title: Porous titanium construct cup compared to porous coated titanium cup in total hip arthroplasty. A randomised controlled trial.
abstract: OBJECTIVE
  The purpose of this study was to determine if a new titanium cup with increased porosity resulted in different periacetabular bone loss and migration compared to a porous coated cup.
  
  
  METHODS
  Fifty-one patients with primary hip osteoarthritis were randomized to either a cup with porous titanium construct backside (porous titanium group, n = 25) or a conventional porous coated titanium cup (control group, n = 26). The primary outcome variable was change in periacetabular bone mineral density two years after surgery measured with dual energy X-ray absorptiometry (DXA). Secondary outcomes were implant fixation measured with radiostereometry (RSA) and clinical outcome scores.
  
  
  RESULTS
  The pattern of bone remodelling was similar in the two groups with almost complete restoration to baseline values. BMD diminished in the two proximal zones and increased in the two distal zones. After minimal migration up to six months all implants in both groups became stable. We found no difference between the two groups in clinical outcome scores.
  
  
  CONCLUSIONS
  In this prospective, randomized, controlled trial on a new porous titanium cup we found, compared to the control group, no clinically relevant differences regarding periacetabular bone preservation, implant fixation or clinical outcome up to two years postoperatively.
authors.affiliation: Unit of Orthopaedics, Department of Clinical Sciences at Danderyd Hospital, Karolinska Institutet, 182 88, Stockholm, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Salemyr
authors.forename: Olle
authors.initials: O
authors.lastname: Muren
authors.forename: Thomas
authors.initials: T
authors.lastname: Eisler
authors.forename: Henrik
authors.initials: H
authors.lastname: Bodén
authors.forename: Ghazi
authors.initials: G
authors.lastname: Chammout
authors.forename: André
authors.initials: A
authors.lastname: Stark
authors.forename: Olof
authors.initials: O
authors.lastname: Sköldenberg
mesh_terms: D015502:Absorptiometry, Photon; D000077:Acetabulum / Q000503:physiopathology; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D015519:Bone Density; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000601:surgery; D016062:Porosity; D011446:Prospective Studies; D011474:Prosthesis Design; D014025:Titanium
chemical_list: D014025:Titanium