The Biomet Bi-Metric Total Hip Arthroplasty and Universal Acetabular Cup

Acetabular UHMWPE Survival and Wear Changes With Different Manufacturing Techniques

“…Third, we used a two-dimensional technique to determine wear. The computer edge detection technique of Martell has been extensively studied in the literature and is more than 10 times more reliable than the Livermore technique [10]. The Martell technique will generally measure more wear, however, than radiostereometric analysis [7].…”

“…The Martell technique will generally measure more wear, however, than radiostereometric analysis [7]. Furthermore, the two-dimensional measurement has been more precise because the AP radiograph is four times more reliable than the lateral radiograph [10]. The three-dimensional technique is likely more accurate and may measure up to 10% more wear as compared to the two-dimensional technique [9].…”

“…The three-dimensional technique is likely more accurate and may measure up to 10% more wear as compared to the two-dimensional technique [9]. Thus, the three-dimensional technique has been noted to have limited clinical value [6,10]. Therefore, only the two-dimensional technique was used in this study.…”

“…The PE manufacturing technique was not specifically noted. Isaac et al [10] reported on 45 cups followed for an average of 7.6 years. 13% of the cups were revised or loosened.…”

Inferior Survival of Hydroxyapatite versus Titanium-coated Cups at 15 Years

“…A recent study from the Finnish Arthroplasty Registry suggests the most common reason for revision of the Universal 1 cup (combined data for the Ti-and HA-coated cups) is wear leading to liner exchange, with a 13-year revision rate of 26% [24]. Other studies of the same acetabular component reveal revision rates between 13% and 26% at means of 7 and 10 years followup [28,32]. Numerous authors have described a larger main group of well-performing cups with a smaller group of cup failures attributable to osteolysis, wear, aseptic loosening, and PE fracture (Table 3).…”