10-Year Follow-Up Wear Analysis of First-Generation Highly Crosslinked Polyethylene in Primary Total Hip Arthroplasty

Our goal was to report a 10-year follow up of linear penetration rates for HCLPE, and to determine whether a difference exists between penetrations measured on pelvis or hip anterior–posterior radiographs. We reviewed 48 total hip arthroplasties where a first-generation HCLPE liner was used. Femoral head penetration was measured on both AP pelvis and hip radiographs. Total wear and wear rate at 10 years were 1.26 mm and 0.122 mm/y, respectively. The rate decreased significantly after the first 2–3 years, plateauing at a wear rate of 0.05 mm/y for the last 5 years. The AP hip total wear and wear rate were 1.38 mm and 0.133 mm/y respectively, while rates were 1.13 mm and 0.109 mm/y respectively for the pelvis radiographs (P < .05). We found a significant difference in measurements of linear penetration when comparing AP pelvis vs. hip radiographs with lower rates recorded using an AP pelvis.     

Up to 18-Year Follow-Up Wear Analysis of a First-Generation Highly Cross-Linked Polyethylene in Primary Total Hip Arthroplasty

Background

The advent of highly cross-linked polyethylene (HCLPE) has significantly improved total hip arthroplasty survivorship. HCLPE has been shown to improve wear properties in midterm outcomes when compared to traditional polyethylene liners; however, there is a paucity of studies evaluating long-term outcomes. In addition, there is concern that wear rates may accelerate as the implant ages. Thus, the aims of this study are to report on the longest-to-date follow-up of a specific first-generation HCLPE liner and to determine whether there is a change in the annual wear rate over time.

Comparison of Surgical Outcomes Between Standard and Elevated-Rim Highly Cross-Linked Polyethylene Acetabular Liners in Primary Total Hip Arthroplasty With Minimum 15-Year Follow-Up: Single-Center,Retrospective Cohort Study

BackgroundThe aims of the present study are to (1) conduct the longest-to-date follow-up wear analysis of the highly cross-linked polyethylene acetabular liners, (2) assess the incidence of femoral and acetabular osteolysis, and (3) compare the surgical outcomes between standard and elevated-rim acetabular liners in primary total hip arthroplasty (THA).MethodsIn this retrospective cohort study, we evaluated 112 primary THAs performed by a single experienced arthroplasty surgeon at our institution between March 2000 and December 2003. Patients were classified based on the type of acetabular liner used: standard or elevated-rim liner. For evaluation of surgical outcomes, the following data were collected: acetabular cup position (anteversion and inclination), wear rate (linear and volumetric), presence of osteolysis, history of reoperation (all-cause and wear-related), complications (deep joint infection, dislocation, and periprosthetic fracture), and Harris hip score at last follow-up.ResultsLinear and volumetric wear rates were 0.028 mm/y (0.000-0.145 mm/y) and 11.641 mm³/y (0.000-70.000 mm³/y) in the standard group and 0.026 mm/y (0.000-0.094mm/y) and 9.706 mm³/y (0.000-33.000 mm³/y) in the elevated-rim group, respectively. These rates were not significantly different between groups. One case of osteolysis was confirmed in the standard group, whereas no osteolysis was observed in the elevated-rim group.ConclusionWe suggest that elevated-rim highly cross-linked polyethylene acetabular liners might be a good implant option that can be used safely.     

Total Hip Arthroplasty Using Highly Cross-Linked Polyethylene in Patients Younger Than 50 Years With Minimum 10-Year Follow-Up

The purpose of this study was to investigate the relatively long-term outcomes in 50 patients (54 hips) younger than 50 years of age who underwent total hip arthroplasty using highly cross-linked polyethylene (HXLPE) liners. With a minimum follow-up of 10 years, mean age at time of surgery was 38.9 years (range, 15–50 years). Survivorship was 100%. There was no radiographic evidence of osteolysis or component loosening. Mean steady-state femoral head penetration rate was 0.020 ± 0.0047 mm/yr. Clinical outcomes were excellent, with mean Harris hip score of 91.2 (range, 72–99) points at final follow-up.     

