Highly crosslinked polyethylene wear rates and acetabular component orientation

2018 ◽  
Vol 100-B (7) ◽  
pp. 891-897 ◽  
Author(s):  
M. G. Teeter ◽  
B. A. Lanting ◽  
D. D. Naudie ◽  
R. W. McCalden ◽  
J. L. Howard ◽  
...  
Keyword(s):  
Wear Rate ◽  
Acetabular Component ◽  
Inclination Angle ◽  
Polyethylene Wear ◽  
Safe Zone ◽  
Anteversion Angle ◽  
Median Difference ◽  
Head Penetration ◽  
The Mean ◽  
Acetabular Components

Aims The aim of this study was to determine whether there is a difference in the rate of wear between acetabular components positioned within and outside the ‘safe zones’ of anteversion and inclination angle. Patients and Methods We reviewed 100 hips in 94 patients who had undergone primary total hip arthroplasty (THA) at least ten years previously. Patients all had the same type of acetabular component with a bearing couple which consisted of a 28 mm cobalt-chromium head on a highly crosslinked polyethylene (HXLPE) liner. A supine radiostereometric analysis (RSA) examination was carried out which acquired anteroposterior (AP) and lateral paired images. Acetabular component anteversion and inclination angles were measured as well as total femoral head penetration, which was divided by the length of implantation to determine the rate of polyethylene wear. Results The mean anteversion angle was 19.4° (-15.2° to 48°, sd 11.4°), the mean inclination angle 43.4° (27.3° to 60.5°, sd 6.6°), and the mean wear rate 0.055 mm/year (sd 0.060). Exactly half of the hips were positioned inside the ‘safe zone’. There was no difference (median difference, 0.012 mm/year; p = 0.091) in the rate of wear between acetabular components located within or outside the ‘safe zone’. When compared to acetabular components located inside the ‘safe zone’, the wear rate was no different for acetabular components that only achieved the target anteversion angle (median difference, 0.012 mm/year; p = 0.138), target inclination angle (median difference, 0.013 mm/year; p = 0.354), or neither target (median difference, 0.012 mm/year; p = 0.322). Conclusion Placing the acetabular component within or outside the ‘safe zone’ did not alter the wear rate of HXLPE at long-term follow-up to a level that risked osteolysis. HXLPE appears to be a forgiving bearing material in terms of articular surface wear, but care must still be taken to position the acetabular component correctly so that the implant is stable. Cite this article: Bone Joint J 2018;100-B:891-7.

Medial Placement of a Cementless Acetabular Component in a Modern Alumina-on-Alumina THA

2007 ◽  
Vol 330-332 ◽  
pp. 1243-1246
Author(s):  
Jeong Joon Yoo ◽  
Hee Joong Kim ◽  
Young Min Kim ◽  
Kang Sup Yoon ◽  
Kyung Hoi Koo ◽  
...  
Keyword(s):  
Acetabular Component ◽  
Polyethylene Wear ◽  
Clinical Results ◽  
Harris Hip Score ◽  
Bearing Surface ◽  
The Mean ◽  
Acetabular Components ◽  
Cementless Acetabular Component ◽  
Acetabular Wall

Medial placement of a cementless acetabular component into or beyond the medial wall of a shallow, dysplastic acetabulum is a technique to enhance its coverage during difficult total hip arthroplasty (THA). Dysplastic hips almost always need small size of acetabular component, so an accelerated polyethylene wear can occur when a conventional bearing surface is used. Modern alumina-on-alumina couplings can be an alternative for these patients. We evaluated the clinical results of 43 medially placed cementless acetabular components (PLASMACUP®SC) incorporating a modern alumina bearing surface (BIOLOX® forte). Acetabular components were inserted medially beyond the ilioischial line and, therefore, beyond the level of the cortical bone of the cotyloid notch, and followed up for more than 5 years (range, 60 – 93 months). In 14 hips, the medial acetabular wall was perforated purposefully and the medial aspect of the cup was placed beyond both the ilioischial and the iliopubic line on radiographs. The mean Harris hip score improved from 55.3 points preoperatively to 94.5 points postoperatively. Postoperatively, the hip center migrated 12.1 mm medially and 1.5 mm inferiorly. The average amount of cup protrusion beyond the ilioischial and the iliopubic line was 3.1 mm and 1.9 mm, respectively. The average superolateral coverage of the cup was 98.5 percent. During follow-up, no osteolysis or loosening of acetabular components was observed and no revision was required. Medial placement of a cementless acetabular component into or beyond the medial acetabular wall offers predictable clinical results and durable fixation in modern alumina-on-alumina THA.

