title: Radiographic Subsidence in Asymptomatic Patients After THR Using the Furlong Active HAP Stem.
abstract: BACKGROUND
  The short, tapered, collarless Furlong Active stem has been recently associated in the published literature with significant subsidence using Roentgen stereophotogrammetric analysis.
  
  
  OBJECTIVE
  The purpose of this study was to analyze the short-term radiographic subsidence in Furlong Active HAP stems and correlate the results with the age, gender, bone morphology, and bone quality of the proximal femur, stem diameter, and medullary canal filling.
  
  
  METHODS
  Sixty-five consecutive patients (70 hips) receiving the Furlong Active HAP stems were enrolled in this prospective series. The average follow-up was 2.99 ± 1.38 years. All patients were evaluated clinically using the Harris Hip Score (HHS) and radiographically for femoral stem subsidence. In addition, proximal femoral osteopenia, proximal femur morphology, and medullary canal filling were also evaluated.
  
  
  RESULTS
  The average subsidence was 2.4 mm (from 0 to 13 mm) at the end of the follow-up period. The average HHS score at the end of follow-up was 90 (range, 81-98). There was one intraoperative fracture.
  
  
  CONCLUSIONS
  Of the Furlong Active stems 61% subsided with initial weight bearing. Subsidence is higher in males, but no correlation has been found with age, stem diameter, morphology, osteopenia, or canal filling.
authors.affiliation: Hospital Universitario La Princesa, c/ Diego de León 62, 28006 Madrid, Spain ; Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Cordero-Ampuero
authors.affiliation: Hospital Universitario La Princesa, c/ Diego de León 62, 28006 Madrid, Spain ; Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Peñalver
authors.affiliation: Hospital Universitario La Princesa, c/ Diego de León 62, 28006 Madrid, Spain ; Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Antón
authors.affiliation: Hospital Universitario La Princesa, c/ Diego de León 62, 28006 Madrid, Spain ; Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Galán
authors.affiliation: Hospital Universitario La Princesa, c/ Diego de León 62, 28006 Madrid, Spain ; Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Cordero
keywords: Furlong Active; cementless; stem; subsidence