title: Total hip arthroplasty using a posterior minimally invasive approach - results after six years.
abstract: OBJECTIVE
  To evaluate the medium-term clinical-functional results (minimum follow-up of six years) from total uncemented hip arthroplasty performed by means of a posterior minimally invasive access, in comparison with the traditional right lateral access.
  
  
  METHODS
  In a comparative prospective study, 224 adult patients underwent elective total hip arthroplasty due to a diagnosis of primary or secondary osteoarthrosis. A group of 103 patients with posterior minimally invasive access was compared with a group of 121 patients with the traditional right lateral access. The mean length of follow-up among the patients of this sample was 7.2 years. We evaluated the clinical-functional and radiographic results and occurrences of loosening, along with any complications that occurred, with a minimum follow-up of six years.
  
  
  RESULTS
  The clinical-functional analyses before the surgical procedure and six years afterwards were similar in the two groups (p = 0.88 and p = 0.55). One patient in the minimally invasive group underwent revision of the acetabular component and two patients in the control group underwent the same procedure (p = 0.46). The Trendelenburg clinical test, which showed weakness of the hip abductor musculature, was present in five patients operated using the traditional lateral route and absent in all those who underwent the minimally invasive procedure (p = 0.06). There was no difference regarding the radiographic parameters obtained, either in acetabular or in femoral positioning (p = 0.32 and p = 0.58).
  
  
  CONCLUSIONS
  The medium-term clinical and radiographic results and the complication rates were similar between the patients who underwent total hip arthroplasty by means of the posterior minimally invasive access and those with the traditional lateral access.
authors.affiliation: Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: José Ricardo Negreiros
authors.initials: JR
authors.lastname: Vicente
authors.affiliation: Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Helder Souza
authors.initials: HS
authors.lastname: Miyahara
authors.affiliation: Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Carlos Malheiros
authors.initials: CM
authors.lastname: Luzo
authors.affiliation: Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Henrique Melo
authors.initials: HM
authors.lastname: Gurgel
authors.affiliation: Instituto de Ortopedia e Traumatologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Alberto Tesconi
authors.initials: AT
authors.lastname: Croci
keywords: Hip arthroplasty; Hip osteoarthritis; Minimally invasive surgical procedures