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

BackgroundA 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.MethodsAll 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. Two-dimensional linear head penetration wear measurements were obtained using the Martell Hip Analysis Suite, and retrieval analysis was performed on two liners.ResultsThe study group had a significantly higher average penetration rate of 0.089 mm/y than the control group average rate of 0.047 mm/y (P = .04). Forty-five percent of the study group had a wear rate above the osteolysis threshold (0.1 mm/y), compared to 24% in the control group. Macroscopic analysis of two retrieved liners validated the radiographic findings.ConclusionThe data suggest unexpectedly higher wear rates for a moderately cross-linked polyethylene design, with nearly half of the study group at risk for osteolysis. Further registry or database analyses of this particular moderately cross-linked polyethylene are warranted.     

Minimum Five-Year Follow-Up Wear Measurement of Longevity Highly Cross-Linked Polyethylene Cup Against Cobalt-Chromium or Zirconia Heads

We investigated the efficacy of combining highly cross-linked polyethylene with ceramic heads on further reduction in polyethylene wear compared with the combination with cobalt-chromium heads via PolyWare computer-assisted method. A prospective cohort study was performed on 102 cementless total hip arthroplasties using Longevity (Zimmer, Warsaw, Ind) highly cross-linked polyethylene liners. Either 26-mm zirconia heads or 26-mm cobalt-chromium heads were randomly used in 51 hips each. At a mean follow-up of 6.7 years, no significant differences were identified between the groups for total penetration rate and steady-state wear rate. Osteolysis was not observed in any hips in either group. In conclusion, no advantage was seen for the 26-mm zirconia head compared with the 26-mm cobalt-chromium head in this period.     

Highly Cross-Linked Polyethylene in Total Hip Arthroplasty for Osteonecrosis of the Femoral Head : A Minimum 5-Year Follow-Up Study

We evaluated 162 hips with osteonecrosis of the femoral head that had undergone THA using highly cross-linked polyethylene liner after a minimum follow-up of 5 years. Neither femoral nor acetabular components displayed radiographic evidence of mechanical loosening or osteolysis, and no components had been revised at the latest follow-up. The mean rate of linear liner wear was 0.038 mm/year. Univariate regression analysis did not demonstrate that age, gender, weight, activity level or cup inclination had any influence on penetration. While the long term effects of altered mechanical properties of highly cross-linked PE remain unknown, the clinical and radiographic results at a minimum of 5 years are promising for this high-risk population.     

Minimum 10-Year Follow-Up of Cementless Total Hip Arthroplasty With a 32-mm Cobalt-Chromium Head on Highly Cross-Linked Polyethylene and a Tapered,Fiber Metal Proximally Coated Femoral Stem

BackgroundThe clinical and radiographic results of cementless total hip arthroplasty using a 32-mm cobalt-chromium head on remelted highly cross-linked polyethylene (HXLPE) and a tapered, fiber metal proximally coated femoral stem were evaluated at a mean follow-up of 12 years.MethodsA total of 57 cementless total hip arthroplasties using remelted HXLPE combined with a 32-mm cobalt-chromium head, and a tapered, fiber metal proximally coated femoral stem were performed from October 2004 to December 2006. Clinical evaluation was performed using the Merle d’Aubigné and Postel scoring system. Standardized anteroposterior and lateral radiographs of the pelvis and femur without weight-bearing were analyzed. Radiographic measurements of two-dimensional femoral head penetration into the polyethylene were performed with a computerized method. The steady-state wear rates were measured based on the radiographs from the first year after surgery to the final follow-up.ResultsThe mean Merle d’Aubigné and Postel score improved significantly from 10.7 points preoperatively to 15.6 postoperatively (P < .001). No osteolysis was found around the implant. Stem fixation in all cases showed stable bone ingrowth. Third-degree stress shielding was found in 46% of all stems. The total head penetration rate was 0.05 mm/y, and the steady-state wear rate was 0.01 mm/y. The Kaplan–Meier survivorship with the end point of revision was 95% (95% confidence interval, 85%-98%) at 12 years.ConclusionA 32-mm cobalt-chromium head on remelted HXLPE demonstrated low wear properties, and a tapered, fiber metal proximally coated femoral stem showed good results at long-term follow-up.     

