Accolade TMZF trunnion corrosion and mechanical failure 9 yr after primary surgery: A case report and treatment options

Adverse Local Tissue Reaction and Osteolysis After Ceramic-on-Ceramic Total Hip Arthroplasty

Adverse local tissue reaction (ALTR) and osteolysis formation are more frequently described complications after total hip arthroplasty (THA) with metal-on-metal bearings. In this report, we present a unique case of ALTR and osteolysis formation with ceramic-on-ceramic bearing THA, which has been less commonly described in the existing literature. This rare case occurred in a 54-year-old patient who had a primary THA done 17 years prior to representing to our institution. As part of the workup for our patient to find out the underlying cause of his complications, we have carried out extensive investigations that have not been previously reported. We conclude that ceramic bearings in THA may not be entirely inert and may cause complications such as osteolysis and ALTR.

Large head metal-on-metal bearing surface with a TMZF titanium alloy femoral stem with high rates of revision and trunnion failure

Background

Mechanically assisted crevice corrosion at the head-neck interface puts implants at risk of trunnionosis, femoral head dissociation, implant failure and the development of metallosis. Metal-on-Metal bearings have very low wear rates, significantly lower than metal-on-polytethylene, but their wear results in cobalt and chromium ion systemic distribution. This is a study of the MITCH metal-on-metal bearing surface coupled with an Accolade TMZF stem.

Methods

This was a retrospective review of 24 total hip replacements 21 patients in that underwent MITCH TRH/Accolade TMZF implantation at a minimum of 12 years post operatively. The primary outcome of this study was all-cause revision with particular attention to revision due to trunnion failure and/or cobalt and chromium ion level.

Results

There was a revision rate of 66.7 % (n = 16) at a minimum of twelve years post operatively. Most notably there were six revisions for a gross trunnion failure. Two cases were revised for impending trunnion failure. There were seven cases revised for elevated serum cobalt and chromium levels and one was revised for unexplained pain.

Discussion

Patients in our study that underwent TMZF alloy cementless stems coupled with large cobalt chromium alloy heads are at high risk of catastrophic trunnion failure. The high rate of trunnnionosis in this implant combination is thought to be related to a significantly different Young's modulus due to a material mismatch coupled with galvanic corrosion.

Intermediate to Long-Term Outcomes and Causes of Aseptic Failure of an At-Risk Femoral Stem

BACKGROUND

The Accolade TMZF is a tapered-wedge cementless metaphyseal-coated femoral stem that was widely utilized from 2002 to 2012. In recent years, there have been reports of early catastrophic failure of this implant. The purposes of the present study were to establish the long-term survival of this stem and to analyze patients who underwent aseptic revision to understand the causes and risk factors for failure.

METHODS

We retrospectively reviewed the records of all patients who had undergone primary total hip arthroplasty with use of an Accolade TMZF stem at a high-volume arthroplasty center. The causes and timing of revision surgery were documented. Survivorship analysis was performed with use of Kaplan-Meier curves to determine the overall and aseptic survival rates at the time of the latest follow-up. Patient and implant factors commonly associated with aseptic failure were extracted, and a Cox proportional hazards model was used.

RESULTS

A consecutive series of 2,609 patients who had undergone unilateral primary total hip arthroplasty with use of an Accolade TMZF femoral stem were included. The mean time from the primary procedure was 11.3 years (range, 0 days to 19.4 years). The cumulative survival rate was 95.5% ± 0.1% at the time of the latest follow-up. One hundred and seven patients underwent revision surgery, with aseptic loosening of the femoral component being the most common cause of aseptic failure in this cohort (33 of 2,609; 1.3%). Smaller femoral size and larger femoral head offset were independent risk factors for aseptic failure.

CONCLUSIONS

To our knowledge, this is the largest series representing the longest follow-up of this tapered-wedge cementless femoral implant. Despite early concerns, the Accolade TMZF stem had excellent survivorship in this cohort. Trunnionosis as the cause for revision surgery was rare.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Catastrophic Trunnion Failure in an Anatomic Titanium Alloy Stem

Introduction

Certain titanium alloy stems have been shown to be susceptible to failure at the neck with catastrophic trunnion failure. Failure has been particularly noted in the single wedge Accolade 1 stem design. Other stems also used this alloy including the anatomic designed Citation stem.

Methods

This case series details 3 catastrophic failures of the TMZF version of the Citation femoral stem.

Results

Each of these failures appear to be attributed to cyclical wear of the TMZF trunnion against the cobalt chromium femoral head. Wear resulted in ultimate implant failure and significant metal debris in the joint capsule at the time of revision surgery.

Discussion

While surgeons are aware of the risk of catastrophic failure for the Accolade 1 stem, failure may similarly happen in the TMZF Citation stem. Surgeons should monitor these implants with care and discuss the potential for trunnion failure with their patients.