5-year experience of highly cross-linked polyethylene in cemented and uncemented sockets: Two randomized studies using radiostereometric analysis

Background One cross-linked polyethylene (XLPE) liner is manufactured using a lower dose of radiation, 5 Mrad, which may result in less cross-linking. The reported in vivo wear rate of this XLPE liner in patients undergoing THA has varied, and has included some patients in each reported cohort who had greater than 0.1 mm/year of wear, which is an historical threshold for osteolysis. Previous studies have measured wear on plain radiographs, an approach that has limited sensitivity.Questions/purposes We therefore measured the amount and direction of wear at 6 years using Radiostereometric analysis (RSA) in patients who had THAs that included a cross-linked polyethylene liner manufactured using 5 Mrad radiation. Methods We prospectively reviewed wear in 30 patients who underwent primary THAs with the same design of cross-linked acetabular liner and a 28-mm articulation. Tantalum markers were inserted during surgery and all patients had RSA radiographic examinations at 1 week, 6 months, 1, 2, and 6 years postoperatively. Results The mean proximal, two-dimensional (2-D) and three-dimensional (3-D) wear rates calculated between 1 year and 6 years were 0.014, 0.014, and 0.018 mm/per year, respectively. The direction of the head penetration recorded between 1 week and 6 years was in a proximal direction for all patients, proximolateral for 16 of 24 patients, and proximomedial for eight of 24 patients. Conclusions The proximal, 2-D and 3-D wear of a XLPE liner produced using 5 Mrad of radiation was low but measurable by RSA after 6 years. No patients had proximal 2-D or 3-D wear rates exceeding 0.1 mm/year. Further followup is needed to evaluate the effect of XLPE wear particles on the development of long-term osteolysis.

Section: Discussionsupporting

confidence: 91%

Wear of a 5 Megarad Cross-linked Polyethylene Liner: A 6-year RSA Study

Callary

Campbell

Mercer

et al. 2013

“…These clinically meaningful differences were calculated as follows. The mean annual wear measurements of eight HCLPE studies [1,9,12,14,17,18,33,43] (Table 2) were averaged. We presumed a meaningful difference would be the difference between this number and the mean annual wear of our control group generated from our historical cohort [21].…”

Section: Methodsmentioning

confidence: 99%

“…However, studies reporting on the midterm (C 5 years average followup) in vivo performance of these PE liners are scant [1,4,7,9,37]. Such studies are of utmost importance because radiographic osteolysis is a phenomenon rarely seen before 5 years of followup.…”

Section: Introductionmentioning

confidence: 99%

Wear is Reduced in THA Performed with Highly Cross-linked Polyethylene

Beksaç

Salas²,

Valle

et al. 2009

Highly cross-linked polyethylene (HCLPE) has been used extensively to decrease osteolysis and related implant failure in THA. We compared the wear rate of HCLPE and noncross-linked conventional PE (CPE) liners and the rate of radiographic calcar resorption and osteolysis in young patients (35-60 years of age) who underwent THA by one surgeon. Thirty-four patients (41 THAs) who received a hybrid THA using a HCLPE liner were matchpaired for age, gender, body mass index, and diagnosis with a group of patients who underwent THA with identical implants but with a CPE liner. The minimum followup was 4 years (average, 5.3; range, 4-8 years). Using the Livermore measurement technique, the averages of total wear of the HCLPE and CPE liners were 0.01 mm (range, -0.23-0.4) and 0.64 mm (range, 0-1.7), respectively. The average annual wear was less for the HCLPE than the noncross-linked PE (0.002 mm, range, -0.05-0.1 versus 0.12 mm, range, 0-0.29, respectively). Four hips in the HCLPE group and 23 in the CPE group had calcar resorption measuring averages of 2.5 mm (range, 2-3) and 7.5 mm (range, 1.8-23.8), respectively. Periprosthetic osteolysis occurred in two and eight hips in the HCLPE and CPE groups, respectively. Longer followup is needed to determine if these findings will result in improved implant survivorship.

“…Another study excluded from the weighted-averages analysis was by Fukui et al [45], which did not separate out radiographic outcomes by HXLPE formulation, implying the femoral head penetration behavior was similar between the two groups. Other studies excluded from the analysis included Miyanishi et al [100], Ayers et al [5], McCalden et al [92], Garcia-Rey et al [46], Bragdon et al [20], Digas et al [38], Geller et al [49], and Mutimer et al [104] because they lacked comparable clinical outcome measures. GlynJones et al [51], Heisel et al [60], Rohrl et al [121], and Digas et al [39] were all cases of multiple publications on the same study.…”

Section: Search Strategy and Criteriamentioning

confidence: 99%

History and Systematic Review of Wear and Osteolysis Outcomes for First-generation Highly Crosslinked Polyethylene

Kurtz

Gawel

Patel

2011

411

282

Background Highly crosslinked polyethylene (HXLPE) was introduced to reduce wear and osteolysis in total joint arthroplasty. While many studies report wear and osteolysis associated with HXLPE, analytical techniques, clinical study design and followup, HXLPE formulation and implant design characteristics, and patient populations differ substantially among investigations, complicating a unified perspective. Questions/purposes Literature on first-generation HXLPE was summarized. We systematically reviewed the radiographic wear data and incidence of osteolysis for HXLPE in hip and knee arthroplasty. Methods PubMed identified 391 studies; 28 met inclusion criteria for a weighted-averages analysis of two-dimensional femoral head penetration rates. To determine the incidence of osteolysis, we estimated a pooled odds ratio using a random-effects model.Results Weighted-averages analyses of femoral head penetration rates in HXLPE liners and conventional UHMWPE liners resulted, respectively, in a mean twodimensional linear penetration rate of 0.042 mm/year based on 28 studies (n = 1503 hips) and 0.137 mm/year based on 18 studies (n = 695 hips). The pooled odds ratio for the risk of osteolysis in HXLPE versus conventional liners was 0.13 (95% confidence interval, 0.06-0.27) among studies with minimum 5-year followup. We identified two clinical studies of HXLPE in TKA, preventing systematic analysis of outcomes. Conclusions HXLPE liner studies consistently report lower femoral head penetration and an 87% lower risk of osteolysis. Reduction in femoral head penetration or osteolysis risk is not established for large-diameter ([ 32 mm) metallic femoral heads or ceramic femoral heads of any size. Few studies document the clinical performance of HXLPE in knees.