus cuniculus) were used in the analysis. This sample presents similar size to human flexor tendon that has approximately 4.5 mm (varying from 2mm). The selected sample showed the same mass (2.5 to 3kg) and were male or female adults (from 8 ½ months). For the flexor tendons of the hind paws, sterile and driven techniques were used in accordance to the Committee on Animal Research and Ethics (CETEA) of the University of the State of Santa Catarina (UDESC), municipality of Lages, in Brazil (protocol # 1.33.09).
  
  
  RESULTS
  In the biomechanical analysis (deformity) carried out between tendinous stumps, there was no statistically significant difference (p>0.01). There was no statistical difference in relation to surgical time in all three suture techniques with a mean of 6.0 minutes for Tsai (6- strands), 5.7 minutes for Indiana (4-strands) and 5.6 minutes for Brazil (4-strands) (p>0.01). With the early active mobility, there was qualitative and quantitative evidence of thickening of collagen in 38.9% on the 15(th) day and in 66.7% on the 30(th) day, making the biological tissue stronger and more resistant (p=0.095).
  
  
  CONCLUSIONS
  This study demonstrated that there was no histological difference between the results achieved with an inside or outside end knot with respect to the repaired tendon and the number of strands did not affect healing, vascularization or sliding of the tendon in the osteofibrous tunnel, which are associated with early active mobility, with the repair techniques applied.
authors.affiliation: Doctor, Master's Degree in Biomechanics of the Upper Limb Surgery Center of the Instituto de Ortopedia e Traumatologia (IOT) - Passo Fundo, RS.
authors.forename: Antônio Lourenço
authors.initials: AL
authors.lastname: Severo
authors.affiliation: Professor and Master in Biomechanics at the Universidade Regional Integrada (URI) - Erechim - RS, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Arenhart
authors.affiliation: Professor and Master in Clinical Pathology at the Universidade de Passo Fundo (UPF) - Passo Fundo, RS, Brazil.
authors.forename: Daniela
authors.initials: D
authors.lastname: Silveira
authors.affiliation: Professor and Doctor at the Biomechanics Laboratory of the Universidade Estadual de Santa Catarina (UDESC) - Florianópolis, SC, Brazil.
authors.forename: Aluísio Otávio Vargas
authors.initials: AO
authors.lastname: Ávila
authors.affiliation: Professor and Doctor, Director of the Sports and Information Technology Department of the Universidade Pablo de Olavide (UPO) - Sevilha, Spain.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: Berral
authors.affiliation: Doctor of Upper Limb Surgery Center of the IOT - Passo Fundo, RS.
authors.forename: Marcelo Barreto
authors.initials: MB
authors.lastname: Lemos
authors.affiliation: Doctor of Upper Limb Surgery Center of the IOT - Passo Fundo, RS.
authors.forename: Paulo César Faiad
authors.initials: PC
authors.lastname: Piluski
authors.affiliation: Head of Medical Residency of the IOT - Passo Fundo, RS, Brazil.
authors.forename: Osvandré Luís Canfield
authors.initials: OL
authors.lastname: Lech
authors.affiliation: Professor and Doctor of the Faculty of medicine, ABC (FMABC) - Santo André, SP, Brazil.
authors.forename: Walter Yoshinori
authors.initials: WY
authors.lastname: Fukushima
keywords: Calcaneal Tendon; Suture; Wound Healing