scholarly journals Accuracy of cup placement in total hip arthroplasty by means of a mechanical positioning device: a comprehensive cadaveric 3d analysis of 16 specimens

2019 ◽  
pp. 112070001987482
Author(s):  
Arthur J Kievit ◽  
Johannes G G Dobbe ◽  
Wouter H Mallee ◽  
Leendert Blankevoort ◽  
Geert J Streekstra ◽  
...  
Keyword(s):  
3D Models ◽  
Safe Zone ◽  
3D Analysis ◽  
Anterior Pelvic Plane ◽  
Mechanical Device ◽  
Acetabular Cup ◽  
Anteversion Angle ◽  
Positioning Device ◽  
The Mean ◽  
Safe Zones

Introduction: We tested whether a mechanical device (such as Hipsecure) to pinpoint the anterior pelvic plane (APP) as a guide can improve acetabular cup placement. To assess accuracy we asked: (1) is the APP an effective guide to position acetabular cup placement within acceptable ° of divergence from the optimal 40° inclination and 15° anteversion; (2) could a mechanical device increase the number of acetabular cup placements within Lewinnek’s safe zone (i.e. inclination 30° to 50°; anteversion 5° to 25°)? Methods: 16 cadaveric specimens were used to assess the 3D surgical success of using a mechanical device APP to guide acetabular cup placement along the APP. We used the Hipsecure mechanical device to implant acetabular cups at 40° inclination and 15° anteversion. Subequently, all cadaveric specimens with implants were scanned with a CT and 3D models were created of the pelvis and acetabular cups to assess the outcome in terms of Lewinnek’s safe zones. Results: The mean inclination of the 16 implants was 40.6° (95% CI, 37.7–43.4) and the mean anteversion angle was 13.4° (95% CI, 10.7–16.1). All 16 cup placements were within Lewinnek’s safe zone for inclination (between 30° and 50°) and all but 2 were within Lewinnek’s safe zone for anteversion (between 5° and 25°). Conclusion: In cadaveric specimens, the use of a mechanical device and the APP as a guide for acetabular cup placement resulted in good positioning with respect to both of Lewinnek’s safe zones.

Polyethylene Wear in Retrieved Canine Acetabular Components

2000 ◽  
Vol 13 (02) ◽  
pp. 78-86 ◽  
Author(s):  
D. Tompkins ◽  
B. Bhushan ◽  
M. L. Olmstead ◽  
J. Dyce
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Total Hip Replacement ◽  
Acetabular Component ◽  
Hip Replacement ◽  
Polyethylene Wear ◽  
Total Hip ◽  
Particulate Debris ◽  
Acetabular Components ◽  
Scanning Electron

