title: The rates of wear of X3 highly cross-linked polyethylene at five years when coupled with a 36 mm diameter ceramic femoral head in young patients.
abstract: Polyethylene wear debris can cause osteolysis and the failure of total hip arthroplasty. We present the five-year wear rates of a highly cross-linked polyethylene (X3) bearing surface when used in conjunction with a 36 mm ceramic femoral head. This was a prospective study of a cohort of 100 THAs in 93 patients. Pain and activity scores were measured pre- and post-operatively. Femoral head penetration was measured at two months, one year, two years and at five years using validated edge-detecting software (PolyWare Auto). At a mean of 5.08 years (3.93 to 6.01), 85 hips in 78 patients were available for study. The mean age of these patients was 59.08 years (42 to 73, the mean age of males (n = 34) was 59.15 years, and females (n = 44) was 59.02 years). All patients had significant improvement in their functional scores (p < 0.001). The steady state two-dimensional linear wear rate was 0.109 mm/year. The steady state volumetric wear rate was 29.61 mm(3)/year. No significant correlation was found between rate of wear and age (p = 0.34), acetabular component size (p = 0.12) or clinical score (p = 0.74). Our study shows low steady state wear rates at five years in X3 highly cross-linked polyethylene in conjunction with a 36 mm ceramic femoral head. The linear wear rate was almost identical to the osteolysis threshold of 0.1 mm/year recommended in the literature.
authors.affiliation: Christchurch Public Hospital, 2 Riccarton Avenue, Christchurch 4710, New Zealand.
authors.forename: E
authors.initials: E
authors.lastname: Selvarajah
authors.affiliation: University of Otago Christchurch, 2 Riccarton Avenue, Christchurch 8011, New Zealand.
authors.forename: G
authors.initials: G
authors.lastname: Hooper
authors.affiliation: University of Otago Christchurch, 2 Riccarton Avenue, Christchurch 8011, New Zealand.
authors.forename: K
authors.initials: K
authors.lastname: Grabowski
authors.affiliation: University of Otago Christchurch, 2 Riccarton Avenue, Christchurch 8011, New Zealand.
authors.forename: C
authors.initials: C
authors.lastname: Frampton
authors.affiliation: University of Otago Christchurch, 2 Riccarton Avenue, Christchurch 8011, New Zealand.
authors.forename: T B F
authors.initials: TB
authors.lastname: Woodfield
authors.affiliation: Christchurch Public Hospital, 2 Riccarton Avenue, Christchurch 4710, New Zealand.
authors.forename: G
authors.initials: G
authors.lastname: Inglis
mesh_terms: D000077:Acetabulum / Q000601:surgery; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods; D002516:Ceramics; D005260:Female; D005270:Femur Head / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D011095:Polyethylenes; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013499:Surface Properties
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene
keywords: hip arthroplasty 36mm femoral head X3 polyethylene wear