Comparison of Whole-Blood Metal Ion Levels Among Four Types of Large-Head, Metal-on-Metal Total Hip Arthroplasty Implants

Abstract

Few studies of total hip arthroplasty (THA) implants with a large-diameter femoral head and metal-on-metal design have directly compared the progression of metal ion levels over time and the relationship to complications. As we previously reported, 144 patients received one of four types of large-diameter-head, metal-on-metal THA designs (Durom, Birmingham, ASR XL, or Magnum implants). Cobalt, chromium, and titanium ion levels were measured over five years. We compared ion levels and clinical results over time. The Durom group showed the highest levels of cobalt (p ≤ 0.002) and titanium ions (p ≤ 0.03). Both the Durom and Birmingham groups demonstrated significant ongoing cobalt increases up to five years. Eight patients (seven with a Durom implant and one with a Birmingham implant) developed adverse local tissue reaction. Six Durom implants and one Birmingham implant required revision, with one pseudotumor under surveillance at the time of the most recent follow-up. We found that ion generation and related complications varied among designs. More concerning was that, for some designs, ion levels continued to increase. Coupling a cobalt-chromium adapter sleeve to an unmodified titanium femoral trunnion along with a large metal-on-metal bearing may explain the poor performances of two of the designs in the current study.

Mid-term changes in blood metal ion levels after Articular Surface Replacement arthroplasty of the hip

“…If we use the cutoffs for the levels of metal ions established by Van Der Straeten et al 28 (4.6 ppb for Cr and 4.0 ppb for Co), even in our short follow-up of two years, 12 patients with a HRA and 30 with a THA went from having safe levels to having unsafe levels. In contrast to other studies, [11][12][13][14][15][16][17] we show that the shedding of metal particles has not reached a state of equilibrium.…”

“…Currently, no such recommendations exist, and the data on mid-term changes in the levels of metal ions are sparse and inconsistent. 7,[9][10][11][12][13][14][15][16] Our aims were to determine whether measurements of metal ions in the blood change during extended follow-up, and whether specific cohorts of MoM patients merit closer follow-up than others. We found that for patients with both MoM HRAs and MoM THAs the levels of both Co and Cr ions increase between early and midterm follow-up.…”

“…As is the case in the literature about MoM HRA, most authors have found an increase which peaks at one year and then either stabilises or decreases. [13][14][15][16] A study considering 254 ASR XL THAs found a significant increase in the levels of Co ions at early follow-up. 7 While both the levels of Co and Cr ions increased, the Co/Cr ratio decreased over time for both groups.…”

Effect of Femoral Stem Modular Neck’s Material on Metal Ion Release

“…Although, it does not follow a linear relationship, measuring metal ion levels in blood is an indirect way to estimate the extent of ion release from metallic implants. Since corrosion liberates metal ions, its magnitude may be estimated by quantifying the metal ion concentration in the blood of patients [ 13 , 14 ].…”

A Mid- to Long-Term Follow-Up Experience with a Specific Metal-on-Metal Total Hip Arthroplasty Design

“…10,44,45 Patients with ASR presented elevated blood and urinary levels of chrome (Cr) and cobalt (Co), while patients with other types of MoM implants usually have a slight elevation of such values. 46,47 However, for the latter implants, no symptoms or early failures have been addressed, as the experience reported in this series. Recently, patients with M2a acetabular MoM components (Biomet Orthopaedics, Warsaw, Indiana, United States) have shown high rates of pseudotumor at a mid-term follow-up, leading to revision in a percentage ranging from 4 to 8% and loosening in 31%; 13.8% of the studied hips had a definite adverse reaction to metal debris (ARMD), and 53.8% of the studied hips had a definite, probable, or possible ARMD.…”