title: Early acetabular cartilage wear following hemiarthroplasty: An ovine model.
abstract: OBJECTIVE
  Hemiarthroplasty induces degenerative changes in the hip joint, which are difficult to evaluate in vivo. Radiostereometric analysis (RSA) is a radiographic measurement technique that has recently been used to measure acetabular cartilage wear in vivo. The aim of the study was to measure acetabular cartilage wear, using this technique, in an ovine model during the first 14 weeks post-implantation.
  
  
  METHODS
  Measurements of three-dimensional femoral head migration, combined with visual assessments at necropsy and safranin O staining for cartilage integrity, were undertaken.
  
  
  RESULTS
  Mean femoral head migration during the first six weeks was 0.525 mm in the medial, 0.144 mm in the cranial, and 0.517 mm in the dorsal direction. The majority of this migration was confirmed to be cartilage wear in the medial and dorsal aspects of the acetabulum at necropsy and with subsequent histological evaluation depicting significant cartilage degeneration.
  
  
  CONCLUSIONS
  Radiostereometric analysis is the current gold standard technique for in vivo assessment of implant migration following total hip replacement. This study has utilized RSA to quantify the amount of early cartilage wear in vivo, which was supported by ex vivo evaluations. Accurately measuring the amount of cartilage wear will allow future studies to compare component material and design characteristics prior to clinical use.
authors.affiliation: John R. Field, Centre for Orthopaedic and Trauma Research, Level 4, Bice Building, Royal Adelaide Hospital, Adelaide, South Australia, Australia, Phone: +61 422 469 263, E-mail: lantbruks@bigpond.com.
authors.forename: John R
authors.initials: JR
authors.lastname: Field
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Callary
authors.forename: Lucian B
authors.initials: LB
authors.lastname: Solomon
authors.forename: Roumen
authors.initials: R
authors.lastname: Stamenkov
authors.forename: Margaret A
authors.initials: MA
authors.lastname: McGee
authors.forename: Donald W
authors.initials: DW
authors.lastname: Howie
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000473:pathology*; D004195:Disease Models, Animal; D062785:Hemiarthroplasty / Q000009:adverse effects; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D009336:Necrosis; D011509:Proteoglycans / Q000378:metabolism; D011859:Radiography; D012756:Sheep
chemical_list: D011509:Proteoglycans
keywords: Hemiarthroplasty; acetabular cartilage; cartilage wear; radiostereometric analysis