title: Titanium-titanium modular neck for primary THA. Result of a prospective series of 170 cemented THA with a minimum follow-up of 5 years.
abstract: BACKGROUND
  Although they have been in use since the end of the 1980s, modular titanium neck components are associated with a risk of wear or fracture, and their safety has recently become a subject of debate and has never been evaluated in a consecutive series of patients. The goal of this study was to evaluate: revision-free survival of these implants after a minimum follow-up of 5 years; clinical and radiographic results; and the potential complications associated with the use of modular titanium neck components.
  
  
  OBJECTIVE
  The use of titanium modular neck on cemented titanium THA is safe at a minimum follow-up of 5 years.
  
  
  METHODS
  Between January 2006 and December 2008, we prospectively followed 170 patients (170 hips) who underwent primary anatomical THA with a modular cemented titanium stem design implant. The indications were unilateral THA for primary (n=160) or secondary (n=10) hip osteoarthritis (aseptic osteonecrosis of the femoral head or hip dysplasia). Mean age of patients was 75.4±5.8 years old (52-85), and mean BMI was 26.1±4.5 kg/m(2) (16.6-42.1). Patients were operated on by a modified Watson-Jones anterolateral approach based on preoperative 2D planning. All patients underwent annual clinical and radiological follow-up by an independent observer.
  
  
  RESULTS
  At a mean follow-up of 71±8 months (60-84), 5 patients died and 7 were lost to follow-up. There was no revision of THA after a maximum follow-up of 84 months. The Harris score improved significantly from 50.4±11.3 (0-76) preoperatively to 84.5±15.2 (14-100) at the final follow-up. There was no difference in postoperative femoral offset or the position of the center of rotation compared to the opposite side. On the other hand, the neck-shaft angle (NSA) and limb length were corrected (2±5° [-11 to +14°] and 2.16±3.6 mm [-7.4 to +12.7 mm]) respectively. Fifteen patients (9%) had limb length discrepancies of more than 5 mm and 4 patients (2%) of more than 10 mm. There were no complications due to the modular implant design.
  
  
  CONCLUSIONS
  Our study suggests that the use of cemented titanium implants with a modular titanium stem is safe at a follow-up of 5 years. The modular design does not prevent limb length discrepancies but restores femoral offset.
  
  
  METHODS
  IV: prospective, non-comparative study.
authors.affiliation: Institut du mouvement et de l'appareil locomoteur, UMR CNRS 787/AMU, hôpital Sainte-Marguerite, centre hospitalo-universitaire Sud, boulevard de Sainte-Marguerite, 13009 Marseille, France.
authors.forename: M
authors.initials: M
authors.lastname: Ollivier
authors.affiliation: Institut du mouvement et de l'appareil locomoteur, UMR CNRS 787/AMU, hôpital Sainte-Marguerite, centre hospitalo-universitaire Sud, boulevard de Sainte-Marguerite, 13009 Marseille, France. Electronic address: sebastien@parratte.fr.
authors.forename: S
authors.initials: S
authors.lastname: Parratte
authors.affiliation: Institut du mouvement et de l'appareil locomoteur, UMR CNRS 787/AMU, hôpital Sainte-Marguerite, centre hospitalo-universitaire Sud, boulevard de Sainte-Marguerite, 13009 Marseille, France.
authors.forename: A
authors.initials: A
authors.lastname: Galland
authors.affiliation: Institut du mouvement et de l'appareil locomoteur, UMR CNRS 787/AMU, hôpital Sainte-Marguerite, centre hospitalo-universitaire Sud, boulevard de Sainte-Marguerite, 13009 Marseille, France.
authors.forename: A
authors.initials: A
authors.lastname: Lunebourg
authors.affiliation: Institut du mouvement et de l'appareil locomoteur, UMR CNRS 787/AMU, hôpital Sainte-Marguerite, centre hospitalo-universitaire Sud, boulevard de Sainte-Marguerite, 13009 Marseille, France.
authors.forename: X
authors.initials: X
authors.lastname: Flecher
authors.affiliation: Institut du mouvement et de l'appareil locomoteur, UMR CNRS 787/AMU, hôpital Sainte-Marguerite, centre hospitalo-universitaire Sud, boulevard de Sainte-Marguerite, 13009 Marseille, France.
authors.forename: J-N
authors.initials: JN
authors.lastname: Argenson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001843:Bone Cements; D005260:Female; D005270:Femur Head / Q000601:surgery*; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D013997:Time Factors; D014025:Titanium; D055815:Young Adult
chemical_list: D001843:Bone Cements; D014025:Titanium
keywords: Cemented stem; Hip anatomy; Modular neck; Total hip replacement