Wear Rates With Large Metal and Ceramic Heads on a Second Generation Highly Cross-Linked Polyethylene at Mean 6-Year Follow-Up

Background

Bearing surface wear and osteolysis are major factors limiting the durability of total hip arthroplasty (THA). Second generation annealed highly cross-linked polyethylene (HXLPE) and ceramics were introduced to THA for their excellent wear rates. However, there is little data comparing the wear rates of metal and ceramic heads on second generation HXLPE.

Wear Analysis of Highly Cross-Linked Polyethylene in Young and Active Patients at Average Fourteen Years: A Concise Follow-Up of a Previous Report

Background

Concerns persist regarding the oxidative stability of annealed highly cross-linked polyethylene (HXLPE) and hence its wear performance especially long term in young and active patients. The purpose of this study is to assess the wear rates and clinical outcomes of a first-generation annealed HXLPE.

Medium-Term Results of Cementation of a Highly Cross-Linked Polyethylene Liner Into a Well-Fixed Acetabular Shell in Revision Hip Arthroplasty

The present study was undertaken to document outcomes of cementation of a highly cross-linked polyethylene (PE) liner into a well-fixed acetabular metal shell in 36 hips. All operations were performed by a single surgeon using only one type of liner. Patients were followed for a mean of 6.1 years (range, 3–8 years). Mean Harris hip score improved from 58 points preoperatively to 91 points postoperatively. There were no cases of PE liner dislodgement or progressive osteolysis. 1 hip (2.8%) required revision surgery for acetabular cup loosening with greater trochanteric fracture. Complications included 1 peroneal nerve palsy and 1 dislocation. The results of this study and previous reports demonstrated that cementation of highly cross-linked PE liner into well-fixed metal shell could provide good midterm durability.     

The Relationship Between Polyethylene Wear and Periprosthetic Osteolysis in Total Hip Arthroplasty at 12 Years in a Randomized Controlled Trial Cohort

Background

Polyethylene acetabular components are common in hip arthroplasty. Highly cross-linked polyethylene (HXLPE) has lower wear than ultra-high molecular weight polyethylene (UHMWPE). Evidence suggests that wear particles induce inflammation causing periprosthetic osteolysis contributing to implant loosening with wear rates of 0.05 mm/y were considered safe. We aimed to compare incidence and volume of periacetabular osteolysis between HXLPE and UHMWPE using computed tomography.

Wear Comparison Between a Highly Cross-Linked Polyethylene and Conventional Polyethylene Against a Zirconia Femoral Head : Minimum 5-Year Follow-Up

Highly cross-linked polyethylene (HXLPE) was developed to reduce wear of articular bearing surface in total hip arthroplasty patients. Several studies have shown reduced wear of HXLPE compared with conventional polyethylene; however, these studies had used HXLPE in combination with a Co-Cr metal head. The purpose of this study was to compare the 5-year in vivo wear of HXLPE with that of conventional PE using a zirconia femoral head. Forty-five hips with a Trilogy HXLPE (Zimmer, Warsaw, Ind) were matched and compared with a control group of 20 conventional Trilogy PE hips. The 2-dimensional linear wear rate was significantly less in the HXLPE group between 1 and 5 years postoperation (P < .001). The results show that HXLPE reduces short-term polyethylene wear against not only a Co-Cr head but also a zirconia head.     

Long-Term Wear-Related Complications of Cross-Linked Versus Conventional Polyethylene After Total Hip Arthroplasty: A Meta-Analysis

BackgroundHighly cross-linked polyethylene (HXLPE) liners have been developed to address the wear-related problems associated with conventional polyethylene (CPE) such as osteolysis or aseptic loosening in total hip arthroplasty (THA). In this systematic meta-analysis, we compared the long-term efficacy in preventing radiological osteolysis and revision surgery between HXLPE and CPE.MethodsWe included 14 studies that compared HXLPE and CPE reporting the incidence of wear-related complications with a minimum follow-up of 10 years. We investigated 5 wear-related complications: osteolysis, excessive wear, linear wear rate, revision surgery due to wear, and progress of osteolysis/aseptic loosening. We conducted a pair-wise meta-analysis to estimate odds ratio (OR) and a proportional meta-analysis to estimate the incidence of each complication.ResultsAmong 1,175 THAs, 220 osteolysis and 78 wear-related revisions were detected. The use of HXLPE reduced the risk of overall osteolysis (OR 0.30; P = .001), excessive wear (OR 0.10; P < .001), linear wear rate (weighted mean difference 0.09; P < .001), the risk of overall wear-related revisions (OR 0.06; P < .001), and revisions due to aseptic loosening (OR 0.23; P = .015). As per the proportional meta-analysis, the pooled prevalence of osteolysis, excessive wear, and the overall wear-related revision rate were 14%, 8%, and 3% in HXLPE and 25%, 33%, and 20% in CPE, respectively.ConclusionThe current evidence shows that HXLPE dramatically reduced the rate of osteolysis and wear-related revision surgery. However, as polyethylene wear and osteolysis still lead to revision surgery, ongoing clinical and retrieval studies are required to analyze long-term outcomes.     

