Assessment of Polyethylene Wear in Total Hip Replacement

Section: Discussionmentioning

confidence: 96%

Acetabular UHMWPE Survival and Wear Changes With Different Manufacturing Techniques

Meding

Keating

Davis

2011

“…A failure to reproduce femoral offset in THA can result in limp, fatigue, impingement, and recurrent subluxation and dislocation [3]. It may result in increased joint reaction forces and PE wear [6]. The questions from this study are: (1) does a THA with an acetabular inclination angle greater than 458 increase linear and volumetric UHMWPE wear, and (2) does a THA with a femoral offset greater than 5 mm of native femoral offset increase linear and volumetric UHMWPE wear.…”

Section: Discussionmentioning

confidence: 99%

Acetabular Polyethylene Wear and Acetabular Inclination and Femoral Offset

Little

Busch²,

Gallagher³

et al. 2009

281

184

Restoration of femoral offset and acetabular inclination may have an effect on polyethylene (PE) wear in THA. We therefore assessed the effect of femoral offset and acetabular inclination (angle) on acetabular conventional (not highly cross-linked) PE wear in uncemented THA. We prospectively followed 43 uncemented THAs for a minimum of 49 months (mean, 64 months; range, 49-88 months). Radiographs were assessed for femoral offset, acetabular inclination, and conventional PE wear. The mean (± standard deviation) linear wear rate in all THAs was 0.14 mm/year (± 0.01 mm/year) and the mean volumetric wear rate was 53.1 mm 3 /year (± 5.5 mm 3 /year). InTHAs with an acetabular angle less than 45°, the mean wear was 0.12 mm/year (± 0.01 mm/year) compared with 0.18 mm/year (± 0.02 mm/year) in those with a reconstructed acetabular angle greater than 45°. Reproduction of a reconstructed femoral offset to within 5 mm of the native femoral offset was associated with a reduction in conventional PE wear (0.12 mm/year versus 0.16 mm/year). Careful placement of the acetabular component to ensure an acetabular angle less than 45°in the reconstructed hip allows for reduced conventional PE wear.

“…For the in vivo wear study, PolyWare Auto Revision 6 computer software (Draftware Inc, Vevay, IN, USA) was used [9,10,27]. Every radiograph (AP and lateral) was digitized with a scanner and analyzed by the software automatically, detecting the circles that correspond with the femoral head and acetabular shell and thus their centers (dual-circle technique) (Fig.…”

Section: Methodsmentioning

confidence: 99%

Oxidized Zirconium Head on Crosslinked Polyethylene Liner in Total Hip Arthroplasty: A 7- to 12-year In Vivo Comparative Wear Study

Karidakis

Karachalios

2015

Background Osteolysis resulting from wear debris production from the bearing surfaces is a major factor limiting long-term survival of hip implants. Oxidized zirconium head on crosslinked polyethylene (XLPE) is a modern bearing coupling. However, midterm in vivo wear data of this coupling are not known. Questions/purposes The purpose of this study was to investigate in vivo whether the combination of an oxidized zirconium femoral head on XLPE produces less wear than a ceramic head on XLPE or a ceramic head on conventional polyethylene (CPE) couplings and whether any of these bearing combinations results in higher hip scores. Methods Between 2003 and 2007, we performed 356 total hip arthroplasties in 288 patients; of those, 199 (69.1%) patients (199 hips) were enrolled in what began as a randomized trial. Unfortunately, after the 57 th patient, the randomization process was halted because of patients' preference for the oxidized zirconium bearing instead of the ceramic after (as they were informed by the consent form), and after that, alternate allocation to the study groups was performed. Hips were allocated into four groups: in Group A, a 28-mm ceramic head on CPE was used; in Group B, a 28-mm ceramic head on XLPE; in Group C, a 28-mm Oxinium head on XLPE; and in Group D, a 32-mm Oxinium head on XLPE. The authors prospectively collected in vivo wear data (linear wear, linear wear rate, volumetric wear, and volumetric wear rate) using PolyWare software. Preoperative and postoperative clinical data, including Harris and Oxford hip scores, were also collected at regular intervals. Of those patients enrolled, 188 (95%) were available for final followup at a minimum of 7 years (mean, 9 years; range, 7-12 years). Results All bearing surfaces showed a varying high bedding-in effect (plastic deformation of the liner) up to the second postoperative year. At 5 years both oxidized zirconium on XLPE groups showed lower (p \ 0.01) volumetric wear (mean ± SD mm 3 ) and volumetric wear rates (mean ± SD mm 3 /year) ( Res (2015) 473:3836-3845 DOI 10.1007 Clinical Orthopaedics and Related Research ® A Publication of The Association of Bone and Joint Surgeons® (Group C: 356 ± 64 to 215 ± 54 mm 3 /year, Group D: 354 ± 50 to 210 ± 64 mm 3 /year) when compared with ceramic on CPE (Group A: 895 ± 131 to 380 ± 80 mm 3 /year) and ceramic on XLPE (Group B: 1625 ± 253 to 480 ± 101 mm 3 /year) groups. When wear rates of both oxidized zirconium groups were compared, no differences were found at any time interval with the numbers available. Two hips (one from Group A and one from Group B) are scheduled for revision as a result of wear and osteolysis. There were no differences in hip scores among the groups with the numbers available. Conclusions In this study, in vivo wear parameters were lower when the combination of an oxidized zirconium head on XLPE liner was used at an average of 9 years (range, 7-12 years) followup. Further larger-scale clinical studies should confirm these findings and evaluate osteolysis and revision rates...