Outcomes of a metal-on-metal total hip replacement system

Abstract

INTRODUCTION High short-term failure rates have been reported for a variety of metal-on-metal (MoM) total hip replacements (THRs) owing to adverse reactions to metal debris (ARMD). This has led to the withdrawal of certain poorly performing THRs. This study analysed the outcomes of a MoM THR system. METHODS Between 2004 and 2010, 578 uncemented MoM THRs (511 patients, mean age: 60.0 years) were implanted at one specialist centre. The THR system used consisted of the Corail ® stem, Pinnacle ® cup, Ultamet ® liner and Articul/eze ® femoral head (all DePuy, Leeds, UK). All patients were recalled for clinical review with imaging performed as necessary. RESULTS The mean follow-up duration was 5.0 years (range: 1.0-9.1 years). Overall, 39 hips (6.7%) in 38 patients (all 36mm femoral head size) underwent revision at a mean time of 3.5 years (range: 0.01-8.3 years) from the index THR with 30 revisions (77%) performed in women. The cumulative eight-year survival rate for all THRs was 88.9% (95% confidence interval [CI]: 78.5-93.4%), with no difference (p=0.053) between male (95.2%, 95% CI: 84.2-98.7%) and female patients (85.3%, 95% CI: 70.2-92.1%) at eight years. Seventeen revisions (44%) were performed for ARMD. There was no significant difference in absolute postoperative Oxford hip scores between men and women (p=0.608). The mean acetabular inclination in unrevised THRs was 44.0°. Forty-seven non-revised THRs (8.7%) had blood metal ion concentrations above recommended thresholds (seven had periprosthetic effusions). CONCLUSIONS Although this MoM THR system has not failed as dramatically as other similar designs, we recommend against continued use and advise regular clinical surveillance to identify ARMD early.

Frequent Femoral Neck Osteolysis With Birmingham Mid-head Resection Resurfacing Arthroplasty in Young Patients

“…These functional results are comparable to the BMHR results of the implant developers at 3.5 years followup [35]. They are also comparable to the mid-term functional and survivorship results of various currently used, traditional hip resurfacing systems [3,8,25,41,49] and far better than the mid-term survivorship and functional results of conventional MoM THA [9,31,32,47]. So, despite the fact that the BMHR is technically considered a stemmed LHMoM implant, its design, fixation (neck-fixed), and loading-bearing concepts [35,36] appear to produce a clinical performance that is better than the notorious traditional stemmed LHMoM THAs and comparable to traditional resurfacing arthroplasties at mid-term.…”

“…Patients' median OHS (using the 48-point OHS) improved from 26 (range, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] preoperatively to 46 (range, [35][36][37][38][39][40][41][42][43][44][45][46][47][48], and UCLA score improved from 5 (range, 2-8) to 8 (range, 4-10) at latest review (paired t-test p \ 0.001 for both). There was no difference in median [35][36][37][38][39][40][41][42][43][44][45][46][47][48] or in the median postoperative UCLA scores between males (8; range, 5-10) and females (8; range, 4-10) (Mann-Whitney U p = 0.293 and p = 0.115, respectively).…”

Risk factors for failure of the 36 mm metal-on-metal Pinnacle total hip arthroplasty system

“…10,12-14 However, the failure rate continues to increase steadily up to ten years (Fig. 1) rather than plateau as one may expect following early revision of poorly performing implants.…”

“…We previously reported the medium-term outcomes of the 36 mm MoM Pinnacle THA system at our specialist centre, 12 which represents the second largest study of this particular device. 9,10,13,14 The failure rate at eight years (11.1%) was unacceptably high in our initial study with many revisions performed for ARMD.…”

Grave fraudulence in medical device research: a narrative review of the PIN seeding study for the Pinnacle hip system

“…Unfortunately, unscientific findings like those reported in the PIN Study can spread through the literature like ink in milk. According to the Web of Science as of July 2017, 27 publications directly cite PIN Study publications (Bernasek et al 2013;Burge et al 2015;Dhotare et al 2016;Greiner et al 2016;Hosny et al 2013;Klingenstein et al 2012Klingenstein et al , 2013Lainiala et al 2014;Langton et al 2016;Liudahl et al 2013;Lohmann et al 2013;Lombardi et al 2015;Maloney, Ha, and Miller 2015;Matharu et al 2014;Mihalko et al 2014;Plummer et al 2016;Reito et al 2016;Ricciardi et al 2016;Schmitz et al 2013;Singh et al 2013Singh et al , 2015Stihsen et al 2013;Stryker et al 2015;Tsukagoshi et al 2015;Tvermoes et al 2015;Wagner et al 2012;Wyles et al 2014). J&J/DePuy also included PIN Study publications in their 2012 presentation to the FDA on the safety of Metal-on-Metal hip implants, suggesting the potential for mismanaged and manipulated seeding trials to influence regulatory decision making (Voorhorst 2012).…”