SummaryThe aim of this pilot study was to define the mechanism and mode of polyethylene wear in acetabular components retrieved from seven dogs following therapeutic total hip replacement. The articular surface of each acetabular component was examined using contact profilometry and scanning electron microscopy (SEM). Peak-tovalley distance (P-V) and arithmetic average surface roughness (Ra) were calculated for each quadrant of the surface. Deformation of the regular profile of the machining lines was the least severe form of surface alteration. Randomly orientated scratches, fine tapered filaments, ripples, and coarse surface shredding were common SEM observations. Gouging of the convex surface of the cup was seen in two cases following failure of the polyethylenecement interface. Wear of the nonarticular acetabular rim suggested neck impingement in one case. P-V and Ra were significantly lower in the craniodorsal zone, compared to the average roughness of the other three quadrants (p < 0.05). Abrasion, adhesion and fatigue were the principal mechanisms of polyethylene wear, and were implicated in the production of polyethylene particulate debris. Meticulous removal of abrasive third bodies at the time of surgery, and correct orientation of the acetabular component, should reduce early and severe wear.Polyethylene wear is inevitable following metal-on-polyethylene total hip replacement. In this study, the nature of polyethylene wear in retrieved canine acetabular components was defined, using contact profilometry and scanning electron microscopy. Abrasion, adhesion and fatigue were the principal mechanisms of wear, and were implicated in the production of polyethylene particulate debris.

Performance analysis of an orthopaedic biomaterial 100-station wear test system

2009 ◽  
Vol 224 (3) ◽  
pp. 697-701 ◽  
Author(s):  
V Saikko
Keyword(s):  
Wear Rate ◽  
Polyethylene Wear ◽  
Calf Serum ◽  
High Capacity ◽  
Wear Test ◽  
High Standard ◽  
Test System ◽  
Wear Rates ◽  
Two Samples ◽  
The Mean

Until recently, wear studies of orthopaedic biomaterials have suffered from inadequate testing capacity and high standard deviation (SD) of results. In the present article, the previously validated 100-station hip wear simulator, the SuperCTPOD, is evaluated with regard to its capability of producing statistically significant differences in mean wear rates. SuperCTPOD wear tests were done for 38 different types of polyethylene pins against polished CoCr discs with diluted calf serum lubrication. A total of 200 pins were worn in two consecutive tests of 6 weeks, duration each. The sample size varied from four to six. The mean wear rates of the samples ranged from 0.52 to 77.1 mg per one million cycles. On the average, the SD of the wear rate was 4.2 per cent of the mean value (range 1–8.5 per cent). A difference in the mean wear rates below 5 per cent was large enough to be statistically significant ( p <0.05) in 21 comparisons between two samples, the lowest statistically significant mean difference being 3.2 per cent. In conclusion, the high capacity and the low SD of the wear rate make the SuperCTPOD wear test system unparalleled in efficiency. The observations regarding the effect of crosslinking and molecular weight on polyethylene wear resistance were in agreement with studies published earlier.

scholarly journals Salvaging Unstable or Recurrent Dislocating Total Hip Arthroplasty with the Constrained Acetabular Component

2002 ◽  
Vol 10 (2) ◽  
pp. 165-169 ◽  
Author(s):  
DA Stanton ◽  
WJ Bruce ◽  
JA Goldberg ◽  
W Walsh
Keyword(s):  
Total Hip Arthroplasty ◽  
Acetabular Component ◽  
Hip Arthroplasty ◽  
Recurrent Dislocation ◽  
Total Hip ◽  
Hip Replacements ◽  
The Mean ◽  
Acetabular Components ◽  
Constrained Acetabular Component

Purpose. To review cases of implantation of constraining acetabular components for unstable or recurrent dislocating total hip arthroplasty at the Department of Orthopaedics, Concord Hospital, Sydney. Methods. A retrospective analysis was performed on prospectively collected data of 13 consecutively enrolled patients. Results. From 1989 to 2000, 13 constraining acetabular components were implanted into 13 patients as a revision procedure. The surgical approach for the implantation of the constrained liner was posterolateral in 11 cases; a modified Hardinge approach was applied in 2 cases. The mean clinical follow-up duration was 43 months (range, 14–121 months) and the mean age at the time of surgery was 73 years (range, 52–84 years). No patients were lost to follow-up. Indications for using the constrained acetabular component were recurrent dislocation in revision hip replacements (n=8), and intra-operative instability (n=5). There were no episodes of dislocation of the constrained arthroplasty. In 7 cases, the constrained component was implanted into a previously well-fixed shell. Conclusion. We recommend the judicious use of the constrained component in cases of hip instability during or after total hip arthroplasty when other methods are not successful.

