Raised levels of metal ions in the blood in patients who have undergone uncemented metal-on-polyethylene Trident–Accolade total hip replacement

Abstract

The issues surrounding raised levels of metal ions in the blood following large head metal-on-metal total hip replacement (THR), such as cobalt and chromium, have been well documented. Despite the national popularity of uncemented metal-on-polyethylene (MoP) THR using a large-diameter femoral head, few papers have reported the levels of metal ions in the blood following this combination. Following an isolated failure of a 44 mm Trident-Accolade uncemented THR associated with severe wear between the femoral head and the trunnion in the presence of markedly elevated levels of cobalt ions in the blood, we investigated the relationship between modular femoral head diameter and the levels of cobalt and chromium ions in the blood following this THR. A total of 69 patients received an uncemented Trident-Accolade MoP THR in 2009. Of these, 43 patients (23 men and 20 women, mean age 67.0 years) were recruited and had levels of cobalt and chromium ions in the blood measured between May and June 2012. The patients were then divided into three groups according to the diameter of the femoral head used: 12 patients in the 28 mm group (controls), 18 patients in the 36 mm group and 13 patients in the 40 mm group. A total of four patients had identical bilateral prostheses in situ at phlebotomy: one each in the 28 mm and 36 mm groups and two in the 40 mm group. There was a significant increase in the mean levels of cobalt ions in the blood in those with a 36 mm diameter femoral head compared with those with a 28 mm diameter head (p = 0.013). The levels of cobalt ions in the blood were raised in those with a 40 mm diameter head but there was no statistically significant difference between this group and the control group (p = 0.152). The levels of chromium ions in the blood were normal in all patients. The clinical significance of this finding is unclear, but we have stopped using femoral heads with a diameter of ≤ 36 mm, and await further larger studies to clarify whether, for instance, this issue particularly affects this combination of components.

Adverse Reactions to Metal Debris in Metal-On-Polyethylene Total Hip Arthroplasty Using a Titanium-Molybdenum-Zirconium-Iron Alloy Stem

“…Increased cobalt ions were seen in a series with the same implants as our cases that used 36 mm diameter heads [21]. Although the significance of this finding is not fully clear, we now suggest that metal ion testing should form part of the investigation protocol of a symptomatic THA.…”

Head Taper Corrosion Causing Head Bottoming Out and Consecutive Gross Stem Taper Failure in Total Hip Arthroplasty

“…Several studies on elevated metal ion levels or even catastrophic gross taper failures (GTF) after hip joint replacement highlight one particular stem design with a small V-40 taper made from a less stiff Ti-12Mo-6Zr-2Fe titanium-alloy (TMZF; Accolade I, Stryker, Mahwah, NJ) in combination with head sizes of mostly 36mm and above ( Figure 1) [9][10][11][12][13][14][15][16][17][18]. This proprietary beta titanium alloy was introduced in 2002 based on the potential benefits of more closely mimicking the modulus of elasticity of cortical bone than standard Ti-6Al-4V alloys [19].…”

Hip simulator testing of the taper‐trunnion junction and bearing surfaces of contemporary metal‐on‐cross‐linked‐polyethylene hip prostheses

“…65 Additionally, Craig et al reported increased serum metal ion levels in LD MoP hips compared with small diameter from a single manufacturer. 66 Furthermore, the NJR shows higher revision rates for MoP hips ≥36 mm head diameter. 4 Therefore, pseudotumor formation in MoP THRs is perhaps associated with increased bearing diameter size.…”

“…In contrast to this Balso et al conducted a semiquantitative scoring study on retrieved of MoP THRs and reported the possibility of accelerated fretting damage due to increased femoral head size . Additionally, Craig et al reported increased serum metal ion levels in LD MoP hips compared with small diameter from a single manufacturer . Furthermore, the NJR shows higher revision rates for MoP hips ≥36 mm head diameter .…”