Clinical Results of the Wear Performance of Cross-Linked Polyethylene in Total Hip Arthroplasty : Prospective Randomized Trial

To investigate the clinical results of cross-linked polyethylene (CLPE) and to compare the CLPE wear against zirconia and stainless steel heads, we studied the radiographic wear after a minimum 3-year follow-up in total hip arthroplasty (THA). Ninety-four hips were randomly implanted with a 22.225-mm head cemented THA—the group of non-CLPE against zirconia and CLPE against 2 different zirconias and stainless steel. The linear wear rate was significantly lower in the group of CLPE against zirconia (0.067, 0.059 mm/y) and against stainless steel (0.068 mm/y) compared with non-CLPE against zirconia (0.170 mm/y). In the short-term results, the wear performance of CLPE against zirconia was superior to that of non-CLPE; however, it did not show a better wear rate than CLPE against stainless steel. Furthermore, long-term investigations will be necessary for understanding CLPE wear in vivo.     

Cementless Total Hip Arthroplasty With Alumina-on-Highly Cross-Linked Polyethylene Bearing in Young Patients With Femoral Head Osteonecrosis

We asked whether total hip arthroplasties (THAs) using alumina-on-highly cross-linked polyethylene bearing would improve functional activity and reduce aseptic loosening, polyethylene wear, and osteolysis. Consecutive primary THAs were performed in 71 patients (73 hips) who were younger than 50 years (mean age, 45.5 years) with femoral head osteonecrosis. There were 48 men (50 hips) and 23 women (23 hips). Osteolysis was evaluated using radiographs and computed tomographic scanning. The average follow-up was 8.5 years (range, 7-9 years). The mean preoperative Harris hip score was 50.6 points, which improved to 96 points at the final follow-up. Preoperative functional activity was improved significantly at the latest follow-up. The mean polyethylene linear penetration was 0.05 ± 0.02 mm/y and no hip had aseptic loosening or osteolysis.     

Differences in Femoral Head Penetration Between Highly Cross-Linked Polyethylene Cemented Sockets and Uncemented Liners

BackgroundThis study aimed at investigating differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets and uncemented liners during 5 years postoperatively.MethodsNinety-six patients (106 hips) with a mean age of 64.4 (range, 35-83) years underwent total hip arthroplasty using a HXLPE cemented socket or liner and were respectively divided into cemented (35 patients [37 hips]) and uncemented (61 patients [69 hips]) groups. Femoral head penetrations were evaluated on both anteroposterior (AP)-view and Lauenstein-view radiographs, and mean polyethylene (PE) wear rates were calculated based on femoral head penetration from 2 to 5 years. Multivariate analyses were performed to assess risk factors for PE wear.ResultsAt 5 years postoperatively, the cemented and uncemented groups exhibited proximal direction femoral head penetrations of 0.103 mm and 0.124 mm (P = .226) and anterior direction penetrations of 0.090 mm and 0.151 mm (P = .002), respectively. The corresponding mean PE wear rates were 0.004 mm/y and 0.009 mm/y in the AP-view (P = .286) and 0.005 mm/y and 0.012 mm/y in the Lauenstein-view (P = .168), respectively. Left-side operation and high activity were independent risk factors for PE wear on AP-view.ConclusionWhen HXLPE was used, all mean PE wear rates were very low and those of cemented sockets and uncemented liners were very similar. PE particle theory suggests that the occurrence of osteolysis and related aseptic loosening might consequently decrease.