Wear Characteristics of Conventional Ultrahigh-Molecular-Weight Polyethylene Versus Highly Cross-Linked Polyethylene in Total Ankle Arthroplasty

2018 ◽  
Vol 39 (11) ◽  
pp. 1335-1344 ◽  
Author(s):  
Oliver N. Schipper ◽  
Steven L. Haddad ◽  
Spencer Fullam ◽  
Robin Pourzal ◽  
Markus A. Wimmer
Keyword(s):  
Particle Size ◽  
Wear Rate ◽  
Particle Shape ◽  
Polyethylene Wear ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Total Ankle Arthroplasty ◽  
Fixed Bearing ◽  
Ankle Arthroplasty ◽  
Ultrahigh Molecular Weight ◽  
The Mean

Background: The aim of this study was to compare the polyethylene wear rate, particle size, and particle shape of primary semiconstrained, fixed-bearing, bone-sparing total ankle arthroplasty using conventional ultrahigh-molecular-weight polyethylene (CPE) versus highly cross-linked polyethylene (HXLPE) by applying a level walking input using a joint simulator. Methods: Two fixed-bearing total ankle replacement systems with different types of polyethylene liners were tested: (1) CPE sterilized in ethylene oxide, and (2) HXLPE sterilized with gas plasma after electron beam irradiation. Three implants for each design underwent wear testing using gravimetric analysis over 5 million simulated walking cycles. A fourth implant was used as a load soak control. Equivalent circle diameter (ECD) and equivalent shape ratio (ESR) were computed to determine particle size and particle shape, respectively. Results: The mean wear rate from 1.5 to 5 million cycles (MC) was 2.0 ± 0.3 mg/MC for HXLPE and 16.7 ± 1.3 mg/MC for CPE ( P < .001). The total number of particles per cycle generated for HXLPE and CPE were 0.17 × 106 particles/cycle and 0.53 × 106 particles/cycle, respectively ( P < .001). The mean ECD of HXLPE particles (0.22 ± 0.11 μm) was significantly smaller than the mean ECD of CPE particles (0.32 ± 0.14 μm) ( P < .001). HXLPE particles were significantly more round than CPE particles ( P < .001). Conclusions: HXLPE liners had a significantly lower wear rate and produced significantly fewer and rounder particles than CPE liners. The results of this study suggest that HXLPE has more favorable wear characteristics for total ankle arthroplasty. Clinical Relevance: Polyethylene wear particles have been linked to osteolysis after total ankle arthroplasty. There is no consensus on the importance of highly cross-linked polyethylene in total ankle arthroplasty with regard to implant wear. This is the first nonindustry study to compare the polyethylene wear rate, particle size, and particle shape of fixed-bearing total ankle arthroplasty conventional polyethylene versus highly cross-linked polyethylene. The lower wear rate and different particle size/morphology of highly cross-linked polyethylene could be beneficial in vivo to decrease osteolysis.

Hip resurfacing with a highly cross-linked polyethylene acetabular liner and a titanium nitride-coated femoral component

2018 ◽  
Vol 28 (4) ◽  
pp. 422-428 ◽  
Author(s):  
James W Pritchett
Keyword(s):  
Titanium Nitride ◽  
Femoral Component ◽  
Acetabular Component ◽  
Polyethylene Wear ◽  
Hip Resurfacing ◽  
Harris Hip Score ◽  
Kaplan Meier ◽  
Joint Biomechanics ◽  
Cementless Femoral Component ◽  
The Mean

