Dual-Energy X-Ray Absorptiometry (DEXA) Evaluation of the Bone Remodeling Effects of a Low-Modulus Composite Hip Stem After 2 Decades of Follow-Up.

The Epoch FullCoat Hip Stem (Zimmer) was an isoelastic composite femoral stem developed to address stem stiffness concerns. : We sought to evaluate the long-term bone mineral density (BMD) of a cohort of patients who underwent total hip arthroplasty (THA) using the Epoch isoelastic stem and having more than 2-decade follow-up. : We conducted a retrospective chart review of all patients who were study subjects at our institution in a multicenter prospective trial for the Food and Drug Administration of the Epoch implant in the mid-1990s.

Unexpected Wear of a Uniquely Designed Moderately Cross-Linked Polyethylene in Total Hip Arthroplasty.

Background: A uniquely designed, non-heat-treated moderately cross-linked acetabular polyethylene liner used in total hip arthroplasty (THA) demonstrated excessive wear during routine follow-up, prompting an evaluation of the linear wear rate.

Methods: All THAs were performed by the senior author. The study group included 38 THAs using the uniquely designed polyethylene in question, compared to a control group of 21 THAs using another moderately cross-linked polyethylene with good 10-year outcomes.

Are Radiographic and Direct Measures of Acetabular Polyethylene Wear Comparable?

Background: All polyethylene acetabular liners wear over time, and numerous methods for calculating linear wear rates exist. The objective of this study was to compare 2-dimensional wear rates between direct, micrometer measurements and the computerized, edge-detection method using Hip Analysis Suite (HAS) 8.0.

No Difference in Conventional Polyethylene Wear Between Yttria-stabilized Zirconia and Cobalt-chromium-molybdenum Femoral Heads at 10 Years.

Background: Concerns have arisen regarding deterioration of wear properties of yttria-stabilized zirconia (YSZ) femoral head on conventional polyethylene (PE) bearings due to YSZ phase transformation.

Questions/purposes: The purpose of this study was to determine if there is a difference in long-term PE wear properties between YSZ and cobalt-chromium-molybdenum (Co-Cr-Mo) femoral heads.

Methods: Ten-year radiographic wear assessment was performed on a cohort of patients enrolled in a prospective randomized clinical trial comparing total hip arthroplasty with YSZ or Co-Cr-Mo femoral heads on conventional, non-cross-linked PE.

Reassessment of computerized wear measurement for total hip arthroplasty with correction for projectional image distortion: a brief follow-up report.

Background: Wear of the ultra-high molecular weight polyethylene articular surface has been recognized as a major factor threatening the long-term success of total hip arthroplasty. Manual techniques that have been used to measure femoral head penetration into the polyethylene have been plagued with poor reproducibility and limited accuracy. Using a previously described phantom model simulating an unworn total hip arthroplasty, we previously demonstrated significant limitations in the accuracy of several widely used computerized wear measurement programs.