Convened under the auspicious of esteemed endorsers - ISTA

Bearing Surfaces in Primary Total Hip Arthroplasty*James Waddell - University of Toronto - Toronto, CanadaVasileios Nikolaou - St Michale's Hospital - Montreal, CanadaMax Edwards - University of Toronto - Toronto, CamadaEarl Bogoch - University of Toronto - Toronto, CanadaEmil Schemitsch - University of Toronto - Toronto, Canada*Email: waddellj@smh.caAim: This prospective randomised controlled trial aims to compare the clinical and radiologicaloutcomes of ceramic on ceramic, cobalt chrome on ultra-high molecular weight polyethylene,and cobalt chrome on highly cross-linked polyethylene bearing surfaces at a minimum of fiveyears.Methods: One hundred and two primary total hip replacements were performed in ninety onepatients between February 2003 and March 2005. All patients were younger than 65 (mean 52.7,19-64). They were randomised to receive one of the three bearing surfaces. All patients had28mm articulations with a Reflection uncemented acetabular component and a Synergy stem(Smith & Nephew, Memphis, Tennessee). Patients were followed up periodically up to at leastsixty months following surgery. Outcome measures included WOMAC and SF12 scores.Radiological assessment included implant position, evidence of osteolysis and measurement oflinear wear.Results: Ninety seven hip replacements in eighty seven patients were available for review at aminimum of five years. Two hips were revised (one for infection and one for periprostheticfracture), leaving a total of ninety four hips available for final review. There were nodifferences in age, gender, body mass index, diagnosis, level of activity, and comorbiditiesbetween the three groups. At a minimum of five years there were no statistical differences in theclinical outcomes using the WOMAC or SF12 scores. Three patients in the ceramic groupreported squeaking. Radiological evaluation revealed mean annual wear rates in the ceramicgroup of 0.006mm/yr, standard polyethylene of 0.151mm/yr and highly cross linkedpolyethylene of 0.059mm/yr. ANOVA analysis revealed these differences in wear rates to besignificant (p