Aims: This study evaluated a specific hip resurfacing system to determine the: (1) function and complications, (2) implant survivorship, (3) acetabular bone conservation and joint biomechanics and (4) osteolysis and polyethylene wear. Methods: I performed 234 resurfacing procedures (192 patients) using a two-piece titanium acetabular component with a 4 mm highly cross-linked polyethylene liner and a cementless titanium nitride-coated titanium femoral component. Function was assessed with Harris Hip, WOMAC, SF-12, and UCLA scores. Radiography and CT scans were used to evaluate bone retention, component position, joint biomechanics, and osteolysis. Retrieved polyethylene liners were analyzed for wear. Results: Median follow-up was 8 years and patients averaged 48 years of age at surgery. The mean Harris Hip Score was 96 and all scores improved significantly. Kaplan-Meier survivorship was 97%. The mean medial acetabular thickness was 9 mm postoperatively versus 14 mm preoperatively ( p = 0.019). Femoral bone conservation (head:neck ratio) was 1.36 postoperatively versus 1.42 preoperatively ( p = 0.02). There was no polyethylene wear through or osteolysis. Eight polyethylene retrievals had a mean wear of 0.05 mm/yr. Conclusions: Resurfacing with a highly cross-linked polyethylene acetabular component and a titanium nitride-coated titanium cementless femoral component is a reliable and bone-conserving procedure at mid-term.

Higher UHMWPE wear-rate in cementless compared with cemented cups with the Saturne® Dual-Mobility acetabular system

2018 ◽  
Vol 28 (2) ◽  
pp. 125-132 ◽  
Author(s):  
Steffan Tabori-Jensen ◽  
Christina Frølich ◽  
Torben B. Hansen ◽  
Søren Bøvling ◽  
Morten Homilius ◽  
...  
Keyword(s):  
Wear Rate ◽  
Polyethylene Wear ◽  
Walking Distance ◽  
Harris Hip Score ◽  
Evaluation Activity ◽  
Dual Mobility ◽  
Time Of Surgery ◽  
Activity Measurements ◽  
The Mean

Introduction: Dual mobility (DM) total hip arthroplasty (THA) may reduce dislocation risk, but might increase the risk of high polyethylene (PE) wear due to double wearing surfaces. Methods: 127 patients (97 female) with 129 hips operated with THA after displaced femoral neck fracture FNF between 2005 and 2011, were seen for a cross-sectional clinical follow-up. Acetabular components were Saturne® DM cups with 28mm chrome-cobalt heads in UHMWPE. Cementless cups (n = 73) were hydroxyapatite coated. Radiographs were obtained for analysis of cup placement, 2D polyethylene wear and wear-rate (PolyWare 3D), and further radiological evaluation. Activity measurements included Timed Up and Go test (TUG) and walking distance from Harris Hip Score (HHS). Results: At a mean follow-up of 2.83 (1.0-7.7) years the mean wear was 0.82 mm (range 0.17-4.51, SD 0.50), and the wear-rate was 0.37 mm (range 0.06-1.90, SD 0.29). Wear-rate of 0.43 mm/year (SD 0.30) in cementless cups was higher (p = 0.004) than 0.30 mm/year (SD 0.27) in cemented cups. Mean age at time of surgery was 75.1 years (range 30-95). There was no correlation between age at time of surgery and wear (p = 0.56). There was no correlation between cup inclination and wear-rate (p = 0.35). TUG was mean 13.4 seconds (range 4.5-30.1) and correlated with wear rate (p = 0.03). Conclusions: At short term follow-up, the mean wear-rate in old and low demand patients was high, correlated to activity, and was above the generally accepted osteolysis threshold (0.1 mm/yr.). Cementless HA-coated cups had higher wear-rate than cemented cups.

