Polyethylene Wear Associated With 26- and 32-mm Heads in Total Hip Arthroplasty: A Multicenter, Prospective Study.

Abstract Background Although there were many clinical studies of highly cross-linked polyethylene (XLPE) wear among different femoral head diameters, few referred to thickness of XLPE in case larger femoral heads were used because smaller sockets were frequently used for Asian population. Methods This prospective study included 240 hips that underwent primary total hip arthroplasty using XLPE combined with 26-mm (group S) or 32-mm (group L) cobalt–chromium head with maximum follow-up of 10 years. We measured 3-dimensional (3-D) linear penetration rate of XLPE among same implant design groups except head diameter and estimated the validity of thinner XLPE. Results Our study demonstrated comparable 3-D linear penetration rates, which were 0.06 ± 0.07 mm/y for group S and 0.03 ± 0.02 mm/y for group L at 10 years after surgery and penetration rates seemed to be almost constant with no significant difference after 3 years. Minimum liner thickness (5.3 mm for 48-mm socket in combination with 32-mm femoral head) and the second thinnest XLPE (6.3 mm in case of socket from 50 mm to 54 mm combined with 32-mm femoral head) was distributed in 25% and 72% with group L, respectively, and there were no significant differences in penetration rates between 5.3-mm– and 6.3-mm–thickness groups. Conclusion Our study suggested that whether to select 26- or 32-mm diameters of femoral head does not affect XLPE wear in combination with this type of articulation.