Measurement of Acetabular Component Position in Total Hip Arthroplasty in Dogs: Comparison of a Radio-Opaque Cup Position Assessment Device Using Fluoroscopy with CT Assessment and Direct Measurement

2020 ◽  
Vol 33 (05) ◽  
pp. 340-347
Author(s):  
Brianna N. Dalbeth ◽  
William M. Karlin ◽  
Ross A. Lirtzman ◽  
Michael P. Kowaleski
Keyword(s):  
Direct Measurement ◽  
Acetabular Component ◽  
Intraoperative Imaging ◽  
Accurate Method ◽  
Mean Difference ◽  
Radiopaque Marker ◽  
The Mean ◽  
Acetabular Components ◽  
Acetabular Component Position ◽  
Cup Position

Abstract Objectives The aim of this study was to compare measurements of angle of lateral opening (ALO) and version determined using a radioopaque cup position assessment device imaged with fluoroscopy to measurements obtained by CT and direct measurement in a cadaveric model. Our null hypothesis was that there would not be any difference in the angles measured by the techniques. Methods Six cadavers were implanted with BFX acetabular components. The CPAD was placed and images were obtained with fluoroscopy. Measurements were obtained from the radiopaque marker bars on the CPAD device, and version and ALO were calculated. The ALO and version were determined by CT and DM. Comparisons were made using a two-way analysis of variance and a generalized linear model procedure analysis. Results There were no significant differences between the measurements for ALO (p = 0.275) or version (p = 0.226). Correlation between methods was 0.948 and 0.951 for ALO and version, respectively. The mean difference (standard deviation [SD], and 95% confidence interval [CI]) for ALO were: CT versus CPAD 1.85 degrees (± 2.32 degrees [-2.99–3.31]), CT versus DM 1.96 degrees (± 1.99 degrees [−2.2–4.27]), CPAD versus DM1.74 degrees (±2.21 degrees [−1.13 and 5.24]). The mean difference (SD [CI]) for version was CT versus CPAD 2.86 degrees (±1.56 degrees [ −2.63–1.69]), CT versus DM 1.10 degrees (±1.42 degrees [−1.57–2.09]), CPAD versus DM 1.07 degrees (±0.76 degrees [0.13–2.09]). Clinical Relevance The results demonstrate that intraoperative imaging in cadaveric specimens with the CPAD is an accurate method to determine ALO and version of the acetabular component.

scholarly journals A double mobility acetabular implant for primary hip arthroplasty in patients at high risk of dislocation

2014 ◽  
Vol 96 (8) ◽  
pp. 597-601 ◽  
Author(s):  
NL Vasukutty ◽  
RG Middleton ◽  
P Young ◽  
C Uzoigwe ◽  
B Barkham ◽  
...  
Keyword(s):  
High Risk ◽  
Acetabular Component ◽  
Polyethylene Wear ◽  
Large Diameter ◽  
Wear Rates ◽  
Total Hip ◽  
Hip Function ◽  
The Mean ◽  
Acetabular Implant

Introduction Dislocation following total hip replacement continues to be a problem for which no completely satisfactory solution has been found. Several methods have been proposed to reduce the incidence of hip dislocations with varying degrees of success, including elevated rim liners, constrained liners and large diameter bearings. We present our experience with the double mobility acetabular component in patients at high risk of instability. Methods This was a retrospective review of 65 primary total hip arthroplasties in 55 patients (15 men, 40 women), performed between October 2005 and November 2009. The majority (80%) of patients had at least two and 26% had at least three risk factors for instability. The mean age was 76 years (range: 44–92 years). The patients were followed up for a mean duration of 60 months (range: 36–85 months). Results Fourteen patients died and one was lost to follow-up, leaving fifty hips for final assessment. Until the final follow-up appointment, no patients had dislocation and none required revision surgery. The mean Oxford hip score improved from 45.0 to 26.5 (p<0.0001). The mean Merle d’Aubigné pain score improved from 1.4 to 4.9 (p<0.0001), the walking score from 2.3 to 3.1 (p<0.07) and the absolute hip function score from 5.4 to 10.8 (p<0.0001). There were no clinical or radiographic signs of loosening. Conclusions The double mobility acetabular component was successful at preventing dislocation during early to medium-term follow-up. However, as data are still lacking with regard to polyethylene wear rates at the additional bearing surface, it would be prudent to restrict the use of this implant to selected patients at high risk of instability.

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